MR job live lock caused by completed state container leak in heartbeat between node manager and RM

This was a bug we had seen multiple times on Hadoop 2.6.2. And the following analysis is based on the core dump, logs, and code in 2017 with Hadoop 2.6.2. We hadn't seen it after 2.9 in our env. However, it was because of the RPC retry policy change and other changes. There's still a possibility even with the current code if I didn't miss anything.

High-level description:

We had seen a starving mapper issue several times. The MR job stuck in a live lock state and couldn't make any progress. The queue is full so the pending mapper can’t get any resource to continue, and the application master failed to preempt the reducer, thus causing the job to be stuck. The reason why the application master didn’t preempt the reducer was that there was a leaked container in assigned mappers. The node manager failed to report the completed container to the resource manager.

Detailed steps:

1. Container_1501226097332_249991_01_000199 was assigned to attempt_1501226097332_249991_m_000095_0 on 2017-08-08 16:00:00,417.

   appmaster.log:6464:2017-08-08 16:00:00,417 INFO [RMCommunicator Allocator] org.apache.hadoop.mapreduce.v2.app.rm.RMContainerAllocator: Assigned container container_1501226097332_249991_01_000199 to attempt_1501226097332_249991_m_000095_0
   

2. The container finished on 2017-08-08 16:02:53,313.

   yarn-mapred-nodemanager-.log.1:2017-08-08 16:02:53,313 INFO org.apache.hadoop.yarn.server.nodemanager.containermanager.container.Container: Container container_1501226097332_249991_01_000199 transitioned from RUNNING to EXITED_WITH_SUCCESS
   yarn-mapred-nodemanager-.log.1:2017-08-08 16:02:53,313 INFO org.apache.hadoop.yarn.server.nodemanager.containermanager.launcher.ContainerLaunch: Cleaning up container container_1501226097332_249991_01_000199
   

3. The NodeStatusUpdater go an exception in the heartbeat on 2017-08-08 16:07:04,238. In fact, the heartbeat request is actually handled by resource manager, however, the node manager failed to receive the response. Let’s assume the heartBeatResponseId=$hid in node manager. According to our current configuration, next heartbeat will be 10s later.

   2017-08-08 16:07:04,238 ERROR org.apache.hadoop.yarn.server.nodemanager.NodeStatusUpdaterImpl: Caught exception in status-updater
   java.io.IOException: Failed on local exception: java.io.IOException: Connection reset by peer; Host Details : local host is: ; destination host is: XXXXXXX
           at org.apache.hadoop.net.NetUtils.wrapException(NetUtils.java:772)
           at org.apache.hadoop.ipc.Client.call(Client.java:1472)
           at org.apache.hadoop.ipc.Client.call(Client.java:1399)
           at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:232)
           at com.sun.proxy.$Proxy33.nodeHeartbeat(Unknown Source)
           at org.apache.hadoop.yarn.server.api.impl.pb.client.ResourceTrackerPBClientImpl.nodeHeartbeat(ResourceTrackerPBClientImpl.java:80)
           at sun.reflect.GeneratedMethodAccessor61.invoke(Unknown Source)
           at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
           at java.lang.reflect.Method.invoke(Method.java:606)
           at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:187)
           at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
           at com.sun.proxy.$Proxy34.nodeHeartbeat(Unknown Source)
           at org.apache.hadoop.yarn.server.nodemanager.NodeStatusUpdaterImpl$1.run(NodeStatusUpdaterImpl.java:597)
           at java.lang.Thread.run(Thread.java:745)
   Caused by: java.io.IOException: Connection reset by peer
           at sun.nio.ch.FileDispatcherImpl.read0(Native Method)
           at sun.nio.ch.SocketDispatcher.read(SocketDispatcher.java:39)
           at sun.nio.ch.IOUtil.readIntoNativeBuffer(IOUtil.java:223)
           at sun.nio.ch.IOUtil.read(IOUtil.java:197)
           at sun.nio.ch.SocketChannelImpl.read(SocketChannelImpl.java:384)
           at org.apache.hadoop.net.SocketInputStream$Reader.performIO(SocketInputStream.java:57)
           at org.apache.hadoop.net.SocketIOWithTimeout.doIO(SocketIOWithTimeout.java:142)
           at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:161)
           at org.apache.hadoop.net.SocketInputStream.read(SocketInputStream.java:131)
           at java.io.FilterInputStream.read(FilterInputStream.java:133)
           at java.io.FilterInputStream.read(FilterInputStream.java:133)
           at org.apache.hadoop.ipc.Client$Connection$PingInputStream.read(Client.java:513)
           at java.io.BufferedInputStream.fill(BufferedInputStream.java:235)
           at java.io.BufferedInputStream.read(BufferedInputStream.java:254)
           at java.io.DataInputStream.readInt(DataInputStream.java:387)
           at org.apache.hadoop.ipc.Client$Connection.receiveRpcResponse(Client.java:1071)
           at org.apache.hadoop.ipc.Client$Connection.run(Client.java:966)
   

4. NodeStatusUpdaterImpl try to send another heart beart 10s after last exception. Container_1501226097332_249991_01_000199 was added to the heartbeat request as a completed container for the first time. We can confirm this point from the timestamp in recentlyStoppedContainers@NodeStatusUpdaterImpl.

   Java.util.LinkedHashMap$Entry@0x7889caca0
   http://localhost:7000/object/0x7889cacc8
   Value 1502209034239 
   Time add to recently stopped 
   1502208434239 = 1502209034239 - 600000
   $date -d@1502208434
   Tue Aug  8 16:07:14 UTC 2017
   

5. RM thought the request as duplication heartbeat as the $hid is the same as the heartBeatId it received last time. So it returned the last response generated from previous heartbeat and didn’t handle the request, in other words, it didn't add container_1501226097332_249991_01_000199 as a completed container to its own data structure.

   // 3. Check if it's a 'fresh' heartbeat i.e. not duplicate heartbeat
   NodeHeartbeatResponse lastNodeHeartbeatResponse = rmNode.getLastNodeHeartBeatResponse();
   if (remoteNodeStatus.getResponseId() + 1 == lastNodeHeartbeatResponse
      .getResponseId()) {
    LOG.info("Received duplicate heartbeat from node "
        + rmNode.getNodeAddress()+ " responseId=" + remoteNodeStatus.getResponseId());
    return lastNodeHeartbeatResponse;
   

6. Node manager received the response and clear container_1501226097332_249991_01_000199 from pendingCompletedContainers@nodeStatusUpdaterImpl. However, container_1501226097332_249991_01_000199 is still in recentlyStoppedContainers@NodeStautsUpdaterImp. So the container won’t report container_1501226097332_249991_01_000199 again as a complete container in the heartbeat request.

                if (containerStatus.getState() == ContainerState.COMPLETE) {
    if (isApplicationStopped(applicationId)) {
      if (LOG.isDebugEnabled()) {
        LOG.debug(applicationId + " is completing, " + " remove "
            + containerId + " from NM context.");
      }
      context.getContainers().remove(containerId);
      pendingCompletedContainers.put(containerId, containerStatus);
    } else {
      if (!isContainerRecentlyStopped(containerId)) {
        pendingCompletedContainers.put(containerId, containerStatus);
        // Adding to finished containers cache. Cache will keep it around at
        // least for #durationToTrackStoppedContainers duration. In the
        // subsequent call to stop the container will get removed from cache.
        addCompletedContainer(containerId);
      }
    }
   } else {
    containerStatuses.add(containerStatus);
   }
   

7. The application master relies on getResources() to get completed containers and remove them from assignedRequests. As the container will never be reported to the RM by the nodemanager again, thus application master can’t remove the attempt associated with the container. And the preemption calculation returns false due to following codes, thus causing the starving mapper.

   boolean preemptReducesIfNeeded() {
    if (reduceResourceRequest.equals(Resources.none())) {
      return false; // no reduces
    }
    if (assignedRequests.maps.size() > 0) {
      // there are assigned mappers
      return false;
    }