[jira] [Created] (SPARK-29965) Race in executor shutdown handling can lead to executor never fully unregistering

["Marcelo Masiero Vanzin (Jira)" <ji...@apache.org>]

Marcelo Masiero Vanzin created SPARK-29965:
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             Summary: Race in executor shutdown handling can lead to executor never fully unregistering
                 Key: SPARK-29965
                 URL: https://issues.apache.org/jira/browse/SPARK-29965
             Project: Spark
          Issue Type: Bug
          Components: Spark Core
    Affects Versions: 3.0.0
            Reporter: Marcelo Masiero Vanzin


I ran into a situation that I had never noticed before, but I seem to be able to hit with just a few retries when using K8S with dynamic allocation.

Basically, there's a race when killing an executor, where it may send a heartbeat to the driver right at the wrong time during shutdown, e.g.:

{noformat}
19/11/19 21:14:05 INFO CoarseGrainedExecutorBackend: Driver commanded a shutdown
19/11/19 21:14:05 INFO Executor: Told to re-register on heartbeat
19/11/19 21:14:05 INFO BlockManager: BlockManager BlockManagerId(10, 192.168.3.99, 39923, None) re-registering with master
19/11/19 21:14:05 INFO BlockManagerMaster: Registering BlockManager BlockManagerId(10, 192.168.3.99, 39923, None)
19/11/19 21:14:05 INFO BlockManagerMaster: Registered BlockManager BlockManagerId(10, 192.168.3.99, 39923, None)
19/11/19 21:14:06 INFO BlockManager: Reporting 0 blocks to the master.
{noformat}

On the driver side it will happily re-register the executor (time diff is just because of time zone in log4j config):

{noformat}
19/11/19 13:14:05 INFO BlockManagerMasterEndpoint: Trying to remove executor 10 from BlockManagerMaster.
19/11/19 13:14:05 INFO BlockManagerMasterEndpoint: Removing block manager BlockManagerId(10, 192.168.3.99, 39923, None)
19/11/19 13:14:05 INFO BlockManagerMaster: Removed 10 successfully in removeExecutor
19/11/19 13:14:05 INFO DAGScheduler: Shuffle files lost for executor: 10 (epoch 18)
{noformat}

And a little later:

{noformat}
19/11/19 13:14:05 DEBUG HeartbeatReceiver: Received heartbeat from unknown executor 10
19/11/19 13:14:05 INFO BlockManagerMasterEndpoint: Registering block manager 192.168.3.99:39923 with 413.9 MiB RAM, BlockManagerId(10, 192.168.3.99, 39923, None)
{noformat}

This becomes a problem later, where you start to see period exceptions in the driver's logs:

{noformat}
19/11/19 13:14:39 WARN BlockManagerMasterEndpoint: Error trying to remove broadcast 4 from block manager BlockManagerId(10, 192.168.3.99, 39923, None)
java.io.IOException: Failed to send RPC RPC 4999007301825869809 to /10.65.55.240:14233: java.nio.channels.ClosedChannelException
        at org.apache.spark.network.client.TransportClient$RpcChannelListener.handleFailure(TransportClient.java:362)
        at org.apache.spark.network.client.TransportClient$StdChannelListener.operationComplete(TransportClient.java:339)
        at io.netty.util.concurrent.DefaultPromise.notifyListener0(DefaultPromise.java:577)
        at io.netty.util.concurrent.DefaultPromise.notifyListenersNow(DefaultPromise.java:551)
{noformat}

That happens every time some code calls into the block manager to request stuff from all executors. Meaning that the dead executor re-registered, and then was never removed from the block manager.

I found a few races in the code that can lead to this situation. I'll post a PR once I test it more.




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