Inconsistent expunge performance
ken at oceana.com
Wed Aug 18 19:42:51 EDT 2004
Nels Lindquist wrote:
> Hi there.
> Since upgrading to Cyrus IMAP 2.2.x, I've noticed some fairly extreme
> performance degradation when it comes to expunging deleted mail.
Which 2.2.x version?
> This behaviour is inconsistent from folder to folder, but quite
> consistent WRT an individual folder.
> I haven't been able to find much of a pattern involving numbers of
> messages, ages of folders, etc. Some folders complete an expunge
> almost immediately, some take nearly five minutes while generating
> quite a high load on the server.
Sounds like the folder may be corrupt, you are deleting a *lot* of
messages, or you may be running 2.2.4-2.2.7.
> Is there some explanation for this? I've gone through the Wiki
> regarding DB backends and I seem to have everything set up according
> to the recommendations. Which database is most directly impacted by
> an "expunge" operation?
None. The only files involved in an expunge are cyrus.index,
cyrus.cache, the message files, and the quota file (which in 2.2.4+ uses
the cyrusdb interface).
> Is there anything I can do to alleviate this
> problem? I tried putting imap/proc on tmpfs as discussed in the
> performance documentation, but it didn't make any difference for the
> expunge behaviour (though it would seem opening a folder is slightly
> The server isn't very heavily loaded; there are less than 200
> mailboxes and usually less than 20 concurrent users. IO shouldn't be
> a problem; the disk is 10,000 RPM SCSI.
> Any advice would be greatly appreciated!
> Nels Lindquist <*>
> Information Systems Manager
> Morningstar Air Express Inc.
> Cyrus Home Page: http://asg.web.cmu.edu/cyrus
> Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu
> List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
Kenneth Murchison Oceana Matrix Ltd.
Software Engineer 21 Princeton Place
716-662-8973 x26 Orchard Park, NY 14127
--PGP Public Key-- http://www.oceana.com/~ken/ksm.pgp
Cyrus Home Page: http://asg.web.cmu.edu/cyrus
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