Hello Kudu Jenkins,
I'd like you to reexamine a change. Please visit
http://gerrit.cloudera.org:8080/7950
to look at the new patch set (#3).
Change subject: catalog_manager: improve IsAlterInProgress performance
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catalog_manager: improve IsAlterInProgress performance
To mentally prepare for KUDU-1807, I decided to also tackle the O(n)
behavior of IsAlterInProgress. It's not nearly as bad as IsCreateInProgress
(since we aren't taking cow locks on each tablet) but is still not great
since IsAlterInProgress is called repeatedly by clients.
The solution involves a new map in TableInfo to track the schema versions
of all tablets. Keeping the map up-to-date requires additional work when
adding/removing tablets and when tablet reports include a schema change, but
these are infrequent operations relative to IsAlterInProgress so I figured
the trade off is worth it.
I'm not particularly happy about the lock acquisition in
set_reported_schema_version() but couldn't see a good way to avoid it.
I looped 1000 runs of alter_table-randomized-test. The ~5 failures I saw
were due to KUDU-1539, which I don't think this patch makes us any more or
less vulnerable to.
Change-Id: Id8c1f48c0febad038833edd555ee88f1db83249d
---
M src/kudu/master/catalog_manager.cc
M src/kudu/master/catalog_manager.h
2 files changed, 105 insertions(+), 22 deletions(-)
git pull ssh://gerrit.cloudera.org:29418/kudu refs/changes/50/7950/3
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Gerrit-MessageType: newpatchset
Gerrit-Change-Id: Id8c1f48c0febad038833edd555ee88f1db83249d
Gerrit-PatchSet: 3
Gerrit-Project: kudu
Gerrit-Branch: master
Gerrit-Owner: Adar Dembo <[email protected]>
Gerrit-Reviewer: Dan Burkert <[email protected]>
Gerrit-Reviewer: Kudu Jenkins
Gerrit-Reviewer: Todd Lipcon <[email protected]>
