YARN-5170. Eliminate singleton converters and static method access. (Joep Rottinghuis via Varun Saxena)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase-tests/src/test/java/org/apache/hadoop/yarn/server/timelineservice/storage/TestHBaseTimelineStorage.java

@@ -70,12 +70,14 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.application.Applica
 import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnName;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnNameConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.StringKeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumn;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnFamily;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKeyPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityTable;
 import org.junit.After;
 import org.junit.AfterClass;
@@ -649,8 +651,9 @@ public class TestHBaseTimelineStorage {
 
       infoMap.putAll(infoMap1);
       // retrieve the row
-      byte[] rowKey =
-          ApplicationRowKey.getRowKey(cluster, user, flow, runid, appId);
+      ApplicationRowKey applicationRowKey =
+          new ApplicationRowKey(cluster, user, flow, runid, appId);
+      byte[] rowKey = applicationRowKey.getRowKey();
       Get get = new Get(rowKey);
       get.setMaxVersions(Integer.MAX_VALUE);
       Connection conn = ConnectionFactory.createConnection(c1);
@@ -674,7 +677,7 @@ public class TestHBaseTimelineStorage {
 
       Map<String, Object> infoColumns =
           ApplicationColumnPrefix.INFO.readResults(result,
-              StringKeyConverter.getInstance());
+              new StringKeyConverter());
       assertEquals(infoMap, infoColumns);
 
       // Remember isRelatedTo is of type Map<String, Set<String>>
@@ -710,15 +713,16 @@ public class TestHBaseTimelineStorage {
         }
       }
 
+      KeyConverter<String> stringKeyConverter = new StringKeyConverter();
       // Configuration
       Map<String, Object> configColumns =
-          ApplicationColumnPrefix.CONFIG.readResults(result,
-              StringKeyConverter.getInstance());
+          ApplicationColumnPrefix.CONFIG
+              .readResults(result, stringKeyConverter);
       assertEquals(conf, configColumns);
 
       NavigableMap<String, NavigableMap<Long, Number>> metricsResult =
-          ApplicationColumnPrefix.METRIC.readResultsWithTimestamps(
-              result, StringKeyConverter.getInstance());
+          ApplicationColumnPrefix.METRIC.readResultsWithTimestamps(result,
+              stringKeyConverter);
 
       NavigableMap<Long, Number> metricMap = metricsResult.get(m1.getId());
       matchMetrics(metricValues, metricMap);
@@ -908,7 +912,8 @@ public class TestHBaseTimelineStorage {
       // scan the table and see that entity exists
       Scan s = new Scan();
       byte[] startRow =
-          EntityRowKey.getRowKeyPrefix(cluster, user, flow, runid, appName);
+          new EntityRowKeyPrefix(cluster, user, flow, runid, appName)
+              .getRowKeyPrefix();
       s.setStartRow(startRow);
       s.setMaxVersions(Integer.MAX_VALUE);
       Connection conn = ConnectionFactory.createConnection(c1);
@@ -916,6 +921,7 @@ public class TestHBaseTimelineStorage {
 
       int rowCount = 0;
       int colCount = 0;
+      KeyConverter<String> stringKeyConverter = new StringKeyConverter();
       for (Result result : scanner) {
         if (result != null && !result.isEmpty()) {
           rowCount++;
@@ -936,7 +942,7 @@ public class TestHBaseTimelineStorage {
 
           Map<String, Object> infoColumns =
               EntityColumnPrefix.INFO.readResults(result,
-                  StringKeyConverter.getInstance());
+                  new StringKeyConverter());
           assertEquals(infoMap, infoColumns);
 
           // Remember isRelatedTo is of type Map<String, Set<String>>
@@ -975,13 +981,12 @@ public class TestHBaseTimelineStorage {
 
           // Configuration
           Map<String, Object> configColumns =
-              EntityColumnPrefix.CONFIG.readResults(result,
-                  StringKeyConverter.getInstance());
+              EntityColumnPrefix.CONFIG.readResults(result, stringKeyConverter);
           assertEquals(conf, configColumns);
 
           NavigableMap<String, NavigableMap<Long, Number>> metricsResult =
-              EntityColumnPrefix.METRIC.readResultsWithTimestamps(
-                  result, StringKeyConverter.getInstance());
+              EntityColumnPrefix.METRIC.readResultsWithTimestamps(result,
+                  stringKeyConverter);
 
           NavigableMap<Long, Number> metricMap = metricsResult.get(m1.getId());
           matchMetrics(metricValues, metricMap);
@@ -1116,8 +1121,9 @@ public class TestHBaseTimelineStorage {
       hbi.stop();
 
       // retrieve the row
-      byte[] rowKey =
-          ApplicationRowKey.getRowKey(cluster, user, flow, runid, appName);
+      ApplicationRowKey applicationRowKey =
+          new ApplicationRowKey(cluster, user, flow, runid, appName);
+      byte[] rowKey = applicationRowKey.getRowKey();
       Get get = new Get(rowKey);
       get.setMaxVersions(Integer.MAX_VALUE);
       Connection conn = ConnectionFactory.createConnection(c1);
@@ -1132,7 +1138,7 @@ public class TestHBaseTimelineStorage {
 
       Map<EventColumnName, Object> eventsResult =
           ApplicationColumnPrefix.EVENT.readResults(result,
-              EventColumnNameConverter.getInstance());
+              new EventColumnNameConverter());
       // there should be only one event
       assertEquals(1, eventsResult.size());
       for (Map.Entry<EventColumnName, Object> e : eventsResult.entrySet()) {
@@ -1212,7 +1218,8 @@ public class TestHBaseTimelineStorage {
       String appName = ApplicationId.newInstance(System.currentTimeMillis() +
           9000000L, 1).toString();
       byte[] startRow =
-          EntityRowKey.getRowKeyPrefix(cluster, user, flow, runid, appName);
+          new EntityRowKeyPrefix(cluster, user, flow, runid, appName)
+              .getRowKeyPrefix();
       hbi.write(cluster, user, flow, flowVersion, runid, appName, entities);
       hbi.stop();
       // scan the table and see that entity exists
@@ -1234,7 +1241,7 @@ public class TestHBaseTimelineStorage {
 
           Map<EventColumnName, Object> eventsResult =
               EntityColumnPrefix.EVENT.readResults(result,
-                  EventColumnNameConverter.getInstance());
+                  new EventColumnNameConverter());
           // there should be only one event
           assertEquals(1, eventsResult.size());
           for (Map.Entry<EventColumnName, Object> e : eventsResult.entrySet()) {

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase-tests/src/test/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/TestHBaseStorageFlowActivity.java

@@ -158,7 +158,7 @@ public class TestHBaseStorageFlowActivity {
     Table table1 = conn.getTable(TableName
         .valueOf(FlowActivityTable.DEFAULT_TABLE_NAME));
     byte[] startRow =
-        FlowActivityRowKey.getRowKey(cluster, minStartTs, user, flow);
+        new FlowActivityRowKey(cluster, minStartTs, user, flow).getRowKey();
     Get g = new Get(startRow);
     Result r1 = table1.get(g);
     assertNotNull(r1);
@@ -278,11 +278,12 @@ public class TestHBaseStorageFlowActivity {
     Scan s = new Scan();
     s.addFamily(FlowActivityColumnFamily.INFO.getBytes());
     byte[] startRow =
-        FlowActivityRowKey.getRowKey(cluster, appCreatedTime, user, flow);
+        new FlowActivityRowKey(cluster, appCreatedTime, user, flow).getRowKey();
     s.setStartRow(startRow);
     String clusterStop = cluster + "1";
     byte[] stopRow =
-        FlowActivityRowKey.getRowKey(clusterStop, appCreatedTime, user, flow);
+        new FlowActivityRowKey(clusterStop, appCreatedTime, user, flow)
+            .getRowKey();
     s.setStopRow(stopRow);
     Connection conn = ConnectionFactory.createConnection(c1);
     Table table1 = conn.getTable(TableName
@@ -420,11 +421,11 @@ public class TestHBaseStorageFlowActivity {
     Scan s = new Scan();
     s.addFamily(FlowActivityColumnFamily.INFO.getBytes());
     byte[] startRow =
-        FlowActivityRowKey.getRowKey(cluster, appCreatedTime, user, flow);
+        new FlowActivityRowKey(cluster, appCreatedTime, user, flow).getRowKey();
     s.setStartRow(startRow);
     String clusterStop = cluster + "1";
     byte[] stopRow =
-        FlowActivityRowKey.getRowKey(clusterStop, appCreatedTime, user, flow);
+        new FlowActivityRowKey(clusterStop, appCreatedTime, user, flow).getRowKey();
     s.setStopRow(stopRow);
     Connection conn = ConnectionFactory.createConnection(c1);
     Table table1 = conn.getTable(TableName

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase-tests/src/test/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/TestHBaseStorageFlowRun.java

@@ -59,8 +59,8 @@ import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineFilte
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelinePrefixFilter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.HBaseTimelineReaderImpl;
 import org.apache.hadoop.yarn.server.timelineservice.storage.HBaseTimelineWriterImpl;
-import org.apache.hadoop.yarn.server.timelineservice.storage.TimelineSchemaCreator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.TimelineReader.Field;
+import org.apache.hadoop.yarn.server.timelineservice.storage.TimelineSchemaCreator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnHelper;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityTable;
@@ -224,7 +224,7 @@ public class TestHBaseStorageFlowRun {
         .valueOf(FlowRunTable.DEFAULT_TABLE_NAME));
     // scan the table and see that we get back the right min and max
     // timestamps
-    byte[] startRow = FlowRunRowKey.getRowKey(cluster, user, flow, runid);
+    byte[] startRow = new FlowRunRowKey(cluster, user, flow, runid).getRowKey();
     Get g = new Get(startRow);
     g.addColumn(FlowRunColumnFamily.INFO.getBytes(),
         FlowRunColumn.MIN_START_TIME.getColumnQualifierBytes());
@@ -354,10 +354,11 @@ public class TestHBaseStorageFlowRun {
       long runid, Configuration c1) throws IOException {
     Scan s = new Scan();
     s.addFamily(FlowRunColumnFamily.INFO.getBytes());
-    byte[] startRow = FlowRunRowKey.getRowKey(cluster, user, flow, runid);
+    byte[] startRow = new FlowRunRowKey(cluster, user, flow, runid).getRowKey();
     s.setStartRow(startRow);
     String clusterStop = cluster + "1";
-    byte[] stopRow = FlowRunRowKey.getRowKey(clusterStop, user, flow, runid);
+    byte[] stopRow =
+        new FlowRunRowKey(clusterStop, user, flow, runid).getRowKey();
     s.setStopRow(stopRow);
     Connection conn = ConnectionFactory.createConnection(c1);
     Table table1 = conn.getTable(TableName
@@ -629,7 +630,7 @@ public class TestHBaseStorageFlowRun {
         .valueOf(FlowRunTable.DEFAULT_TABLE_NAME));
     // scan the table and see that we get back the right min and max
     // timestamps
-    byte[] startRow = FlowRunRowKey.getRowKey(cluster, user, flow, runid);
+    byte[] startRow = new FlowRunRowKey(cluster, user, flow, runid).getRowKey();
     Get g = new Get(startRow);
     g.addColumn(FlowRunColumnFamily.INFO.getBytes(),
         FlowRunColumn.MIN_START_TIME.getColumnQualifierBytes());

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase-tests/src/test/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/TestHBaseStorageFlowRunCompaction.java

@@ -19,24 +19,24 @@
 package org.apache.hadoop.yarn.server.timelineservice.storage.flow;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.assertNotEquals;
 
 import java.io.IOException;
-import java.util.Map;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.SortedSet;
 import java.util.TreeSet;
-import java.util.ArrayList;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.TableName;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.hbase.client.Get;
@@ -46,21 +46,21 @@ import org.apache.hadoop.hbase.client.ResultScanner;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.client.Table;
 import org.apache.hadoop.hbase.regionserver.HRegion;
+import org.apache.hadoop.hbase.regionserver.HRegionServer;
+import org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntities;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.HBaseTimelineWriterImpl;
 import org.apache.hadoop.yarn.server.timelineservice.storage.TimelineSchemaCreator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnHelper;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimestampGenerator;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimestampGenerator;
 import org.junit.AfterClass;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import org.apache.hadoop.hbase.regionserver.HRegionServer;
-import org.apache.hadoop.hbase.regionserver.compactions.CompactionRequest;
 
 /**
  * Tests the FlowRun and FlowActivity Tables
@@ -194,10 +194,11 @@ public class TestHBaseStorageFlowRunCompaction {
       long runid, Configuration c1, int valueCount) throws IOException {
     Scan s = new Scan();
     s.addFamily(FlowRunColumnFamily.INFO.getBytes());
-    byte[] startRow = FlowRunRowKey.getRowKey(cluster, user, flow, runid);
+    byte[] startRow = new FlowRunRowKey(cluster, user, flow, runid).getRowKey();
     s.setStartRow(startRow);
     String clusterStop = cluster + "1";
-    byte[] stopRow = FlowRunRowKey.getRowKey(clusterStop, user, flow, runid);
+    byte[] stopRow =
+        new FlowRunRowKey(clusterStop, user, flow, runid).getRowKey();
     s.setStopRow(stopRow);
     Connection conn = ConnectionFactory.createConnection(c1);
     Table table1 = conn.getTable(TableName
@@ -302,8 +303,9 @@ public class TestHBaseStorageFlowRunCompaction {
         cell4Ts, Bytes.toBytes(cellValue4), tagByteArray);
     currentColumnCells.add(c4);
 
-    List<Cell> cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+    List<Cell> cells =
+        fs.processSummationMajorCompaction(currentColumnCells,
+            new LongConverter(), currentTimestamp);
     assertNotNull(cells);
 
     // we should be getting back 4 cells
@@ -387,8 +389,9 @@ public class TestHBaseStorageFlowRunCompaction {
       cellTsNotFinal++;
     }
 
-    List<Cell> cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+    List<Cell> cells =
+        fs.processSummationMajorCompaction(currentColumnCells,
+            new LongConverter(), currentTimestamp);
     assertNotNull(cells);
 
     // we should be getting back count + 1 cells
@@ -489,8 +492,9 @@ public class TestHBaseStorageFlowRunCompaction {
       cellTsNotFinal++;
     }
 
-    List<Cell> cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+    List<Cell> cells =
+        fs.processSummationMajorCompaction(currentColumnCells,
+            new LongConverter(), currentTimestamp);
     assertNotNull(cells);
 
     // we should be getting back
@@ -554,7 +558,7 @@ public class TestHBaseStorageFlowRunCompaction {
         130L, Bytes.toBytes(cellValue2), tagByteArray);
     currentColumnCells.add(c2);
     List<Cell> cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+        new LongConverter(), currentTimestamp);
     assertNotNull(cells);
 
     // we should be getting back two cells
@@ -602,7 +606,7 @@ public class TestHBaseStorageFlowRunCompaction {
     currentColumnCells.add(c1);
 
     List<Cell> cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+        new LongConverter(), currentTimestamp);
     assertNotNull(cells);
     // we should not get the same cell back
     // but we get back the flow cell
@@ -639,7 +643,7 @@ public class TestHBaseStorageFlowRunCompaction {
         currentTimestamp, Bytes.toBytes(1110L), tagByteArray);
     currentColumnCells.add(c1);
     List<Cell> cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+        new LongConverter(), currentTimestamp);
     assertNotNull(cells);
     // we expect the same cell back
     assertEquals(1, cells.size());
@@ -653,15 +657,19 @@ public class TestHBaseStorageFlowRunCompaction {
     FlowScanner fs = getFlowScannerForTestingCompaction();
     long currentTimestamp = System.currentTimeMillis();
 
+    LongConverter longConverter = new LongConverter();
+
     SortedSet<Cell> currentColumnCells = null;
-    List<Cell> cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+    List<Cell> cells =
+        fs.processSummationMajorCompaction(currentColumnCells, longConverter,
+            currentTimestamp);
     assertNotNull(cells);
     assertEquals(0, cells.size());
 
     currentColumnCells = new TreeSet<Cell>(KeyValue.COMPARATOR);
-    cells = fs.processSummationMajorCompaction(currentColumnCells,
-        LongConverter.getInstance(), currentTimestamp);
+    cells =
+        fs.processSummationMajorCompaction(currentColumnCells, longConverter,
+            currentTimestamp);
     assertNotNull(cells);
     assertEquals(0, cells.size());
   }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/reader/filter/TimelineFilterUtils.java

@@ -31,14 +31,9 @@ import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
 import org.apache.hadoop.hbase.filter.Filter;
 import org.apache.hadoop.hbase.filter.FilterList;
 import org.apache.hadoop.hbase.filter.FilterList.Operator;
-import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.Column;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnFamily;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnName;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnNameConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.StringKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnPrefix;
 import org.apache.hadoop.hbase.filter.QualifierFilter;
 import org.apache.hadoop.hbase.filter.SingleColumnValueFilter;
 
@@ -209,39 +204,6 @@ public final class TimelineFilterUtils {
     return singleColValFilter;
   }
 
-  private static <T> byte[] createColQualifierPrefix(ColumnPrefix<T> colPrefix,
-      String column) {
-    if (colPrefix == ApplicationColumnPrefix.EVENT ||
-        colPrefix == EntityColumnPrefix.EVENT) {
-      return EventColumnNameConverter.getInstance().encode(
-          new EventColumnName(column, null, null));
-    } else {
-      return StringKeyConverter.getInstance().encode(column);
-    }
-  }
-
-  /**
-   * Create a filter list of qualifier filters based on passed set of columns.
-   *
-   * @param <T> Describes the type of column prefix.
-   * @param colPrefix Column Prefix.
-   * @param columns set of column qualifiers.
-   * @return filter list.
-   */
-  public static <T> FilterList createFiltersFromColumnQualifiers(
-      ColumnPrefix<T> colPrefix, Set<String> columns) {
-    FilterList list = new FilterList(Operator.MUST_PASS_ONE);
-    for (String column : columns) {
-      // For columns which have compound column qualifiers (eg. events), we need
-      // to include the required separator.
-      byte[] compoundColQual = createColQualifierPrefix(colPrefix, column);
-      list.addFilter(new QualifierFilter(CompareOp.EQUAL,
-          new BinaryPrefixComparator(
-              colPrefix.getColumnPrefixBytes(compoundColQual))));
-    }
-    return list;
-  }
-
   /**
    * Fetch columns from filter list containing exists and multivalue equality
    * filters. This is done to fetch only required columns from back-end and

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineWriterImpl.java

@@ -32,6 +32,7 @@ import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.service.AbstractService;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntities;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
+import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntityType;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEvent;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineWriteResponse;
@@ -45,11 +46,10 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlow
 import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnName;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnNameConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongKeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.StringKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TypedBufferedMutator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumn;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnPrefix;
@@ -86,6 +86,17 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
   private TypedBufferedMutator<FlowActivityTable> flowActivityTable;
   private TypedBufferedMutator<FlowRunTable> flowRunTable;
 
+  /**
+   * Used to convert strings key components to and from storage format.
+   */
+  private final KeyConverter<String> stringKeyConverter =
+      new StringKeyConverter();
+
+  /**
+   * Used to convert Long key components to and from storage format.
+   */
+  private final KeyConverter<Long> longKeyConverter = new LongKeyConverter();
+
   public HBaseTimelineWriterImpl() {
     super(HBaseTimelineWriterImpl.class.getName());
   }
@@ -138,12 +149,19 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
 
       // if the entity is the application, the destination is the application
       // table
-      boolean isApplication = TimelineStorageUtils.isApplicationEntity(te);
-      byte[] rowKey = isApplication ?
-          ApplicationRowKey.getRowKey(clusterId, userId, flowName, flowRunId,
-              appId) :
-          EntityRowKey.getRowKey(clusterId, userId, flowName, flowRunId, appId,
-              te.getType(), te.getId());
+      boolean isApplication = isApplicationEntity(te);
+      byte[] rowKey;
+      if (isApplication) {
+        ApplicationRowKey applicationRowKey =
+            new ApplicationRowKey(clusterId, userId, flowName, flowRunId,
+                appId);
+        rowKey = applicationRowKey.getRowKey();
+      } else {
+        EntityRowKey entityRowKey =
+            new EntityRowKey(clusterId, userId, flowName, flowRunId, appId,
+                te.getType(), te.getId());
+        rowKey = entityRowKey.getRowKey();
+      }
 
       storeInfo(rowKey, te, flowVersion, isApplication);
       storeEvents(rowKey, te.getEvents(), isApplication);
@@ -152,102 +170,101 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
       storeRelations(rowKey, te, isApplication);
 
       if (isApplication) {
-        TimelineEvent event = TimelineStorageUtils.getApplicationEvent(te,
-            ApplicationMetricsConstants.CREATED_EVENT_TYPE);
+        TimelineEvent event =
+            getApplicationEvent(te,
+                ApplicationMetricsConstants.CREATED_EVENT_TYPE);
+        FlowRunRowKey flowRunRowKey =
+            new FlowRunRowKey(clusterId, userId, flowName, flowRunId);
         if (event != null) {
-          onApplicationCreated(clusterId, userId, flowName, flowVersion,
-              flowRunId, appId, te, event.getTimestamp());
+          AppToFlowRowKey appToFlowRowKey =
+              new AppToFlowRowKey(clusterId, appId);
+          onApplicationCreated(flowRunRowKey, appToFlowRowKey, appId, userId,
+              flowVersion, te, event.getTimestamp());
         }
         // if it's an application entity, store metrics
-        storeFlowMetricsAppRunning(clusterId, userId, flowName, flowRunId,
-            appId, te);
+        storeFlowMetricsAppRunning(flowRunRowKey, appId, te);
         // if application has finished, store it's finish time and write final
         // values of all metrics
-        event = TimelineStorageUtils.getApplicationEvent(te,
+        event = getApplicationEvent(te,
             ApplicationMetricsConstants.FINISHED_EVENT_TYPE);
         if (event != null) {
-          onApplicationFinished(clusterId, userId, flowName, flowVersion,
-              flowRunId, appId, te, event.getTimestamp());
+          onApplicationFinished(flowRunRowKey, flowVersion, appId, te,
+              event.getTimestamp());
         }
       }
     }
     return putStatus;
   }
 
-  private void onApplicationCreated(String clusterId, String userId,
-      String flowName, String flowVersion, long flowRunId, String appId,
-      TimelineEntity te, long appCreatedTimeStamp) throws IOException {
+  private void onApplicationCreated(FlowRunRowKey flowRunRowKey,
+      AppToFlowRowKey appToFlowRowKey, String appId, String userId,
+      String flowVersion, TimelineEntity te, long appCreatedTimeStamp)
+      throws IOException {
+
+    String flowName = flowRunRowKey.getFlowName();
+    Long flowRunId = flowRunRowKey.getFlowRunId();
+
     // store in App to flow table
-    storeInAppToFlowTable(clusterId, userId, flowName, flowRunId, appId, te);
+    byte[] rowKey = appToFlowRowKey.getRowKey();
+    AppToFlowColumn.FLOW_ID.store(rowKey, appToFlowTable, null, flowName);
+    AppToFlowColumn.FLOW_RUN_ID.store(rowKey, appToFlowTable, null, flowRunId);
+    AppToFlowColumn.USER_ID.store(rowKey, appToFlowTable, null, userId);
+
     // store in flow run table
-    storeAppCreatedInFlowRunTable(clusterId, userId, flowName, flowVersion,
-        flowRunId, appId, te);
-    // store in flow activity table
-    storeInFlowActivityTable(clusterId, userId, flowName, flowVersion,
-        flowRunId, appId, appCreatedTimeStamp);
-  }
+    storeAppCreatedInFlowRunTable(flowRunRowKey, appId, te);
 
-  /*
-   * updates the {@link FlowActivityTable} with the Application TimelineEntity
-   * information
-   */
-  private void storeInFlowActivityTable(String clusterId, String userId,
-      String flowName, String flowVersion, long flowRunId, String appId,
-      long activityTimeStamp) throws IOException {
-    byte[] rowKey = FlowActivityRowKey.getRowKey(clusterId, activityTimeStamp,
-        userId, flowName);
-    byte[] qualifier = LongKeyConverter.getInstance().encode(flowRunId);
-    FlowActivityColumnPrefix.RUN_ID.store(rowKey, flowActivityTable, qualifier,
-        null, flowVersion,
+    // store in flow activity table
+    byte[] flowActivityRowKeyBytes =
+        new FlowActivityRowKey(flowRunRowKey.getClusterId(),
+            appCreatedTimeStamp, flowRunRowKey.getUserId(), flowName)
+            .getRowKey();
+    byte[] qualifier = longKeyConverter.encode(flowRunRowKey.getFlowRunId());
+    FlowActivityColumnPrefix.RUN_ID.store(flowActivityRowKeyBytes,
+        flowActivityTable, qualifier, null, flowVersion,
         AggregationCompactionDimension.APPLICATION_ID.getAttribute(appId));
   }
 
   /*
    * updates the {@link FlowRunTable} with Application Created information
    */
-  private void storeAppCreatedInFlowRunTable(String clusterId, String userId,
-      String flowName, String flowVersion, long flowRunId, String appId,
-      TimelineEntity te) throws IOException {
-    byte[] rowKey = FlowRunRowKey.getRowKey(clusterId, userId, flowName,
-        flowRunId);
+  private void storeAppCreatedInFlowRunTable(FlowRunRowKey flowRunRowKey,
+      String appId, TimelineEntity te) throws IOException {
+    byte[] rowKey = flowRunRowKey.getRowKey();
     FlowRunColumn.MIN_START_TIME.store(rowKey, flowRunTable, null,
         te.getCreatedTime(),
         AggregationCompactionDimension.APPLICATION_ID.getAttribute(appId));
   }
 
-  private void storeInAppToFlowTable(String clusterId, String userId,
-      String flowName, long flowRunId, String appId, TimelineEntity te)
-      throws IOException {
-    byte[] rowKey = AppToFlowRowKey.getRowKey(clusterId, appId);
-    AppToFlowColumn.FLOW_ID.store(rowKey, appToFlowTable, null, flowName);
-    AppToFlowColumn.FLOW_RUN_ID.store(rowKey, appToFlowTable, null, flowRunId);
-    AppToFlowColumn.USER_ID.store(rowKey, appToFlowTable, null, userId);
-  }
 
   /*
    * updates the {@link FlowRunTable} and {@link FlowActivityTable} when an
    * application has finished
    */
-  private void onApplicationFinished(String clusterId, String userId,
-      String flowName, String flowVersion, long flowRunId, String appId,
-      TimelineEntity te, long appFinishedTimeStamp) throws IOException {
+  private void onApplicationFinished(FlowRunRowKey flowRunRowKey,
+      String flowVersion, String appId, TimelineEntity te,
+      long appFinishedTimeStamp) throws IOException {
     // store in flow run table
-    storeAppFinishedInFlowRunTable(clusterId, userId, flowName, flowRunId,
-        appId, te, appFinishedTimeStamp);
+    storeAppFinishedInFlowRunTable(flowRunRowKey, appId, te,
+        appFinishedTimeStamp);
 
     // indicate in the flow activity table that the app has finished
-    storeInFlowActivityTable(clusterId, userId, flowName, flowVersion,
-        flowRunId, appId, appFinishedTimeStamp);
+    byte[] rowKey =
+        new FlowActivityRowKey(flowRunRowKey.getClusterId(),
+            appFinishedTimeStamp, flowRunRowKey.getUserId(),
+            flowRunRowKey.getFlowName()).getRowKey();
+    byte[] qualifier = longKeyConverter.encode(flowRunRowKey.getFlowRunId());
+    FlowActivityColumnPrefix.RUN_ID.store(rowKey, flowActivityTable, qualifier,
+        null, flowVersion,
+        AggregationCompactionDimension.APPLICATION_ID.getAttribute(appId));
   }
 
   /*
    * Update the {@link FlowRunTable} with Application Finished information
    */
-  private void storeAppFinishedInFlowRunTable(String clusterId, String userId,
-      String flowName, long flowRunId, String appId, TimelineEntity te,
-      long appFinishedTimeStamp) throws IOException {
-    byte[] rowKey =
-        FlowRunRowKey.getRowKey(clusterId, userId, flowName, flowRunId);
+  private void storeAppFinishedInFlowRunTable(FlowRunRowKey flowRunRowKey,
+      String appId, TimelineEntity te, long appFinishedTimeStamp)
+      throws IOException {
+    byte[] rowKey = flowRunRowKey.getRowKey();
     Attribute attributeAppId =
         AggregationCompactionDimension.APPLICATION_ID.getAttribute(appId);
     FlowRunColumn.MAX_END_TIME.store(rowKey, flowRunTable, null,
@@ -264,13 +281,11 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
   /*
    * Updates the {@link FlowRunTable} with Application Metrics
    */
-  private void storeFlowMetricsAppRunning(String clusterId, String userId,
-      String flowName, long flowRunId, String appId, TimelineEntity te)
-      throws IOException {
+  private void storeFlowMetricsAppRunning(FlowRunRowKey flowRunRowKey,
+      String appId, TimelineEntity te) throws IOException {
     Set<TimelineMetric> metrics = te.getMetrics();
     if (metrics != null) {
-      byte[] rowKey = FlowRunRowKey.getRowKey(clusterId, userId, flowName,
-          flowRunId);
+      byte[] rowKey = flowRunRowKey.getRowKey();
       storeFlowMetrics(rowKey, metrics,
           AggregationCompactionDimension.APPLICATION_ID.getAttribute(appId),
           AggregationOperation.SUM.getAttribute());
@@ -280,8 +295,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
   private void storeFlowMetrics(byte[] rowKey, Set<TimelineMetric> metrics,
       Attribute... attributes) throws IOException {
     for (TimelineMetric metric : metrics) {
-      byte[] metricColumnQualifier =
-          StringKeyConverter.getInstance().encode(metric.getId());
+      byte[] metricColumnQualifier = stringKeyConverter.encode(metric.getId());
       Map<Long, Number> timeseries = metric.getValues();
       for (Map.Entry<Long, Number> timeseriesEntry : timeseries.entrySet()) {
         Long timestamp = timeseriesEntry.getKey();
@@ -320,8 +334,8 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
       String compoundValue =
           Separator.VALUES.joinEncoded(connectedEntity.getValue());
       columnPrefix.store(rowKey, table,
-          StringKeyConverter.getInstance().encode(connectedEntity.getKey()),
-          null, compoundValue);
+          stringKeyConverter.encode(connectedEntity.getKey()), null,
+          compoundValue);
     }
   }
 
@@ -341,7 +355,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
       if (info != null) {
         for (Map.Entry<String, Object> entry : info.entrySet()) {
           ApplicationColumnPrefix.INFO.store(rowKey, applicationTable,
-              StringKeyConverter.getInstance().encode(entry.getKey()), null,
+              stringKeyConverter.encode(entry.getKey()), null,
               entry.getValue());
         }
       }
@@ -355,7 +369,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
       if (info != null) {
         for (Map.Entry<String, Object> entry : info.entrySet()) {
           EntityColumnPrefix.INFO.store(rowKey, entityTable,
-              StringKeyConverter.getInstance().encode(entry.getKey()), null,
+              stringKeyConverter.encode(entry.getKey()), null,
               entry.getValue());
         }
       }
@@ -371,8 +385,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
       return;
     }
     for (Map.Entry<String, String> entry : config.entrySet()) {
-      byte[] configKey =
-          StringKeyConverter.getInstance().encode(entry.getKey());
+      byte[] configKey = stringKeyConverter.encode(entry.getKey());
       if (isApplication) {
         ApplicationColumnPrefix.CONFIG.store(rowKey, applicationTable,
             configKey, null, entry.getValue());
@@ -392,7 +405,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
     if (metrics != null) {
       for (TimelineMetric metric : metrics) {
         byte[] metricColumnQualifier =
-            StringKeyConverter.getInstance().encode(metric.getId());
+            stringKeyConverter.encode(metric.getId());
         Map<Long, Number> timeseries = metric.getValues();
         for (Map.Entry<Long, Number> timeseriesEntry : timeseries.entrySet()) {
           Long timestamp = timeseriesEntry.getKey();
@@ -425,12 +438,11 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
                   "! Using the current timestamp");
               eventTimestamp = System.currentTimeMillis();
             }
-            EventColumnNameConverter converter =
-                EventColumnNameConverter.getInstance();
             Map<String, Object> eventInfo = event.getInfo();
             if ((eventInfo == null) || (eventInfo.size() == 0)) {
-              byte[] columnQualifierBytes = converter.encode(
-                  new EventColumnName(eventId, eventTimestamp, null));
+              byte[] columnQualifierBytes =
+                  new EventColumnName(eventId, eventTimestamp, null)
+                      .getColumnQualifier();
               if (isApplication) {
                 ApplicationColumnPrefix.EVENT.store(rowKey, applicationTable,
                     columnQualifierBytes, null, Separator.EMPTY_BYTES);
@@ -441,9 +453,9 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
             } else {
               for (Map.Entry<String, Object> info : eventInfo.entrySet()) {
                 // eventId=infoKey
-                byte[] columnQualifierBytes = converter.encode(
-                    new EventColumnName(eventId, eventTimestamp,
-                        info.getKey()));
+                byte[] columnQualifierBytes =
+                    new EventColumnName(eventId, eventTimestamp, info.getKey())
+                        .getColumnQualifier();
                 if (isApplication) {
                   ApplicationColumnPrefix.EVENT.store(rowKey, applicationTable,
                       columnQualifierBytes, null, info.getValue());
@@ -459,12 +471,56 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
     }
   }
 
+  /**
+   * Checks if the input TimelineEntity object is an ApplicationEntity.
+   *
+   * @param te TimelineEntity object.
+   * @return true if input is an ApplicationEntity, false otherwise
+   */
+  static boolean isApplicationEntity(TimelineEntity te) {
+    return te.getType().equals(TimelineEntityType.YARN_APPLICATION.toString());
+  }
+
+  /**
+   * @param te TimelineEntity object.
+   * @param eventId event with this id needs to be fetched
+   * @return TimelineEvent if TimelineEntity contains the desired event.
+   */
+  private static TimelineEvent getApplicationEvent(TimelineEntity te,
+      String eventId) {
+    if (isApplicationEntity(te)) {
+      for (TimelineEvent event : te.getEvents()) {
+        if (event.getId().equals(eventId)) {
+          return event;
+        }
+      }
+    }
+    return null;
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage
+   * .TimelineWriter#aggregate
+   * (org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity,
+   * org.apache
+   * .hadoop.yarn.server.timelineservice.storage.TimelineAggregationTrack)
+   */
   @Override
   public TimelineWriteResponse aggregate(TimelineEntity data,
       TimelineAggregationTrack track) throws IOException {
     return null;
   }
 
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.TimelineWriter#flush
+   * ()
+   */
   @Override
   public void flush() throws IOException {
     // flush all buffered mutators

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/application/ApplicationColumn.java

@@ -45,7 +45,7 @@ public enum ApplicationColumn implements Column<ApplicationTable> {
    * When the application was created.
    */
   CREATED_TIME(ApplicationColumnFamily.INFO, "created_time",
-      LongConverter.getInstance()),
+      new LongConverter()),
 
   /**
    * The version of the flow that this app belongs to.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/application/ApplicationColumnPrefix.java

@@ -67,8 +67,7 @@ public enum ApplicationColumnPrefix implements ColumnPrefix<ApplicationTable> {
   /**
    * Metrics are stored with the metric name as the column name.
    */
-  METRIC(ApplicationColumnFamily.METRICS, null,
-      LongConverter.getInstance());
+  METRIC(ApplicationColumnFamily.METRICS, null, new LongConverter());
 
   private final ColumnHelper<ApplicationTable> column;
   private final ColumnFamily<ApplicationTable> columnFamily;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/application/ApplicationRowKey.java

@@ -18,6 +18,12 @@
 
 package org.apache.hadoop.yarn.server.timelineservice.storage.application;
 
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.AppIdKeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
+
 /**
  * Represents a rowkey for the application table.
  */
@@ -27,6 +33,8 @@ public class ApplicationRowKey {
   private final String flowName;
   private final Long flowRunId;
   private final String appId;
+  private final KeyConverter<ApplicationRowKey> appRowKeyConverter =
+      new ApplicationRowKeyConverter();
 
   public ApplicationRowKey(String clusterId, String userId, String flowName,
       Long flowRunId, String appId) {
@@ -57,61 +65,142 @@ public class ApplicationRowKey {
     return appId;
   }
 
-  /**
-   * Constructs a row key prefix for the application table as follows:
-   * {@code clusterId!userName!flowName!}.
-   *
-   * @param clusterId Cluster Id.
-   * @param userId User Id.
-   * @param flowName Flow Name.
-   * @return byte array with the row key prefix
-   */
-  public static byte[] getRowKeyPrefix(String clusterId, String userId,
-      String flowName) {
-    return ApplicationRowKeyConverter.getInstance().encode(
-        new ApplicationRowKey(clusterId, userId, flowName, null, null));
-  }
-
-  /**
-   * Constructs a row key prefix for the application table as follows:
-   * {@code clusterId!userName!flowName!flowRunId!}.
-   *
-   * @param clusterId Cluster Id.
-   * @param userId User Id.
-   * @param flowName Flow Name.
-   * @param flowRunId Run Id for the flow.
-   * @return byte array with the row key prefix
-   */
-  public static byte[] getRowKeyPrefix(String clusterId, String userId,
-      String flowName, Long flowRunId) {
-    return ApplicationRowKeyConverter.getInstance().encode(
-        new ApplicationRowKey(clusterId, userId, flowName, flowRunId, null));
-  }
-
   /**
    * Constructs a row key for the application table as follows:
    * {@code clusterId!userName!flowName!flowRunId!AppId}.
    *
-   * @param clusterId Cluster Id.
-   * @param userId User Id.
-   * @param flowName Flow Name.
-   * @param flowRunId Run Id for the flow.
-   * @param appId App Id.
    * @return byte array with the row key
    */
-  public static byte[] getRowKey(String clusterId, String userId,
-      String flowName, Long flowRunId, String appId) {
-    return ApplicationRowKeyConverter.getInstance().encode(
-        new ApplicationRowKey(clusterId, userId, flowName, flowRunId, appId));
+  public byte[] getRowKey() {
+    return appRowKeyConverter.encode(this);
   }
 
   /**
    * Given the raw row key as bytes, returns the row key as an object.
    *
-   * @param rowKey Byte representation  of row key.
+   * @param rowKey Byte representation of row key.
    * @return An <cite>ApplicationRowKey</cite> object.
    */
   public static ApplicationRowKey parseRowKey(byte[] rowKey) {
-    return ApplicationRowKeyConverter.getInstance().decode(rowKey);
+    return new ApplicationRowKeyConverter().decode(rowKey);
   }
+
+  /**
+   * Encodes and decodes row key for application table. The row key is of the
+   * form: clusterId!userName!flowName!flowRunId!appId. flowRunId is a long,
+   * appId is encoded and decoded using {@link AppIdKeyConverter} and rest are
+   * strings.
+   * <p>
+   */
+  final private static class ApplicationRowKeyConverter implements
+      KeyConverter<ApplicationRowKey> {
+
+    private final KeyConverter<String> appIDKeyConverter =
+        new AppIdKeyConverter();
+
+    /**
+     * Intended for use in ApplicationRowKey only.
+     */
+    private ApplicationRowKeyConverter() {
+    }
+
+    /**
+     * Application row key is of the form
+     * clusterId!userName!flowName!flowRunId!appId with each segment separated
+     * by !. The sizes below indicate sizes of each one of these segements in
+     * sequence. clusterId, userName and flowName are strings. flowrunId is a
+     * long hence 8 bytes in size. app id is represented as 12 bytes with
+     * cluster timestamp part of appid takes 8 bytes(long) and seq id takes 4
+     * bytes(int). Strings are variable in size (i.e. end whenever separator is
+     * encountered). This is used while decoding and helps in determining where
+     * to split.
+     */
+    private static final int[] SEGMENT_SIZES = {Separator.VARIABLE_SIZE,
+        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
+        AppIdKeyConverter.getKeySize() };
+
+    /*
+     * (non-Javadoc)
+     *
+     * Encodes ApplicationRowKey object into a byte array with each
+     * component/field in ApplicationRowKey separated by Separator#QUALIFIERS.
+     * This leads to an application table row key of the form
+     * clusterId!userName!flowName!flowRunId!appId If flowRunId in passed
+     * ApplicationRowKey object is null (and the fields preceding it i.e.
+     * clusterId, userId and flowName are not null), this returns a row key
+     * prefix of the form clusterId!userName!flowName! and if appId in
+     * ApplicationRowKey is null (other 4 components all are not null), this
+     * returns a row key prefix of the form
+     * clusterId!userName!flowName!flowRunId! flowRunId is inverted while
+     * encoding as it helps maintain a descending order for row keys in the
+     * application table.
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#encode(java.lang.Object)
+     */
+    @Override
+    public byte[] encode(ApplicationRowKey rowKey) {
+      byte[] cluster =
+          Separator.encode(rowKey.getClusterId(), Separator.SPACE,
+              Separator.TAB, Separator.QUALIFIERS);
+      byte[] user =
+          Separator.encode(rowKey.getUserId(), Separator.SPACE, Separator.TAB,
+              Separator.QUALIFIERS);
+      byte[] flow =
+          Separator.encode(rowKey.getFlowName(), Separator.SPACE,
+              Separator.TAB, Separator.QUALIFIERS);
+      byte[] first = Separator.QUALIFIERS.join(cluster, user, flow);
+      // Note that flowRunId is a long, so we can't encode them all at the same
+      // time.
+      if (rowKey.getFlowRunId() == null) {
+        return Separator.QUALIFIERS.join(first, Separator.EMPTY_BYTES);
+      }
+      byte[] second =
+          Bytes.toBytes(LongConverter.invertLong(
+              rowKey.getFlowRunId()));
+      if (rowKey.getAppId() == null || rowKey.getAppId().isEmpty()) {
+        return Separator.QUALIFIERS.join(first, second, Separator.EMPTY_BYTES);
+      }
+      byte[] third = appIDKeyConverter.encode(rowKey.getAppId());
+      return Separator.QUALIFIERS.join(first, second, third);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * Decodes an application row key of the form
+     * clusterId!userName!flowName!flowRunId!appId represented in byte format
+     * and converts it into an ApplicationRowKey object.flowRunId is inverted
+     * while decoding as it was inverted while encoding.
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#decode(byte[])
+     */
+    @Override
+    public ApplicationRowKey decode(byte[] rowKey) {
+      byte[][] rowKeyComponents =
+          Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
+      if (rowKeyComponents.length != 5) {
+        throw new IllegalArgumentException("the row key is not valid for "
+            + "an application");
+      }
+      String clusterId =
+          Separator.decode(Bytes.toString(rowKeyComponents[0]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String userId =
+          Separator.decode(Bytes.toString(rowKeyComponents[1]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String flowName =
+          Separator.decode(Bytes.toString(rowKeyComponents[2]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      Long flowRunId =
+          LongConverter.invertLong(Bytes.toLong(rowKeyComponents[3]));
+      String appId = appIDKeyConverter.decode(rowKeyComponents[4]);
+      return new ApplicationRowKey(clusterId, userId, flowName, flowRunId,
+          appId);
+    }
+  }
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/application/ApplicationRowKeyConverter.java

@@ -1,130 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.hadoop.yarn.server.timelineservice.storage.application;
-
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.AppIdKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
-
-/**
- * Encodes and decodes row key for application table.
- * The row key is of the form : clusterId!userName!flowName!flowRunId!appId.
- * flowRunId is a long, appId is encoded and decoded using
- * {@link AppIdKeyConverter} and rest are strings.
- */
-public final class ApplicationRowKeyConverter implements
-    KeyConverter<ApplicationRowKey> {
-  private static final ApplicationRowKeyConverter INSTANCE =
-      new ApplicationRowKeyConverter();
-
-  public static ApplicationRowKeyConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private ApplicationRowKeyConverter() {
-  }
-
-  // Application row key is of the form
-  // clusterId!userName!flowName!flowRunId!appId with each segment separated
-  // by !. The sizes below indicate sizes of each one of these segements in
-  // sequence. clusterId, userName and flowName are strings. flowrunId is a long
-  // hence 8 bytes in size. app id is represented as 12 bytes with cluster
-  // timestamp part of appid being 8 bytes(long) and seq id being 4 bytes(int).
-  // Strings are variable in size (i.e. end whenever separator is encountered).
-  // This is used while decoding and helps in determining where to split.
-  private static final int[] SEGMENT_SIZES = {
-      Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-      Bytes.SIZEOF_LONG, AppIdKeyConverter.getKeySize() };
-
-  /*
-   * (non-Javadoc)
-   *
-   * Encodes ApplicationRowKey object into a byte array with each
-   * component/field in ApplicationRowKey separated by Separator#QUALIFIERS.
-   * This leads to an application table row key of the form
-   * clusterId!userName!flowName!flowRunId!appId
-   * If flowRunId in passed ApplicationRowKey object is null (and the fields
-   * preceding it i.e. clusterId, userId and flowName are not null), this
-   * returns a row key prefix of the form clusterId!userName!flowName! and if
-   * appId in ApplicationRowKey is null (other 4 components are not null), this
-   * returns a row key prefix of the form clusterId!userName!flowName!flowRunId!
-   * flowRunId is inverted while encoding as it helps maintain a descending
-   * order for row keys in application table.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #encode(java.lang.Object)
-   */
-  @Override
-  public byte[] encode(ApplicationRowKey rowKey) {
-    byte[] cluster = Separator.encode(rowKey.getClusterId(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] user = Separator.encode(rowKey.getUserId(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] flow = Separator.encode(rowKey.getFlowName(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] first = Separator.QUALIFIERS.join(cluster, user, flow);
-    // Note that flowRunId is a long, so we can't encode them all at the same
-    // time.
-    if (rowKey.getFlowRunId() == null) {
-      return Separator.QUALIFIERS.join(first, Separator.EMPTY_BYTES);
-    }
-    byte[] second = Bytes.toBytes(
-        TimelineStorageUtils.invertLong(rowKey.getFlowRunId()));
-    if (rowKey.getAppId() == null || rowKey.getAppId().isEmpty()) {
-      return Separator.QUALIFIERS.join(first, second, Separator.EMPTY_BYTES);
-    }
-    byte[] third = AppIdKeyConverter.getInstance().encode(rowKey.getAppId());
-    return Separator.QUALIFIERS.join(first, second, third);
-  }
-
-  /*
-   * (non-Javadoc)
-   *
-   * Decodes an application row key of the form
-   * clusterId!userName!flowName!flowRunId!appId represented in byte format and
-   * converts it into an ApplicationRowKey object.flowRunId is inverted while
-   * decoding as it was inverted while encoding.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #decode(byte[])
-   */
-  @Override
-  public ApplicationRowKey decode(byte[] rowKey) {
-    byte[][] rowKeyComponents =
-        Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
-    if (rowKeyComponents.length != 5) {
-      throw new IllegalArgumentException("the row key is not valid for " +
-          "an application");
-    }
-    String clusterId = Separator.decode(Bytes.toString(rowKeyComponents[0]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String userId = Separator.decode(Bytes.toString(rowKeyComponents[1]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String flowName = Separator.decode(Bytes.toString(rowKeyComponents[2]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    Long flowRunId =
-        TimelineStorageUtils.invertLong(Bytes.toLong(rowKeyComponents[3]));
-    String appId = AppIdKeyConverter.getInstance().decode(rowKeyComponents[4]);
-    return new ApplicationRowKey(clusterId, userId, flowName, flowRunId, appId);
-  }
-}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/application/ApplicationRowKeyPrefix.java

@@ -0,0 +1,69 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.server.timelineservice.storage.application;
+
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
+
+/**
+ * Represents a partial rowkey (without flowName or without flowName and
+ * flowRunId) for the application table.
+ */
+public class ApplicationRowKeyPrefix extends ApplicationRowKey implements
+    RowKeyPrefix<ApplicationRowKey> {
+
+  /**
+   * Creates a prefix which generates the following rowKeyPrefixes for the
+   * application table: {@code clusterId!userName!flowName!}.
+   *
+   * @param clusterId the cluster on which applications ran
+   * @param userId the user that ran applications
+   * @param flowName the name of the flow that was run by the user on the
+   *          cluster
+   */
+  public ApplicationRowKeyPrefix(String clusterId, String userId,
+      String flowName) {
+    super(clusterId, userId, flowName, null, null);
+  }
+
+  /**
+   * Creates a prefix which generates the following rowKeyPrefixes for the
+   * application table: {@code clusterId!userName!flowName!flowRunId!}.
+   *
+   * @param clusterId identifying the cluster
+   * @param userId identifying the user
+   * @param flowName identifying the flow
+   * @param flowRunId identifying the instance of this flow
+   */
+  public ApplicationRowKeyPrefix(String clusterId, String userId,
+      String flowName, Long flowRunId) {
+    super(clusterId, userId, flowName, flowRunId, null);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.application.
+   * RowKeyPrefix#getRowKeyPrefix()
+   */
+  @Override
+  public byte[] getRowKeyPrefix() {
+    return super.getRowKey();
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/apptoflow/AppToFlowRowKey.java

@@ -17,12 +17,19 @@
  */
 package org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow;
 
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.AppIdKeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
+
 /**
  * Represents a rowkey for the app_flow table.
  */
 public class AppToFlowRowKey {
   private final String clusterId;
   private final String appId;
+  private final KeyConverter<AppToFlowRowKey> appToFlowRowKeyConverter =
+      new AppToFlowRowKeyConverter();
 
   public AppToFlowRowKey(String clusterId, String appId) {
     this.clusterId = clusterId;
@@ -41,13 +48,10 @@ public class AppToFlowRowKey {
    * Constructs a row key prefix for the app_flow table as follows:
    * {@code clusterId!AppId}.
    *
-   * @param clusterId Cluster Id.
-   * @param appId Application Id.
    * @return byte array with the row key
    */
-  public static byte[] getRowKey(String clusterId, String appId) {
-    return AppToFlowRowKeyConverter.getInstance().encode(
-        new AppToFlowRowKey(clusterId, appId));
+  public  byte[] getRowKey() {
+    return appToFlowRowKeyConverter.encode(this);
   }
 
   /**
@@ -57,6 +61,83 @@ public class AppToFlowRowKey {
    * @return an <cite>AppToFlowRowKey</cite> object.
    */
   public static AppToFlowRowKey parseRowKey(byte[] rowKey) {
-    return AppToFlowRowKeyConverter.getInstance().decode(rowKey);
+    return new AppToFlowRowKeyConverter().decode(rowKey);
+  }
+
+  /**
+   * Encodes and decodes row key for app_flow table. The row key is of the form
+   * clusterId!appId. clusterId is a string and appId is encoded/decoded using
+   * {@link AppIdKeyConverter}.
+   * <p>
+   */
+  final private static class AppToFlowRowKeyConverter implements
+      KeyConverter<AppToFlowRowKey> {
+
+    private final KeyConverter<String> appIDKeyConverter =
+        new AppIdKeyConverter();
+
+    /**
+     * Intended for use in AppToFlowRowKey only.
+     */
+    private AppToFlowRowKeyConverter() {
+    }
+
+
+    /**
+     * App to flow row key is of the form clusterId!appId with the 2 segments
+     * separated by !. The sizes below indicate sizes of both of these segments
+     * in sequence. clusterId is a string. appId is represented as 12 bytes w.
+     * cluster Timestamp part of appid taking 8 bytes(long) and seq id taking 4
+     * bytes(int). Strings are variable in size (i.e. end whenever separator is
+     * encountered). This is used while decoding and helps in determining where
+     * to split.
+     */
+    private static final int[] SEGMENT_SIZES = {Separator.VARIABLE_SIZE,
+        Bytes.SIZEOF_LONG + Bytes.SIZEOF_INT };
+
+    /*
+     * (non-Javadoc)
+     *
+     * Encodes AppToFlowRowKey object into a byte array with each
+     * component/field in AppToFlowRowKey separated by Separator#QUALIFIERS.
+     * This leads to an app to flow table row key of the form clusterId!appId
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#encode(java.lang.Object)
+     */
+    @Override
+    public byte[] encode(AppToFlowRowKey rowKey) {
+      byte[] first =
+          Separator.encode(rowKey.getClusterId(), Separator.SPACE,
+              Separator.TAB, Separator.QUALIFIERS);
+      byte[] second = appIDKeyConverter.encode(rowKey.getAppId());
+      return Separator.QUALIFIERS.join(first, second);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * Decodes an app to flow row key of the form clusterId!appId represented
+     * in byte format and converts it into an AppToFlowRowKey object.
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#decode(byte[])
+     */
+    @Override
+    public AppToFlowRowKey decode(byte[] rowKey) {
+      byte[][] rowKeyComponents =
+          Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
+      if (rowKeyComponents.length != 2) {
+        throw new IllegalArgumentException("the row key is not valid for "
+            + "the app-to-flow table");
+      }
+      String clusterId =
+          Separator.decode(Bytes.toString(rowKeyComponents[0]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String appId = appIDKeyConverter.decode(rowKeyComponents[1]);
+      return new AppToFlowRowKey(clusterId, appId);
+    }
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/apptoflow/AppToFlowRowKeyConverter.java

@@ -1,96 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow;
-
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.AppIdKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
-
-/**
- * Encodes and decodes row key for app_flow table.
- * The row key is of the form : clusterId!appId.
- * clusterId is a string and appId is encoded/decoded using
- * {@link AppIdKeyConverter}.
- */
-public final class AppToFlowRowKeyConverter
-    implements KeyConverter<AppToFlowRowKey> {
-  private static final AppToFlowRowKeyConverter INSTANCE =
-      new AppToFlowRowKeyConverter();
-
-  public static AppToFlowRowKeyConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private AppToFlowRowKeyConverter() {
-  }
-
-  // App to flow row key is of the form clusterId!appId with the 2 segments
-  // separated by !. The sizes below indicate sizes of both of these segments
-  // in sequence. clusterId is a string. appId is represented as 12 bytes with
-  // cluster Timestamp part of appid being 8 bytes(long) and seq id being 4
-  // bytes(int).
-  // Strings are variable in size (i.e. end whenever separator is encountered).
-  // This is used while decoding and helps in determining where to split.
-  private static final int[] SEGMENT_SIZES = {
-      Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG + Bytes.SIZEOF_INT };
-
-  /*
-   * (non-Javadoc)
-   *
-   * Encodes AppToFlowRowKey object into a byte array with each component/field
-   * in AppToFlowRowKey separated by Separator#QUALIFIERS. This leads to an
-   * app to flow table row key of the form clusterId!appId
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #encode(java.lang.Object)
-   */
-  @Override
-  public byte[] encode(AppToFlowRowKey rowKey) {
-    byte[] first = Separator.encode(rowKey.getClusterId(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] second = AppIdKeyConverter.getInstance().encode(rowKey.getAppId());
-    return Separator.QUALIFIERS.join(first, second);
-  }
-
-  /*
-   * (non-Javadoc)
-   *
-   * Decodes an app to flow row key of the form clusterId!appId represented in
-   * byte format and converts it into an AppToFlowRowKey object.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #decode(byte[])
-   */
-  @Override
-  public AppToFlowRowKey decode(byte[] rowKey) {
-    byte[][] rowKeyComponents =
-        Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
-    if (rowKeyComponents.length != 2) {
-      throw new IllegalArgumentException("the row key is not valid for " +
-          "the app-to-flow table");
-    }
-    String clusterId = Separator.decode(Bytes.toString(rowKeyComponents[0]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String appId = AppIdKeyConverter.getInstance().decode(rowKeyComponents[1]);
-    return new AppToFlowRowKey(clusterId, appId);
-  }
-}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/AppIdKeyConverter.java

@@ -28,13 +28,8 @@ import org.apache.hadoop.yarn.util.ConverterUtils;
  * (long - 8 bytes) followed by sequence id section of app id (int - 4 bytes).
  */
 public final class AppIdKeyConverter implements KeyConverter<String> {
-  private static final AppIdKeyConverter INSTANCE = new AppIdKeyConverter();
 
-  public static AppIdKeyConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private AppIdKeyConverter() {
+  public AppIdKeyConverter() {
   }
 
   /*
@@ -58,7 +53,7 @@ public final class AppIdKeyConverter implements KeyConverter<String> {
     ApplicationId appId = ConverterUtils.toApplicationId(appIdStr);
     byte[] appIdBytes = new byte[getKeySize()];
     byte[] clusterTs = Bytes.toBytes(
-        TimelineStorageUtils.invertLong(appId.getClusterTimestamp()));
+        LongConverter.invertLong(appId.getClusterTimestamp()));
     System.arraycopy(clusterTs, 0, appIdBytes, 0, Bytes.SIZEOF_LONG);
     byte[] seqId = Bytes.toBytes(TimelineStorageUtils.invertInt(appId.getId()));
     System.arraycopy(seqId, 0, appIdBytes, Bytes.SIZEOF_LONG, Bytes.SIZEOF_INT);
@@ -83,7 +78,7 @@ public final class AppIdKeyConverter implements KeyConverter<String> {
     if (appIdBytes.length != getKeySize()) {
       throw new IllegalArgumentException("Invalid app id in byte format");
     }
-    long clusterTs = TimelineStorageUtils.invertLong(
+    long clusterTs = LongConverter.invertLong(
         Bytes.toLong(appIdBytes, 0, Bytes.SIZEOF_LONG));
     int seqId = TimelineStorageUtils.invertInt(
         Bytes.toInt(appIdBytes, Bytes.SIZEOF_LONG, Bytes.SIZEOF_INT));

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/EventColumnName.java

@@ -26,6 +26,8 @@ public class EventColumnName {
   private final String id;
   private final Long timestamp;
   private final String infoKey;
+  private final KeyConverter<EventColumnName> eventColumnNameConverter =
+      new EventColumnNameConverter();
 
   public EventColumnName(String id, Long timestamp, String infoKey) {
     this.id = id;
@@ -45,4 +47,17 @@ public class EventColumnName {
     return infoKey;
   }
 
+  /**
+   * @return a byte array with each components/fields separated by
+   *         Separator#VALUES. This leads to an event column name of the form
+   *         eventId=timestamp=infokey. If both timestamp and infokey are null,
+   *         then a qualifier of the form eventId=timestamp= is returned. If
+   *         only infokey is null, then a qualifier of the form eventId= is
+   *         returned. These prefix forms are useful for queries that intend to
+   *         retrieve more than one specific column name.
+   */
+  public byte[] getColumnQualifier() {
+    return eventColumnNameConverter.encode(this);
+  }
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/EventColumnNameConverter.java

@@ -30,14 +30,8 @@ import org.apache.hadoop.hbase.util.Bytes;
  */
 public final class EventColumnNameConverter
     implements KeyConverter<EventColumnName> {
-  private static final EventColumnNameConverter INSTANCE =
-      new EventColumnNameConverter();
 
-  public static EventColumnNameConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private EventColumnNameConverter() {
+  public EventColumnNameConverter() {
   }
 
   // eventId=timestamp=infokey are of types String, Long String
@@ -69,7 +63,7 @@ public final class EventColumnNameConverter
       return Separator.VALUES.join(first, Separator.EMPTY_BYTES);
     }
     byte[] second = Bytes.toBytes(
-        TimelineStorageUtils.invertLong(key.getTimestamp()));
+        LongConverter.invertLong(key.getTimestamp()));
     if (key.getInfoKey() == null) {
       return Separator.VALUES.join(first, second, Separator.EMPTY_BYTES);
     }
@@ -96,7 +90,7 @@ public final class EventColumnNameConverter
     }
     String id = Separator.decode(Bytes.toString(components[0]),
         Separator.VALUES, Separator.TAB, Separator.SPACE);
-    Long ts = TimelineStorageUtils.invertLong(Bytes.toLong(components[1]));
+    Long ts = LongConverter.invertLong(Bytes.toLong(components[1]));
     String infoKey = components[2].length == 0 ? null :
         Separator.decode(Bytes.toString(components[2]),
             Separator.VALUES, Separator.TAB, Separator.SPACE);

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/LongConverter.java

@@ -19,6 +19,7 @@
 package org.apache.hadoop.yarn.server.timelineservice.storage.common;
 
 import java.io.IOException;
+import java.io.Serializable;
 
 import org.apache.hadoop.hbase.util.Bytes;
 
@@ -26,14 +27,15 @@ import org.apache.hadoop.hbase.util.Bytes;
  * Encodes a value by interpreting it as a Long and converting it to bytes and
  * decodes a set of bytes as a Long.
  */
-public final class LongConverter implements NumericValueConverter {
-  private static final LongConverter INSTANCE = new LongConverter();
+public final class LongConverter implements NumericValueConverter,
+    Serializable {
 
-  private LongConverter() {
-  }
+  /**
+   * Added because we implement Comparator<Number>.
+   */
+  private static final long serialVersionUID = 1L;
 
-  public static LongConverter getInstance() {
-    return INSTANCE;
+  public LongConverter() {
   }
 
   @Override
@@ -76,4 +78,17 @@ public final class LongConverter implements NumericValueConverter {
     }
     return sum;
   }
+
+  /**
+   * Converts a timestamp into it's inverse timestamp to be used in (row) keys
+   * where we want to have the most recent timestamp in the top of the table
+   * (scans start at the most recent timestamp first).
+   *
+   * @param key value to be inverted so that the latest version will be first in
+   *          a scan.
+   * @return inverted long
+   */
+  public static long invertLong(long key) {
+    return Long.MAX_VALUE - key;
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/LongKeyConverter.java

@@ -23,13 +23,13 @@ import java.io.IOException;
  * Encodes and decodes column names / row keys which are long.
  */
 public final class LongKeyConverter implements KeyConverter<Long> {
-  private static final LongKeyConverter INSTANCE = new LongKeyConverter();
 
-  public static LongKeyConverter getInstance() {
-    return INSTANCE;
-  }
+  /**
+   * To delegate the actual work to.
+   */
+  private final LongConverter longConverter = new LongConverter();
 
-  private LongKeyConverter() {
+  public LongKeyConverter() {
   }
 
   /*
@@ -44,7 +44,7 @@ public final class LongKeyConverter implements KeyConverter<Long> {
     try {
       // IOException will not be thrown here as we are explicitly passing
       // Long.
-      return LongConverter.getInstance().encodeValue(key);
+      return longConverter.encodeValue(key);
     } catch (IOException e) {
       return null;
     }
@@ -60,7 +60,7 @@ public final class LongKeyConverter implements KeyConverter<Long> {
   @Override
   public Long decode(byte[] bytes) {
     try {
-      return (Long) LongConverter.getInstance().decodeValue(bytes);
+      return (Long) longConverter.decodeValue(bytes);
     } catch (IOException e) {
       return null;
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/RowKeyPrefix.java

@@ -0,0 +1,42 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.server.timelineservice.storage.common;
+
+/**
+ * In queries where a single result is needed, an exact rowkey can be used
+ * through the corresponding rowkey#getRowKey() method. For queries that need to
+ * scan over a range of rowkeys, a partial (the initial part) of rowkeys are
+ * used. Classes implementing RowKeyPrefix indicate that they are the initial
+ * part of rowkeys, with different constructors with fewer number of argument to
+ * form a partial rowkey, a prefix.
+ *
+ * @param <R> indicating the type of rowkey that a particular implementation is
+ *          a prefix for.
+ */
+public interface RowKeyPrefix<R> {
+
+  /**
+   * Create a row key prefix, meaning a partial rowkey that can be used in range
+   * scans. Which fields are included in the prefix will depend on the
+   * constructor of the specific instance that was used. Output depends on which
+   * constructor was used.
+   * @return a prefix of the following form {@code fist!second!...!last!}
+   */
+  byte[] getRowKeyPrefix();
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/StringKeyConverter.java

@@ -24,13 +24,8 @@ package org.apache.hadoop.yarn.server.timelineservice.storage.common;
  * added later, if required in the associated ColumnPrefix implementations.
  */
 public final class StringKeyConverter implements KeyConverter<String> {
-  private static final StringKeyConverter INSTANCE = new StringKeyConverter();
 
-  public static StringKeyConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private StringKeyConverter() {
+  public StringKeyConverter() {
   }
 
   /*

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TimelineStorageUtils.java

@@ -18,14 +18,12 @@
 package org.apache.hadoop.yarn.server.timelineservice.storage.common;
 
 import java.io.IOException;
-import java.util.EnumSet;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
-import java.util.SortedSet;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -37,13 +35,10 @@ import org.apache.hadoop.hbase.CellUtil;
 import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.Tag;
-import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
-import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntityType;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEvent;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric;
-import org.apache.hadoop.yarn.server.metrics.ApplicationMetricsConstants;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineCompareFilter;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineCompareOp;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineExistsFilter;
@@ -52,7 +47,6 @@ import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineFilte
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineFilterList;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineKeyValueFilter;
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineKeyValuesFilter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.TimelineReader.Field;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.AggregationCompactionDimension;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.AggregationOperation;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.Attribute;
@@ -72,19 +66,6 @@ public final class TimelineStorageUtils {
   /** milliseconds in one day. */
   public static final long MILLIS_ONE_DAY = 86400000L;
 
-  /**
-   * Converts a timestamp into it's inverse timestamp to be used in (row) keys
-   * where we want to have the most recent timestamp in the top of the table
-   * (scans start at the most recent timestamp first).
-   *
-   * @param key value to be inverted so that the latest version will be first in
-   *          a scan.
-   * @return inverted long
-   */
-  public static long invertLong(long key) {
-    return Long.MAX_VALUE - key;
-  }
-
   /**
    * Converts an int into it's inverse int to be used in (row) keys
    * where we want to have the largest int value in the top of the table
@@ -163,66 +144,6 @@ public final class TimelineStorageUtils {
     return 0;
   }
 
-  /**
-   * checks if an application has finished.
-   *
-   * @param te TimlineEntity object.
-   * @return true if application has finished else false
-   */
-  public static boolean isApplicationFinished(TimelineEntity te) {
-    SortedSet<TimelineEvent> allEvents = te.getEvents();
-    if ((allEvents != null) && (allEvents.size() > 0)) {
-      TimelineEvent event = allEvents.last();
-      if (event.getId().equals(
-          ApplicationMetricsConstants.FINISHED_EVENT_TYPE)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  /**
-   * Check if we have a certain field amongst fields to retrieve. This method
-   * checks against {@link Field#ALL} as well because that would mean field
-   * passed needs to be matched.
-   *
-   * @param fieldsToRetrieve fields to be retrieved.
-   * @param requiredField fields to be checked in fieldsToRetrieve.
-   * @return true if has the required field, false otherwise.
-   */
-  public static boolean hasField(EnumSet<Field> fieldsToRetrieve,
-      Field requiredField) {
-    return fieldsToRetrieve.contains(Field.ALL) ||
-        fieldsToRetrieve.contains(requiredField);
-  }
-
-  /**
-   * Checks if the input TimelineEntity object is an ApplicationEntity.
-   *
-   * @param te TimelineEntity object.
-   * @return true if input is an ApplicationEntity, false otherwise
-   */
-  public static boolean isApplicationEntity(TimelineEntity te) {
-    return te.getType().equals(TimelineEntityType.YARN_APPLICATION.toString());
-  }
-
-  /**
-   * @param te TimelineEntity object.
-   * @param eventId event with this id needs to be fetched
-   * @return TimelineEvent if TimelineEntity contains the desired event.
-   */
-  public static TimelineEvent getApplicationEvent(TimelineEntity te,
-      String eventId) {
-    if (isApplicationEntity(te)) {
-      for (TimelineEvent event : te.getEvents()) {
-        if (event.getId().equals(eventId)) {
-          return event;
-        }
-      }
-    }
-    return null;
-  }
-
   /**
    * Returns the first seen aggregation operation as seen in the list of input
    * tags or null otherwise.
@@ -646,98 +567,6 @@ public final class TimelineStorageUtils {
     return appId;
   }
 
-  /**
-   * Helper method for reading relationship.
-   *
-   * @param <T> Describes the type of column prefix.
-   * @param entity entity to fill.
-   * @param result result from HBase.
-   * @param prefix column prefix.
-   * @param isRelatedTo if true, means relationship is to be added to
-   *     isRelatedTo, otherwise its added to relatesTo.
-   * @throws IOException if any problem is encountered while reading result.
-   */
-  public static <T> void readRelationship(
-      TimelineEntity entity, Result result, ColumnPrefix<T> prefix,
-      boolean isRelatedTo) throws IOException {
-    // isRelatedTo and relatesTo are of type Map<String, Set<String>>
-    Map<String, Object> columns =
-        prefix.readResults(result, StringKeyConverter.getInstance());
-    for (Map.Entry<String, Object> column : columns.entrySet()) {
-      for (String id : Separator.VALUES.splitEncoded(
-          column.getValue().toString())) {
-        if (isRelatedTo) {
-          entity.addIsRelatedToEntity(column.getKey(), id);
-        } else {
-          entity.addRelatesToEntity(column.getKey(), id);
-        }
-      }
-    }
-  }
-
-  /**
-   * Helper method for reading key-value pairs for either info or config.
-   *
-   * @param <T> Describes the type of column prefix.
-   * @param entity entity to fill.
-   * @param result result from HBase.
-   * @param prefix column prefix.
-   * @param isConfig if true, means we are reading configs, otherwise info.
-   * @throws IOException if any problem is encountered while reading result.
-   */
-  public static <T> void readKeyValuePairs(
-      TimelineEntity entity, Result result, ColumnPrefix<T> prefix,
-      boolean isConfig) throws IOException {
-    // info and configuration are of type Map<String, Object or String>
-    Map<String, Object> columns =
-        prefix.readResults(result, StringKeyConverter.getInstance());
-    if (isConfig) {
-      for (Map.Entry<String, Object> column : columns.entrySet()) {
-        entity.addConfig(column.getKey(), column.getValue().toString());
-      }
-    } else {
-      entity.addInfo(columns);
-    }
-  }
-
-  /**
-   * Read events from the entity table or the application table. The column name
-   * is of the form "eventId=timestamp=infoKey" where "infoKey" may be omitted
-   * if there is no info associated with the event.
-   *
-   * @param <T> Describes the type of column prefix.
-   * @param entity entity to fill.
-   * @param result HBase Result.
-   * @param prefix column prefix.
-   * @throws IOException if any problem is encountered while reading result.
-   */
-  public static <T> void readEvents(TimelineEntity entity, Result result,
-      ColumnPrefix<T> prefix) throws IOException {
-    Map<String, TimelineEvent> eventsMap = new HashMap<>();
-    Map<EventColumnName, Object> eventsResult =
-        prefix.readResults(result, EventColumnNameConverter.getInstance());
-    for (Map.Entry<EventColumnName, Object>
-             eventResult : eventsResult.entrySet()) {
-      EventColumnName eventColumnName = eventResult.getKey();
-      String key = eventColumnName.getId() +
-          Long.toString(eventColumnName.getTimestamp());
-      // Retrieve previously seen event to add to it
-      TimelineEvent event = eventsMap.get(key);
-      if (event == null) {
-        // First time we're seeing this event, add it to the eventsMap
-        event = new TimelineEvent();
-        event.setId(eventColumnName.getId());
-        event.setTimestamp(eventColumnName.getTimestamp());
-        eventsMap.put(key, event);
-      }
-      if (eventColumnName.getInfoKey() != null) {
-        event.addInfo(eventColumnName.getInfoKey(), eventResult.getValue());
-      }
-    }
-    Set<TimelineEvent> eventsSet = new HashSet<>(eventsMap.values());
-    entity.addEvents(eventsSet);
-  }
-
   public static boolean isFlowRunTable(HRegionInfo hRegionInfo,
       Configuration conf) {
     String regionTableName = hRegionInfo.getTable().getNameAsString();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/entity/EntityColumn.java

@@ -49,8 +49,7 @@ public enum EntityColumn implements Column<EntityTable> {
   /**
    * When the entity was created.
    */
-  CREATED_TIME(EntityColumnFamily.INFO, "created_time",
-      LongConverter.getInstance()),
+  CREATED_TIME(EntityColumnFamily.INFO, "created_time", new LongConverter()),
 
   /**
    * The version of the flow that this entity belongs to.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/entity/EntityColumnPrefix.java

@@ -67,8 +67,7 @@ public enum EntityColumnPrefix implements ColumnPrefix<EntityTable> {
   /**
    * Metrics are stored with the metric name as the column name.
    */
-  METRIC(EntityColumnFamily.METRICS, null,
-      LongConverter.getInstance());
+  METRIC(EntityColumnFamily.METRICS, null, new LongConverter());
 
   private final ColumnHelper<EntityTable> column;
   private final ColumnFamily<EntityTable> columnFamily;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/entity/EntityRowKey.java

@@ -17,6 +17,12 @@
  */
 package org.apache.hadoop.yarn.server.timelineservice.storage.entity;
 
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.AppIdKeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
+
 /**
  * Represents a rowkey for the entity table.
  */
@@ -28,6 +34,8 @@ public class EntityRowKey {
   private final String appId;
   private final String entityType;
   private final String entityId;
+  private final KeyConverter<EntityRowKey> entityRowKeyConverter =
+      new EntityRowKeyConverter();
 
   public EntityRowKey(String clusterId, String userId, String flowName,
       Long flowRunId, String appId, String entityType, String entityId) {
@@ -68,62 +76,15 @@ public class EntityRowKey {
     return entityId;
   }
 
-  /**
-   * Constructs a row key prefix for the entity table as follows:
-   * {@code userName!clusterId!flowName!flowRunId!AppId}.
-   *
-   * @param clusterId Context cluster id.
-   * @param userId User name.
-   * @param flowName Flow name.
-   * @param flowRunId Run Id for the flow.
-   * @param appId Application Id.
-   * @return byte array with the row key prefix.
-   */
-  public static byte[] getRowKeyPrefix(String clusterId, String userId,
-      String flowName, Long flowRunId, String appId) {
-    return EntityRowKeyConverter.getInstance().encode(new EntityRowKey(
-        clusterId, userId, flowName, flowRunId, appId, null, null));
-  }
-
-  /**
-   * Constructs a row key prefix for the entity table as follows:
-   * {@code userName!clusterId!flowName!flowRunId!AppId!entityType!}.
-   * Typically used while querying multiple entities of a particular entity
-   * type.
-   *
-   * @param clusterId Context cluster id.
-   * @param userId User name.
-   * @param flowName Flow name.
-   * @param flowRunId Run Id for the flow.
-   * @param appId Application Id.
-   * @param entityType Entity type.
-   * @return byte array with the row key prefix.
-   */
-  public static byte[] getRowKeyPrefix(String clusterId, String userId,
-      String flowName, Long flowRunId, String appId, String entityType) {
-    return EntityRowKeyConverter.getInstance().encode(new EntityRowKey(
-        clusterId, userId, flowName, flowRunId, appId, entityType, null));
-  }
-
   /**
    * Constructs a row key for the entity table as follows:
    * {@code userName!clusterId!flowName!flowRunId!AppId!entityType!entityId}.
    * Typically used while querying a specific entity.
    *
-   * @param clusterId Context cluster id.
-   * @param userId User name.
-   * @param flowName Flow name.
-   * @param flowRunId Run Id for the flow.
-   * @param appId Application Id.
-   * @param entityType Entity type.
-   * @param entityId Entity Id.
    * @return byte array with the row key.
    */
-  public static byte[] getRowKey(String clusterId, String userId,
-      String flowName, Long flowRunId, String appId, String entityType,
-      String entityId) {
-    return EntityRowKeyConverter.getInstance().encode(new EntityRowKey(
-        clusterId, userId, flowName, flowRunId, appId, entityType, entityId));
+  public byte[] getRowKey() {
+    return entityRowKeyConverter.encode(this);
   }
 
   /**
@@ -133,6 +94,132 @@ public class EntityRowKey {
    * @return An <cite>EntityRowKey</cite> object.
    */
   public static EntityRowKey parseRowKey(byte[] rowKey) {
-    return EntityRowKeyConverter.getInstance().decode(rowKey);
+    return new EntityRowKeyConverter().decode(rowKey);
+  }
+
+  /**
+   * Encodes and decodes row key for entity table. The row key is of the form :
+   * userName!clusterId!flowName!flowRunId!appId!entityType!entityId. flowRunId
+   * is a long, appId is encoded/decoded using {@link AppIdKeyConverter} and
+   * rest are strings.
+   * <p>
+   */
+  final private static class EntityRowKeyConverter implements
+      KeyConverter<EntityRowKey> {
+
+    private final AppIdKeyConverter appIDKeyConverter = new AppIdKeyConverter();
+
+    private EntityRowKeyConverter() {
+    }
+
+    /**
+     * Entity row key is of the form
+     * userName!clusterId!flowName!flowRunId!appId!entityType!entityId w. each
+     * segment separated by !. The sizes below indicate sizes of each one of
+     * these segments in sequence. clusterId, userName, flowName, entityType and
+     * entityId are strings. flowrunId is a long hence 8 bytes in size. app id
+     * is represented as 12 bytes with cluster timestamp part of appid being 8
+     * bytes (long) and seq id being 4 bytes(int). Strings are variable in size
+     * (i.e. end whenever separator is encountered). This is used while decoding
+     * and helps in determining where to split.
+     */
+    private static final int[] SEGMENT_SIZES = {Separator.VARIABLE_SIZE,
+        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
+        AppIdKeyConverter.getKeySize(), Separator.VARIABLE_SIZE,
+        Separator.VARIABLE_SIZE };
+
+    /*
+     * (non-Javadoc)
+     *
+     * Encodes EntityRowKey object into a byte array with each component/field
+     * in EntityRowKey separated by Separator#QUALIFIERS. This leads to an
+     * entity table row key of the form
+     * userName!clusterId!flowName!flowRunId!appId!entityType!entityId If
+     * entityType in passed EntityRowKey object is null (and the fields
+     * preceding it i.e. clusterId, userId and flowName, flowRunId and appId
+     * are not null), this returns a row key prefix of the form
+     * userName!clusterId!flowName!flowRunId!appId! and if entityId in
+     * EntityRowKey is null (other 6 components are not null), this returns a
+     * row key prefix of the form
+     * userName!clusterId!flowName!flowRunId!appId!entityType! flowRunId is
+     * inverted while encoding as it helps maintain a descending order for row
+     * keys in entity table.
+     *
+     * @see org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#encode(java.lang.Object)
+     */
+    @Override
+    public byte[] encode(EntityRowKey rowKey) {
+      byte[] user =
+          Separator.encode(rowKey.getUserId(), Separator.SPACE, Separator.TAB,
+              Separator.QUALIFIERS);
+      byte[] cluster =
+          Separator.encode(rowKey.getClusterId(), Separator.SPACE,
+              Separator.TAB, Separator.QUALIFIERS);
+      byte[] flow =
+          Separator.encode(rowKey.getFlowName(), Separator.SPACE,
+              Separator.TAB, Separator.QUALIFIERS);
+      byte[] first = Separator.QUALIFIERS.join(user, cluster, flow);
+      // Note that flowRunId is a long, so we can't encode them all at the same
+      // time.
+      byte[] second =
+          Bytes.toBytes(LongConverter.invertLong(rowKey.getFlowRunId()));
+      byte[] third = appIDKeyConverter.encode(rowKey.getAppId());
+      if (rowKey.getEntityType() == null) {
+        return Separator.QUALIFIERS.join(first, second, third,
+            Separator.EMPTY_BYTES);
+      }
+      byte[] entityType =
+          Separator.encode(rowKey.getEntityType(), Separator.SPACE,
+              Separator.TAB, Separator.QUALIFIERS);
+      byte[] entityId =
+          rowKey.getEntityId() == null ? Separator.EMPTY_BYTES : Separator
+              .encode(rowKey.getEntityId(), Separator.SPACE, Separator.TAB,
+                  Separator.QUALIFIERS);
+      byte[] fourth = Separator.QUALIFIERS.join(entityType, entityId);
+      return Separator.QUALIFIERS.join(first, second, third, fourth);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * Decodes an application row key of the form
+     * userName!clusterId!flowName!flowRunId!appId!entityType!entityId
+     * represented in byte format and converts it into an EntityRowKey object.
+     * flowRunId is inverted while decoding as it was inverted while encoding.
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#decode(byte[])
+     */
+    @Override
+    public EntityRowKey decode(byte[] rowKey) {
+      byte[][] rowKeyComponents =
+          Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
+      if (rowKeyComponents.length != 7) {
+        throw new IllegalArgumentException("the row key is not valid for "
+            + "an entity");
+      }
+      String userId =
+          Separator.decode(Bytes.toString(rowKeyComponents[0]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String clusterId =
+          Separator.decode(Bytes.toString(rowKeyComponents[1]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String flowName =
+          Separator.decode(Bytes.toString(rowKeyComponents[2]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      Long flowRunId =
+          LongConverter.invertLong(Bytes.toLong(rowKeyComponents[3]));
+      String appId = appIDKeyConverter.decode(rowKeyComponents[4]);
+      String entityType =
+          Separator.decode(Bytes.toString(rowKeyComponents[5]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String entityId =
+          Separator.decode(Bytes.toString(rowKeyComponents[6]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      return new EntityRowKey(clusterId, userId, flowName, flowRunId, appId,
+          entityType, entityId);
+    }
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/entity/EntityRowKeyConverter.java

@@ -1,143 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.hadoop.yarn.server.timelineservice.storage.entity;
-
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.AppIdKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
-
-/**
- * Encodes and decodes row key for entity table.
- * The row key is of the form :
- * userName!clusterId!flowName!flowRunId!appId!entityType!entityId.
- * flowRunId is a long, appId is encoded/decoded using
- * {@link AppIdKeyConverter} and rest are strings.
- */
-public final class EntityRowKeyConverter implements KeyConverter<EntityRowKey> {
-  private static final EntityRowKeyConverter INSTANCE =
-      new EntityRowKeyConverter();
-
-  public static EntityRowKeyConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private EntityRowKeyConverter() {
-  }
-
-  // Entity row key is of the form
-  // userName!clusterId!flowName!flowRunId!appId!entityType!entityId with each
-  // segment separated by !. The sizes below indicate sizes of each one of these
-  // segements in sequence. clusterId, userName, flowName, entityType and
-  // entityId are strings. flowrunId is a long hence 8 bytes in size. app id is
-  // represented as 12 bytes with cluster timestamp part of appid being 8 bytes
-  // (long) and seq id being 4 bytes(int).
-  // Strings are variable in size (i.e. end whenever separator is encountered).
-  // This is used while decoding and helps in determining where to split.
-  private static final int[] SEGMENT_SIZES = {
-      Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-      Bytes.SIZEOF_LONG, AppIdKeyConverter.getKeySize(),
-      Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE };
-
-  /*
-   * (non-Javadoc)
-   *
-   * Encodes EntityRowKey object into a byte array with each component/field in
-   * EntityRowKey separated by Separator#QUALIFIERS. This leads to an entity
-   * table row key of the form
-   * userName!clusterId!flowName!flowRunId!appId!entityType!entityId
-   * If entityType in passed EntityRowKey object is null (and the fields
-   * preceding it i.e. clusterId, userId and flowName, flowRunId and appId are
-   * not null), this returns a row key prefix of the form
-   * userName!clusterId!flowName!flowRunId!appId! and if entityId in
-   * EntityRowKey is null (other 6 components are not null), this returns a row
-   * key prefix of the form
-   * userName!clusterId!flowName!flowRunId!appId!entityType!
-   * flowRunId is inverted while encoding as it helps maintain a descending
-   * order for row keys in entity table.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #encode(java.lang.Object)
-   */
-  @Override
-  public byte[] encode(EntityRowKey rowKey) {
-    byte[] user = Separator.encode(rowKey.getUserId(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] cluster = Separator.encode(rowKey.getClusterId(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] flow = Separator.encode(rowKey.getFlowName(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] first = Separator.QUALIFIERS.join(user, cluster, flow);
-    // Note that flowRunId is a long, so we can't encode them all at the same
-    // time.
-    byte[] second = Bytes.toBytes(TimelineStorageUtils.invertLong(
-        rowKey.getFlowRunId()));
-    byte[] third = AppIdKeyConverter.getInstance().encode(rowKey.getAppId());
-    if (rowKey.getEntityType() == null) {
-      return Separator.QUALIFIERS.join(
-          first, second, third, Separator.EMPTY_BYTES);
-    }
-    byte[] entityType = Separator.encode(rowKey.getEntityType(),
-        Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
-    byte[] entityId = rowKey.getEntityId() == null ? Separator.EMPTY_BYTES :
-        Separator.encode(rowKey.getEntityId(), Separator.SPACE, Separator.TAB,
-        Separator.QUALIFIERS);
-    byte[] fourth = Separator.QUALIFIERS.join(entityType, entityId);
-    return Separator.QUALIFIERS.join(first, second, third, fourth);
-  }
-
-  /*
-   * (non-Javadoc)
-   *
-   * Decodes an application row key of the form
-   * userName!clusterId!flowName!flowRunId!appId!entityType!entityId represented
-   * in byte format and converts it into an EntityRowKey object. flowRunId is
-   * inverted while decoding as it was inverted while encoding.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #decode(byte[])
-   */
-  @Override
-  public EntityRowKey decode(byte[] rowKey) {
-    byte[][] rowKeyComponents =
-        Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
-    if (rowKeyComponents.length != 7) {
-      throw new IllegalArgumentException("the row key is not valid for " +
-          "an entity");
-    }
-    String userId = Separator.decode(Bytes.toString(rowKeyComponents[0]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String clusterId = Separator.decode(Bytes.toString(rowKeyComponents[1]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String flowName = Separator.decode(Bytes.toString(rowKeyComponents[2]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    Long flowRunId =
-        TimelineStorageUtils.invertLong(Bytes.toLong(rowKeyComponents[3]));
-    String appId = AppIdKeyConverter.getInstance().decode(rowKeyComponents[4]);
-    String entityType = Separator.decode(Bytes.toString(rowKeyComponents[5]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String entityId =Separator.decode(Bytes.toString(rowKeyComponents[6]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    return new EntityRowKey(clusterId, userId, flowName, flowRunId, appId,
-        entityType, entityId);
-  }
-}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/entity/EntityRowKeyPrefix.java

@@ -0,0 +1,74 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.server.timelineservice.storage.entity;
+
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
+
+/**
+ * Represents a partial rowkey without the entityId or without entityType and
+ * entityId for the entity table.
+ *
+ */
+public class EntityRowKeyPrefix extends EntityRowKey implements
+    RowKeyPrefix<EntityRowKey> {
+
+  /**
+   * Creates a prefix which generates the following rowKeyPrefixes for the
+   * entity table:
+   * {@code userName!clusterId!flowName!flowRunId!AppId!entityType!}.
+   *
+   * @param clusterId identifying the cluster
+   * @param userId identifying the user
+   * @param flowName identifying the flow
+   * @param flowRunId identifying the individual run of this flow
+   * @param appId identifying the application
+   * @param entityType which entity type
+   */
+  public EntityRowKeyPrefix(String clusterId, String userId, String flowName,
+      Long flowRunId, String appId, String entityType) {
+    super(clusterId, userId, flowName, flowRunId, appId, entityType, null);
+  }
+
+  /**
+   * Creates a prefix which generates the following rowKeyPrefixes for the
+   * entity table:
+   * {@code userName!clusterId!flowName!flowRunId!AppId!entityType!entityId}.
+   *
+   * @param clusterId identifying the cluster
+   * @param userId identifying the user
+   * @param flowName identifying the flow
+   * @param flowRunId identifying the individual run of this flow
+   * @param appId identifying the application
+   */
+  public EntityRowKeyPrefix(String clusterId, String userId, String flowName,
+      Long flowRunId, String appId) {
+    super(clusterId, userId, flowName, flowRunId, appId, null, null);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.application.
+   * RowKeyPrefix#getRowKeyPrefix()
+   */
+  public byte[] getRowKeyPrefix() {
+    return super.getRowKey();
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowActivityRowKey.java

@@ -17,6 +17,10 @@
  */
 package org.apache.hadoop.yarn.server.timelineservice.storage.flow;
 
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 
 /**
@@ -28,11 +32,37 @@ public class FlowActivityRowKey {
   private final Long dayTs;
   private final String userId;
   private final String flowName;
+  private final KeyConverter<FlowActivityRowKey> flowActivityRowKeyConverter =
+      new FlowActivityRowKeyConverter();
 
+  /**
+   * @param clusterId identifying the cluster
+   * @param dayTs to be converted to the top of the day timestamp
+   * @param userId identifying user
+   * @param flowName identifying the flow
+   */
   public FlowActivityRowKey(String clusterId, Long dayTs, String userId,
       String flowName) {
+    this(clusterId, dayTs, userId, flowName, true);
+  }
+
+  /**
+   * @param clusterId identifying the cluster
+   * @param timestamp when the flow activity happened. May be converted to the
+   *          top of the day depending on the convertDayTsToTopOfDay argument.
+   * @param userId identifying user
+   * @param flowName identifying the flow
+   * @param convertDayTsToTopOfDay if true and timestamp isn't null, then
+   *          timestamp will be converted to the top-of-the day timestamp
+   */
+  protected FlowActivityRowKey(String clusterId, Long timestamp, String userId,
+      String flowName, boolean convertDayTsToTopOfDay) {
     this.clusterId = clusterId;
-    this.dayTs = dayTs;
+    if (convertDayTsToTopOfDay && (timestamp != null)) {
+      this.dayTs = TimelineStorageUtils.getTopOfTheDayTimestamp(timestamp);
+    } else {
+      this.dayTs = timestamp;
+    }
     this.userId = userId;
     this.flowName = flowName;
   }
@@ -53,47 +83,14 @@ public class FlowActivityRowKey {
     return flowName;
   }
 
-  /**
-   * Constructs a row key prefix for the flow activity table as follows:
-   * {@code clusterId!}.
-   *
-   * @param clusterId Cluster Id.
-   * @return byte array with the row key prefix
-   */
-  public static byte[] getRowKeyPrefix(String clusterId) {
-    return FlowActivityRowKeyConverter.getInstance().encode(
-        new FlowActivityRowKey(clusterId, null, null, null));
-  }
-
-  /**
-   * Constructs a row key prefix for the flow activity table as follows:
-   * {@code clusterId!dayTimestamp!}.
-   *
-   * @param clusterId Cluster Id.
-   * @param dayTs Start of the day timestamp.
-   * @return byte array with the row key prefix
-   */
-  public static byte[] getRowKeyPrefix(String clusterId, long dayTs) {
-    return FlowActivityRowKeyConverter.getInstance().encode(
-        new FlowActivityRowKey(clusterId, dayTs, null, null));
-  }
-
   /**
    * Constructs a row key for the flow activity table as follows:
    * {@code clusterId!dayTimestamp!user!flowName}.
    *
-   * @param clusterId Cluster Id.
-   * @param eventTs event's TimeStamp.
-   * @param userId User Id.
-   * @param flowName Flow Name.
    * @return byte array for the row key
    */
-  public static byte[] getRowKey(String clusterId, long eventTs, String userId,
-      String flowName) {
-    // convert it to Day's time stamp
-    eventTs = TimelineStorageUtils.getTopOfTheDayTimestamp(eventTs);
-    return FlowActivityRowKeyConverter.getInstance().encode(
-        new FlowActivityRowKey(clusterId, eventTs, userId, flowName));
+  public byte[] getRowKey() {
+    return flowActivityRowKeyConverter.encode(this);
   }
 
   /**
@@ -103,6 +100,97 @@ public class FlowActivityRowKey {
    * @return A <cite>FlowActivityRowKey</cite> object.
    */
   public static FlowActivityRowKey parseRowKey(byte[] rowKey) {
-    return FlowActivityRowKeyConverter.getInstance().decode(rowKey);
+    return new FlowActivityRowKeyConverter().decode(rowKey);
+  }
+
+  /**
+   * Encodes and decodes row key for flow activity table. The row key is of the
+   * form : clusterId!dayTimestamp!user!flowName. dayTimestamp(top of the day
+   * timestamp) is a long and rest are strings.
+   * <p>
+   */
+  final private static class FlowActivityRowKeyConverter implements
+      KeyConverter<FlowActivityRowKey> {
+
+    private FlowActivityRowKeyConverter() {
+    }
+
+    /**
+     * The flow activity row key is of the form
+     * clusterId!dayTimestamp!user!flowName with each segment separated by !.
+     * The sizes below indicate sizes of each one of these segements in
+     * sequence. clusterId, user and flowName are strings. Top of the day
+     * timestamp is a long hence 8 bytes in size. Strings are variable in size
+     * (i.e. they end whenever separator is encountered). This is used while
+     * decoding and helps in determining where to split.
+     */
+    private static final int[] SEGMENT_SIZES = {Separator.VARIABLE_SIZE,
+        Bytes.SIZEOF_LONG, Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE };
+
+    /*
+     * (non-Javadoc)
+     *
+     * Encodes FlowActivityRowKey object into a byte array with each
+     * component/field in FlowActivityRowKey separated by Separator#QUALIFIERS.
+     * This leads to an flow activity table row key of the form
+     * clusterId!dayTimestamp!user!flowName. If dayTimestamp in passed
+     * FlowActivityRowKey object is null and clusterId is not null, then this
+     * returns a row key prefix as clusterId! and if userId in
+     * FlowActivityRowKey is null (and the fields preceding it i.e. clusterId
+     * and dayTimestamp are not null), this returns a row key prefix as
+     * clusterId!dayTimeStamp! dayTimestamp is inverted while encoding as it
+     * helps maintain a descending order for row keys in flow activity table.
+     *
+     * @see org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#encode(java.lang.Object)
+     */
+    @Override
+    public byte[] encode(FlowActivityRowKey rowKey) {
+      if (rowKey.getDayTimestamp() == null) {
+        return Separator.QUALIFIERS.join(Separator.encode(
+            rowKey.getClusterId(), Separator.SPACE, Separator.TAB,
+            Separator.QUALIFIERS), Separator.EMPTY_BYTES);
+      }
+      if (rowKey.getUserId() == null) {
+        return Separator.QUALIFIERS.join(Separator.encode(
+            rowKey.getClusterId(), Separator.SPACE, Separator.TAB,
+            Separator.QUALIFIERS), Bytes.toBytes(LongConverter
+            .invertLong(rowKey.getDayTimestamp())), Separator.EMPTY_BYTES);
+      }
+      return Separator.QUALIFIERS.join(Separator.encode(rowKey.getClusterId(),
+          Separator.SPACE, Separator.TAB, Separator.QUALIFIERS), Bytes
+          .toBytes(LongConverter.invertLong(rowKey.getDayTimestamp())),
+          Separator.encode(rowKey.getUserId(), Separator.SPACE, Separator.TAB,
+              Separator.QUALIFIERS), Separator.encode(rowKey.getFlowName(),
+              Separator.SPACE, Separator.TAB, Separator.QUALIFIERS));
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#decode(byte[])
+     */
+    @Override
+    public FlowActivityRowKey decode(byte[] rowKey) {
+      byte[][] rowKeyComponents =
+          Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
+      if (rowKeyComponents.length != 4) {
+        throw new IllegalArgumentException("the row key is not valid for "
+            + "a flow activity");
+      }
+      String clusterId =
+          Separator.decode(Bytes.toString(rowKeyComponents[0]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      Long dayTs = LongConverter.invertLong(Bytes.toLong(rowKeyComponents[1]));
+      String userId =
+          Separator.decode(Bytes.toString(rowKeyComponents[2]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String flowName =
+          Separator.decode(Bytes.toString(rowKeyComponents[3]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      return new FlowActivityRowKey(clusterId, dayTs, userId, flowName);
+    }
   }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowActivityRowKeyConverter.java

@@ -1,115 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.hadoop.yarn.server.timelineservice.storage.flow;
-
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
-
-/**
- * Encodes and decodes row key for flow activity table.
- * The row key is of the form : clusterId!dayTimestamp!user!flowName.
- * dayTimestamp(top of the day timestamp) is a long and rest are strings.
- */
-public final class FlowActivityRowKeyConverter implements
-    KeyConverter<FlowActivityRowKey> {
-  private static final FlowActivityRowKeyConverter INSTANCE =
-      new FlowActivityRowKeyConverter();
-
-  public static FlowActivityRowKeyConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private FlowActivityRowKeyConverter() {
-  }
-
-  // Flow activity row key is of the form clusterId!dayTimestamp!user!flowName
-  // with each segment separated by !. The sizes below indicate sizes of each
-  // one of these segements in sequence. clusterId, user and flowName are
-  // strings. Top of the day timestamp is a long hence 8 bytes in size.
-  // Strings are variable in size (i.e. end whenever separator is encountered).
-  // This is used while decoding and helps in determining where to split.
-  private static final int[] SEGMENT_SIZES = {
-      Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG, Separator.VARIABLE_SIZE,
-      Separator.VARIABLE_SIZE };
-
-  /*
-   * (non-Javadoc)
-   *
-   * Encodes FlowActivityRowKey object into a byte array with each
-   * component/field in FlowActivityRowKey separated by Separator#QUALIFIERS.
-   * This leads to an flow activity table row key of the form
-   * clusterId!dayTimestamp!user!flowName
-   * If dayTimestamp in passed FlowActivityRowKey object is null and clusterId
-   * is not null, this returns a row key prefix as clusterId! and if userId in
-   * FlowActivityRowKey is null (and the fields preceding it i.e. clusterId and
-   * dayTimestamp are not null), this returns a row key prefix as
-   * clusterId!dayTimeStamp!
-   * dayTimestamp is inverted while encoding as it helps maintain a descending
-   * order for row keys in flow activity table.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #encode(java.lang.Object)
-   */
-
-  @Override
-  public byte[] encode(FlowActivityRowKey rowKey) {
-    if (rowKey.getDayTimestamp() == null) {
-      return Separator.QUALIFIERS.join(Separator.encode(rowKey.getClusterId(),
-          Separator.SPACE, Separator.TAB, Separator.QUALIFIERS),
-              Separator.EMPTY_BYTES);
-    }
-    if (rowKey.getUserId() == null) {
-      return Separator.QUALIFIERS.join(Separator.encode(rowKey.getClusterId(),
-          Separator.SPACE, Separator.TAB, Separator.QUALIFIERS),
-          Bytes.toBytes(TimelineStorageUtils.invertLong(
-              rowKey.getDayTimestamp())), Separator.EMPTY_BYTES);
-    }
-    return Separator.QUALIFIERS.join(
-        Separator.encode(rowKey.getClusterId(), Separator.SPACE, Separator.TAB,
-            Separator.QUALIFIERS),
-        Bytes.toBytes(
-            TimelineStorageUtils.invertLong(rowKey.getDayTimestamp())),
-        Separator.encode(rowKey.getUserId(), Separator.SPACE, Separator.TAB,
-            Separator.QUALIFIERS),
-        Separator.encode(rowKey.getFlowName(), Separator.SPACE, Separator.TAB,
-            Separator.QUALIFIERS));
-  }
-
-  @Override
-  public FlowActivityRowKey decode(byte[] rowKey) {
-    byte[][] rowKeyComponents =
-        Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
-    if (rowKeyComponents.length != 4) {
-      throw new IllegalArgumentException("the row key is not valid for "
-          + "a flow activity");
-    }
-    String clusterId = Separator.decode(Bytes.toString(rowKeyComponents[0]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    Long dayTs =
-        TimelineStorageUtils.invertLong(Bytes.toLong(rowKeyComponents[1]));
-    String userId = Separator.decode(Bytes.toString(rowKeyComponents[2]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String flowName = Separator.decode(Bytes.toString(rowKeyComponents[3]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    return new FlowActivityRowKey(clusterId, dayTs, userId, flowName);
-  }
-}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowActivityRowKeyPrefix.java

@@ -0,0 +1,60 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.server.timelineservice.storage.flow;
+
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
+
+/**
+ * A prefix partial rowkey for flow activities.
+ */
+public class FlowActivityRowKeyPrefix extends FlowActivityRowKey implements
+    RowKeyPrefix<FlowActivityRowKey> {
+
+  /**
+   * Constructs a row key prefix for the flow activity table as follows:
+   * {@code clusterId!dayTimestamp!}.
+   *
+   * @param clusterId Cluster Id.
+   * @param dayTs Start of the day timestamp.
+   */
+  public FlowActivityRowKeyPrefix(String clusterId, Long dayTs) {
+    super(clusterId, dayTs, null, null, false);
+  }
+
+  /**
+   * Constructs a row key prefix for the flow activity table as follows:
+   * {@code clusterId!}.
+   *
+   * @param clusterId identifying the cluster
+   */
+  public FlowActivityRowKeyPrefix(String clusterId) {
+    super(clusterId, null, null, null, false);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.application.
+   * RowKeyPrefix#getRowKeyPrefix()
+   */
+  public byte[] getRowKeyPrefix() {
+    return super.getRowKey();
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowRunColumn.java

@@ -25,10 +25,10 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.common.Column;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnFamily;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnHelper;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.GenericConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TypedBufferedMutator;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ValueConverter;
 
 /**
@@ -41,14 +41,14 @@ public enum FlowRunColumn implements Column<FlowRunTable> {
    * application start times.
    */
   MIN_START_TIME(FlowRunColumnFamily.INFO, "min_start_time",
-      AggregationOperation.GLOBAL_MIN, LongConverter.getInstance()),
+      AggregationOperation.GLOBAL_MIN, new LongConverter()),
 
   /**
    * When the flow ended. This is the maximum of currently known application end
    * times.
    */
   MAX_END_TIME(FlowRunColumnFamily.INFO, "max_end_time",
-      AggregationOperation.GLOBAL_MAX, LongConverter.getInstance()),
+      AggregationOperation.GLOBAL_MAX, new LongConverter()),
 
   /**
    * The version of the flow that this flow belongs to.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowRunColumnPrefix.java

@@ -41,7 +41,7 @@ public enum FlowRunColumnPrefix implements ColumnPrefix<FlowRunTable> {
   /**
    * To store flow run info values.
    */
-  METRIC(FlowRunColumnFamily.INFO, "m", null, LongConverter.getInstance());
+  METRIC(FlowRunColumnFamily.INFO, "m", null, new LongConverter());
 
   private final ColumnHelper<FlowRunTable> column;
   private final ColumnFamily<FlowRunTable> columnFamily;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowRunRowKey.java

@@ -17,6 +17,11 @@
  */
 package org.apache.hadoop.yarn.server.timelineservice.storage.flow;
 
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
+
 /**
  * Represents a rowkey for the flow run table.
  */
@@ -25,6 +30,8 @@ public class FlowRunRowKey {
   private final String userId;
   private final String flowName;
   private final Long flowRunId;
+  private final FlowRunRowKeyConverter flowRunRowKeyConverter =
+      new FlowRunRowKeyConverter();
 
   public FlowRunRowKey(String clusterId, String userId, String flowName,
       Long flowRunId) {
@@ -50,37 +57,17 @@ public class FlowRunRowKey {
     return flowRunId;
   }
 
-  /**
-   * Constructs a row key prefix for the flow run table as follows: {
-   * clusterId!userI!flowName!}.
-   *
-   * @param clusterId Cluster Id.
-   * @param userId User Id.
-   * @param flowName Flow Name.
-   * @return byte array with the row key prefix
-   */
-  public static byte[] getRowKeyPrefix(String clusterId, String userId,
-      String flowName) {
-    return FlowRunRowKeyConverter.getInstance().encode(new FlowRunRowKey(
-        clusterId, userId, flowName, null));
-  }
-
   /**
    * Constructs a row key for the entity table as follows: {
    * clusterId!userId!flowName!Inverted Flow Run Id}.
    *
-   * @param clusterId Cluster Id.
-   * @param userId User Id.
-   * @param flowName Flow Name.
-   * @param flowRunId Run Id for the flow name.
    * @return byte array with the row key
    */
-  public static byte[] getRowKey(String clusterId, String userId,
-      String flowName, Long flowRunId) {
-    return FlowRunRowKeyConverter.getInstance().encode(new FlowRunRowKey(
-        clusterId, userId, flowName, flowRunId));
+  public byte[] getRowKey() {
+    return flowRunRowKeyConverter.encode(this);
   }
 
+
   /**
    * Given the raw row key as bytes, returns the row key as an object.
    *
@@ -88,7 +75,7 @@ public class FlowRunRowKey {
    * @return A <cite>FlowRunRowKey</cite> object.
    */
   public static FlowRunRowKey parseRowKey(byte[] rowKey) {
-    return FlowRunRowKeyConverter.getInstance().decode(rowKey);
+    return new FlowRunRowKeyConverter().decode(rowKey);
   }
 
   /**
@@ -106,4 +93,98 @@ public class FlowRunRowKey {
     flowKeyStr.append("}");
     return flowKeyStr.toString();
   }
+
+  /**
+   * Encodes and decodes row key for flow run table.
+   * The row key is of the form : clusterId!userId!flowName!flowrunId.
+   * flowrunId is a long and rest are strings.
+   * <p>
+   */
+  final private static class FlowRunRowKeyConverter implements
+      KeyConverter<FlowRunRowKey> {
+
+    private FlowRunRowKeyConverter() {
+    }
+
+    /**
+     * The flow run row key is of the form clusterId!userId!flowName!flowrunId
+     * with each segment separated by !. The sizes below indicate sizes of each
+     * one of these segments in sequence. clusterId, userId and flowName are
+     * strings. flowrunId is a long hence 8 bytes in size. Strings are variable
+     * in size (i.e. end whenever separator is encountered). This is used while
+     * decoding and helps in determining where to split.
+     */
+    private static final int[] SEGMENT_SIZES = {Separator.VARIABLE_SIZE,
+        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG };
+
+    /*
+     * (non-Javadoc)
+     *
+     * Encodes FlowRunRowKey object into a byte array with each component/field
+     * in FlowRunRowKey separated by Separator#QUALIFIERS. This leads to an flow
+     * run row key of the form clusterId!userId!flowName!flowrunId If flowRunId
+     * in passed FlowRunRowKey object is null (and the fields preceding it i.e.
+     * clusterId, userId and flowName are not null), this returns a row key
+     * prefix of the form clusterId!userName!flowName! flowRunId is inverted
+     * while encoding as it helps maintain a descending order for flow keys in
+     * flow run table.
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#encode(java.lang.Object)
+     */
+    @Override
+    public byte[] encode(FlowRunRowKey rowKey) {
+      byte[] first =
+          Separator.QUALIFIERS.join(Separator.encode(rowKey.getClusterId(),
+              Separator.SPACE, Separator.TAB, Separator.QUALIFIERS), Separator
+              .encode(rowKey.getUserId(), Separator.SPACE, Separator.TAB,
+                  Separator.QUALIFIERS), Separator.encode(rowKey.getFlowName(),
+              Separator.SPACE, Separator.TAB, Separator.QUALIFIERS));
+      if (rowKey.getFlowRunId() == null) {
+        return Separator.QUALIFIERS.join(first, Separator.EMPTY_BYTES);
+      } else {
+        // Note that flowRunId is a long, so we can't encode them all at the
+        // same
+        // time.
+        byte[] second =
+            Bytes.toBytes(LongConverter.invertLong(rowKey.getFlowRunId()));
+        return Separator.QUALIFIERS.join(first, second);
+      }
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * Decodes an flow run row key of the form
+     * clusterId!userId!flowName!flowrunId represented in byte format and
+     * converts it into an FlowRunRowKey object. flowRunId is inverted while
+     * decoding as it was inverted while encoding.
+     *
+     * @see
+     * org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#decode(byte[])
+     */
+    @Override
+    public FlowRunRowKey decode(byte[] rowKey) {
+      byte[][] rowKeyComponents =
+          Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
+      if (rowKeyComponents.length != 4) {
+        throw new IllegalArgumentException("the row key is not valid for "
+            + "a flow run");
+      }
+      String clusterId =
+          Separator.decode(Bytes.toString(rowKeyComponents[0]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String userId =
+          Separator.decode(Bytes.toString(rowKeyComponents[1]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String flowName =
+          Separator.decode(Bytes.toString(rowKeyComponents[2]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      Long flowRunId =
+          LongConverter.invertLong(Bytes.toLong(rowKeyComponents[3]));
+      return new FlowRunRowKey(clusterId, userId, flowName, flowRunId);
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowRunRowKeyConverter.java

@@ -1,120 +0,0 @@
-/**
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you under the Apache License, Version 2.0 (the
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.apache.hadoop.yarn.server.timelineservice.storage.flow;
-
-import org.apache.hadoop.hbase.util.Bytes;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
-
-/**
- * Encodes and decodes row key for flow run table.
- * The row key is of the form : clusterId!userId!flowName!flowrunId.
- * flowrunId is a long and rest are strings.
- */
-public final class FlowRunRowKeyConverter implements
-    KeyConverter<FlowRunRowKey> {
-  private static final FlowRunRowKeyConverter INSTANCE =
-      new FlowRunRowKeyConverter();
-
-  public static FlowRunRowKeyConverter getInstance() {
-    return INSTANCE;
-  }
-
-  private FlowRunRowKeyConverter() {
-  }
-
-  // Flow run row key is of the form
-  // clusterId!userId!flowName!flowrunId with each segment separated by !.
-  // The sizes below indicate sizes of each one of these segments in sequence.
-  // clusterId, userId and flowName are strings. flowrunId is a long hence 8
-  // bytes in size. Strings are variable in size (i.e. end whenever separator is
-  // encountered). This is used while decoding and helps in determining where to
-  // split.
-  private static final int[] SEGMENT_SIZES = {
-      Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-      Bytes.SIZEOF_LONG };
-
-  /*
-   * (non-Javadoc)
-   *
-   * Encodes FlowRunRowKey object into a byte array with each component/field in
-   * FlowRunRowKey separated by Separator#QUALIFIERS. This leads to an
-   * flow run row key of the form clusterId!userId!flowName!flowrunId
-   * If flowRunId in passed FlowRunRowKey object is null (and the fields
-   * preceding it i.e. clusterId, userId and flowName are not null), this
-   * returns a row key prefix of the form clusterId!userName!flowName!
-   * flowRunId is inverted while encoding as it helps maintain a descending
-   * order for flow keys in flow run table.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #encode(java.lang.Object)
-   */
-  @Override
-  public byte[] encode(FlowRunRowKey rowKey) {
-    byte[] first = Separator.QUALIFIERS.join(
-        Separator.encode(rowKey.getClusterId(), Separator.SPACE, Separator.TAB,
-            Separator.QUALIFIERS),
-        Separator.encode(rowKey.getUserId(), Separator.SPACE, Separator.TAB,
-            Separator.QUALIFIERS),
-        Separator.encode(rowKey.getFlowName(), Separator.SPACE, Separator.TAB,
-            Separator.QUALIFIERS));
-    if (rowKey.getFlowRunId() == null) {
-      return Separator.QUALIFIERS.join(first, Separator.EMPTY_BYTES);
-    } else {
-      // Note that flowRunId is a long, so we can't encode them all at the same
-      // time.
-      byte[] second = Bytes.toBytes(TimelineStorageUtils.invertLong(
-          rowKey.getFlowRunId()));
-      return Separator.QUALIFIERS.join(first, second);
-    }
-  }
-
-  /*
-   * (non-Javadoc)
-   *
-   * Decodes an flow run row key of the form
-   * clusterId!userId!flowName!flowrunId represented in byte format and converts
-   * it into an FlowRunRowKey object. flowRunId is inverted while decoding as
-   * it was inverted while encoding.
-   *
-   * @see
-   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter
-   * #decode(byte[])
-   */
-  @Override
-  public FlowRunRowKey decode(byte[] rowKey) {
-    byte[][] rowKeyComponents =
-        Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
-    if (rowKeyComponents.length != 4) {
-      throw new IllegalArgumentException("the row key is not valid for " +
-          "a flow run");
-    }
-    String clusterId = Separator.decode(Bytes.toString(rowKeyComponents[0]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String userId = Separator.decode(Bytes.toString(rowKeyComponents[1]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    String flowName = Separator.decode(Bytes.toString(rowKeyComponents[2]),
-        Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
-    Long flowRunId =
-        TimelineStorageUtils.invertLong(Bytes.toLong(rowKeyComponents[3]));
-    return new FlowRunRowKey(clusterId, userId, flowName, flowRunId);
-  }
-}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/flow/FlowRunRowKeyPrefix.java

@@ -0,0 +1,54 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.server.timelineservice.storage.flow;
+
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
+
+/**
+ * Represents a partial rowkey (without the flowRunId) for the flow run table.
+ */
+public class FlowRunRowKeyPrefix extends FlowRunRowKey implements
+    RowKeyPrefix<FlowRunRowKey> {
+
+  /**
+   * Constructs a row key prefix for the flow run table as follows:
+   * {@code clusterId!userI!flowName!}.
+   *
+   * @param clusterId identifying the cluster
+   * @param userId identifying the user
+   * @param flowName identifying the flow
+   */
+  public FlowRunRowKeyPrefix(String clusterId, String userId,
+      String flowName) {
+    super(clusterId, userId, flowName, null);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.application.
+   * RowKeyPrefix#getRowKeyPrefix()
+   */
+  public byte[] getRowKeyPrefix() {
+    // We know we're a FlowRunRowKey with null florRunId, so we can simply
+    // delegate
+    return super.getRowKey();
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/ApplicationEntityReader.java

@@ -46,8 +46,11 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.application.Applica
 import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationColumnFamily;
 import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationRowKeyPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationTable;
+import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowRowKey;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.BaseTable;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 
 import com.google.common.base.Preconditions;
@@ -150,13 +153,13 @@ class ApplicationEntityReader extends GenericEntityReader {
     EnumSet<Field> fieldsToRetrieve = getDataToRetrieve().getFieldsToRetrieve();
     // If INFO field has to be retrieved, add a filter for fetching columns
     // with INFO column prefix.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.INFO)) {
+    if (hasField(fieldsToRetrieve, Field.INFO)) {
       infoFamilyColsFilter.addFilter(
           TimelineFilterUtils.createHBaseQualifierFilter(
               CompareOp.EQUAL, ApplicationColumnPrefix.INFO));
     }
     TimelineFilterList relatesTo = getFilters().getRelatesTo();
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO)) {
+    if (hasField(fieldsToRetrieve, Field.RELATES_TO)) {
       // If RELATES_TO field has to be retrieved, add a filter for fetching
       // columns with RELATES_TO column prefix.
       infoFamilyColsFilter.addFilter(
@@ -169,12 +172,11 @@ class ApplicationEntityReader extends GenericEntityReader {
       // matched after fetching rows from HBase.
       Set<String> relatesToCols =
           TimelineFilterUtils.fetchColumnsFromFilterList(relatesTo);
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createFiltersFromColumnQualifiers(
-              ApplicationColumnPrefix.RELATES_TO, relatesToCols));
+      infoFamilyColsFilter.addFilter(createFiltersFromColumnQualifiers(
+          ApplicationColumnPrefix.RELATES_TO, relatesToCols));
     }
     TimelineFilterList isRelatedTo = getFilters().getIsRelatedTo();
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
+    if (hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
       // If IS_RELATED_TO field has to be retrieved, add a filter for fetching
       // columns with IS_RELATED_TO column prefix.
       infoFamilyColsFilter.addFilter(
@@ -187,12 +189,11 @@ class ApplicationEntityReader extends GenericEntityReader {
       // matched after fetching rows from HBase.
       Set<String> isRelatedToCols =
           TimelineFilterUtils.fetchColumnsFromFilterList(isRelatedTo);
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createFiltersFromColumnQualifiers(
-              ApplicationColumnPrefix.IS_RELATED_TO, isRelatedToCols));
+      infoFamilyColsFilter.addFilter(createFiltersFromColumnQualifiers(
+          ApplicationColumnPrefix.IS_RELATED_TO, isRelatedToCols));
     }
     TimelineFilterList eventFilters = getFilters().getEventFilters();
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS)) {
+    if (hasField(fieldsToRetrieve, Field.EVENTS)) {
       // If EVENTS field has to be retrieved, add a filter for fetching columns
       // with EVENT column prefix.
       infoFamilyColsFilter.addFilter(
@@ -205,9 +206,8 @@ class ApplicationEntityReader extends GenericEntityReader {
       // fetching rows from HBase.
       Set<String> eventCols =
           TimelineFilterUtils.fetchColumnsFromFilterList(eventFilters);
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createFiltersFromColumnQualifiers(
-              ApplicationColumnPrefix.EVENT, eventCols));
+      infoFamilyColsFilter.addFilter(createFiltersFromColumnQualifiers(
+          ApplicationColumnPrefix.EVENT, eventCols));
     }
     return infoFamilyColsFilter;
   }
@@ -222,25 +222,25 @@ class ApplicationEntityReader extends GenericEntityReader {
   private void excludeFieldsFromInfoColFamily(FilterList infoColFamilyList) {
     EnumSet<Field> fieldsToRetrieve = getDataToRetrieve().getFieldsToRetrieve();
     // Events not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS)) {
+    if (!hasField(fieldsToRetrieve, Field.EVENTS)) {
       infoColFamilyList.addFilter(
           TimelineFilterUtils.createHBaseQualifierFilter(
               CompareOp.NOT_EQUAL, ApplicationColumnPrefix.EVENT));
     }
     // info not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.INFO)) {
+    if (!hasField(fieldsToRetrieve, Field.INFO)) {
       infoColFamilyList.addFilter(
           TimelineFilterUtils.createHBaseQualifierFilter(
               CompareOp.NOT_EQUAL, ApplicationColumnPrefix.INFO));
     }
     // is related to not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
+    if (!hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
       infoColFamilyList.addFilter(
           TimelineFilterUtils.createHBaseQualifierFilter(
               CompareOp.NOT_EQUAL, ApplicationColumnPrefix.IS_RELATED_TO));
     }
     // relates to not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO)) {
+    if (!hasField(fieldsToRetrieve, Field.RELATES_TO)) {
       infoColFamilyList.addFilter(
           TimelineFilterUtils.createHBaseQualifierFilter(
               CompareOp.NOT_EQUAL, ApplicationColumnPrefix.RELATES_TO));
@@ -308,9 +308,10 @@ class ApplicationEntityReader extends GenericEntityReader {
   protected Result getResult(Configuration hbaseConf, Connection conn,
       FilterList filterList) throws IOException {
     TimelineReaderContext context = getContext();
-    byte[] rowKey =
-        ApplicationRowKey.getRowKey(context.getClusterId(), context.getUserId(),
+    ApplicationRowKey applicationRowKey =
+        new ApplicationRowKey(context.getClusterId(), context.getUserId(),
             context.getFlowName(), context.getFlowRunId(), context.getAppId());
+    byte[] rowKey = applicationRowKey.getRowKey();
     Get get = new Get(rowKey);
     get.setMaxVersions(getDataToRetrieve().getMetricsLimit());
     if (filterList != null && !filterList.getFilters().isEmpty()) {
@@ -345,10 +346,13 @@ class ApplicationEntityReader extends GenericEntityReader {
     TimelineReaderContext context = getContext();
     if (isSingleEntityRead()) {
       // Get flow context information from AppToFlow table.
-      if (context.getFlowName() == null || context.getFlowRunId() == null ||
-          context.getUserId() == null) {
-        FlowContext flowContext = lookupFlowContext(
-            context.getClusterId(), context.getAppId(), hbaseConf, conn);
+      if (context.getFlowName() == null || context.getFlowRunId() == null
+          || context.getUserId() == null) {
+        AppToFlowRowKey appToFlowRowKey =
+            new AppToFlowRowKey(context.getClusterId(), context.getAppId());
+        FlowContext flowContext =
+            lookupFlowContext(appToFlowRowKey,
+                hbaseConf, conn);
         context.setFlowName(flowContext.getFlowName());
         context.setFlowRunId(flowContext.getFlowRunId());
         context.setUserId(flowContext.getUserId());
@@ -367,15 +371,13 @@ class ApplicationEntityReader extends GenericEntityReader {
       Connection conn, FilterList filterList) throws IOException {
     Scan scan = new Scan();
     TimelineReaderContext context = getContext();
-    if (context.getFlowRunId() != null) {
-      scan.setRowPrefixFilter(ApplicationRowKey.
-          getRowKeyPrefix(context.getClusterId(), context.getUserId(),
-              context.getFlowName(), context.getFlowRunId()));
-    } else {
-      scan.setRowPrefixFilter(ApplicationRowKey.
-          getRowKeyPrefix(context.getClusterId(), context.getUserId(),
-              context.getFlowName()));
-    }
+    // Whether or not flowRunID is null doesn't matter, the
+    // ApplicationRowKeyPrefix will do the right thing.
+    RowKeyPrefix<ApplicationRowKey> applicationRowKeyPrefix =
+        new ApplicationRowKeyPrefix(context.getClusterId(),
+            context.getUserId(), context.getFlowName(),
+            context.getFlowRunId());
+    scan.setRowPrefixFilter(applicationRowKeyPrefix.getRowKeyPrefix());
     FilterList newList = new FilterList();
     newList.addFilter(new PageFilter(getFilters().getLimit()));
     if (filterList != null && !filterList.getFilters().isEmpty()) {
@@ -409,15 +411,14 @@ class ApplicationEntityReader extends GenericEntityReader {
     boolean checkIsRelatedTo =
         !isSingleEntityRead() && filters.getIsRelatedTo() != null &&
         filters.getIsRelatedTo().getFilterList().size() > 0;
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.IS_RELATED_TO) ||
-        checkIsRelatedTo) {
-      TimelineStorageUtils.readRelationship(
-          entity, result, ApplicationColumnPrefix.IS_RELATED_TO, true);
+    if (hasField(fieldsToRetrieve, Field.IS_RELATED_TO) || checkIsRelatedTo) {
+      readRelationship(entity, result, ApplicationColumnPrefix.IS_RELATED_TO,
+          true);
       if (checkIsRelatedTo && !TimelineStorageUtils.matchIsRelatedTo(entity,
           filters.getIsRelatedTo())) {
         return null;
       }
-      if (!TimelineStorageUtils.hasField(fieldsToRetrieve,
+      if (!hasField(fieldsToRetrieve,
           Field.IS_RELATED_TO)) {
         entity.getIsRelatedToEntities().clear();
       }
@@ -430,29 +431,27 @@ class ApplicationEntityReader extends GenericEntityReader {
     boolean checkRelatesTo =
         !isSingleEntityRead() && filters.getRelatesTo() != null &&
         filters.getRelatesTo().getFilterList().size() > 0;
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO) ||
+    if (hasField(fieldsToRetrieve, Field.RELATES_TO) ||
         checkRelatesTo) {
-      TimelineStorageUtils.readRelationship(
-          entity, result, ApplicationColumnPrefix.RELATES_TO, false);
+      readRelationship(entity, result, ApplicationColumnPrefix.RELATES_TO,
+          false);
       if (checkRelatesTo && !TimelineStorageUtils.matchRelatesTo(entity,
           filters.getRelatesTo())) {
         return null;
       }
-      if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO)) {
+      if (!hasField(fieldsToRetrieve, Field.RELATES_TO)) {
         entity.getRelatesToEntities().clear();
       }
     }
 
     // fetch info if fieldsToRetrieve contains INFO or ALL.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.INFO)) {
-      TimelineStorageUtils.readKeyValuePairs(
-          entity, result, ApplicationColumnPrefix.INFO, false);
+    if (hasField(fieldsToRetrieve, Field.INFO)) {
+      readKeyValuePairs(entity, result, ApplicationColumnPrefix.INFO, false);
     }
 
     // fetch configs if fieldsToRetrieve contains CONFIGS or ALL.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.CONFIGS)) {
-      TimelineStorageUtils.readKeyValuePairs(
-          entity, result, ApplicationColumnPrefix.CONFIG, true);
+    if (hasField(fieldsToRetrieve, Field.CONFIGS)) {
+      readKeyValuePairs(entity, result, ApplicationColumnPrefix.CONFIG, true);
     }
 
     // fetch events and match event filters if they exist. If event filters do
@@ -462,21 +461,19 @@ class ApplicationEntityReader extends GenericEntityReader {
     boolean checkEvents =
         !isSingleEntityRead() && filters.getEventFilters() != null &&
         filters.getEventFilters().getFilterList().size() > 0;
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS) ||
-        checkEvents) {
-      TimelineStorageUtils.readEvents(
-          entity, result, ApplicationColumnPrefix.EVENT);
+    if (hasField(fieldsToRetrieve, Field.EVENTS) || checkEvents) {
+      readEvents(entity, result, ApplicationColumnPrefix.EVENT);
       if (checkEvents && !TimelineStorageUtils.matchEventFilters(entity,
           filters.getEventFilters())) {
         return null;
       }
-      if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS)) {
+      if (!hasField(fieldsToRetrieve, Field.EVENTS)) {
         entity.getEvents().clear();
       }
     }
 
     // fetch metrics if fieldsToRetrieve contains METRICS or ALL.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.METRICS)) {
+    if (hasField(fieldsToRetrieve, Field.METRICS)) {
       readMetrics(entity, result, ApplicationColumnPrefix.METRIC);
     }
     return entity;

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/FlowActivityEntityReader.java

@@ -35,9 +35,11 @@ import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrie
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.BaseTable;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.LongKeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityRowKeyPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityTable;
 
 import com.google.common.base.Preconditions;
@@ -50,6 +52,12 @@ class FlowActivityEntityReader extends TimelineEntityReader {
   private static final FlowActivityTable FLOW_ACTIVITY_TABLE =
       new FlowActivityTable();
 
+  /**
+   * Used to convert Long key components to and from storage format.
+   */
+  private final KeyConverter<Long> longKeyConverter = new LongKeyConverter();
+
+
   public FlowActivityEntityReader(TimelineReaderContext ctxt,
       TimelineEntityFilters entityFilters, TimelineDataToRetrieve toRetrieve) {
     super(ctxt, entityFilters, toRetrieve, true);
@@ -105,15 +113,14 @@ class FlowActivityEntityReader extends TimelineEntityReader {
     if (getFilters().getCreatedTimeBegin() == 0L &&
         getFilters().getCreatedTimeEnd() == Long.MAX_VALUE) {
        // All records have to be chosen.
-      scan.setRowPrefixFilter(FlowActivityRowKey.getRowKeyPrefix(clusterId));
+      scan.setRowPrefixFilter(new FlowActivityRowKeyPrefix(clusterId)
+          .getRowKeyPrefix());
     } else {
-      scan.setStartRow(
-          FlowActivityRowKey.getRowKeyPrefix(clusterId,
-              getFilters().getCreatedTimeEnd()));
-      scan.setStopRow(
-          FlowActivityRowKey.getRowKeyPrefix(clusterId,
-              (getFilters().getCreatedTimeBegin() <= 0 ? 0 :
-              (getFilters().getCreatedTimeBegin() - 1))));
+      scan.setStartRow(new FlowActivityRowKeyPrefix(clusterId, getFilters()
+          .getCreatedTimeEnd()).getRowKeyPrefix());
+      scan.setStopRow(new FlowActivityRowKeyPrefix(clusterId, (getFilters()
+          .getCreatedTimeBegin() <= 0 ? 0
+          : (getFilters().getCreatedTimeBegin() - 1))).getRowKeyPrefix());
     }
     // use the page filter to limit the result to the page size
     // the scanner may still return more than the limit; therefore we need to
@@ -137,8 +144,7 @@ class FlowActivityEntityReader extends TimelineEntityReader {
     // get the list of run ids along with the version that are associated with
     // this flow on this day
     Map<Long, Object> runIdsMap =
-        FlowActivityColumnPrefix.RUN_ID.readResults(result,
-            LongKeyConverter.getInstance());
+        FlowActivityColumnPrefix.RUN_ID.readResults(result, longKeyConverter);
     for (Map.Entry<Long, Object> e : runIdsMap.entrySet()) {
       Long runId = e.getKey();
       String version = (String)e.getValue();

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/FlowRunEntityReader.java

@@ -28,12 +28,12 @@ import org.apache.hadoop.hbase.client.ResultScanner;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.filter.BinaryComparator;
 import org.apache.hadoop.hbase.filter.BinaryPrefixComparator;
+import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
 import org.apache.hadoop.hbase.filter.FamilyFilter;
 import org.apache.hadoop.hbase.filter.FilterList;
+import org.apache.hadoop.hbase.filter.FilterList.Operator;
 import org.apache.hadoop.hbase.filter.PageFilter;
 import org.apache.hadoop.hbase.filter.QualifierFilter;
-import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
-import org.apache.hadoop.hbase.filter.FilterList.Operator;
 import org.apache.hadoop.yarn.api.records.timelineservice.FlowRunEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve;
@@ -43,11 +43,12 @@ import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineFilte
 import org.apache.hadoop.yarn.server.timelineservice.reader.filter.TimelineFilterUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.TimelineReader.Field;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.BaseTable;
-import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunColumn;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunColumnFamily;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunRowKeyPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunTable;
 import org.apache.hadoop.yarn.webapp.BadRequestException;
 
@@ -81,8 +82,8 @@ class FlowRunEntityReader extends TimelineEntityReader {
   @Override
   protected void validateParams() {
     Preconditions.checkNotNull(getContext(), "context shouldn't be null");
-    Preconditions.checkNotNull(
-        getDataToRetrieve(), "data to retrieve shouldn't be null");
+    Preconditions.checkNotNull(getDataToRetrieve(),
+        "data to retrieve shouldn't be null");
     Preconditions.checkNotNull(getContext().getClusterId(),
         "clusterId shouldn't be null");
     Preconditions.checkNotNull(getContext().getUserId(),
@@ -97,8 +98,8 @@ class FlowRunEntityReader extends TimelineEntityReader {
     if (!isSingleEntityRead() && fieldsToRetrieve != null) {
       for (Field field : fieldsToRetrieve) {
         if (field != Field.ALL && field != Field.METRICS) {
-          throw new BadRequestException("Invalid field " + field +
-              " specified while querying flow runs.");
+          throw new BadRequestException("Invalid field " + field
+              + " specified while querying flow runs.");
         }
       }
     }
@@ -119,23 +120,22 @@ class FlowRunEntityReader extends TimelineEntityReader {
     Long createdTimeBegin = getFilters().getCreatedTimeBegin();
     Long createdTimeEnd = getFilters().getCreatedTimeEnd();
     if (createdTimeBegin != 0 || createdTimeEnd != Long.MAX_VALUE) {
-      listBasedOnFilters.addFilter(
-          TimelineFilterUtils.createSingleColValueFiltersByRange(
-          FlowRunColumn.MIN_START_TIME, createdTimeBegin, createdTimeEnd));
+      listBasedOnFilters.addFilter(TimelineFilterUtils
+          .createSingleColValueFiltersByRange(FlowRunColumn.MIN_START_TIME,
+              createdTimeBegin, createdTimeEnd));
     }
     // Filter based on metric filters.
     TimelineFilterList metricFilters = getFilters().getMetricFilters();
     if (metricFilters != null && !metricFilters.getFilterList().isEmpty()) {
-      listBasedOnFilters.addFilter(
-          TimelineFilterUtils.createHBaseFilterList(
-              FlowRunColumnPrefix.METRIC, metricFilters));
+      listBasedOnFilters.addFilter(TimelineFilterUtils.createHBaseFilterList(
+          FlowRunColumnPrefix.METRIC, metricFilters));
     }
     return listBasedOnFilters;
   }
 
   /**
-   * Add {@link QualifierFilter} filters to filter list for each column of
-   * flow run table.
+   * Add {@link QualifierFilter} filters to filter list for each column of flow
+   * run table.
    *
    * @return filter list to which qualifier filters have been added.
    */
@@ -153,20 +153,19 @@ class FlowRunEntityReader extends TimelineEntityReader {
     FilterList list = new FilterList(Operator.MUST_PASS_ONE);
     // By default fetch everything in INFO column family.
     FamilyFilter infoColumnFamily =
-        new FamilyFilter(CompareOp.EQUAL,
-           new BinaryComparator(FlowRunColumnFamily.INFO.getBytes()));
+        new FamilyFilter(CompareOp.EQUAL, new BinaryComparator(
+            FlowRunColumnFamily.INFO.getBytes()));
     TimelineDataToRetrieve dataToRetrieve = getDataToRetrieve();
     // If multiple entities have to be retrieved, check if metrics have to be
     // retrieved and if not, add a filter so that metrics can be excluded.
     // Metrics are always returned if we are reading a single entity.
-    if (!isSingleEntityRead() && !TimelineStorageUtils.hasField(
-        dataToRetrieve.getFieldsToRetrieve(), Field.METRICS)) {
+    if (!isSingleEntityRead()
+        && !hasField(dataToRetrieve.getFieldsToRetrieve(), Field.METRICS)) {
       FilterList infoColFamilyList = new FilterList(Operator.MUST_PASS_ONE);
       infoColFamilyList.addFilter(infoColumnFamily);
-      infoColFamilyList.addFilter(
-          new QualifierFilter(CompareOp.NOT_EQUAL,
-          new BinaryPrefixComparator(
-              FlowRunColumnPrefix.METRIC.getColumnPrefixBytes(""))));
+      infoColFamilyList.addFilter(new QualifierFilter(CompareOp.NOT_EQUAL,
+          new BinaryPrefixComparator(FlowRunColumnPrefix.METRIC
+              .getColumnPrefixBytes(""))));
       list.addFilter(infoColFamilyList);
     } else {
       // Check if metricsToRetrieve are specified and if they are, create a
@@ -176,14 +175,13 @@ class FlowRunEntityReader extends TimelineEntityReader {
       // (in augmentParams()).
       TimelineFilterList metricsToRetrieve =
           dataToRetrieve.getMetricsToRetrieve();
-      if (metricsToRetrieve != null &&
-          !metricsToRetrieve.getFilterList().isEmpty()) {
+      if (metricsToRetrieve != null
+          && !metricsToRetrieve.getFilterList().isEmpty()) {
         FilterList infoColFamilyList = new FilterList();
         infoColFamilyList.addFilter(infoColumnFamily);
         FilterList columnsList = updateFixedColumns();
-        columnsList.addFilter(
-            TimelineFilterUtils.createHBaseFilterList(
-                FlowRunColumnPrefix.METRIC, metricsToRetrieve));
+        columnsList.addFilter(TimelineFilterUtils.createHBaseFilterList(
+            FlowRunColumnPrefix.METRIC, metricsToRetrieve));
         infoColFamilyList.addFilter(columnsList);
         list.addFilter(infoColFamilyList);
       }
@@ -195,9 +193,10 @@ class FlowRunEntityReader extends TimelineEntityReader {
   protected Result getResult(Configuration hbaseConf, Connection conn,
       FilterList filterList) throws IOException {
     TimelineReaderContext context = getContext();
-    byte[] rowKey =
-        FlowRunRowKey.getRowKey(context.getClusterId(), context.getUserId(),
+    FlowRunRowKey flowRunRowKey =
+        new FlowRunRowKey(context.getClusterId(), context.getUserId(),
             context.getFlowName(), context.getFlowRunId());
+    byte[] rowKey = flowRunRowKey.getRowKey();
     Get get = new Get(rowKey);
     get.setMaxVersions(Integer.MAX_VALUE);
     if (filterList != null && !filterList.getFilters().isEmpty()) {
@@ -207,13 +206,14 @@ class FlowRunEntityReader extends TimelineEntityReader {
   }
 
   @Override
-  protected ResultScanner getResults(Configuration hbaseConf,
-      Connection conn, FilterList filterList) throws IOException {
+  protected ResultScanner getResults(Configuration hbaseConf, Connection conn,
+      FilterList filterList) throws IOException {
     Scan scan = new Scan();
     TimelineReaderContext context = getContext();
-    scan.setRowPrefixFilter(
-        FlowRunRowKey.getRowKeyPrefix(context.getClusterId(),
-            context.getUserId(), context.getFlowName()));
+    RowKeyPrefix<FlowRunRowKey> flowRunRowKeyPrefix =
+        new FlowRunRowKeyPrefix(context.getClusterId(), context.getUserId(),
+            context.getFlowName());
+    scan.setRowPrefixFilter(flowRunRowKeyPrefix.getRowKeyPrefix());
     FilterList newList = new FilterList();
     newList.addFilter(new PageFilter(getFilters().getLimit()));
     if (filterList != null && !filterList.getFilters().isEmpty()) {
@@ -238,27 +238,27 @@ class FlowRunEntityReader extends TimelineEntityReader {
     }
 
     // read the start time
-    Long startTime = (Long)FlowRunColumn.MIN_START_TIME.readResult(result);
+    Long startTime = (Long) FlowRunColumn.MIN_START_TIME.readResult(result);
     if (startTime != null) {
       flowRun.setStartTime(startTime.longValue());
     }
 
     // read the end time if available
-    Long endTime = (Long)FlowRunColumn.MAX_END_TIME.readResult(result);
+    Long endTime = (Long) FlowRunColumn.MAX_END_TIME.readResult(result);
     if (endTime != null) {
       flowRun.setMaxEndTime(endTime.longValue());
     }
 
     // read the flow version
-    String version = (String)FlowRunColumn.FLOW_VERSION.readResult(result);
+    String version = (String) FlowRunColumn.FLOW_VERSION.readResult(result);
     if (version != null) {
       flowRun.setVersion(version);
     }
 
     // read metrics if its a single entity query or if METRICS are part of
     // fieldsToRetrieve.
-    if (isSingleEntityRead() || TimelineStorageUtils.hasField(
-        getDataToRetrieve().getFieldsToRetrieve(), Field.METRICS)) {
+    if (isSingleEntityRead()
+        || hasField(getDataToRetrieve().getFieldsToRetrieve(), Field.METRICS)) {
       readMetrics(flowRun, result, FlowRunColumnPrefix.METRIC);
     }
 

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/GenericEntityReader.java

@@ -19,6 +19,7 @@ package org.apache.hadoop.yarn.server.timelineservice.storage.reader;
 
 import java.io.IOException;
 import java.util.EnumSet;
+import java.util.Map;
 import java.util.Set;
 
 import org.apache.hadoop.conf.Configuration;
@@ -28,11 +29,11 @@ import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.ResultScanner;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.filter.BinaryComparator;
+import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
 import org.apache.hadoop.hbase.filter.FamilyFilter;
 import org.apache.hadoop.hbase.filter.FilterList;
-import org.apache.hadoop.hbase.filter.QualifierFilter;
-import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
 import org.apache.hadoop.hbase.filter.FilterList.Operator;
+import org.apache.hadoop.hbase.filter.QualifierFilter;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters;
@@ -44,11 +45,16 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlow
 import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowRowKey;
 import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.BaseTable;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.StringKeyConverter;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineStorageUtils;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumn;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnFamily;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKeyPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityTable;
 import org.apache.hadoop.yarn.webapp.NotFoundException;
 
@@ -66,6 +72,12 @@ class GenericEntityReader extends TimelineEntityReader {
    */
   private final AppToFlowTable appToFlowTable = new AppToFlowTable();
 
+  /**
+   * Used to convert strings key components to and from storage format.
+   */
+  private final KeyConverter<String> stringKeyConverter =
+      new StringKeyConverter();
+
   public GenericEntityReader(TimelineReaderContext ctxt,
       TimelineEntityFilters entityFilters, TimelineDataToRetrieve toRetrieve,
       boolean sortedKeys) {
@@ -95,32 +107,29 @@ class GenericEntityReader extends TimelineEntityReader {
     long createdTimeBegin = filters.getCreatedTimeBegin();
     long createdTimeEnd = filters.getCreatedTimeEnd();
     if (createdTimeBegin != 0 || createdTimeEnd != Long.MAX_VALUE) {
-      listBasedOnFilters.addFilter(
-          TimelineFilterUtils.createSingleColValueFiltersByRange(
-              EntityColumn.CREATED_TIME, createdTimeBegin, createdTimeEnd));
+      listBasedOnFilters.addFilter(TimelineFilterUtils
+          .createSingleColValueFiltersByRange(EntityColumn.CREATED_TIME,
+              createdTimeBegin, createdTimeEnd));
     }
     // Create filter list based on metric filters and add it to
     // listBasedOnFilters.
     TimelineFilterList metricFilters = filters.getMetricFilters();
     if (metricFilters != null && !metricFilters.getFilterList().isEmpty()) {
-      listBasedOnFilters.addFilter(
-          TimelineFilterUtils.createHBaseFilterList(
-              EntityColumnPrefix.METRIC, metricFilters));
+      listBasedOnFilters.addFilter(TimelineFilterUtils.createHBaseFilterList(
+          EntityColumnPrefix.METRIC, metricFilters));
     }
     // Create filter list based on config filters and add it to
     // listBasedOnFilters.
     TimelineFilterList configFilters = filters.getConfigFilters();
     if (configFilters != null && !configFilters.getFilterList().isEmpty()) {
-      listBasedOnFilters.addFilter(
-          TimelineFilterUtils.createHBaseFilterList(
-              EntityColumnPrefix.CONFIG, configFilters));
+      listBasedOnFilters.addFilter(TimelineFilterUtils.createHBaseFilterList(
+          EntityColumnPrefix.CONFIG, configFilters));
     }
     // Create filter list based on info filters and add it to listBasedOnFilters
     TimelineFilterList infoFilters = filters.getInfoFilters();
     if (infoFilters != null && !infoFilters.getFilterList().isEmpty()) {
-      listBasedOnFilters.addFilter(
-          TimelineFilterUtils.createHBaseFilterList(
-              EntityColumnPrefix.INFO, infoFilters));
+      listBasedOnFilters.addFilter(TimelineFilterUtils.createHBaseFilterList(
+          EntityColumnPrefix.INFO, infoFilters));
     }
     return listBasedOnFilters;
   }
@@ -130,10 +139,10 @@ class GenericEntityReader extends TimelineEntityReader {
    *
    * @return true if we need to fetch some of the columns, false otherwise.
    */
-  private static boolean fetchPartialEventCols(TimelineFilterList eventFilters,
+  private boolean fetchPartialEventCols(TimelineFilterList eventFilters,
       EnumSet<Field> fieldsToRetrieve) {
     return (eventFilters != null && !eventFilters.getFilterList().isEmpty() &&
-        !TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS));
+        !hasField(fieldsToRetrieve, Field.EVENTS));
   }
 
   /**
@@ -141,10 +150,10 @@ class GenericEntityReader extends TimelineEntityReader {
    *
    * @return true if we need to fetch some of the columns, false otherwise.
    */
-  private static boolean fetchPartialRelatesToCols(TimelineFilterList relatesTo,
+  private boolean fetchPartialRelatesToCols(TimelineFilterList relatesTo,
       EnumSet<Field> fieldsToRetrieve) {
     return (relatesTo != null && !relatesTo.getFilterList().isEmpty() &&
-        !TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO));
+        !hasField(fieldsToRetrieve, Field.RELATES_TO));
   }
 
   /**
@@ -152,10 +161,10 @@ class GenericEntityReader extends TimelineEntityReader {
    *
    * @return true if we need to fetch some of the columns, false otherwise.
    */
-  private static boolean fetchPartialIsRelatedToCols(
-      TimelineFilterList isRelatedTo, EnumSet<Field> fieldsToRetrieve) {
+  private boolean fetchPartialIsRelatedToCols(TimelineFilterList isRelatedTo,
+      EnumSet<Field> fieldsToRetrieve) {
     return (isRelatedTo != null && !isRelatedTo.getFilterList().isEmpty() &&
-        !TimelineStorageUtils.hasField(fieldsToRetrieve, Field.IS_RELATED_TO));
+        !hasField(fieldsToRetrieve, Field.IS_RELATED_TO));
   }
 
   /**
@@ -163,19 +172,20 @@ class GenericEntityReader extends TimelineEntityReader {
    * relatesto and isrelatedto from info family.
    *
    * @return true, if we need to fetch only some of the columns, false if we
-   *     need to fetch all the columns under info column family.
+   *         need to fetch all the columns under info column family.
    */
   protected boolean fetchPartialColsFromInfoFamily() {
     EnumSet<Field> fieldsToRetrieve = getDataToRetrieve().getFieldsToRetrieve();
     TimelineEntityFilters filters = getFilters();
-    return fetchPartialEventCols(filters.getEventFilters(), fieldsToRetrieve) ||
-        fetchPartialRelatesToCols(filters.getRelatesTo(), fieldsToRetrieve) ||
-        fetchPartialIsRelatedToCols(filters.getIsRelatedTo(), fieldsToRetrieve);
+    return fetchPartialEventCols(filters.getEventFilters(), fieldsToRetrieve)
+        || fetchPartialRelatesToCols(filters.getRelatesTo(), fieldsToRetrieve)
+        || fetchPartialIsRelatedToCols(filters.getIsRelatedTo(),
+            fieldsToRetrieve);
   }
 
   /**
-   * Check if we need to create filter list based on fields. We need to create
-   * a filter list iff all fields need not be retrieved or we have some specific
+   * Check if we need to create filter list based on fields. We need to create a
+   * filter list iff all fields need not be retrieved or we have some specific
    * fields or metrics to retrieve. We also need to create a filter list if we
    * have relationships(relatesTo/isRelatedTo) and event filters specified for
    * the query.
@@ -188,22 +198,24 @@ class GenericEntityReader extends TimelineEntityReader {
     // be retrieved, also check if we have some metrics or configs to
     // retrieve specified for the query because then a filter list will have
     // to be created.
-    boolean flag = !dataToRetrieve.getFieldsToRetrieve().contains(Field.ALL) ||
-        (dataToRetrieve.getConfsToRetrieve() != null &&
-        !dataToRetrieve.getConfsToRetrieve().getFilterList().isEmpty()) ||
-        (dataToRetrieve.getMetricsToRetrieve() != null &&
-        !dataToRetrieve.getMetricsToRetrieve().getFilterList().isEmpty());
+    boolean flag =
+        !dataToRetrieve.getFieldsToRetrieve().contains(Field.ALL)
+            || (dataToRetrieve.getConfsToRetrieve() != null && !dataToRetrieve
+                .getConfsToRetrieve().getFilterList().isEmpty())
+            || (dataToRetrieve.getMetricsToRetrieve() != null && !dataToRetrieve
+                .getMetricsToRetrieve().getFilterList().isEmpty());
     // Filters need to be checked only if we are reading multiple entities. If
     // condition above is false, we check if there are relationships(relatesTo/
     // isRelatedTo) and event filters specified for the query.
     if (!flag && !isSingleEntityRead()) {
       TimelineEntityFilters filters = getFilters();
-      flag = (filters.getEventFilters() != null &&
-          !filters.getEventFilters().getFilterList().isEmpty()) ||
-          (filters.getIsRelatedTo() != null &&
-          !filters.getIsRelatedTo().getFilterList().isEmpty()) ||
-          (filters.getRelatesTo() != null &&
-          !filters.getRelatesTo().getFilterList().isEmpty());
+      flag =
+          (filters.getEventFilters() != null && !filters.getEventFilters()
+              .getFilterList().isEmpty())
+              || (filters.getIsRelatedTo() != null && !filters.getIsRelatedTo()
+                  .getFilterList().isEmpty())
+              || (filters.getRelatesTo() != null && !filters.getRelatesTo()
+                  .getFilterList().isEmpty());
     }
     return flag;
   }
@@ -216,8 +228,8 @@ class GenericEntityReader extends TimelineEntityReader {
    */
   protected void updateFixedColumns(FilterList list) {
     for (EntityColumn column : EntityColumn.values()) {
-      list.addFilter(new QualifierFilter(CompareOp.EQUAL,
-          new BinaryComparator(column.getColumnQualifierBytes())));
+      list.addFilter(new QualifierFilter(CompareOp.EQUAL, new BinaryComparator(
+          column.getColumnQualifierBytes())));
     }
   }
 
@@ -226,30 +238,29 @@ class GenericEntityReader extends TimelineEntityReader {
    * qualifiers in the info column family will be returned in result.
    *
    * @param isApplication If true, it means operations are to be performed for
-   *     application table, otherwise for entity table.
+   *          application table, otherwise for entity table.
    * @return filter list.
    * @throws IOException if any problem occurs while creating filter list.
    */
-  private FilterList createFilterListForColsOfInfoFamily()
-      throws IOException {
+  private FilterList createFilterListForColsOfInfoFamily() throws IOException {
     FilterList infoFamilyColsFilter = new FilterList(Operator.MUST_PASS_ONE);
     // Add filters for each column in entity table.
     updateFixedColumns(infoFamilyColsFilter);
     EnumSet<Field> fieldsToRetrieve = getDataToRetrieve().getFieldsToRetrieve();
     // If INFO field has to be retrieved, add a filter for fetching columns
     // with INFO column prefix.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.INFO)) {
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
+    if (hasField(fieldsToRetrieve, Field.INFO)) {
+      infoFamilyColsFilter
+          .addFilter(TimelineFilterUtils.createHBaseQualifierFilter(
               CompareOp.EQUAL, EntityColumnPrefix.INFO));
     }
     TimelineFilterList relatesTo = getFilters().getRelatesTo();
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO)) {
+    if (hasField(fieldsToRetrieve, Field.RELATES_TO)) {
       // If RELATES_TO field has to be retrieved, add a filter for fetching
       // columns with RELATES_TO column prefix.
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
-              CompareOp.EQUAL, EntityColumnPrefix.RELATES_TO));
+      infoFamilyColsFilter.addFilter(TimelineFilterUtils
+          .createHBaseQualifierFilter(CompareOp.EQUAL,
+              EntityColumnPrefix.RELATES_TO));
     } else if (relatesTo != null && !relatesTo.getFilterList().isEmpty()) {
       // Even if fields to retrieve does not contain RELATES_TO, we still
       // need to have a filter to fetch some of the column qualifiers if
@@ -257,17 +268,16 @@ class GenericEntityReader extends TimelineEntityReader {
       // matched after fetching rows from HBase.
       Set<String> relatesToCols =
           TimelineFilterUtils.fetchColumnsFromFilterList(relatesTo);
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createFiltersFromColumnQualifiers(
-              EntityColumnPrefix.RELATES_TO, relatesToCols));
+      infoFamilyColsFilter.addFilter(createFiltersFromColumnQualifiers(
+          EntityColumnPrefix.RELATES_TO, relatesToCols));
     }
     TimelineFilterList isRelatedTo = getFilters().getIsRelatedTo();
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
+    if (hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
       // If IS_RELATED_TO field has to be retrieved, add a filter for fetching
       // columns with IS_RELATED_TO column prefix.
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
-              CompareOp.EQUAL, EntityColumnPrefix.IS_RELATED_TO));
+      infoFamilyColsFilter.addFilter(TimelineFilterUtils
+          .createHBaseQualifierFilter(CompareOp.EQUAL,
+              EntityColumnPrefix.IS_RELATED_TO));
     } else if (isRelatedTo != null && !isRelatedTo.getFilterList().isEmpty()) {
       // Even if fields to retrieve does not contain IS_RELATED_TO, we still
       // need to have a filter to fetch some of the column qualifiers if
@@ -275,27 +285,26 @@ class GenericEntityReader extends TimelineEntityReader {
       // matched after fetching rows from HBase.
       Set<String> isRelatedToCols =
           TimelineFilterUtils.fetchColumnsFromFilterList(isRelatedTo);
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createFiltersFromColumnQualifiers(
-              EntityColumnPrefix.IS_RELATED_TO, isRelatedToCols));
+      infoFamilyColsFilter.addFilter(createFiltersFromColumnQualifiers(
+          EntityColumnPrefix.IS_RELATED_TO, isRelatedToCols));
     }
     TimelineFilterList eventFilters = getFilters().getEventFilters();
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS)) {
+    if (hasField(fieldsToRetrieve, Field.EVENTS)) {
       // If EVENTS field has to be retrieved, add a filter for fetching columns
       // with EVENT column prefix.
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
+      infoFamilyColsFilter
+          .addFilter(TimelineFilterUtils.createHBaseQualifierFilter(
               CompareOp.EQUAL, EntityColumnPrefix.EVENT));
-    } else if (eventFilters != null && !eventFilters.getFilterList().isEmpty()){
+    } else if (eventFilters != null &&
+        !eventFilters.getFilterList().isEmpty()) {
       // Even if fields to retrieve does not contain EVENTS, we still need to
       // have a filter to fetch some of the column qualifiers on the basis of
       // event filters specified. Event filters will then be matched after
       // fetching rows from HBase.
       Set<String> eventCols =
           TimelineFilterUtils.fetchColumnsFromFilterList(eventFilters);
-      infoFamilyColsFilter.addFilter(
-          TimelineFilterUtils.createFiltersFromColumnQualifiers(
-              EntityColumnPrefix.EVENT, eventCols));
+      infoFamilyColsFilter.addFilter(createFiltersFromColumnQualifiers(
+          EntityColumnPrefix.EVENT, eventCols));
     }
     return infoFamilyColsFilter;
   }
@@ -310,28 +319,28 @@ class GenericEntityReader extends TimelineEntityReader {
   private void excludeFieldsFromInfoColFamily(FilterList infoColFamilyList) {
     EnumSet<Field> fieldsToRetrieve = getDataToRetrieve().getFieldsToRetrieve();
     // Events not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS)) {
-      infoColFamilyList.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
-              CompareOp.NOT_EQUAL, EntityColumnPrefix.EVENT));
+    if (!hasField(fieldsToRetrieve, Field.EVENTS)) {
+      infoColFamilyList.addFilter(TimelineFilterUtils
+          .createHBaseQualifierFilter(CompareOp.NOT_EQUAL,
+              EntityColumnPrefix.EVENT));
     }
     // info not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.INFO)) {
-      infoColFamilyList.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
-              CompareOp.NOT_EQUAL, EntityColumnPrefix.INFO));
+    if (!hasField(fieldsToRetrieve, Field.INFO)) {
+      infoColFamilyList.addFilter(TimelineFilterUtils
+          .createHBaseQualifierFilter(CompareOp.NOT_EQUAL,
+              EntityColumnPrefix.INFO));
     }
     // is related to not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
-      infoColFamilyList.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
-              CompareOp.NOT_EQUAL, EntityColumnPrefix.IS_RELATED_TO));
+    if (!hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
+      infoColFamilyList.addFilter(TimelineFilterUtils
+          .createHBaseQualifierFilter(CompareOp.NOT_EQUAL,
+              EntityColumnPrefix.IS_RELATED_TO));
     }
     // relates to not required.
-    if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO)) {
-      infoColFamilyList.addFilter(
-          TimelineFilterUtils.createHBaseQualifierFilter(
-              CompareOp.NOT_EQUAL, EntityColumnPrefix.RELATES_TO));
+    if (!hasField(fieldsToRetrieve, Field.RELATES_TO)) {
+      infoColFamilyList.addFilter(TimelineFilterUtils
+          .createHBaseQualifierFilter(CompareOp.NOT_EQUAL,
+              EntityColumnPrefix.RELATES_TO));
     }
   }
 
@@ -348,18 +357,18 @@ class GenericEntityReader extends TimelineEntityReader {
     // CONFS to fields to retrieve in augmentParams() even if not specified.
     if (dataToRetrieve.getFieldsToRetrieve().contains(Field.CONFIGS)) {
       // Create a filter list for configs.
-      listBasedOnFields.addFilter(TimelineFilterUtils.
-          createFilterForConfsOrMetricsToRetrieve(
-              dataToRetrieve.getConfsToRetrieve(),
-              EntityColumnFamily.CONFIGS, EntityColumnPrefix.CONFIG));
+      listBasedOnFields.addFilter(TimelineFilterUtils
+          .createFilterForConfsOrMetricsToRetrieve(
+              dataToRetrieve.getConfsToRetrieve(), EntityColumnFamily.CONFIGS,
+              EntityColumnPrefix.CONFIG));
     }
 
     // Please note that if metricsToRetrieve is specified, we would have added
     // METRICS to fields to retrieve in augmentParams() even if not specified.
     if (dataToRetrieve.getFieldsToRetrieve().contains(Field.METRICS)) {
       // Create a filter list for metrics.
-      listBasedOnFields.addFilter(TimelineFilterUtils.
-          createFilterForConfsOrMetricsToRetrieve(
+      listBasedOnFields.addFilter(TimelineFilterUtils
+          .createFilterForConfsOrMetricsToRetrieve(
               dataToRetrieve.getMetricsToRetrieve(),
               EntityColumnFamily.METRICS, EntityColumnPrefix.METRIC));
     }
@@ -375,8 +384,8 @@ class GenericEntityReader extends TimelineEntityReader {
     FilterList infoColFamilyList = new FilterList();
     // By default fetch everything in INFO column family.
     FamilyFilter infoColumnFamily =
-        new FamilyFilter(CompareOp.EQUAL,
-           new BinaryComparator(EntityColumnFamily.INFO.getBytes()));
+        new FamilyFilter(CompareOp.EQUAL, new BinaryComparator(
+            EntityColumnFamily.INFO.getBytes()));
     infoColFamilyList.addFilter(infoColumnFamily);
     if (!isSingleEntityRead() && fetchPartialColsFromInfoFamily()) {
       // We can fetch only some of the columns from info family.
@@ -394,27 +403,27 @@ class GenericEntityReader extends TimelineEntityReader {
   /**
    * Looks up flow context from AppToFlow table.
    *
-   * @param clusterId Cluster Id.
-   * @param appId App Id.
+   * @param appToFlowRowKey to identify Cluster and App Ids.
    * @param hbaseConf HBase configuration.
    * @param conn HBase Connection.
    * @return flow context information.
    * @throws IOException if any problem occurs while fetching flow information.
    */
-  protected FlowContext lookupFlowContext(String clusterId, String appId,
+  protected FlowContext lookupFlowContext(AppToFlowRowKey appToFlowRowKey,
       Configuration hbaseConf, Connection conn) throws IOException {
-    byte[] rowKey = AppToFlowRowKey.getRowKey(clusterId, appId);
+    byte[] rowKey = appToFlowRowKey.getRowKey();
     Get get = new Get(rowKey);
     Result result = appToFlowTable.getResult(hbaseConf, conn, get);
     if (result != null && !result.isEmpty()) {
-      return new FlowContext(
-          AppToFlowColumn.USER_ID.readResult(result).toString(),
-          AppToFlowColumn.FLOW_ID.readResult(result).toString(),
-          ((Number)AppToFlowColumn.FLOW_RUN_ID.readResult(result)).longValue());
+      return new FlowContext(AppToFlowColumn.USER_ID.readResult(result)
+          .toString(), AppToFlowColumn.FLOW_ID.readResult(result).toString(),
+          ((Number) AppToFlowColumn.FLOW_RUN_ID.readResult(result))
+          .longValue());
     } else {
       throw new NotFoundException(
-          "Unable to find the context flow ID and flow run ID for clusterId=" +
-          clusterId + ", appId=" + appId);
+          "Unable to find the context flow ID and flow run ID for clusterId="
+              + appToFlowRowKey.getClusterId() + ", appId="
+              + appToFlowRowKey.getAppId());
     }
   }
 
@@ -425,17 +434,21 @@ class GenericEntityReader extends TimelineEntityReader {
     private final String userId;
     private final String flowName;
     private final Long flowRunId;
+
     public FlowContext(String user, String flowName, Long flowRunId) {
       this.userId = user;
       this.flowName = flowName;
       this.flowRunId = flowRunId;
     }
+
     protected String getUserId() {
       return userId;
     }
+
     protected String getFlowName() {
       return flowName;
     }
+
     protected Long getFlowRunId() {
       return flowRunId;
     }
@@ -444,8 +457,8 @@ class GenericEntityReader extends TimelineEntityReader {
   @Override
   protected void validateParams() {
     Preconditions.checkNotNull(getContext(), "context shouldn't be null");
-    Preconditions.checkNotNull(
-        getDataToRetrieve(), "data to retrieve shouldn't be null");
+    Preconditions.checkNotNull(getDataToRetrieve(),
+        "data to retrieve shouldn't be null");
     Preconditions.checkNotNull(getContext().getClusterId(),
         "clusterId shouldn't be null");
     Preconditions.checkNotNull(getContext().getAppId(),
@@ -463,11 +476,13 @@ class GenericEntityReader extends TimelineEntityReader {
       throws IOException {
     TimelineReaderContext context = getContext();
     // In reality all three should be null or neither should be null
-    if (context.getFlowName() == null || context.getFlowRunId() == null ||
-        context.getUserId() == null) {
+    if (context.getFlowName() == null || context.getFlowRunId() == null
+        || context.getUserId() == null) {
       // Get flow context information from AppToFlow table.
-      FlowContext flowContext = lookupFlowContext(
-          context.getClusterId(), context.getAppId(), hbaseConf, conn);
+      AppToFlowRowKey appToFlowRowKey =
+          new AppToFlowRowKey(context.getClusterId(), context.getAppId());
+      FlowContext flowContext =
+          lookupFlowContext(appToFlowRowKey, hbaseConf, conn);
       context.setFlowName(flowContext.flowName);
       context.setFlowRunId(flowContext.flowRunId);
       context.setUserId(flowContext.userId);
@@ -485,9 +500,9 @@ class GenericEntityReader extends TimelineEntityReader {
       FilterList filterList) throws IOException {
     TimelineReaderContext context = getContext();
     byte[] rowKey =
-        EntityRowKey.getRowKey(context.getClusterId(), context.getUserId(),
+        new EntityRowKey(context.getClusterId(), context.getUserId(),
             context.getFlowName(), context.getFlowRunId(), context.getAppId(),
-            context.getEntityType(), context.getEntityId());
+            context.getEntityType(), context.getEntityId()).getRowKey();
     Get get = new Get(rowKey);
     get.setMaxVersions(getDataToRetrieve().getMetricsLimit());
     if (filterList != null && !filterList.getFilters().isEmpty()) {
@@ -497,15 +512,17 @@ class GenericEntityReader extends TimelineEntityReader {
   }
 
   @Override
-  protected ResultScanner getResults(Configuration hbaseConf,
-      Connection conn, FilterList filterList) throws IOException {
+  protected ResultScanner getResults(Configuration hbaseConf, Connection conn,
+      FilterList filterList) throws IOException {
     // Scan through part of the table to find the entities belong to one app
     // and one type
     Scan scan = new Scan();
     TimelineReaderContext context = getContext();
-    scan.setRowPrefixFilter(EntityRowKey.getRowKeyPrefix(
-        context.getClusterId(), context.getUserId(), context.getFlowName(),
-        context.getFlowRunId(), context.getAppId(), context.getEntityType()));
+    RowKeyPrefix<EntityRowKey> entityRowKeyPrefix =
+        new EntityRowKeyPrefix(context.getClusterId(), context.getUserId(),
+            context.getFlowName(), context.getFlowRunId(), context.getAppId(),
+            context.getEntityType());
+    scan.setRowPrefixFilter(entityRowKeyPrefix.getRowKeyPrefix());
     scan.setMaxVersions(getDataToRetrieve().getMetricsLimit());
     if (filterList != null && !filterList.getFilters().isEmpty()) {
       scan.setFilter(filterList);
@@ -535,18 +552,16 @@ class GenericEntityReader extends TimelineEntityReader {
     // locally as relevant HBase filters to filter out rows on the basis of
     // isRelatedTo are not set in HBase scan.
     boolean checkIsRelatedTo =
-        !isSingleEntityRead() && filters.getIsRelatedTo() != null &&
-        filters.getIsRelatedTo().getFilterList().size() > 0;
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.IS_RELATED_TO) ||
-        checkIsRelatedTo) {
-      TimelineStorageUtils.readRelationship(
-          entity, result, EntityColumnPrefix.IS_RELATED_TO, true);
-      if (checkIsRelatedTo && !TimelineStorageUtils.matchIsRelatedTo(entity,
-          filters.getIsRelatedTo())) {
+        !isSingleEntityRead() && filters.getIsRelatedTo() != null
+            && filters.getIsRelatedTo().getFilterList().size() > 0;
+    if (hasField(fieldsToRetrieve, Field.IS_RELATED_TO) || checkIsRelatedTo) {
+      readRelationship(entity, result, EntityColumnPrefix.IS_RELATED_TO, true);
+      if (checkIsRelatedTo
+          && !TimelineStorageUtils.matchIsRelatedTo(entity,
+              filters.getIsRelatedTo())) {
         return null;
       }
-      if (!TimelineStorageUtils.hasField(fieldsToRetrieve,
-          Field.IS_RELATED_TO)) {
+      if (!hasField(fieldsToRetrieve, Field.IS_RELATED_TO)) {
         entity.getIsRelatedToEntities().clear();
       }
     }
@@ -556,31 +571,29 @@ class GenericEntityReader extends TimelineEntityReader {
     // locally as relevant HBase filters to filter out rows on the basis of
     // relatesTo are not set in HBase scan.
     boolean checkRelatesTo =
-        !isSingleEntityRead() && filters.getRelatesTo() != null &&
-        filters.getRelatesTo().getFilterList().size() > 0;
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO) ||
-        checkRelatesTo) {
-      TimelineStorageUtils.readRelationship(
-          entity, result, EntityColumnPrefix.RELATES_TO, false);
-      if (checkRelatesTo && !TimelineStorageUtils.matchRelatesTo(entity,
-          filters.getRelatesTo())) {
+        !isSingleEntityRead() && filters.getRelatesTo() != null
+            && filters.getRelatesTo().getFilterList().size() > 0;
+    if (hasField(fieldsToRetrieve, Field.RELATES_TO)
+        || checkRelatesTo) {
+      readRelationship(entity, result, EntityColumnPrefix.RELATES_TO, false);
+      if (checkRelatesTo
+          && !TimelineStorageUtils.matchRelatesTo(entity,
+              filters.getRelatesTo())) {
         return null;
       }
-      if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.RELATES_TO)) {
+      if (!hasField(fieldsToRetrieve, Field.RELATES_TO)) {
         entity.getRelatesToEntities().clear();
       }
     }
 
     // fetch info if fieldsToRetrieve contains INFO or ALL.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.INFO)) {
-      TimelineStorageUtils.readKeyValuePairs(
-          entity, result, EntityColumnPrefix.INFO, false);
+    if (hasField(fieldsToRetrieve, Field.INFO)) {
+      readKeyValuePairs(entity, result, EntityColumnPrefix.INFO, false);
     }
 
     // fetch configs if fieldsToRetrieve contains CONFIGS or ALL.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.CONFIGS)) {
-      TimelineStorageUtils.readKeyValuePairs(
-          entity, result, EntityColumnPrefix.CONFIG, true);
+    if (hasField(fieldsToRetrieve, Field.CONFIGS)) {
+      readKeyValuePairs(entity, result, EntityColumnPrefix.CONFIG, true);
     }
 
     // fetch events and match event filters if they exist. If event filters do
@@ -588,24 +601,48 @@ class GenericEntityReader extends TimelineEntityReader {
     // as relevant HBase filters to filter out rows on the basis of events
     // are not set in HBase scan.
     boolean checkEvents =
-        !isSingleEntityRead() && filters.getEventFilters() != null &&
-        filters.getEventFilters().getFilterList().size() > 0;
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS) ||
-        checkEvents) {
-      TimelineStorageUtils.readEvents(entity, result, EntityColumnPrefix.EVENT);
-      if (checkEvents && !TimelineStorageUtils.matchEventFilters(entity,
-          filters.getEventFilters())) {
+        !isSingleEntityRead() && filters.getEventFilters() != null
+            && filters.getEventFilters().getFilterList().size() > 0;
+    if (hasField(fieldsToRetrieve, Field.EVENTS) || checkEvents) {
+      readEvents(entity, result, EntityColumnPrefix.EVENT);
+      if (checkEvents
+          && !TimelineStorageUtils.matchEventFilters(entity,
+              filters.getEventFilters())) {
         return null;
       }
-      if (!TimelineStorageUtils.hasField(fieldsToRetrieve, Field.EVENTS)) {
+      if (!hasField(fieldsToRetrieve, Field.EVENTS)) {
         entity.getEvents().clear();
       }
     }
 
     // fetch metrics if fieldsToRetrieve contains METRICS or ALL.
-    if (TimelineStorageUtils.hasField(fieldsToRetrieve, Field.METRICS)) {
+    if (hasField(fieldsToRetrieve, Field.METRICS)) {
       readMetrics(entity, result, EntityColumnPrefix.METRIC);
     }
     return entity;
   }
+
+  /**
+   * Helper method for reading key-value pairs for either info or config.
+   *
+   * @param <T> Describes the type of column prefix.
+   * @param entity entity to fill.
+   * @param result result from HBase.
+   * @param prefix column prefix.
+   * @param isConfig if true, means we are reading configs, otherwise info.
+   * @throws IOException if any problem is encountered while reading result.
+   */
+  protected <T> void readKeyValuePairs(TimelineEntity entity, Result result,
+      ColumnPrefix<T> prefix, boolean isConfig) throws IOException {
+    // info and configuration are of type Map<String, Object or String>
+    Map<String, Object> columns =
+        prefix.readResults(result, stringKeyConverter);
+    if (isConfig) {
+      for (Map.Entry<String, Object> column : columns.entrySet()) {
+        entity.addConfig(column.getKey(), column.getValue().toString());
+      }
+    } else {
+      entity.addInfo(columns);
+    }
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/reader/TimelineEntityReader.java

@@ -18,6 +18,9 @@
 package org.apache.hadoop.yarn.server.timelineservice.storage.reader;
 
 import java.io.IOException;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.NavigableMap;
 import java.util.NavigableSet;
@@ -30,15 +33,27 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.Result;
 import org.apache.hadoop.hbase.client.ResultScanner;
+import org.apache.hadoop.hbase.filter.BinaryPrefixComparator;
+import org.apache.hadoop.hbase.filter.CompareFilter.CompareOp;
 import org.apache.hadoop.hbase.filter.FilterList;
+import org.apache.hadoop.hbase.filter.FilterList.Operator;
+import org.apache.hadoop.hbase.filter.QualifierFilter;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
+import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEvent;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderContext;
+import org.apache.hadoop.yarn.server.timelineservice.storage.TimelineReader.Field;
+import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationColumnPrefix;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.BaseTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnName;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.EventColumnNameConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
 import org.apache.hadoop.yarn.server.timelineservice.storage.common.StringKeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityColumnPrefix;
 
 /**
  * The base class for reading and deserializing timeline entities from the
@@ -67,6 +82,12 @@ public abstract class TimelineEntityReader {
    */
   private boolean sortedKeys = false;
 
+  /**
+   * Used to convert strings key components to and from storage format.
+   */
+  private final KeyConverter<String> stringKeyConverter =
+      new StringKeyConverter();
+
   /**
    * Instantiates a reader for multiple-entity reads.
    *
@@ -331,7 +352,7 @@ public abstract class TimelineEntityReader {
       ColumnPrefix<?> columnPrefix) throws IOException {
     NavigableMap<String, NavigableMap<Long, Number>> metricsResult =
         columnPrefix.readResultsWithTimestamps(
-            result, StringKeyConverter.getInstance());
+            result, stringKeyConverter);
     for (Map.Entry<String, NavigableMap<Long, Number>> metricResult:
         metricsResult.entrySet()) {
       TimelineMetric metric = new TimelineMetric();
@@ -359,4 +380,117 @@ public abstract class TimelineEntityReader {
   protected void setTable(BaseTable<?> baseTable) {
     this.table = baseTable;
   }
+
+  /**
+   * Check if we have a certain field amongst fields to retrieve. This method
+   * checks against {@link Field#ALL} as well because that would mean field
+   * passed needs to be matched.
+   *
+   * @param fieldsToRetrieve fields to be retrieved.
+   * @param requiredField fields to be checked in fieldsToRetrieve.
+   * @return true if has the required field, false otherwise.
+   */
+  protected boolean hasField(EnumSet<Field> fieldsToRetrieve,
+      Field requiredField) {
+    return fieldsToRetrieve.contains(Field.ALL) ||
+        fieldsToRetrieve.contains(requiredField);
+  }
+
+  /**
+   * Create a filter list of qualifier filters based on passed set of columns.
+   *
+   * @param <T> Describes the type of column prefix.
+   * @param colPrefix Column Prefix.
+   * @param columns set of column qualifiers.
+   * @return filter list.
+   */
+  protected <T> FilterList createFiltersFromColumnQualifiers(
+      ColumnPrefix<T> colPrefix, Set<String> columns) {
+    FilterList list = new FilterList(Operator.MUST_PASS_ONE);
+    for (String column : columns) {
+      // For columns which have compound column qualifiers (eg. events), we need
+      // to include the required separator.
+      byte[] compoundColQual = createColQualifierPrefix(colPrefix, column);
+      list.addFilter(new QualifierFilter(CompareOp.EQUAL,
+          new BinaryPrefixComparator(colPrefix
+              .getColumnPrefixBytes(compoundColQual))));
+    }
+    return list;
+  }
+
+  protected <T> byte[] createColQualifierPrefix(ColumnPrefix<T> colPrefix,
+      String column) {
+    if (colPrefix == ApplicationColumnPrefix.EVENT
+        || colPrefix == EntityColumnPrefix.EVENT) {
+      return new EventColumnName(column, null, null).getColumnQualifier();
+    } else {
+      return stringKeyConverter.encode(column);
+    }
+  }
+
+  /**
+   * Helper method for reading relationship.
+   *
+   * @param <T> Describes the type of column prefix.
+   * @param entity entity to fill.
+   * @param result result from HBase.
+   * @param prefix column prefix.
+   * @param isRelatedTo if true, means relationship is to be added to
+   *          isRelatedTo, otherwise its added to relatesTo.
+   * @throws IOException if any problem is encountered while reading result.
+   */
+  protected <T> void readRelationship(TimelineEntity entity, Result result,
+      ColumnPrefix<T> prefix, boolean isRelatedTo) throws IOException {
+    // isRelatedTo and relatesTo are of type Map<String, Set<String>>
+    Map<String, Object> columns =
+        prefix.readResults(result, stringKeyConverter);
+    for (Map.Entry<String, Object> column : columns.entrySet()) {
+      for (String id : Separator.VALUES.splitEncoded(column.getValue()
+          .toString())) {
+        if (isRelatedTo) {
+          entity.addIsRelatedToEntity(column.getKey(), id);
+        } else {
+          entity.addRelatesToEntity(column.getKey(), id);
+        }
+      }
+    }
+  }
+
+  /**
+   * Read events from the entity table or the application table. The column name
+   * is of the form "eventId=timestamp=infoKey" where "infoKey" may be omitted
+   * if there is no info associated with the event.
+   *
+   * @param <T> Describes the type of column prefix.
+   * @param entity entity to fill.
+   * @param result HBase Result.
+   * @param prefix column prefix.
+   * @throws IOException if any problem is encountered while reading result.
+   */
+  protected static <T> void readEvents(TimelineEntity entity, Result result,
+      ColumnPrefix<T> prefix) throws IOException {
+    Map<String, TimelineEvent> eventsMap = new HashMap<>();
+    Map<EventColumnName, Object> eventsResult =
+        prefix.readResults(result, new EventColumnNameConverter());
+    for (Map.Entry<EventColumnName, Object>
+             eventResult : eventsResult.entrySet()) {
+      EventColumnName eventColumnName = eventResult.getKey();
+      String key = eventColumnName.getId() +
+          Long.toString(eventColumnName.getTimestamp());
+      // Retrieve previously seen event to add to it
+      TimelineEvent event = eventsMap.get(key);
+      if (event == null) {
+        // First time we're seeing this event, add it to the eventsMap
+        event = new TimelineEvent();
+        event.setId(eventColumnName.getId());
+        event.setTimestamp(eventColumnName.getTimestamp());
+        eventsMap.put(key, event);
+      }
+      if (eventColumnName.getInfoKey() != null) {
+        event.addInfo(eventColumnName.getInfoKey(), eventResult.getValue());
+      }
+    }
+    Set<TimelineEvent> eventsSet = new HashSet<>(eventsMap.values());
+    entity.addEvents(eventsSet);
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/test/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TestKeyConverters.java

@@ -24,220 +24,13 @@ import static org.junit.Assert.assertTrue;
 
 import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
-import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationRowKey;
-import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationRowKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowRowKey;
-import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowRowKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKey;
-import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityRowKey;
-import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityRowKeyConverter;
-import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunRowKey;
-import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunRowKeyConverter;
 import org.junit.Test;
 
 public class TestKeyConverters {
-  private final static String QUALIFIER_SEP = Separator.QUALIFIERS.getValue();
-  private final static byte[] QUALIFIER_SEP_BYTES =
-      Bytes.toBytes(QUALIFIER_SEP);
-  private final static String CLUSTER = "cl" + QUALIFIER_SEP + "uster";
-  private final static String USER = QUALIFIER_SEP + "user";
-  private final static String FLOW_NAME =
-      "dummy_" + QUALIFIER_SEP + "flow" + QUALIFIER_SEP;
-  private final static Long FLOW_RUN_ID;
-  private final static String APPLICATION_ID;
-  static {
-    long runid = Long.MAX_VALUE - 900L;
-    byte[] longMaxByteArr = Bytes.toBytes(Long.MAX_VALUE);
-    byte[] byteArr = Bytes.toBytes(runid);
-    int sepByteLen = QUALIFIER_SEP_BYTES.length;
-    if (sepByteLen <= byteArr.length) {
-      for (int i = 0; i < sepByteLen; i++) {
-        byteArr[i] = (byte)(longMaxByteArr[i] - QUALIFIER_SEP_BYTES[i]);
-      }
-    }
-    FLOW_RUN_ID = Bytes.toLong(byteArr);
-    long clusterTs = System.currentTimeMillis();
-    byteArr = Bytes.toBytes(clusterTs);
-    if (sepByteLen <= byteArr.length) {
-      for (int i = 0; i < sepByteLen; i++) {
-        byteArr[byteArr.length - sepByteLen + i] =
-            (byte)(longMaxByteArr[byteArr.length - sepByteLen + i] -
-                QUALIFIER_SEP_BYTES[i]);
-      }
-    }
-    clusterTs = Bytes.toLong(byteArr);
-    int seqId = 222;
-    APPLICATION_ID = ApplicationId.newInstance(clusterTs, seqId).toString();
-  }
-
-  private static void verifyRowPrefixBytes(byte[] byteRowKeyPrefix) {
-    int sepLen = QUALIFIER_SEP_BYTES.length;
-    for (int i = 0; i < sepLen; i++) {
-      assertTrue("Row key prefix not encoded properly.",
-        byteRowKeyPrefix[byteRowKeyPrefix.length - sepLen  + i] ==
-            QUALIFIER_SEP_BYTES[i]);
-    }
-  }
-
-  @Test
-  public void testFlowActivityRowKeyConverter() {
-    Long ts = TimelineStorageUtils.getTopOfTheDayTimestamp(1459900830000L);
-    byte[] byteRowKey = FlowActivityRowKeyConverter.getInstance().encode(
-        new FlowActivityRowKey(CLUSTER, ts, USER, FLOW_NAME));
-    FlowActivityRowKey rowKey =
-        FlowActivityRowKeyConverter.getInstance().decode(byteRowKey);
-    assertEquals(CLUSTER, rowKey.getClusterId());
-    assertEquals(ts, rowKey.getDayTimestamp());
-    assertEquals(USER, rowKey.getUserId());
-    assertEquals(FLOW_NAME, rowKey.getFlowName());
-
-    byte[] byteRowKeyPrefix = FlowActivityRowKeyConverter.getInstance().encode(
-        new FlowActivityRowKey(CLUSTER, null, null, null));
-    byte[][] splits = Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
-        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE });
-    assertEquals(2, splits.length);
-    assertEquals(0, splits[1].length);
-    assertEquals(CLUSTER,
-        Separator.QUALIFIERS.decode(Bytes.toString(splits[0])));
-    verifyRowPrefixBytes(byteRowKeyPrefix);
-
-    byteRowKeyPrefix = FlowActivityRowKeyConverter.getInstance().encode(
-        new FlowActivityRowKey(CLUSTER, ts, null, null));
-    splits = Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
-        Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG, Separator.VARIABLE_SIZE });
-    assertEquals(3, splits.length);
-    assertEquals(0, splits[2].length);
-    assertEquals(CLUSTER,
-        Separator.QUALIFIERS.decode(Bytes.toString(splits[0])));
-    assertEquals(ts, (Long) TimelineStorageUtils.invertLong(
-        Bytes.toLong(splits[1])));
-    verifyRowPrefixBytes(byteRowKeyPrefix);
-  }
-
-  @Test
-  public void testFlowRunRowKeyConverter() {
-    byte[] byteRowKey = FlowRunRowKeyConverter.getInstance().encode(
-        new FlowRunRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID));
-    FlowRunRowKey rowKey =
-        FlowRunRowKeyConverter.getInstance().decode(byteRowKey);
-    assertEquals(CLUSTER, rowKey.getClusterId());
-    assertEquals(USER, rowKey.getUserId());
-    assertEquals(FLOW_NAME, rowKey.getFlowName());
-    assertEquals(FLOW_RUN_ID, rowKey.getFlowRunId());
-
-    byte[] byteRowKeyPrefix = FlowRunRowKeyConverter.getInstance().encode(
-        new FlowRunRowKey(CLUSTER, USER, FLOW_NAME, null));
-    byte[][] splits = Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
-        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE });
-    assertEquals(4, splits.length);
-    assertEquals(0, splits[3].length);
-    assertEquals(FLOW_NAME,
-        Separator.QUALIFIERS.decode(Bytes.toString(splits[2])));
-    verifyRowPrefixBytes(byteRowKeyPrefix);
-  }
-
-  @Test
-  public void testApplicationRowKeyConverter() {
-    byte[] byteRowKey = ApplicationRowKeyConverter.getInstance().encode(
-        new ApplicationRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID,
-            APPLICATION_ID));
-    ApplicationRowKey rowKey =
-        ApplicationRowKeyConverter.getInstance().decode(byteRowKey);
-    assertEquals(CLUSTER, rowKey.getClusterId());
-    assertEquals(USER, rowKey.getUserId());
-    assertEquals(FLOW_NAME, rowKey.getFlowName());
-    assertEquals(FLOW_RUN_ID, rowKey.getFlowRunId());
-    assertEquals(APPLICATION_ID, rowKey.getAppId());
-
-    byte[] byteRowKeyPrefix = ApplicationRowKeyConverter.getInstance().encode(
-        new ApplicationRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID, null));
-    byte[][] splits =
-        Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
-            Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-            Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
-            Separator.VARIABLE_SIZE });
-    assertEquals(5, splits.length);
-    assertEquals(0, splits[4].length);
-    assertEquals(FLOW_NAME,
-        Separator.QUALIFIERS.decode(Bytes.toString(splits[2])));
-    assertEquals(FLOW_RUN_ID, (Long)TimelineStorageUtils.invertLong(
-        Bytes.toLong(splits[3])));
-    verifyRowPrefixBytes(byteRowKeyPrefix);
-
-    byteRowKeyPrefix = ApplicationRowKeyConverter.getInstance().encode(
-        new ApplicationRowKey(CLUSTER, USER, FLOW_NAME, null, null));
-    splits = Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
-        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE });
-    assertEquals(4, splits.length);
-    assertEquals(0, splits[3].length);
-    assertEquals(FLOW_NAME,
-        Separator.QUALIFIERS.decode(Bytes.toString(splits[2])));
-    verifyRowPrefixBytes(byteRowKeyPrefix);
-  }
-
-  @Test
-  public void testEntityRowKeyConverter() {
-    String entityId = "!ent!ity!!id!";
-    String entityType = "entity!Type";
-    byte[] byteRowKey = EntityRowKeyConverter.getInstance().encode(
-        new EntityRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID, APPLICATION_ID,
-            entityType, entityId));
-    EntityRowKey rowKey =
-        EntityRowKeyConverter.getInstance().decode(byteRowKey);
-    assertEquals(CLUSTER, rowKey.getClusterId());
-    assertEquals(USER, rowKey.getUserId());
-    assertEquals(FLOW_NAME, rowKey.getFlowName());
-    assertEquals(FLOW_RUN_ID, rowKey.getFlowRunId());
-    assertEquals(APPLICATION_ID, rowKey.getAppId());
-    assertEquals(entityType, rowKey.getEntityType());
-    assertEquals(entityId, rowKey.getEntityId());
-
-    byte[] byteRowKeyPrefix = EntityRowKeyConverter.getInstance().encode(
-        new EntityRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID, APPLICATION_ID,
-            entityType, null));
-    byte[][] splits =
-        Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
-            Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-            Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
-            AppIdKeyConverter.getKeySize(), Separator.VARIABLE_SIZE,
-            Separator.VARIABLE_SIZE });
-    assertEquals(7, splits.length);
-    assertEquals(0, splits[6].length);
-    assertEquals(APPLICATION_ID,
-        AppIdKeyConverter.getInstance().decode(splits[4]));
-    assertEquals(entityType, Separator.QUALIFIERS.decode(
-        Bytes.toString(splits[5])));
-    verifyRowPrefixBytes(byteRowKeyPrefix);
-
-    byteRowKeyPrefix = EntityRowKeyConverter.getInstance().encode(
-        new EntityRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID, APPLICATION_ID,
-        null, null));
-    splits = Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
-        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
-        Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
-        AppIdKeyConverter.getKeySize(), Separator.VARIABLE_SIZE });
-    assertEquals(6, splits.length);
-    assertEquals(0, splits[5].length);
-    assertEquals(APPLICATION_ID,
-        AppIdKeyConverter.getInstance().decode(splits[4]));
-    verifyRowPrefixBytes(byteRowKeyPrefix);
-  }
-
-  @Test
-  public void testAppToFlowRowKeyConverter() {
-    byte[] byteRowKey = AppToFlowRowKeyConverter.getInstance().encode(
-        new AppToFlowRowKey(CLUSTER, APPLICATION_ID));
-    AppToFlowRowKey rowKey =
-        AppToFlowRowKeyConverter.getInstance().decode(byteRowKey);
-    assertEquals(CLUSTER, rowKey.getClusterId());
-    assertEquals(APPLICATION_ID, rowKey.getAppId());
-  }
 
   @Test
   public void testAppIdKeyConverter() {
+    AppIdKeyConverter appIdKeyConverter = new AppIdKeyConverter();
     long currentTs = System.currentTimeMillis();
     ApplicationId appId1 = ApplicationId.newInstance(currentTs, 1);
     ApplicationId appId2 = ApplicationId.newInstance(currentTs, 2);
@@ -245,18 +38,19 @@ public class TestKeyConverters {
     String appIdStr1 = appId1.toString();
     String appIdStr2 = appId2.toString();
     String appIdStr3 = appId3.toString();
-    byte[] appIdBytes1 = AppIdKeyConverter.getInstance().encode(appIdStr1);
-    byte[] appIdBytes2 = AppIdKeyConverter.getInstance().encode(appIdStr2);
-    byte[] appIdBytes3 = AppIdKeyConverter.getInstance().encode(appIdStr3);
+    byte[] appIdBytes1 = appIdKeyConverter.encode(appIdStr1);
+    byte[] appIdBytes2 = appIdKeyConverter.encode(appIdStr2);
+    byte[] appIdBytes3 = appIdKeyConverter.encode(appIdStr3);
     // App ids' should be encoded in a manner wherein descending order
     // is maintained.
-    assertTrue("Ordering of app ids' is incorrect",
-        Bytes.compareTo(appIdBytes1, appIdBytes2) > 0 &&
-        Bytes.compareTo(appIdBytes1, appIdBytes3) > 0 &&
-        Bytes.compareTo(appIdBytes2, appIdBytes3) > 0);
-    String decodedAppId1 = AppIdKeyConverter.getInstance().decode(appIdBytes1);
-    String decodedAppId2 = AppIdKeyConverter.getInstance().decode(appIdBytes2);
-    String decodedAppId3 = AppIdKeyConverter.getInstance().decode(appIdBytes3);
+    assertTrue(
+        "Ordering of app ids' is incorrect",
+        Bytes.compareTo(appIdBytes1, appIdBytes2) > 0
+            && Bytes.compareTo(appIdBytes1, appIdBytes3) > 0
+            && Bytes.compareTo(appIdBytes2, appIdBytes3) > 0);
+    String decodedAppId1 = appIdKeyConverter.decode(appIdBytes1);
+    String decodedAppId2 = appIdKeyConverter.decode(appIdBytes2);
+    String decodedAppId3 = appIdKeyConverter.decode(appIdBytes3);
     assertTrue("Decoded app id is not same as the app id encoded",
         appIdStr1.equals(decodedAppId1));
     assertTrue("Decoded app id is not same as the app id encoded",
@@ -273,21 +67,64 @@ public class TestKeyConverters {
         Bytes.createMaxByteArray(Bytes.SIZEOF_LONG - valSepBytes.length);
     byte[] ts = Bytes.add(valSepBytes, maxByteArr);
     Long eventTs = Bytes.toLong(ts);
-    byte[] byteEventColName = EventColumnNameConverter.getInstance().encode(
-        new EventColumnName(eventId, eventTs, null));
+    byte[] byteEventColName =
+        new EventColumnName(eventId, eventTs, null).getColumnQualifier();
+    KeyConverter<EventColumnName> eventColumnNameConverter =
+        new EventColumnNameConverter();
     EventColumnName eventColName =
-        EventColumnNameConverter.getInstance().decode(byteEventColName);
+        eventColumnNameConverter.decode(byteEventColName);
     assertEquals(eventId, eventColName.getId());
     assertEquals(eventTs, eventColName.getTimestamp());
     assertNull(eventColName.getInfoKey());
 
     String infoKey = "f=oo_event_in=fo=_key";
-    byteEventColName = EventColumnNameConverter.getInstance().encode(
-        new EventColumnName(eventId, eventTs, infoKey));
-    eventColName =
-        EventColumnNameConverter.getInstance().decode(byteEventColName);
+    byteEventColName =
+        new EventColumnName(eventId, eventTs, infoKey).getColumnQualifier();
+    eventColName = eventColumnNameConverter.decode(byteEventColName);
     assertEquals(eventId, eventColName.getId());
     assertEquals(eventTs, eventColName.getTimestamp());
     assertEquals(infoKey, eventColName.getInfoKey());
   }
+
+  @Test
+  public void testLongKeyConverter() {
+    LongKeyConverter longKeyConverter = new LongKeyConverter();
+    confirmLongKeyConverter(longKeyConverter, Long.MIN_VALUE);
+    confirmLongKeyConverter(longKeyConverter, -1234567890L);
+    confirmLongKeyConverter(longKeyConverter, -128L);
+    confirmLongKeyConverter(longKeyConverter, -127L);
+    confirmLongKeyConverter(longKeyConverter, -1L);
+    confirmLongKeyConverter(longKeyConverter, 0L);
+    confirmLongKeyConverter(longKeyConverter, 1L);
+    confirmLongKeyConverter(longKeyConverter, 127L);
+    confirmLongKeyConverter(longKeyConverter, 128L);
+    confirmLongKeyConverter(longKeyConverter, 1234567890L);
+    confirmLongKeyConverter(longKeyConverter, Long.MAX_VALUE);
+  }
+
+  private void confirmLongKeyConverter(LongKeyConverter longKeyConverter,
+      Long testValue) {
+    Long decoded = longKeyConverter.decode(longKeyConverter.encode(testValue));
+    assertEquals(testValue, decoded);
+  }
+
+  @Test
+  public void testStringKeyConverter() {
+    StringKeyConverter stringKeyConverter = new StringKeyConverter();
+    String phrase = "QuackAttack now!";
+
+    for (int i = 0; i < phrase.length(); i++) {
+      String sub = phrase.substring(i, phrase.length());
+      confirmStrignKeyConverter(stringKeyConverter, sub);
+      confirmStrignKeyConverter(stringKeyConverter, sub + sub);
+    }
+  }
+
+  private void confirmStrignKeyConverter(StringKeyConverter stringKeyConverter,
+      String testValue) {
+    String decoded =
+        stringKeyConverter.decode(stringKeyConverter.encode(testValue));
+    assertEquals(testValue, decoded);
+  }
+
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/test/java/org/apache/hadoop/yarn/server/timelineservice/storage/common/TestRowKeys.java

@@ -0,0 +1,244 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.server.timelineservice.storage.common;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.api.records.ApplicationId;
+import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.application.ApplicationRowKeyPrefix;
+import org.apache.hadoop.yarn.server.timelineservice.storage.apptoflow.AppToFlowRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKeyPrefix;
+import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityRowKeyPrefix;
+import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunRowKey;
+import org.junit.Test;
+
+
+public class TestRowKeys {
+
+  private final static String QUALIFIER_SEP = Separator.QUALIFIERS.getValue();
+  private final static byte[] QUALIFIER_SEP_BYTES = Bytes
+      .toBytes(QUALIFIER_SEP);
+  private final static String CLUSTER = "cl" + QUALIFIER_SEP + "uster";
+  private final static String USER = QUALIFIER_SEP + "user";
+  private final static String FLOW_NAME = "dummy_" + QUALIFIER_SEP + "flow"
+      + QUALIFIER_SEP;
+  private final static Long FLOW_RUN_ID;
+  private final static String APPLICATION_ID;
+  static {
+    long runid = Long.MAX_VALUE - 900L;
+    byte[] longMaxByteArr = Bytes.toBytes(Long.MAX_VALUE);
+    byte[] byteArr = Bytes.toBytes(runid);
+    int sepByteLen = QUALIFIER_SEP_BYTES.length;
+    if (sepByteLen <= byteArr.length) {
+      for (int i = 0; i < sepByteLen; i++) {
+        byteArr[i] = (byte) (longMaxByteArr[i] - QUALIFIER_SEP_BYTES[i]);
+      }
+    }
+    FLOW_RUN_ID = Bytes.toLong(byteArr);
+    long clusterTs = System.currentTimeMillis();
+    byteArr = Bytes.toBytes(clusterTs);
+    if (sepByteLen <= byteArr.length) {
+      for (int i = 0; i < sepByteLen; i++) {
+        byteArr[byteArr.length - sepByteLen + i] =
+            (byte) (longMaxByteArr[byteArr.length - sepByteLen + i] - QUALIFIER_SEP_BYTES[i]);
+      }
+    }
+    clusterTs = Bytes.toLong(byteArr);
+    int seqId = 222;
+    APPLICATION_ID = ApplicationId.newInstance(clusterTs, seqId).toString();
+  }
+
+  private static void verifyRowPrefixBytes(byte[] byteRowKeyPrefix) {
+    int sepLen = QUALIFIER_SEP_BYTES.length;
+    for (int i = 0; i < sepLen; i++) {
+      assertTrue(
+          "Row key prefix not encoded properly.",
+          byteRowKeyPrefix[byteRowKeyPrefix.length - sepLen + i] == QUALIFIER_SEP_BYTES[i]);
+    }
+  }
+
+  @Test
+  public void testApplicationRowKey() {
+    byte[] byteRowKey =
+        new ApplicationRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID,
+            APPLICATION_ID).getRowKey();
+    ApplicationRowKey rowKey = ApplicationRowKey.parseRowKey(byteRowKey);
+    assertEquals(CLUSTER, rowKey.getClusterId());
+    assertEquals(USER, rowKey.getUserId());
+    assertEquals(FLOW_NAME, rowKey.getFlowName());
+    assertEquals(FLOW_RUN_ID, rowKey.getFlowRunId());
+    assertEquals(APPLICATION_ID, rowKey.getAppId());
+
+    byte[] byteRowKeyPrefix =
+        new ApplicationRowKeyPrefix(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID)
+            .getRowKeyPrefix();
+    byte[][] splits =
+        Separator.QUALIFIERS.split(byteRowKeyPrefix,
+            new int[] { Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
+                Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
+                Separator.VARIABLE_SIZE });
+    assertEquals(5, splits.length);
+    assertEquals(0, splits[4].length);
+    assertEquals(FLOW_NAME,
+        Separator.QUALIFIERS.decode(Bytes.toString(splits[2])));
+    assertEquals(FLOW_RUN_ID,
+        (Long) LongConverter.invertLong(Bytes.toLong(splits[3])));
+    verifyRowPrefixBytes(byteRowKeyPrefix);
+
+    byteRowKeyPrefix =
+        new ApplicationRowKeyPrefix(CLUSTER, USER, FLOW_NAME).getRowKeyPrefix();
+    splits =
+        Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
+            Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
+            Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE });
+    assertEquals(4, splits.length);
+    assertEquals(0, splits[3].length);
+    assertEquals(FLOW_NAME,
+        Separator.QUALIFIERS.decode(Bytes.toString(splits[2])));
+    verifyRowPrefixBytes(byteRowKeyPrefix);
+  }
+
+  /**
+   * Tests the converters indirectly through the public methods of the
+   * corresponding rowkey.
+   */
+  @Test
+  public void testAppToFlowRowKey() {
+    byte[] byteRowKey = new AppToFlowRowKey(CLUSTER,
+        APPLICATION_ID).getRowKey();
+    AppToFlowRowKey rowKey = AppToFlowRowKey.parseRowKey(byteRowKey);
+    assertEquals(CLUSTER, rowKey.getClusterId());
+    assertEquals(APPLICATION_ID, rowKey.getAppId());
+  }
+
+  @Test
+  public void testEntityRowKey() {
+    String entityId = "!ent!ity!!id!";
+    String entityType = "entity!Type";
+    byte[] byteRowKey =
+        new EntityRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID, APPLICATION_ID,
+            entityType, entityId).getRowKey();
+    EntityRowKey rowKey = EntityRowKey.parseRowKey(byteRowKey);
+    assertEquals(CLUSTER, rowKey.getClusterId());
+    assertEquals(USER, rowKey.getUserId());
+    assertEquals(FLOW_NAME, rowKey.getFlowName());
+    assertEquals(FLOW_RUN_ID, rowKey.getFlowRunId());
+    assertEquals(APPLICATION_ID, rowKey.getAppId());
+    assertEquals(entityType, rowKey.getEntityType());
+    assertEquals(entityId, rowKey.getEntityId());
+
+    byte[] byteRowKeyPrefix =
+        new EntityRowKeyPrefix(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID,
+            APPLICATION_ID, entityType).getRowKeyPrefix();
+    byte[][] splits =
+        Separator.QUALIFIERS.split(
+            byteRowKeyPrefix,
+            new int[] { Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
+                Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
+                AppIdKeyConverter.getKeySize(), Separator.VARIABLE_SIZE,
+                Separator.VARIABLE_SIZE });
+    assertEquals(7, splits.length);
+    assertEquals(0, splits[6].length);
+    assertEquals(APPLICATION_ID, new AppIdKeyConverter().decode(splits[4]));
+    assertEquals(entityType,
+        Separator.QUALIFIERS.decode(Bytes.toString(splits[5])));
+    verifyRowPrefixBytes(byteRowKeyPrefix);
+
+    byteRowKeyPrefix =
+        new EntityRowKeyPrefix(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID,
+            APPLICATION_ID).getRowKeyPrefix();
+    splits =
+        Separator.QUALIFIERS.split(
+            byteRowKeyPrefix,
+            new int[] { Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
+                Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
+                AppIdKeyConverter.getKeySize(), Separator.VARIABLE_SIZE });
+    assertEquals(6, splits.length);
+    assertEquals(0, splits[5].length);
+    AppIdKeyConverter appIdKeyConverter = new AppIdKeyConverter();
+    assertEquals(APPLICATION_ID, appIdKeyConverter.decode(splits[4]));
+    verifyRowPrefixBytes(byteRowKeyPrefix);
+  }
+
+  @Test
+  public void testFlowActivityRowKey() {
+    Long ts = 1459900830000L;
+    Long dayTimestamp = TimelineStorageUtils.getTopOfTheDayTimestamp(ts);
+    byte[] byteRowKey =
+        new FlowActivityRowKey(CLUSTER, ts, USER, FLOW_NAME).getRowKey();
+    FlowActivityRowKey rowKey = FlowActivityRowKey.parseRowKey(byteRowKey);
+    assertEquals(CLUSTER, rowKey.getClusterId());
+    assertEquals(dayTimestamp, rowKey.getDayTimestamp());
+    assertEquals(USER, rowKey.getUserId());
+    assertEquals(FLOW_NAME, rowKey.getFlowName());
+
+    byte[] byteRowKeyPrefix =
+        new FlowActivityRowKeyPrefix(CLUSTER).getRowKeyPrefix();
+    byte[][] splits =
+        Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
+            Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE });
+    assertEquals(2, splits.length);
+    assertEquals(0, splits[1].length);
+    assertEquals(CLUSTER,
+        Separator.QUALIFIERS.decode(Bytes.toString(splits[0])));
+    verifyRowPrefixBytes(byteRowKeyPrefix);
+
+    byteRowKeyPrefix =
+        new FlowActivityRowKeyPrefix(CLUSTER, ts).getRowKeyPrefix();
+    splits =
+        Separator.QUALIFIERS.split(byteRowKeyPrefix,
+            new int[] { Separator.VARIABLE_SIZE, Bytes.SIZEOF_LONG,
+                Separator.VARIABLE_SIZE });
+    assertEquals(3, splits.length);
+    assertEquals(0, splits[2].length);
+    assertEquals(CLUSTER,
+        Separator.QUALIFIERS.decode(Bytes.toString(splits[0])));
+    assertEquals(ts,
+        (Long) LongConverter.invertLong(Bytes.toLong(splits[1])));
+    verifyRowPrefixBytes(byteRowKeyPrefix);
+  }
+
+  @Test
+  public void testFlowRunRowKey() {
+    byte[] byteRowKey =
+        new FlowRunRowKey(CLUSTER, USER, FLOW_NAME, FLOW_RUN_ID).getRowKey();
+    FlowRunRowKey rowKey = FlowRunRowKey.parseRowKey(byteRowKey);
+    assertEquals(CLUSTER, rowKey.getClusterId());
+    assertEquals(USER, rowKey.getUserId());
+    assertEquals(FLOW_NAME, rowKey.getFlowName());
+    assertEquals(FLOW_RUN_ID, rowKey.getFlowRunId());
+
+    byte[] byteRowKeyPrefix =
+        new FlowRunRowKey(CLUSTER, USER, FLOW_NAME, null).getRowKey();
+    byte[][] splits =
+        Separator.QUALIFIERS.split(byteRowKeyPrefix, new int[] {
+            Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE,
+            Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE });
+    assertEquals(4, splits.length);
+    assertEquals(0, splits[3].length);
+    assertEquals(FLOW_NAME,
+        Separator.QUALIFIERS.decode(Bytes.toString(splits[2])));
+    verifyRowPrefixBytes(byteRowKeyPrefix);
+  }
+
+}