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 faster).
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 Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
