[imp] Slow mailbox list from time to time

[Ronan SALMON]

Tornoci Laszlo <torlasz at xenia.sote.hu> a écrit :

> Hi,
>
> I have a Horde/IMP system that behaves strangely since I upgraded  
> from 3.1.5/4.1.5 to 3.3.4/4.3.4. I have about 400 users with 50-70  
> concurrent sessions usually. The IMAP mailstore (Cyrus) and the MTA

> are on separate boxes. The system is dual Xeon (quad core) 2GHz, 2GB RAM.
>
> We had excellent response times before the upgrade. The problem is,

> we still have excellent response times (practically instantaneous  
> mailbox lists with > 3000 mails in one folder) most of the time, BUT  
> sometimes for long periods of time, I get miserable response times  
> (30-80 sec waiting) for the same large mailbox to be listed. "top"  
> show the http process to shoot up to 100% cpu while waiting, but  
> nothing else remarkable. Restarting http or mysqld doesn't help.  
> Logging in is not slow. The larger a mailbox, the worse the problem

> is.
> After some time, response times get back to normal.
>
> It's not the IMAP box. Using IMAP clients, direct access to the IMAP  
> box shows absolutely no difference.
>
> Access is always fine if I use the "dynamic" mode. This problem  
> appears only if using the "traditional" mode.
>
> Can't see any unusual network or process activity. There is no  
> obvious correlation with the number of concurrent users either.
>
> Any ideas, anyone?

Do you have any hook enabled ?

Ronan.