[imp] Slow mailbox list from time to time

[LALOT Dominique]

I have preview, hook mgslist installed, more than 7500 mails in my inbox, 3
servers serving 1000 users. And nothing bad for the moment..

xcache as accelerator
php5
debian lenny
last versions of horde/IMP
cyrus imap 2.3.14

Dom

2009/6/8 Tornoci Laszlo <torlasz at xenia.sote.hu>

> Webmaster Extraordinaire wrote:
>
>> I think we have the same problem up to and including the top results.
>>  Ours is caused by enabling message preview.  We discovered the problem
>> after I went through message by message in a mailbox, found a 2 MB message
>> (it was an error log), removed it and the mailbox opened significantly
>> faster.
>>
>> When we switch versions back to 3.1.1 the mailbox loads quickly and with
>> no problems.  So something changed somewhere on the way with message
>> preview.
>>
>> Erik
>>
>> --- On Thu, 6/4/09, Tornoci Laszlo <torlasz at xenia.sote.hu> wrote:
>>
>>> 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.
>>>
>>
> Hi, let me summarize the suggestions I got, and my experience with them:
> 1. disable Horde Alarms: it didn't help me
> 2. disable/limit mailbox sorting on anything other than arrival time:
>   also didn't help me
> 3. disable preview: since I disabled it, I don't have the slowdowns, so I
> believe this is the problem. I can confirm what Erik says, I had the preview
> enabled before (with Horde/Imp 3.1.5/4.1.5) and never had a problem like
> this. So indeed something must have been changed in the preview code that
> eats system resources. I'll wait a few days, just to make sure I won't
> experience any slowdowns, and I'll report this as a bug.
>
>
>                                        Yours: Laszlo
>
>
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-- 
Dominique LALOT
Ingénieur Systèmes et Réseaux
http://annuaire.univmed.fr/showuser.php?uid=lalot