YARN-6733. Add table for storing sub-application entities. Contributed by Vrushali C.

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

@@ -43,6 +43,7 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.common.HBaseTimelin
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityTable;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunTable;
+import org.apache.hadoop.yarn.server.timelineservice.storage.subapplication.SubApplicationTable;
 
 import com.google.common.annotations.VisibleForTesting;
 import org.slf4j.Logger;
@@ -63,7 +64,9 @@ public final class TimelineSchemaCreator {
       LoggerFactory.getLogger(TimelineSchemaCreator.class);
   private static final String SKIP_EXISTING_TABLE_OPTION_SHORT = "s";
   private static final String APP_METRICS_TTL_OPTION_SHORT = "ma";
+  private static final String SUB_APP_METRICS_TTL_OPTION_SHORT = "msa";
   private static final String APP_TABLE_NAME_SHORT = "a";
+  private static final String SUB_APP_TABLE_NAME_SHORT = "sa";
   private static final String APP_TO_FLOW_TABLE_NAME_SHORT = "a2f";
   private static final String ENTITY_METRICS_TTL_OPTION_SHORT = "me";
   private static final String ENTITY_TABLE_NAME_SHORT = "e";
@@ -121,6 +124,21 @@ public final class TimelineSchemaCreator {
         new ApplicationTable().setMetricsTTL(appMetricsTTL, hbaseConf);
       }
 
+      // Grab the subApplicationTableName argument
+      String subApplicationTableName = commandLine.getOptionValue(
+          SUB_APP_TABLE_NAME_SHORT);
+      if (StringUtils.isNotBlank(subApplicationTableName)) {
+        hbaseConf.set(SubApplicationTable.TABLE_NAME_CONF_NAME,
+            subApplicationTableName);
+      }
+      // Grab the subApplication metrics TTL
+      String subApplicationTableMetricsTTL = commandLine
+          .getOptionValue(SUB_APP_METRICS_TTL_OPTION_SHORT);
+      if (StringUtils.isNotBlank(subApplicationTableMetricsTTL)) {
+        int subAppMetricsTTL = Integer.parseInt(subApplicationTableMetricsTTL);
+        new SubApplicationTable().setMetricsTTL(subAppMetricsTTL, hbaseConf);
+      }
+
       // create all table schemas in hbase
       final boolean skipExisting = commandLine.hasOption(
           SKIP_EXISTING_TABLE_OPTION_SHORT);
@@ -182,6 +200,18 @@ public final class TimelineSchemaCreator {
     o.setRequired(false);
     options.addOption(o);
 
+    o = new Option(SUB_APP_TABLE_NAME_SHORT, "subApplicationTableName", true,
+        "subApplication table name");
+    o.setArgName("subApplicationTableName");
+    o.setRequired(false);
+    options.addOption(o);
+
+    o = new Option(SUB_APP_METRICS_TTL_OPTION_SHORT, "subApplicationMetricsTTL",
+        true, "TTL for metrics column family");
+    o.setArgName("subApplicationMetricsTTL");
+    o.setRequired(false);
+    options.addOption(o);
+
     // Options without an argument
     // No need to set arg name since we do not need an argument here
     o = new Option(SKIP_EXISTING_TABLE_OPTION_SHORT, "skipExistingTable",
@@ -220,6 +250,11 @@ public final class TimelineSchemaCreator {
         " The name of the Application table\n");
     usage.append("[-applicationMetricsTTL <Application Table Metrics TTL>]" +
         " TTL for metrics in the Application table\n");
+    usage.append("[-subApplicationTableName <SubApplication Table Name>]" +
+        " The name of the SubApplication table\n");
+    usage.append("[-subApplicationMetricsTTL " +
+        " <SubApplication Table Metrics TTL>]" +
+        " TTL for metrics in the SubApplication table\n");
     usage.append("[-skipExistingTable] Whether to skip existing" +
         " hbase tables\n");
     System.out.println(usage.toString());
@@ -312,6 +347,15 @@ public final class TimelineSchemaCreator {
           throw e;
         }
       }
+      try {
+        new SubApplicationTable().createTable(admin, hbaseConf);
+      } catch (IOException e) {
+        if (skipExisting) {
+          LOG.warn("Skip and continue on: " + e.getMessage());
+        } else {
+          throw e;
+        }
+      }
     } finally {
       if (conn != null) {
         conn.close();

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

@@ -70,7 +70,7 @@ import org.slf4j.LoggerFactory;
 public class ApplicationTable extends BaseTable<ApplicationTable> {
   /** application prefix. */
   private static final String PREFIX =
-      YarnConfiguration.TIMELINE_SERVICE_PREFIX + ".application";
+      YarnConfiguration.TIMELINE_SERVICE_PREFIX + "application";
 
   /** config param name that specifies the application table name. */
   public static final String TABLE_NAME_CONF_NAME = PREFIX + ".table.name";

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

@@ -209,18 +209,18 @@ public class EntityRowKey {
             Separator.EMPTY_BYTES);
       }
 
-      byte[] enitityIdPrefix = Bytes.toBytes(rowKey.getEntityIdPrefix());
+      byte[] entityIdPrefix = Bytes.toBytes(rowKey.getEntityIdPrefix());
 
       if (rowKey.getEntityId() == null) {
         return Separator.QUALIFIERS.join(first, second, third, entityType,
-            enitityIdPrefix, Separator.EMPTY_BYTES);
+            entityIdPrefix, Separator.EMPTY_BYTES);
       }
 
       byte[] entityId = Separator.encode(rowKey.getEntityId(), Separator.SPACE,
           Separator.TAB, Separator.QUALIFIERS);
 
       byte[] fourth =
-          Separator.QUALIFIERS.join(entityType, enitityIdPrefix, entityId);
+          Separator.QUALIFIERS.join(entityType, entityIdPrefix, entityId);
 
       return Separator.QUALIFIERS.join(first, second, third, fourth);
     }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/subapplication/SubApplicationColumn.java

@@ -0,0 +1,108 @@
+/**
+ * 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.subapplication;
+
+import java.io.IOException;
+
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.util.Bytes;
+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.TypedBufferedMutator;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.ValueConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.flow.Attribute;
+
+/**
+ * Identifies fully qualified columns for the {@link SubApplicationTable}.
+ */
+public enum SubApplicationColumn implements Column<SubApplicationTable> {
+
+  /**
+   * Identifier for the sub application.
+   */
+  ID(SubApplicationColumnFamily.INFO, "id"),
+
+  /**
+   * The type of sub application.
+   */
+  TYPE(SubApplicationColumnFamily.INFO, "type"),
+
+  /**
+   * When the sub application was created.
+   */
+  CREATED_TIME(SubApplicationColumnFamily.INFO, "created_time",
+      new LongConverter()),
+
+  /**
+   * The version of the flow that this sub application belongs to.
+   */
+  FLOW_VERSION(SubApplicationColumnFamily.INFO, "flow_version");
+
+  private final ColumnHelper<SubApplicationTable> column;
+  private final ColumnFamily<SubApplicationTable> columnFamily;
+  private final String columnQualifier;
+  private final byte[] columnQualifierBytes;
+
+  SubApplicationColumn(ColumnFamily<SubApplicationTable> columnFamily,
+      String columnQualifier) {
+    this(columnFamily, columnQualifier, GenericConverter.getInstance());
+  }
+
+  SubApplicationColumn(ColumnFamily<SubApplicationTable> columnFamily,
+      String columnQualifier, ValueConverter converter) {
+    this.columnFamily = columnFamily;
+    this.columnQualifier = columnQualifier;
+    // Future-proof by ensuring the right column prefix hygiene.
+    this.columnQualifierBytes =
+        Bytes.toBytes(Separator.SPACE.encode(columnQualifier));
+    this.column = new ColumnHelper<SubApplicationTable>(columnFamily,
+        converter);
+  }
+
+
+  public void store(byte[] rowKey,
+      TypedBufferedMutator<SubApplicationTable> tableMutator, Long timestamp,
+      Object inputValue, Attribute... attributes) throws IOException {
+    column.store(rowKey, tableMutator, columnQualifierBytes, timestamp,
+        inputValue, attributes);
+  }
+
+  public Object readResult(Result result) throws IOException {
+    return column.readResult(result, columnQualifierBytes);
+  }
+
+  @Override
+  public byte[] getColumnQualifierBytes() {
+    return columnQualifierBytes.clone();
+  }
+
+  @Override
+  public byte[] getColumnFamilyBytes() {
+    return columnFamily.getBytes();
+  }
+
+  @Override
+  public ValueConverter getValueConverter() {
+    return column.getValueConverter();
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/subapplication/SubApplicationColumnFamily.java

@@ -0,0 +1,68 @@
+/**
+ * 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.subapplication;
+
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnFamily;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
+
+/**
+ * Represents the sub application table column families.
+ */
+public enum SubApplicationColumnFamily
+    implements ColumnFamily<SubApplicationTable> {
+
+  /**
+   * Info column family houses known columns, specifically ones included in
+   * columnfamily filters.
+   */
+  INFO("i"),
+
+  /**
+   * Configurations are in a separate column family for two reasons:
+   * a) the size of the config values can be very large and
+   * b) we expect that config values
+   * are often separately accessed from other metrics and info columns.
+   */
+  CONFIGS("c"),
+
+  /**
+   * Metrics have a separate column family, because they have a separate TTL.
+   */
+  METRICS("m");
+
+  /**
+   * Byte representation of this column family.
+   */
+  private final byte[] bytes;
+
+  /**
+   * @param value
+   *          create a column family with this name. Must be lower case and
+   *          without spaces.
+   */
+  SubApplicationColumnFamily(String value) {
+    // column families should be lower case and not contain any spaces.
+    this.bytes = Bytes.toBytes(Separator.SPACE.encode(value));
+  }
+
+  public byte[] getBytes() {
+    return Bytes.copy(bytes);
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/subapplication/SubApplicationColumnPrefix.java

@@ -0,0 +1,250 @@
+/**
+ * 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.subapplication;
+
+import java.io.IOException;
+import java.util.Map;
+import java.util.NavigableMap;
+
+import org.apache.hadoop.hbase.client.Result;
+import org.apache.hadoop.hbase.util.Bytes;
+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.ColumnPrefix;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.GenericConverter;
+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.TypedBufferedMutator;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.ValueConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.flow.Attribute;
+
+/**
+ * Identifies partially qualified columns for the sub app table.
+ */
+public enum SubApplicationColumnPrefix
+    implements ColumnPrefix<SubApplicationTable> {
+
+  /**
+   * To store TimelineEntity getIsRelatedToEntities values.
+   */
+  IS_RELATED_TO(SubApplicationColumnFamily.INFO, "s"),
+
+  /**
+   * To store TimelineEntity getRelatesToEntities values.
+   */
+  RELATES_TO(SubApplicationColumnFamily.INFO, "r"),
+
+  /**
+   * To store TimelineEntity info values.
+   */
+  INFO(SubApplicationColumnFamily.INFO, "i"),
+
+  /**
+   * Lifecycle events for an entity.
+   */
+  EVENT(SubApplicationColumnFamily.INFO, "e", true),
+
+  /**
+   * Config column stores configuration with config key as the column name.
+   */
+  CONFIG(SubApplicationColumnFamily.CONFIGS, null),
+
+  /**
+   * Metrics are stored with the metric name as the column name.
+   */
+  METRIC(SubApplicationColumnFamily.METRICS, null, new LongConverter());
+
+  private final ColumnHelper<SubApplicationTable> column;
+  private final ColumnFamily<SubApplicationTable> columnFamily;
+
+  /**
+   * Can be null for those cases where the provided column qualifier is the
+   * entire column name.
+   */
+  private final String columnPrefix;
+  private final byte[] columnPrefixBytes;
+
+  /**
+   * Private constructor, meant to be used by the enum definition.
+   *
+   * @param columnFamily that this column is stored in.
+   * @param columnPrefix for this column.
+   */
+  SubApplicationColumnPrefix(ColumnFamily<SubApplicationTable> columnFamily,
+      String columnPrefix) {
+    this(columnFamily, columnPrefix, false, GenericConverter.getInstance());
+  }
+
+  SubApplicationColumnPrefix(ColumnFamily<SubApplicationTable> columnFamily,
+      String columnPrefix, boolean compondColQual) {
+    this(columnFamily, columnPrefix, compondColQual,
+        GenericConverter.getInstance());
+  }
+
+  SubApplicationColumnPrefix(ColumnFamily<SubApplicationTable> columnFamily,
+      String columnPrefix, ValueConverter converter) {
+    this(columnFamily, columnPrefix, false, converter);
+  }
+
+  /**
+   * Private constructor, meant to be used by the enum definition.
+   *
+   * @param columnFamily that this column is stored in.
+   * @param columnPrefix for this column.
+   * @param converter used to encode/decode values to be stored in HBase for
+   * this column prefix.
+   */
+  SubApplicationColumnPrefix(ColumnFamily<SubApplicationTable> columnFamily,
+      String columnPrefix, boolean compondColQual, ValueConverter converter) {
+    column = new ColumnHelper<SubApplicationTable>(columnFamily, converter);
+    this.columnFamily = columnFamily;
+    this.columnPrefix = columnPrefix;
+    if (columnPrefix == null) {
+      this.columnPrefixBytes = null;
+    } else {
+      // Future-proof by ensuring the right column prefix hygiene.
+      this.columnPrefixBytes =
+          Bytes.toBytes(Separator.SPACE.encode(columnPrefix));
+    }
+  }
+
+  /**
+   * @return the column name value
+   */
+  public String getColumnPrefix() {
+    return columnPrefix;
+  }
+
+  @Override
+  public byte[] getColumnPrefixBytes(byte[] qualifierPrefix) {
+    return ColumnHelper.getColumnQualifier(
+        this.columnPrefixBytes, qualifierPrefix);
+  }
+
+  @Override
+  public byte[] getColumnPrefixBytes(String qualifierPrefix) {
+    return ColumnHelper.getColumnQualifier(
+        this.columnPrefixBytes, qualifierPrefix);
+  }
+
+  @Override
+  public byte[] getColumnFamilyBytes() {
+    return columnFamily.getBytes();
+  }
+
+  @Override
+  public ValueConverter getValueConverter() {
+    return column.getValueConverter();
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix
+   * #store(byte[],
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.
+   * TypedBufferedMutator, java.lang.String, java.lang.Long, java.lang.Object,
+   * org.apache.hadoop.yarn.server.timelineservice.storage.flow.Attribute[])
+   */
+  public void store(byte[] rowKey,
+      TypedBufferedMutator<SubApplicationTable> tableMutator, String qualifier,
+      Long timestamp, Object inputValue, Attribute... attributes)
+      throws IOException {
+
+    // Null check
+    if (qualifier == null) {
+      throw new IOException("Cannot store column with null qualifier in "
+          + tableMutator.getName().getNameAsString());
+    }
+
+    byte[] columnQualifier = getColumnPrefixBytes(qualifier);
+
+    column.store(rowKey, tableMutator, columnQualifier, timestamp, inputValue,
+        attributes);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix
+   * #store(byte[],
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.
+   * TypedBufferedMutator, java.lang.String, java.lang.Long, java.lang.Object)
+   */
+  public void store(byte[] rowKey,
+      TypedBufferedMutator<SubApplicationTable> tableMutator, byte[] qualifier,
+      Long timestamp, Object inputValue, Attribute... attributes)
+      throws IOException {
+
+    // Null check
+    if (qualifier == null) {
+      throw new IOException("Cannot store column with null qualifier in "
+          + tableMutator.getName().getNameAsString());
+    }
+
+    byte[] columnQualifier = getColumnPrefixBytes(qualifier);
+
+    column.store(rowKey, tableMutator, columnQualifier, timestamp, inputValue,
+        attributes);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix
+   * #readResult(org.apache.hadoop.hbase.client.Result, java.lang.String)
+   */
+  public Object readResult(Result result, String qualifier) throws IOException {
+    byte[] columnQualifier =
+        ColumnHelper.getColumnQualifier(this.columnPrefixBytes, qualifier);
+    return column.readResult(result, columnQualifier);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix
+   * #readResults(org.apache.hadoop.hbase.client.Result,
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter)
+   */
+  public <K> Map<K, Object> readResults(Result result,
+      KeyConverter<K> keyConverter) throws IOException {
+    return column.readResults(result, columnPrefixBytes, keyConverter);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.ColumnPrefix
+   * #readResultsWithTimestamps(org.apache.hadoop.hbase.client.Result,
+   * org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter)
+   */
+  public <K, V> NavigableMap<K, NavigableMap<Long, V>>
+      readResultsWithTimestamps(Result result, KeyConverter<K> keyConverter)
+      throws IOException {
+    return column.readResultsWithTimestamps(result, columnPrefixBytes,
+        keyConverter);
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/subapplication/SubApplicationRowKey.java

@@ -0,0 +1,290 @@
+/**
+ * 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.subapplication;
+
+import java.util.List;
+
+import org.apache.hadoop.hbase.util.Bytes;
+import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineReaderUtils;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverter;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.KeyConverterToString;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.Separator;
+
+/**
+ * Represents a rowkey for the sub app table.
+ */
+public class SubApplicationRowKey {
+  private final String subAppUserId;
+  private final String clusterId;
+  private final String entityType;
+  private final Long entityIdPrefix;
+  private final String entityId;
+  private final String userId;
+  private final SubApplicationRowKeyConverter subAppRowKeyConverter =
+      new SubApplicationRowKeyConverter();
+
+  public SubApplicationRowKey(String subAppUserId, String clusterId,
+      String entityType, Long entityIdPrefix, String entityId, String userId) {
+    this.subAppUserId = subAppUserId;
+    this.clusterId = clusterId;
+    this.entityType = entityType;
+    this.entityIdPrefix = entityIdPrefix;
+    this.entityId = entityId;
+    this.userId = userId;
+  }
+
+  public String getClusterId() {
+    return clusterId;
+  }
+
+  public String getSubAppUserId() {
+    return subAppUserId;
+  }
+
+  public String getEntityType() {
+    return entityType;
+  }
+
+  public String getEntityId() {
+    return entityId;
+  }
+
+  public Long getEntityIdPrefix() {
+    return entityIdPrefix;
+  }
+
+  public String getUserId() {
+    return userId;
+  }
+
+  /**
+   * Constructs a row key for the sub app table as follows:
+   * {@code subAppUserId!clusterId!entityType
+   * !entityPrefix!entityId!userId}.
+   * Typically used while querying a specific sub app.
+   *
+   * subAppUserId is usually the doAsUser.
+   * userId is the yarn user that the AM runs as.
+   *
+   * @return byte array with the row key.
+   */
+  public byte[] getRowKey() {
+    return subAppRowKeyConverter.encode(this);
+  }
+
+  /**
+   * Given the raw row key as bytes, returns the row key as an object.
+   *
+   * @param rowKey byte representation of row key.
+   * @return An <cite>SubApplicationRowKey</cite> object.
+   */
+  public static SubApplicationRowKey parseRowKey(byte[] rowKey) {
+    return new SubApplicationRowKeyConverter().decode(rowKey);
+  }
+
+  /**
+   * Constructs a row key for the sub app table as follows:
+   * <p>
+   * {@code subAppUserId!clusterId!
+   * entityType!entityIdPrefix!entityId!userId}.
+   *
+   * subAppUserId is usually the doAsUser.
+   * userId is the yarn user that that the AM runs as.
+   *
+   * </p>
+   *
+   * @return String representation of row key.
+   */
+  public String getRowKeyAsString() {
+    return subAppRowKeyConverter.encodeAsString(this);
+  }
+
+  /**
+   * Given the encoded row key as string, returns the row key as an object.
+   *
+   * @param encodedRowKey String representation of row key.
+   * @return A <cite>SubApplicationRowKey</cite> object.
+   */
+  public static SubApplicationRowKey parseRowKeyFromString(
+      String encodedRowKey) {
+    return new SubApplicationRowKeyConverter().decodeFromString(encodedRowKey);
+  }
+
+  /**
+   * Encodes and decodes row key for sub app table.
+   * The row key is of the form :
+   * subAppUserId!clusterId!flowRunId!appId!entityType!entityId!userId
+   *
+   * subAppUserId is usually the doAsUser.
+   * userId is the yarn user that the AM runs as.
+   *
+   * <p>
+   */
+  final private static class SubApplicationRowKeyConverter
+      implements KeyConverter<SubApplicationRowKey>,
+      KeyConverterToString<SubApplicationRowKey> {
+
+    private SubApplicationRowKeyConverter() {
+    }
+
+    /**
+     * sub app row key is of the form
+     * subAppUserId!clusterId!entityType!entityPrefix!entityId!userId
+     * w. each segment separated by !.
+     *
+     * subAppUserId is usually the doAsUser.
+     * userId is the yarn user that the AM runs as.
+     *
+     * The sizes below indicate sizes of each one of these
+     * segments in sequence. clusterId, subAppUserId, entityType,
+     * entityId and userId are strings.
+     * entity prefix 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,
+        Separator.VARIABLE_SIZE, Separator.VARIABLE_SIZE};
+
+    /*
+     * (non-Javadoc)
+     *
+     * Encodes SubApplicationRowKey object into a byte array with each
+     * component/field in SubApplicationRowKey separated by
+     * Separator#QUALIFIERS.
+     * This leads to an sub app table row key of the form
+     * subAppUserId!clusterId!entityType!entityPrefix!entityId!userId
+     *
+     * subAppUserId is usually the doAsUser.
+     * userId is the yarn user that the AM runs as.
+     *
+     * If entityType in passed SubApplicationRowKey object is null (and the
+     * fields preceding it are not null i.e. clusterId, subAppUserId), this
+     * returns a row key prefix of the form subAppUserId!clusterId!
+     * If entityId in SubApplicationRowKey is null
+     * (other components are not null), this returns a row key prefix
+     * of the form subAppUserId!clusterId!entityType!
+     *
+     * @see org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#encode(java.lang.Object)
+     */
+    @Override
+    public byte[] encode(SubApplicationRowKey rowKey) {
+      byte[] subAppUser = Separator.encode(rowKey.getSubAppUserId(),
+          Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
+      byte[] cluster = Separator.encode(rowKey.getClusterId(), Separator.SPACE,
+          Separator.TAB, Separator.QUALIFIERS);
+      byte[] first = Separator.QUALIFIERS.join(subAppUser, cluster);
+      if (rowKey.getEntityType() == null) {
+        return first;
+      }
+      byte[] entityType = Separator.encode(rowKey.getEntityType(),
+          Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
+
+      if (rowKey.getEntityIdPrefix() == null) {
+        return Separator.QUALIFIERS.join(first, entityType,
+            Separator.EMPTY_BYTES);
+      }
+
+      byte[] entityIdPrefix = Bytes.toBytes(rowKey.getEntityIdPrefix());
+
+      if (rowKey.getEntityId() == null) {
+        return Separator.QUALIFIERS.join(first, entityType, entityIdPrefix,
+            Separator.EMPTY_BYTES);
+      }
+
+      byte[] entityId = Separator.encode(rowKey.getEntityId(), Separator.SPACE,
+          Separator.TAB, Separator.QUALIFIERS);
+
+      byte[] userId = Separator.encode(rowKey.getUserId(),
+          Separator.SPACE, Separator.TAB, Separator.QUALIFIERS);
+
+      byte[] second = Separator.QUALIFIERS.join(entityType, entityIdPrefix,
+          entityId, userId);
+
+      return Separator.QUALIFIERS.join(first, second);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * Decodes a sub application row key of the form
+     * subAppUserId!clusterId!entityType!entityPrefix!entityId!userId
+     *
+     * subAppUserId is usually the doAsUser.
+     * userId is the yarn user that the AM runs as.
+     *
+     * represented in byte format
+     * and converts it into an SubApplicationRowKey object.
+     *
+     * @see org.apache.hadoop.yarn.server.timelineservice.storage.common
+     * .KeyConverter#decode(byte[])
+     */
+    @Override
+    public SubApplicationRowKey decode(byte[] rowKey) {
+      byte[][] rowKeyComponents =
+          Separator.QUALIFIERS.split(rowKey, SEGMENT_SIZES);
+      if (rowKeyComponents.length != 6) {
+        throw new IllegalArgumentException(
+            "the row key is not valid for " + "a sub app");
+      }
+      String subAppUserId =
+          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 entityType = Separator.decode(Bytes.toString(rowKeyComponents[2]),
+          Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+
+      Long entityPrefixId = Bytes.toLong(rowKeyComponents[3]);
+
+      String entityId = Separator.decode(Bytes.toString(rowKeyComponents[4]),
+          Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+      String userId =
+          Separator.decode(Bytes.toString(rowKeyComponents[5]),
+              Separator.QUALIFIERS, Separator.TAB, Separator.SPACE);
+
+      return new SubApplicationRowKey(subAppUserId, clusterId, entityType,
+          entityPrefixId, entityId, userId);
+    }
+
+    @Override
+    public String encodeAsString(SubApplicationRowKey key) {
+      if (key.subAppUserId == null || key.clusterId == null
+          || key.entityType == null || key.entityIdPrefix == null
+          || key.entityId == null || key.userId == null) {
+        throw new IllegalArgumentException();
+      }
+      return TimelineReaderUtils.joinAndEscapeStrings(
+          new String[] {key.subAppUserId, key.clusterId, key.entityType,
+              key.entityIdPrefix.toString(), key.entityId, key.userId});
+    }
+
+    @Override
+    public SubApplicationRowKey decodeFromString(String encodedRowKey) {
+      List<String> split = TimelineReaderUtils.split(encodedRowKey);
+      if (split == null || split.size() != 6) {
+        throw new IllegalArgumentException(
+            "Invalid row key for sub app table.");
+      }
+      Long entityIdPrefix = Long.valueOf(split.get(3));
+      return new SubApplicationRowKey(split.get(0), split.get(1),
+          split.get(2), entityIdPrefix, split.get(4), split.get(5));
+    }
+  }
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/subapplication/SubApplicationRowKeyPrefix.java

@@ -0,0 +1,89 @@
+/**
+ * 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.subapplication;
+
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.RowKeyPrefix;
+
+/**
+ * Represents a partial rowkey without the entityId or without entityType and
+ * entityId for the sub application table.
+ *
+ */
+public class SubApplicationRowKeyPrefix extends SubApplicationRowKey
+    implements RowKeyPrefix<SubApplicationRowKey> {
+
+  /**
+   * Creates a prefix which generates the following rowKeyPrefixes for the sub
+   * application table:
+   * {@code subAppUserId!clusterId!entityType!entityPrefix!userId}.
+   *
+   * @param subAppUserId
+   *          identifying the subApp User
+   * @param clusterId
+   *          identifying the cluster
+   * @param entityType
+   *          which entity type
+   * @param entityIdPrefix
+   *          for entityId
+   * @param entityId
+   *          for an entity
+   * @param userId
+   *          for the user who runs the AM
+   *
+   * subAppUserId is usually the doAsUser.
+   * userId is the yarn user that the AM runs as.
+   *
+   */
+  public SubApplicationRowKeyPrefix(String subAppUserId, String clusterId,
+      String entityType, Long entityIdPrefix, String entityId,
+      String userId) {
+    super(subAppUserId, clusterId, entityType, entityIdPrefix, entityId,
+        userId);
+  }
+
+  /**
+   * Creates a prefix which generates the following rowKeyPrefixes for the sub
+   * application table:
+   * {@code subAppUserId!clusterId!entityType!entityPrefix!entityId!userId}.
+   *
+   * subAppUserId is usually the doAsUser.
+   * userId is the yarn user that the AM runs as.
+   *
+   * @param clusterId
+   *          identifying the cluster
+   * @param subAppUserId
+   *          identifying the sub app user
+   * @param userId
+   *          identifying the user who runs the AM
+   */
+  public SubApplicationRowKeyPrefix(String clusterId, String subAppUserId,
+      String userId) {
+    this(subAppUserId, clusterId, null, null, null, userId);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see org.apache.hadoop.yarn.server.timelineservice.storage.subapplication.
+   * RowKeyPrefix#getRowKeyPrefix()
+   */
+  public byte[] getRowKeyPrefix() {
+    return super.getRowKey();
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/subapplication/SubApplicationTable.java

@@ -0,0 +1,174 @@
+/**
+ * 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.subapplication;
+
+import java.io.IOException;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HColumnDescriptor;
+import org.apache.hadoop.hbase.HTableDescriptor;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.Admin;
+import org.apache.hadoop.hbase.regionserver.BloomType;
+import org.apache.hadoop.yarn.conf.YarnConfiguration;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.BaseTable;
+import org.apache.hadoop.yarn.server.timelineservice.storage.common.TimelineHBaseSchemaConstants;
+
+/**
+ * The sub application table has column families:
+ * info, config and metrics.
+ * Info stores information about a timeline entity object
+ * config stores configuration data of a timeline entity object
+ * metrics stores the metrics of a timeline entity object
+ *
+ * Example sub application table record:
+ *
+ * <pre>
+ * |-------------------------------------------------------------------------|
+ * |  Row          | Column Family             | Column Family| Column Family|
+ * |  key          | info                      | metrics      | config       |
+ * |-------------------------------------------------------------------------|
+ * | subAppUserId! | id:entityId               | metricId1:   | configKey1:  |
+ * | clusterId!    | type:entityType           | metricValue1 | configValue1 |
+ * | entityType!   |                           | @timestamp1  |              |
+ * | idPrefix!|    |                           |              | configKey2:  |
+ * | entityId!     | created_time:             | metricId1:   | configValue2 |
+ * | userId        | 1392993084018             | metricValue2 |              |
+ * |               |                           | @timestamp2  |              |
+ * |               | i!infoKey:                |              |              |
+ * |               | infoValue                 | metricId1:   |              |
+ * |               |                           | metricValue1 |              |
+ * |               |                           | @timestamp2  |              |
+ * |               | e!eventId=timestamp=      |              |              |
+ * |               | infoKey:                  |              |              |
+ * |               | eventInfoValue            |              |              |
+ * |               |                           |              |              |
+ * |               | r!relatesToKey:           |              |              |
+ * |               | id3=id4=id5               |              |              |
+ * |               |                           |              |              |
+ * |               | s!isRelatedToKey          |              |              |
+ * |               | id7=id9=id6               |              |              |
+ * |               |                           |              |              |
+ * |               | flowVersion:              |              |              |
+ * |               | versionValue              |              |              |
+ * |-------------------------------------------------------------------------|
+ * </pre>
+ */
+public class SubApplicationTable extends BaseTable<SubApplicationTable> {
+  /** sub app prefix. */
+  private static final String PREFIX =
+      YarnConfiguration.TIMELINE_SERVICE_PREFIX + "subapplication";
+
+  /** config param name that specifies the subapplication table name. */
+  public static final String TABLE_NAME_CONF_NAME = PREFIX + ".table.name";
+
+  /**
+   * config param name that specifies the TTL for metrics column family in
+   * subapplication table.
+   */
+  private static final String METRICS_TTL_CONF_NAME = PREFIX
+      + ".table.metrics.ttl";
+
+  /**
+   * config param name that specifies max-versions for
+   * metrics column family in subapplication table.
+   */
+  private static final String METRICS_MAX_VERSIONS =
+      PREFIX + ".table.metrics.max-versions";
+
+  /** default value for subapplication table name. */
+  public static final String DEFAULT_TABLE_NAME =
+      "timelineservice.subapplication";
+
+  /** default TTL is 30 days for metrics timeseries. */
+  private static final int DEFAULT_METRICS_TTL = 2592000;
+
+  /** default max number of versions. */
+  private static final int DEFAULT_METRICS_MAX_VERSIONS = 10000;
+
+  private static final Log LOG = LogFactory.getLog(
+      SubApplicationTable.class);
+
+  public SubApplicationTable() {
+    super(TABLE_NAME_CONF_NAME, DEFAULT_TABLE_NAME);
+  }
+
+  /*
+   * (non-Javadoc)
+   *
+   * @see
+   * org.apache.hadoop.yarn.server.timelineservice.storage.BaseTable#createTable
+   * (org.apache.hadoop.hbase.client.Admin,
+   * org.apache.hadoop.conf.Configuration)
+   */
+  public void createTable(Admin admin, Configuration hbaseConf)
+      throws IOException {
+
+    TableName table = getTableName(hbaseConf);
+    if (admin.tableExists(table)) {
+      // do not disable / delete existing table
+      // similar to the approach taken by map-reduce jobs when
+      // output directory exists
+      throw new IOException("Table " + table.getNameAsString()
+          + " already exists.");
+    }
+
+    HTableDescriptor subAppTableDescp = new HTableDescriptor(table);
+    HColumnDescriptor infoCF =
+        new HColumnDescriptor(SubApplicationColumnFamily.INFO.getBytes());
+    infoCF.setBloomFilterType(BloomType.ROWCOL);
+    subAppTableDescp.addFamily(infoCF);
+
+    HColumnDescriptor configCF =
+        new HColumnDescriptor(SubApplicationColumnFamily.CONFIGS.getBytes());
+    configCF.setBloomFilterType(BloomType.ROWCOL);
+    configCF.setBlockCacheEnabled(true);
+    subAppTableDescp.addFamily(configCF);
+
+    HColumnDescriptor metricsCF =
+        new HColumnDescriptor(SubApplicationColumnFamily.METRICS.getBytes());
+    subAppTableDescp.addFamily(metricsCF);
+    metricsCF.setBlockCacheEnabled(true);
+    // always keep 1 version (the latest)
+    metricsCF.setMinVersions(1);
+    metricsCF.setMaxVersions(
+        hbaseConf.getInt(METRICS_MAX_VERSIONS, DEFAULT_METRICS_MAX_VERSIONS));
+    metricsCF.setTimeToLive(hbaseConf.getInt(METRICS_TTL_CONF_NAME,
+        DEFAULT_METRICS_TTL));
+    subAppTableDescp.setRegionSplitPolicyClassName(
+        "org.apache.hadoop.hbase.regionserver.KeyPrefixRegionSplitPolicy");
+    subAppTableDescp.setValue("KeyPrefixRegionSplitPolicy.prefix_length",
+        TimelineHBaseSchemaConstants.USERNAME_SPLIT_KEY_PREFIX_LENGTH);
+    admin.createTable(subAppTableDescp,
+        TimelineHBaseSchemaConstants.getUsernameSplits());
+    LOG.info("Status of table creation for " + table.getNameAsString() + "="
+        + admin.tableExists(table));
+  }
+
+  /**
+   * @param metricsTTL time to live parameter for the metricss in this table.
+   * @param hbaseConf configururation in which to set the metrics TTL config
+   *          variable.
+   */
+  public void setMetricsTTL(int metricsTTL, Configuration hbaseConf) {
+    hbaseConf.setInt(METRICS_TTL_CONF_NAME, metricsTTL);
+  }
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/subapplication/package-info.java

@@ -0,0 +1,28 @@
+/*
+ * 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.subapplication
+ * contains classes related to implementation for subapplication table.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
+package org.apache.hadoop.yarn.server.timelineservice.storage.subapplication;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;

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

@@ -26,6 +26,10 @@ import org.apache.hadoop.hbase.util.Bytes;
 import org.apache.hadoop.yarn.api.records.ApplicationId;
 import org.junit.Test;
 
+/**
+ * Unit tests for key converters for various tables' row keys.
+ *
+ */
 public class TestKeyConverters {
 
   @Test

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

@@ -31,9 +31,14 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKey
 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.apache.hadoop.yarn.server.timelineservice.storage.subapplication.SubApplicationRowKey;
 import org.junit.Test;
 
 
+/**
+ * Class to test the row key structures for various tables.
+ *
+ */
 public class TestRowKeys {
 
   private final static String QUALIFIER_SEP = Separator.QUALIFIERS.getValue();
@@ -41,6 +46,7 @@ public class TestRowKeys {
       .toBytes(QUALIFIER_SEP);
   private final static String CLUSTER = "cl" + QUALIFIER_SEP + "uster";
   private final static String USER = QUALIFIER_SEP + "user";
+  private final static String SUB_APP_USER = QUALIFIER_SEP + "subAppUser";
   private final static String FLOW_NAME = "dummy_" + QUALIFIER_SEP + "flow"
       + QUALIFIER_SEP;
   private final static Long FLOW_RUN_ID;
@@ -247,4 +253,24 @@ public class TestRowKeys {
     verifyRowPrefixBytes(byteRowKeyPrefix);
   }
 
+  @Test
+  public void testSubAppRowKey() {
+    TimelineEntity entity = new TimelineEntity();
+    entity.setId("entity1");
+    entity.setType("DAG");
+    entity.setIdPrefix(54321);
+
+    byte[] byteRowKey =
+        new SubApplicationRowKey(SUB_APP_USER, CLUSTER,
+            entity.getType(), entity.getIdPrefix(),
+            entity.getId(), USER).getRowKey();
+    SubApplicationRowKey rowKey = SubApplicationRowKey.parseRowKey(byteRowKey);
+    assertEquals(CLUSTER, rowKey.getClusterId());
+    assertEquals(SUB_APP_USER, rowKey.getSubAppUserId());
+    assertEquals(entity.getType(), rowKey.getEntityType());
+    assertEquals(entity.getIdPrefix(), rowKey.getEntityIdPrefix().longValue());
+    assertEquals(entity.getId(), rowKey.getEntityId());
+    assertEquals(USER, rowKey.getUserId());
+  }
+
 }

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

@@ -26,6 +26,7 @@ import org.apache.hadoop.yarn.server.timelineservice.storage.application.Applica
 import org.apache.hadoop.yarn.server.timelineservice.storage.entity.EntityRowKey;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowActivityRowKey;
 import org.apache.hadoop.yarn.server.timelineservice.storage.flow.FlowRunRowKey;
+import org.apache.hadoop.yarn.server.timelineservice.storage.subapplication.SubApplicationRowKey;
 import org.junit.Test;
 
 /**
@@ -38,6 +39,9 @@ public class TestRowKeysAsString {
           + TimelineReaderUtils.DEFAULT_ESCAPE_CHAR;
   private final static String USER =
       TimelineReaderUtils.DEFAULT_ESCAPE_CHAR + "user";
+  private final static String SUB_APP_USER =
+      TimelineReaderUtils.DEFAULT_ESCAPE_CHAR + "subAppUser";
+
   private final static String FLOW_NAME =
       "dummy_" + TimelineReaderUtils.DEFAULT_DELIMITER_CHAR
           + TimelineReaderUtils.DEFAULT_ESCAPE_CHAR + "flow"
@@ -112,4 +116,29 @@ public class TestRowKeysAsString {
     assertEquals(FLOW_NAME, rowKey.getFlowName());
     assertEquals(FLOW_RUN_ID, rowKey.getFlowRunId());
   }
+
+  @Test(timeout = 10000)
+  public void testSubApplicationRowKey() {
+    char del = TimelineReaderUtils.DEFAULT_DELIMITER_CHAR;
+    char esc = TimelineReaderUtils.DEFAULT_ESCAPE_CHAR;
+    String id = del + esc + "ent" + esc + del + "ity" + esc + del + esc + "id"
+        + esc + del + esc;
+    String type = "entity" + esc + del + esc + "Type";
+    TimelineEntity entity = new TimelineEntity();
+    entity.setId(id);
+    entity.setType(type);
+    entity.setIdPrefix(54321);
+
+    String rowKeyAsString = new SubApplicationRowKey(SUB_APP_USER, CLUSTER,
+        entity.getType(), entity.getIdPrefix(), entity.getId(), USER)
+            .getRowKeyAsString();
+    SubApplicationRowKey rowKey = SubApplicationRowKey
+        .parseRowKeyFromString(rowKeyAsString);
+    assertEquals(SUB_APP_USER, rowKey.getSubAppUserId());
+    assertEquals(CLUSTER, rowKey.getClusterId());
+    assertEquals(entity.getType(), rowKey.getEntityType());
+    assertEquals(entity.getIdPrefix(), rowKey.getEntityIdPrefix().longValue());
+    assertEquals(entity.getId(), rowKey.getEntityId());
+    assertEquals(USER, rowKey.getUserId());
+  }
 }