Hello Tim Armstrong, Impala Public Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/14539
to look at the new patch set (#2).
Change subject: IMPALA-8995: Fix synchronization in dequeue thread
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IMPALA-8995: Fix synchronization in dequeue thread
The admission controller's dequeue thread currently wakes up either
when queries release their admission resources or when a statestore
update is received. The dequeue loop releases the admission lock at
the end of the loop, then acquires it back and calls wait on it.
In this small window, a query can complete, update the admission
stats by acquiring the admission lock, and then call send a notify
to wake the dequeue thread. But since the dequeue thread has not
called wait yet, it can miss this notify. Moreover if the statestore
is down there is no way of waking it up. This will cause the queued
queries to eventually timeout. This patch attempts to fix this by
removing that window.
Testing:
Was able to trigger this manually by adding a sleep right before
the dequeue loop acquires the admission lock.
Change-Id: I91080ce54e59cc7e6361f7c50d6b2156a8a180c8
---
M be/src/scheduling/admission-controller.cc
M be/src/scheduling/admission-controller.h
2 files changed, 13 insertions(+), 2 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/39/14539/2
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I91080ce54e59cc7e6361f7c50d6b2156a8a180c8
Gerrit-Change-Number: 14539
Gerrit-PatchSet: 2
Gerrit-Owner: Bikramjeet Vig <[email protected]>
Gerrit-Reviewer: Bikramjeet Vig <[email protected]>
Gerrit-Reviewer: Impala Public Jenkins <[email protected]>
Gerrit-Reviewer: Tim Armstrong <[email protected]>
