[
https://issues.apache.org/jira/browse/HBASE-14522?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14946138#comment-14946138
]
Misty Stanley-Jones commented on HBASE-14522:
---------------------------------------------
This says that it is ready for review, but the last comment seems to indicate
that there is still work to do. Update?
> Document and/or disable hsperfdata GC pauses
> --------------------------------------------
>
> Key: HBASE-14522
> URL: https://issues.apache.org/jira/browse/HBASE-14522
> Project: HBase
> Issue Type: Task
> Components: documentation, Performance
> Reporter: Nick Dimiduk
> Assignee: Lars Francke
> Attachments: HBASE-14522.patch
>
>
> {quote}
> The JVM by default exports statistics by mmap-ing a file in /tmp
> (hsperfdata). On Linux, modifying a memory mapped file can block until disk
> I/O completes, which can be hundreds of milliseconds. Since the JVM modifies
> these statistics during garbage collection and safepoints, this causes pauses
> that are hundreds of milliseconds long.
> {quote}
> Via [JVM mmap pause|http://www.evanjones.ca/jvm-mmap-pause.html].
> We should add {{-XX:+PerfDisableSharedMem}} to our default options as was
> apparently done in CASSANDRA-9242 and/or document the presence of this bug so
> operators know to use tmpfs.
> Hat-tip [~vrodionov]
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
