[jira] [Comment Edited] (FLINK-15687) Potential test instabilities due to concurrent access to TaskSlotTable.

["Xintong Song (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-15687?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17118281#comment-17118281 ] 

Xintong Song edited comment on FLINK-15687 at 5/28/20, 5:54 AM:
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I've printed the thread names for all testing scope accesses to {{TaskSlotTable}}. The following cases are discovered with the reported problem. I'll try to provide fixes asap.
 * -TaskExecutorTest-
 ** -testDynamicSlotAllocation-
 ** -testOfferSlotToJobMasterAfterTimeout-
 ** -testShouldShutDownTaskManagerServicesInPostStop-
 * TaskExecutorSubmissionTest
 ** testFailingScheduleOrUpdateConsumers
 ** testUpdateTaskInputPartitionsFailure
 ** testRunJobWithForwardChannel
 ** testTaskSubmissionAndCancelling
 ** testCancellingDependentAndStateUpdateFails
 ** testLocalPartitionNotFound
 ** testRemotePartitionNotFound
 ** testTaskSubmission
 ** testGateChannelEdgeMismatch
 ** testRequestTaskBackPressure
 * TaskExecutorOperatorEventHandlingTest
 ** eventHandlingInTaskFailureFailsTask
 ** eventToCoordinatorDeliveryFailureFailsTask

*EDIT:* Looking more into these cases, I think the three cases of {{TaskExecutorTest}} should be fine. Accesses to {{TaskSlotTable}} from the testing thread are guaranteed ({{CompletableFuture#get}}, {{OneShotLatch#await}}) to take place after the main thread activities are finished.


was (Author: xintongsong):
I've printed the thread names for all testing scope accesses to {{TaskSlotTable}}. The following cases are discovered with the reported problem. I'll try to provide fixes asap.

* TaskExecutorTest
** testDynamicSlotAllocation
** testOfferSlotToJobMasterAfterTimeout
** testShouldShutDownTaskManagerServicesInPostStop
* TaskExecutorSubmissionTest
** testFailingScheduleOrUpdateConsumers
** testUpdateTaskInputPartitionsFailure
** testRunJobWithForwardChannel
** testTaskSubmissionAndCancelling
** testCancellingDependentAndStateUpdateFails
** testLocalPartitionNotFound
** testRemotePartitionNotFound
** testTaskSubmission
** testGateChannelEdgeMismatch
** testRequestTaskBackPressure
* TaskExecutorOperatorEventHandlingTest
** eventHandlingInTaskFailureFailsTask
** eventToCoordinatorDeliveryFailureFailsTask

> Potential test instabilities due to concurrent access to TaskSlotTable.
> -----------------------------------------------------------------------
>
>                 Key: FLINK-15687
>                 URL: https://issues.apache.org/jira/browse/FLINK-15687
>             Project: Flink
>          Issue Type: Task
>          Components: Runtime / Coordination, Tests
>    Affects Versions: 1.10.0
>            Reporter: Kostas Kloudas
>            Assignee: Xintong Song
>            Priority: Critical
>              Labels: test-stability
>             Fix For: 1.11.0
>
>
> Working on [FLINK-14742|https://issues.apache.org/jira/browse/FLINK-14742] revealed that the problem with that test instability was the modification of the {{taskSlotTable}} of the {{TaskManager}} under test from multiple threads, namely the test thread and the main thread of the {{rpcEnpoint}}. This data-structure is not thread-safe and this should not happen.
> This anti-pattern seems to be repeated in multiple tests like most of the tests in the {{TaskExecutorSubmissionTest}} (look for the call to the {{TaskSlotTable.allocateSlot()}}). There we seem to call {{taskSlotTable.allocateSlot()}} and then \{{tmGateway.submitTask()}} which is essentially accessing the slot table from within the main rpc-endpoint thread.
> This JIRA is just to investigate if this is also a problem in those tests or not.
> cc [~trohrmann], [~chesnay] , [~yangwang166]



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