hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Todd Lipcon (JIRA)" <j...@apache.org>
Subject [jira] Updated: (HBASE-3455) Heap fragmentation in region server
Date Fri, 28 Jan 2011 22:22:47 GMT

     [ https://issues.apache.org/jira/browse/HBASE-3455?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Todd Lipcon updated HBASE-3455:
-------------------------------

    Attachment: mslab-3.txt

Oops, missed one test change before.

This patch should be good to go. I tested under heavy load (95% write, 5% increment, large
working set to trigger block cache churn) on a cluster for about 16 hours, no full GCs at
all in 8G heap with CMS.

But it's still off by default because of the worrisome theoretical possibilities with upsert.

> Heap fragmentation in region server
> -----------------------------------
>
>                 Key: HBASE-3455
>                 URL: https://issues.apache.org/jira/browse/HBASE-3455
>             Project: HBase
>          Issue Type: Brainstorming
>          Components: performance, regionserver
>            Reporter: Todd Lipcon
>            Priority: Critical
>         Attachments: collapse-arrays.patch, HBasefragmentation.pdf, icv-frag.png, mslab-1.txt,
mslab-2.txt, mslab-3.txt, parse-fls-statistics.py, with-kvallocs.png
>
>
> Stop-the-world GC pauses have long been a problem in HBase. "Concurrent mode failures"
can usually be tuned around by setting the initiating occupancy fraction low, but eventually
the heap becomes fragmented and a promotion failure occurs.
> This JIRA is to do research/experiments about the heap fragmentation issue and possible
solutions.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message