Hello Bharath Vissapragada, Michael Ho, Sailesh Mukil,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/9038
to look at the new patch set (#4).
Change subject: IMPALA-2642: Fix a potential deadlock in statestore
......................................................................
IMPALA-2642: Fix a potential deadlock in statestore
The statestored can deadlock if the number of subscribers has
reached STATESTORE_MAX_SUBSCRIBERS, because the DoSubscriberUpdate()
method calls OfferUpdate(), while holding subscribers_lock_, which
also tries to take the same lock in this situation.
Fix the issue by moving out the call to acquire subscribers_lock_ from
OfferUpdate(), and depend on the callers to take it. We also make
the maximum number of statestore subscribers a start-up time tuneable,
to allow us to test the limit more easily.
Testing: The problem is easily reproduced by lowering the value of
STATESTORE_MAX_SUBSCRIBERS to 3, and then launching a mini cluster
with 3 impalads. Without the fix, the statestored becomes completely
deadlocked.
A new EE test has been added to exercise this scenario. The test
verifies that statestored correctly rejects new subscription
requests when the limit it reached.
Change-Id: I5d49dede221ce1f50ec299643b5532c61f93f0c6
---
M be/src/statestore/statestore.cc
M be/src/statestore/statestore.h
A tests/custom_cluster/test_custom_statestore.py
3 files changed, 107 insertions(+), 15 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/38/9038/4
--
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I5d49dede221ce1f50ec299643b5532c61f93f0c6
Gerrit-Change-Number: 9038
Gerrit-PatchSet: 4
Gerrit-Owner: Zoram Thanga <zo...@cloudera.com>
Gerrit-Reviewer: Bharath Vissapragada <bhara...@cloudera.com>
Gerrit-Reviewer: Michael Ho <k...@cloudera.com>
Gerrit-Reviewer: Sailesh Mukil <sail...@cloudera.com>
Gerrit-Reviewer: Zoram Thanga <zo...@cloudera.com>
