[imp] Slow mailbox list from time to time

[Tornoci Laszlo]

lst_hoe02 at kwsoft.de wrote:
> Zitat von Tornoci Laszlo <torlasz at xenia.sote.hu>:
> 
>> 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 *may* be Horde Alarms. As far as i remember there was a problem with 
> the way Horde Alarms uses the Database in some configurations but i 
> can't remember for sure. This could explain why you see it only 
> occasionally. Another point to check is if you are using a PHP 
> accelerator which do maintenance at the slow times.

Thanks for the tip, I've disabled the alarms, I'll see if it makes any 
difference. I don't use any PHP accelerators (by the way: are there any 
reliable ones that are free?)

					Yours: Laszlo