[
https://issues.apache.org/jira/browse/LUCENE-2143?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Michael McCandless resolved LUCENE-2143.
----------------------------------------
Resolution: Not A Problem
This is a hotspot issue ... not much we can do about it.
> Understand why NRT performance is affected by flush frequency
> -------------------------------------------------------------
>
> Key: LUCENE-2143
> URL: https://issues.apache.org/jira/browse/LUCENE-2143
> Project: Lucene - Core
> Issue Type: Bug
> Components: core/index
> Reporter: Michael McCandless
> Assignee: Michael McCandless
> Fix For: 4.1
>
> Attachments: SearchTest.java
>
>
> In LUCENE-2061 (perf tests for NRT), I test NRT performance by first
> getting a baseline QPS with only searching, using enough threads to
> saturate.
> Then, I pick an indexing rate (I used 100 docs/sec), and index docs at
> that rate, and I also reopen a NRT reader at different frequencies
> (10/sec, 1/sec, every 5 seconds, etc.), and then again test QPS
> (saturated).
> I think this is a good approach for testing NRT -- apps can see, as a
> function of "freshness" and at a fixed indexing rate, what the cost is
> to QPS. You'd expect as index rate goes up, and freshness goes up,
> QPS will go down.
> But I found something very strange: the low frequency reopen rates
> often caused a highish hit to QPS. When I forced IW to flush every
> 100 docs (= once per second), the performance was generally much
> better.
> I actually would've expected the reverse -- flushing in batch ought to
> use fewer resoruces.
> One theory is something odd about my test env (based on OpenSolaris),
> so I'd like to retest on a more mainstream OS.
> I'm opening this issue to get to the bottom of it...
--
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]
