Thomas Tauber-Marshall has uploaded this change for review. ( http://gerrit.cloudera.org:8080/15857
Change subject: IMPALA-9716: Add jitter to the exponential backoff in status reporting ...................................................................... IMPALA-9716: Add jitter to the exponential backoff in status reporting When status reports fail, we use exponential backoff when retrying sending them. However, currently the backoff is deterministic, leading to a thundering herd problem where all of the backends for a particular query may try to report at the same time, the coordinator is overwhelmed and rejects some of the rpcs, then the backends all backoff by the same amount and retry sending at the same time, leading the coordinator to be overwhelmed again. This patch alleviates this problem by adding some random jitter to the exponential backoff used when a status report fails. Testing: - Passed a full run of existing tests. - Code path is covered by test_reportexecstatus_retries Change-Id: I1fa78b97887aa1235899779c9a309b346c31fcca --- M be/src/runtime/query-state.cc 1 file changed, 7 insertions(+), 1 deletion(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/57/15857/1 -- To view, visit http://gerrit.cloudera.org:8080/15857 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: I1fa78b97887aa1235899779c9a309b346c31fcca Gerrit-Change-Number: 15857 Gerrit-PatchSet: 1 Gerrit-Owner: Thomas Tauber-Marshall <[email protected]>
