YARN-9374. Improve Timeline service resilience when HBase is unavailable.

            Contributed by Prabhu Joseph and Szilard Nemeth

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

@@ -150,7 +150,14 @@ public class TestTimelineReaderHBaseDown {
       waitForHBaseDown(htr);
 
       util.startMiniHBaseCluster(1, 1);
-      GenericTestUtils.waitFor(() -> !htr.isHBaseDown(), 1000, 150000);
+      GenericTestUtils.waitFor(() -> {
+        try {
+          htr.getTimelineStorageMonitor().checkStorageIsUp();
+          return true;
+        } catch (IOException e) {
+          return false;
+        }
+      }, 1000, 150000);
     } finally {
       util.shutdownMiniCluster();
     }
@@ -158,8 +165,15 @@ public class TestTimelineReaderHBaseDown {
 
   private static void waitForHBaseDown(HBaseTimelineReaderImpl htr) throws
       TimeoutException, InterruptedException {
-    GenericTestUtils.waitFor(() -> htr.isHBaseDown(), 1000, 150000);
     try {
+      GenericTestUtils.waitFor(() -> {
+        try {
+          htr.getTimelineStorageMonitor().checkStorageIsUp();
+          return false;
+        } catch (IOException e) {
+          return true;
+        }
+      }, 1000, 150000);
       checkQuery(htr);
       Assert.fail("Query should fail when HBase is down");
     } catch (IOException e) {

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

@@ -0,0 +1,117 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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;
+
+import java.io.IOException;
+
+import org.junit.Test;
+import org.junit.Assert;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.security.UserGroupInformation;
+import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.hadoop.yarn.server.timelineservice.collector.TimelineCollectorContext;
+import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntities;
+import org.apache.hadoop.yarn.api.records.timelineservice.ApplicationEntity;
+
+import static org.apache.hadoop.yarn.conf.YarnConfiguration.TIMELINE_SERVICE_READER_STORAGE_MONITOR_INTERVAL_MS;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * This class tests HbaseTimelineWriter with Hbase Down.
+ */
+public class TestTimelineWriterHBaseDown {
+
+  @Test(timeout=300000)
+  public void testTimelineWriterHBaseDown() throws Exception {
+    HBaseTestingUtility util = new HBaseTestingUtility();
+    HBaseTimelineWriterImpl writer = new HBaseTimelineWriterImpl();
+    try {
+      Configuration c1 = util.getConfiguration();
+      c1.setLong(TIMELINE_SERVICE_READER_STORAGE_MONITOR_INTERVAL_MS, 5000);
+      writer.init(c1);
+      writer.start();
+
+      util.startMiniCluster();
+      DataGeneratorForTest.createSchema(util.getConfiguration());
+
+      TimelineStorageMonitor storageMonitor = writer.
+          getTimelineStorageMonitor();
+      waitForHBaseToUp(storageMonitor);
+
+      try {
+        storageMonitor.checkStorageIsUp();
+      } catch(IOException e) {
+        Assert.fail("HBaseStorageMonitor failed to detect HBase Up");
+      }
+
+      util.shutdownMiniHBaseCluster();
+      waitForHBaseToDown(storageMonitor);
+
+      TimelineEntities te = new TimelineEntities();
+      ApplicationEntity entity = new ApplicationEntity();
+      String appId = "application_1000178881110_2002";
+      entity.setId(appId);
+      Long cTime = 1425016501000L;
+      entity.setCreatedTime(cTime);
+      te.addEntity(entity);
+
+      boolean exceptionCaught = false;
+      try{
+        writer.write(new TimelineCollectorContext("ATS1", "user1", "flow2",
+            "AB7822C10F1111", 1002345678919L, appId), te,
+            UserGroupInformation.createRemoteUser("user1"));
+      } catch (IOException e) {
+        if (e.getMessage().equals("HBase is down")) {
+          exceptionCaught = true;
+        }
+      }
+      assertTrue("HBaseStorageMonitor failed to detect HBase Down",
+          exceptionCaught);
+    } finally {
+      writer.stop();
+      util.shutdownMiniCluster();
+    }
+  }
+
+  public void waitForHBaseToUp(TimelineStorageMonitor storageMonitor)
+      throws Exception {
+    GenericTestUtils.waitFor(() -> {
+      try {
+        storageMonitor.checkStorageIsUp();
+        return true;
+      } catch (IOException e) {
+        return false;
+      }
+    }, 1000, 150000);
+  }
+
+  public void waitForHBaseToDown(TimelineStorageMonitor storageMonitor)
+      throws Exception {
+    GenericTestUtils.waitFor(() -> {
+      try {
+        storageMonitor.checkStorageIsUp();
+        return false;
+      } catch (IOException e) {
+        return true;
+      }
+    }, 1000, 150000);
+  }
+
+}

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

@@ -78,10 +78,6 @@ public class HBaseTimelineReaderImpl
     super.serviceStop();
   }
 
-  public boolean isHBaseDown() {
-    return storageMonitor.isStorageDown();
-  }
-
   @Override
   public TimelineEntity getEntity(TimelineReaderContext context,
       TimelineDataToRetrieve dataToRetrieve) throws IOException {
@@ -113,14 +109,19 @@ public class HBaseTimelineReaderImpl
 
   @Override
   public TimelineHealth getHealthStatus() {
-    if (!this.isHBaseDown()) {
+    try {
+      storageMonitor.checkStorageIsUp();
       return new TimelineHealth(TimelineHealth.TimelineHealthStatus.RUNNING,
           "");
-    } else {
+    } catch (IOException e){
       return new TimelineHealth(
           TimelineHealth.TimelineHealthStatus.READER_CONNECTION_FAILURE,
           "HBase connection is down");
     }
   }
 
+  protected TimelineStorageMonitor getTimelineStorageMonitor() {
+    return storageMonitor;
+  }
+
 }

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

@@ -100,6 +100,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
       .getLogger(HBaseTimelineWriterImpl.class);
 
   private Connection conn;
+  private TimelineStorageMonitor storageMonitor;
   private TypedBufferedMutator<EntityTable> entityTable;
   private TypedBufferedMutator<AppToFlowTable> appToFlowTable;
   private TypedBufferedMutator<ApplicationTable> applicationTable;
@@ -150,9 +151,16 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
     UserGroupInformation ugi = UserGroupInformation.isSecurityEnabled() ?
         UserGroupInformation.getLoginUser() :
         UserGroupInformation.getCurrentUser();
+    storageMonitor = new HBaseStorageMonitor(conf);
     LOG.info("Initialized HBaseTimelineWriterImpl UGI to " + ugi);
   }
 
+  @Override
+  protected void serviceStart() throws Exception {
+    super.serviceStart();
+    storageMonitor.start();
+  }
+
   /**
    * Stores the entire information in TimelineEntities to the timeline store.
    */
@@ -160,7 +168,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
   public TimelineWriteResponse write(TimelineCollectorContext context,
       TimelineEntities data, UserGroupInformation callerUgi)
       throws IOException {
-
+    storageMonitor.checkStorageIsUp();
     TimelineWriteResponse putStatus = new TimelineWriteResponse();
 
     String clusterId = context.getClusterId();
@@ -242,6 +250,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
   public TimelineWriteResponse write(TimelineCollectorContext context,
       TimelineDomain domain)
       throws IOException {
+    storageMonitor.checkStorageIsUp();
     TimelineWriteResponse putStatus = new TimelineWriteResponse();
 
     String clusterId = context.getClusterId();
@@ -591,6 +600,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
   @Override
   public TimelineWriteResponse aggregate(TimelineEntity data,
       TimelineAggregationTrack track) throws IOException {
+    storageMonitor.checkStorageIsUp();
     return null;
   }
 
@@ -603,6 +613,7 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
    */
   @Override
   public void flush() throws IOException {
+    storageMonitor.checkStorageIsUp();
     // flush all buffered mutators
     entityTable.flush();
     appToFlowTable.flush();
@@ -653,6 +664,12 @@ public class HBaseTimelineWriterImpl extends AbstractService implements
       LOG.info("closing the hbase Connection");
       conn.close();
     }
+    storageMonitor.stop();
     super.serviceStop();
   }
+
+  protected TimelineStorageMonitor getTimelineStorageMonitor() {
+    return storageMonitor;
+  }
+
 }

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

@@ -81,10 +81,6 @@ public abstract class TimelineStorageMonitor  {
     }
   }
 
-  public boolean isStorageDown() {
-    return storageDown.get();
-  }
-
   private class MonitorThread implements Runnable {
     @Override
     public void run() {