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https://issues.apache.org/jira/browse/SPARK-35011?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Dongjoon Hyun updated SPARK-35011:
----------------------------------
    Fix Version/s:     (was: 3.0.4)
                       (was: 3.1.3)
                       (was: 3.2.0)

> Avoid Block Manager registerations when StopExecutor msg is in-flight.
> ----------------------------------------------------------------------
>
>                 Key: SPARK-35011
>                 URL: https://issues.apache.org/jira/browse/SPARK-35011
>             Project: Spark
>          Issue Type: Bug
>          Components: Spark Core
>    Affects Versions: 3.1.1, 3.2.0
>            Reporter: Sumeet
>            Priority: Major
>              Labels: BlockManager, core
>
> *Note:* This is a follow-up on SPARK-34949, even after the heartbeat fix, 
> driver reports dead executors as alive.
> *Problem:*
> I was testing Dynamic Allocation on K8s with about 300 executors. While doing 
> so, when the executors were torn down due to 
> "spark.dynamicAllocation.executorIdleTimeout", I noticed all the executor 
> pods being removed from K8s, however, under the "Executors" tab in SparkUI, I 
> could see some executors listed as alive. 
> [spark.sparkContext.statusTracker.getExecutorInfos.length|https://github.com/apache/spark/blob/65da9287bc5112564836a555cd2967fc6b05856f/core/src/main/scala/org/apache/spark/SparkStatusTracker.scala#L100]
>  also returned a value greater than 1. 
>  
> *Cause:*
>  * "CoarseGrainedSchedulerBackend" issues async "StopExecutor" on 
> executorEndpoint
>  * "CoarseGrainedSchedulerBackend" removes that executor from Driver's 
> internal data structures and publishes "SparkListenerExecutorRemoved" on the 
> "listenerBus".
>  * Executor has still not processed "StopExecutor" from the Driver
>  * Driver receives heartbeat from the Executor, since it cannot find the 
> "executorId" in its data structures, it responds with 
> "HeartbeatResponse(reregisterBlockManager = true)"
>  * "BlockManager" on the Executor reregisters with the "BlockManagerMaster" 
> and "SparkListenerBlockManagerAdded" is published on the "listenerBus"
>  * Executor starts processing the "StopExecutor" and exits
>  * "AppStatusListener" picks the "SparkListenerBlockManagerAdded" event and 
> updates "AppStatusStore"
>  * "statusTracker.getExecutorInfos" refers "AppStatusStore" to get the list 
> of executors which returns the dead executor as alive.
>  
> *Proposed Solution:*
> Maintain a Cache of recently removed executors on Driver. During the 
> registration in BlockManagerMasterEndpoint if the BlockManager belongs to a 
> recently removed executor, return None indicating the registration is ignored 
> since the executor will be shutting down soon.
> On BlockManagerHeartbeat, if the BlockManager belongs to a recently removed 
> executor, return true indicating the driver knows about it, thereby 
> preventing reregisteration.



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