Thomas Tauber-Marshall has uploaded this change for review. ( 
http://gerrit.cloudera.org:8080/15848


Change subject: IMPALA-9716: Add jitter to the exponential backoff in status 
reporting
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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.

Change-Id: I16ce8f9b0ac1374653cdca4dc43077d8ad0db5f1
---
M be/src/runtime/query-state.cc
1 file changed, 8 insertions(+), 1 deletion(-)



  git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/48/15848/1
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Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-MessageType: newchange
Gerrit-Change-Id: I16ce8f9b0ac1374653cdca4dc43077d8ad0db5f1
Gerrit-Change-Number: 15848
Gerrit-PatchSet: 1
Gerrit-Owner: Thomas Tauber-Marshall <[email protected]>

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