[jira] [Work logged] (BEAM-9399) Possible deadlock between DataflowWorkerLoggingHandler and overridden System.err PrintStream

["ASF GitHub Bot (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/BEAM-9399?focusedWorklogId=418828&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-418828 ]

ASF GitHub Bot logged work on BEAM-9399:
----------------------------------------

                Author: ASF GitHub Bot
            Created on: 08/Apr/20 19:45
            Start Date: 08/Apr/20 19:45
    Worklog Time Spent: 10m 
      Work Description: lukecwik commented on issue #11351: [BEAM-9399] Ensure that empty messages are not flushed to handler.
URL: https://github.com/apache/beam/pull/11351#issuecomment-611156042
 
 
   retest this please
 
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Issue Time Tracking
-------------------

    Worklog Id:     (was: 418828)
    Time Spent: 5h 40m  (was: 5.5h)

> Possible deadlock between DataflowWorkerLoggingHandler and overridden System.err PrintStream
> --------------------------------------------------------------------------------------------
>
>                 Key: BEAM-9399
>                 URL: https://issues.apache.org/jira/browse/BEAM-9399
>             Project: Beam
>          Issue Type: Bug
>          Components: runner-dataflow
>            Reporter: Sam Whittle
>            Assignee: Sam Whittle
>            Priority: Minor
>             Fix For: 2.21.0
>
>          Time Spent: 5h 40m
>  Remaining Estimate: 0h
>
> When an exception is encountered in DataflowWorkerLoggingHandler the ErrorManager is used to log the exception.  ErrorManager uses System.err which is overridden to be a PrintStream that writes back into DataflowWorkerLoggingHandler.
> This has the lock ordering DataflowWorkerLoggingHandler -> PrintStream.
> Other logging of System.err has the inverse lock ordering PrintStream->DataflowWorkerLoggingHandler so there is potential for deadlock.
> This is one known cause of the inversion, but any other System.err logs from inside DataflowWorkerLoggingHandler could cause the same issue.
> Proposed fix is to address low-hanging fruit of having ErrorManager output to the original System.err.  A full fix would be to improve our override of System.err to a PrintStream that can detect the locking inversion or possibly we could use the PrintStream mutex in both cases.



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