hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jean-Daniel Cryans (Commented) (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-4714) Don't ship w/ icms enabled by default
Date Tue, 01 Nov 2011 16:19:32 GMT

    [ https://issues.apache.org/jira/browse/HBASE-4714?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13141278#comment-13141278
] 

Jean-Daniel Cryans commented on HBASE-4714:
-------------------------------------------

+1 on v2
                
> Don't ship w/ icms enabled by default
> -------------------------------------
>
>                 Key: HBASE-4714
>                 URL: https://issues.apache.org/jira/browse/HBASE-4714
>             Project: HBase
>          Issue Type: Task
>            Reporter: stack
>            Assignee: stack
>             Fix For: 0.92.0
>
>         Attachments: icms-v2.txt, icms.txt
>
>
> "Incremental CMS (iCMS) was written for a specific use case - 1 or 2 hardware
> threads where concurrent activity by CMS would look like a STW (if
> only 1 hardware thread) or a high tax on the cpu cycles (2 hardware
> threads).   It has a higher overhead and also is less efficient in terms
> of identifying garbage.  The latter is because iCMS spreads out the
> concurrent work so that objects that it has identified as live earlier
> may actually be dead when the dead objects are swept up.  It's
> worth testing with regular CMS instead of iCMS."
> From recent hotspot mailing list message.
> Rare is the case where we run on systems of 1 or 2 hardware threads (other than fellows
laptops and there the above likely doesn't matter).

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Mime
View raw message