Zoram Thanga has uploaded this change for review. ( http://gerrit.cloudera.org:8080/9038
Change subject: IMPALA-2624: Fix a potential deadlock in statestore ...................................................................... IMPALA-2624: 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. 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. With the fix, we can see the following entry in the statestore log: I0116 11:56:19.050271 6884 status.cc:125] Maximum subscriber limit reached: 3 Without the fix, the statestored becomes completely deadlocked. Change-Id: I5d49dede221ce1f50ec299643b5532c61f93f0c6 --- M be/src/statestore/statestore.cc 1 file changed, 6 insertions(+), 6 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/38/9038/1 -- To view, visit http://gerrit.cloudera.org:8080/9038 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: I5d49dede221ce1f50ec299643b5532c61f93f0c6 Gerrit-Change-Number: 9038 Gerrit-PatchSet: 1 Gerrit-Owner: Zoram Thanga <zo...@cloudera.com>
