Hello Timo, I just switched from dovecot-1.0.14 to dovecot-1.1.2 and noticed a significant drop in the server load average (which has become lower and above all doesn't seem to have unexplained peaks). Indexes are still locally stored and nfs attribute caching is still off). I searched the list archives for an explanation of what changed in the code that could explain such an improvement but mostly (except maybe some index code rewrite mentions) found differences in features. Where does that performance gap come from ? -- Thomas Hummel | Institut Pasteur <hummel at pasteur.fr> | P?le informatique - syst?mes et r?seau
On Aug 5, 2008, at 9:43 AM, Thomas Hummel wrote:> I just switched from dovecot-1.0.14 to dovecot-1.1.2 and noticed a > significant > drop in the server load average (which has become lower and above > all doesn't > seem to have unexplained peaks). Indexes are still locally stored > and nfs > attribute caching is still off). > > I searched the list archives for an explanation of what changed in > the code > that could explain such an improvement but mostly (except maybe some > index code > rewrite mentions) found differences in features. > > Where does that performance gap come from ?Do you use POP3? That should work better. There are also less reads/ writes to index files. And dovecot-uidlist is usually updated by appending to it instead of rewriting it. -------------- next part -------------- A non-text attachment was scrubbed... Name: PGP.sig Type: application/pgp-signature Size: 194 bytes Desc: This is a digitally signed message part URL: <http://dovecot.org/pipermail/dovecot/attachments/20080805/b75a834f/attachment-0002.bin>
On Tue, Aug 05, 2008 at 06:40:00PM -0400, Timo Sirainen wrote:> Do you use POP3?Yes. I don't have the stats right now but I'd say, on 2500 users, 60% are using IMAP, 40% POP3. But I had the feeling that it was the IMAP processes which were causing the load, particulary because some IMAP users were complaining about low speed while moving messages from mailboxes (I'm talking 1.0.14 here). However, I don't know if it was a cause or a consequence...> That should work better.A lot indeed.> There are also less reads/ > writes to index files. And dovecot-uidlist is usually updated by > appending to it instead of rewriting it.So no big architectural changes ? Or maybe changes in the locking code ? What about the upcomming 2.0 ? Is the new master expected to provide load improvement ? Great work anyway ! ;-) Thanks. -- Thomas Hummel | Institut Pasteur <hummel at pasteur.fr> | P?le informatique - syst?mes et r?seau