[
https://issues.apache.org/jira/browse/LUCENE-2164?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12790986#action_12790986
]
Jason Rutherglen commented on LUCENE-2164:
------------------------------------------
{quote}I've been wondering whether we need to take IO
prioritization into our own hands. {quote}
I think we discussed IO throttling at the directory level
before. A controller could be passed to createOutput that has a
setPriority method. The priority level would be set based on the
demand for IO from IndexWriter. SegmentMerger could know if it's
creating a large segment from the sizes of the source segments,
and set the IO priority accordingly?
I wonder what algorithm would be suitable for this?
> Make CMS smarter about thread priorities
> ----------------------------------------
>
> Key: LUCENE-2164
> URL: https://issues.apache.org/jira/browse/LUCENE-2164
> Project: Lucene - Java
> Issue Type: Improvement
> Components: Index
> Reporter: Michael McCandless
> Assignee: Michael McCandless
> Priority: Minor
> Fix For: 3.1
>
> Attachments: LUCENE-2164.patch
>
>
> Spinoff from LUCENE-2161...
> The hard throttling CMS does (blocking the incoming thread that wants
> to launch a new merge) can be devastating when it strikes during NRT
> reopen.
> It can easily happen if a huge merge is off and running, but then a
> tiny merge is needed to clean up recently created segments due to
> frequent reopens.
> I think a small change to CMS, whereby it assigns a higher thread
> priority to tiny merges than big merges, should allow us to increase
> the max merge thread count again, and greatly reduce the chance that
> NRT's reopen would hit this.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
---------------------------------------------------------------------
To unsubscribe, e-mail: java-dev-unsubscr...@lucene.apache.org
For additional commands, e-mail: java-dev-h...@lucene.apache.org
