[
https://issues.apache.org/jira/browse/LUCENE-4740?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13568665#comment-13568665
]
Uwe Schindler commented on LUCENE-4740:
---------------------------------------
bq. Right, but the already existing indexinputs will have buffers pointing to
the same bytebuffer, so if you close the master, you would get SIGSEGV in the
clones, since the master can not forcibly close the clones.
Right that can happen, the fix is to make the freeBuffer method use the setting
of the actual IndexInput, not the global one of MMapDirectory.
> Weak references cause extreme GC churn
> --------------------------------------
>
> Key: LUCENE-4740
> URL: https://issues.apache.org/jira/browse/LUCENE-4740
> Project: Lucene - Core
> Issue Type: Bug
> Components: core/store
> Affects Versions: 3.6.1
> Environment: Linux debian squeeze 64 bit, Oracle JDK 6, 32 GB RAM, 16
> cores
> Reporter: Kristofer Karlsson
> Priority: Critical
> Attachments: LUCENE-4740.patch
>
>
> We are running a set of independent search machines, running our custom
> software using lucene as a search library. We recently upgraded from lucene
> 3.0.3 to 3.6.1 and noticed a severe degradation of performance.
> After doing some heap dump digging, it turns out the process is stalling
> because it's spending so much time in GC. We noticed about 212 million
> WeakReference, originating from WeakIdentityMap, originating from
> MMapIndexInput.
> Our problem completely went away after removing the clones weakhashmap from
> MMapIndexInput, and as a side-effect, disabling support for explictly
> unmapping the mmapped data.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
