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From "Tim Armstrong (Code Review)" <>
Subject [Impala-CR](cdh5-trunk) IMPALA-3633: cancel fragment if coordinator is gone
Date Fri, 27 May 2016 18:21:23 GMT
Tim Armstrong has uploaded a new patch set (#2).

Change subject: IMPALA-3633: cancel fragment if coordinator is gone

IMPALA-3633: cancel fragment if coordinator is gone

The bug is that return_val.status is an optional field, so setting
the status without __isset is equivalent to Status::OK(). This
meant that fragment did not get notified when reporting status
if the coordinator had gone away. This means that is a cancel
RPC was lost, we could be left with zombie fragments with no
coordinator that kept on running until completion.

I couldn't see a way to replicate this reliably with our existing test
setup, since it requires some RPCs to be dropped to get into this state.
I manually tested by commenting out CancelRemoteFragments(), starting a
long-running query then cancelling it. Before the patch, perf top showed
that the fragments continue to execute the query. After the patch, the
fragments stopped executing quickly.

Change-Id: I62ab6f4df7c0ee60c6aa6291513f9f0cbfac3fe7
M be/src/service/
1 file changed, 4 insertions(+), 7 deletions(-)

  git pull ssh:// refs/changes/38/3238/2
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I62ab6f4df7c0ee60c6aa6291513f9f0cbfac3fe7
Gerrit-PatchSet: 2
Gerrit-Project: Impala
Gerrit-Branch: cdh5-trunk
Gerrit-Owner: Tim Armstrong <>
Gerrit-Reviewer: Sailesh Mukil <>

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