Hello Csaba Ringhofer, Bikramjeet Vig, Impala Public Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/15672
to look at the new patch set (#2).
Change subject: IMPALA-9611: fix hang when cancelling join builder
......................................................................
IMPALA-9611: fix hang when cancelling join builder
The error could occur in the following scenario, where
thread A is executing a join build fragment and thread
B is cancelling the fragment instance.
1. Thread A is in HandoffToProbesAndWait(), reads is_cancelled_
and sees false.
2. Thread B in RuntimeState::Cancel() sets is_cancelled_ = true,
acquires cancellation_cvs_lock_, then calls NotifyAll() on the
condition variable
3. Thread A calls Wait() on the condition variable, blocks forever
because cancellation already happened.
The fix is for thread B to acquire the lock that thread A is
holding. That prevents the race because #1 and #3 above are in the
same critical section and thread B won't be able to signal the
condition variable until thread A has released it.
Testing:
Added metric check to test_failpoints to make it easier to detect
hangs caused by those tests in future.
Looped test_failpoints.py overnight, which was previously enough
to reproduce the failure within a couple of hours.
Ran exhaustive tests.
Change-Id: I996ad2055d6542eb57e12c663b89de5f84208f77
---
M be/src/exec/join-builder.cc
M be/src/runtime/runtime-state.cc
M be/src/runtime/runtime-state.h
M tests/failure/test_failpoints.py
4 files changed, 40 insertions(+), 12 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/72/15672/2
--
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I996ad2055d6542eb57e12c663b89de5f84208f77
Gerrit-Change-Number: 15672
Gerrit-PatchSet: 2
Gerrit-Owner: Tim Armstrong <[email protected]>
Gerrit-Reviewer: Bikramjeet Vig <[email protected]>
Gerrit-Reviewer: Csaba Ringhofer <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
