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Posted to issues@hbase.apache.org by "Lars Hofhansl (JIRA)" <ji...@apache.org> on 2012/11/13 07:57:15 UTC
[jira] [Resolved] (HBASE-5898) Consider double-checked locking for
block cache lock
[ https://issues.apache.org/jira/browse/HBASE-5898?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Lars Hofhansl resolved HBASE-5898.
----------------------------------
Resolution: Fixed
Committed to 0.94 and 0.96.
(Removal of those unneeded AtomicLongs will give some additional cycles back)
> Consider double-checked locking for block cache lock
> ----------------------------------------------------
>
> Key: HBASE-5898
> URL: https://issues.apache.org/jira/browse/HBASE-5898
> Project: HBase
> Issue Type: Improvement
> Components: Performance
> Affects Versions: 0.94.1
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
> Priority: Critical
> Fix For: 0.94.3, 0.96.0
>
> Attachments: 5898-0.94.txt, 5898-TestBlocksRead.txt, 5898-v2.txt, 5898-v3.txt, 5898-v4.txt, 5898-v4.txt, HBASE-5898-0.patch, HBASE-5898-1.patch, HBASE-5898-1.patch, hbase-5898.txt
>
>
> Running a workload with a high query rate against a dataset that fits in cache, I saw a lot of CPU being used in IdLock.getLockEntry, being called by HFileReaderV2.readBlock. Even though it was all cache hits, it was wasting a lot of CPU doing lock management here. I wrote a quick patch to switch to a double-checked locking and it improved throughput substantially for this workload.
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