[imp] login slowness with large inboxes after upgrade from Horde 3.0.10+IMP 4.0.4 to Horde 3.3.8 + IMP 4.3.7

[lst_hoe02 at kwsoft.de]

Zitat von Aria Bamdad <aria at bsc.gwu.edu>:

>
>
>> -----Original Message-----
>> From: imp-bounces at lists.horde.org [mailto:imp-bounces at lists.horde.org]
>> On Behalf Of lst_hoe02 at kwsoft.de
>> Sent: Monday, October 25, 2010 2:34 PM
>> To: imp at lists.horde.org
>> Subject: Re: [imp] login slowness with large inboxes after upgrade from
>> Horde 3.0.10+IMP 4.0.4 to Horde 3.3.8 + IMP 4.3.7
>>
>> Zitat von Jose Manuel Blanco <jmblanco at sciops.esa.int>:
>>
>> > Hi
>> >
>> > After I recently installed in my new server Horde 3.3.8 + IMP 4.3.7,
>> > users with a large inbox take around 4 to 5 minutes to login.
>> > I know this has been reported and I have read the PERFORMANCE
>> > document and all I could find on the web about increasing the cache
>> > (horde_cache, memcache, mysql memory, etc). The problem is
>> > that my configuration is almost identical to the one I had before
>> > (except the server is newer and I can set bigger cache values). Even
>> > more,
>> > with my old webmail, logins of users with more than 40000 mails in
>> > their inboxes were almost instantaneous (even the first time they
>> > login), so it looks
>> > to me as if it's not a cache issue. Could it be that my old server
>> > is only refreshing from the IMAP backend the 20 mails it shows in
>> > the first screen, while the new one is trying to download the whole
>> > 40000 headers? If so, I haven't been able to see what parameter
>> > could be changed to make my new webmail to behave like that, and
>> > that's the only logical explanation for my old webmail behaviour
>> > that I can think of.
>>
>> There are some real performance killers like image preview and the
>> like which where not available in older releases. Try disable them.
>> There are also some new features which can stress the DB. Have a look
>> if you are using old datatree for shares and the like. There also has
>> been some change in detecting IMAP root. Maybe you are scanning too
>> much at login.
>>
>> Regards
>>
>> Andreas
>>
>>
>>
>
> Andreas,
>
> I have the same problem with my setup.  I use an IBM IMAP server and after
> running several traces, we found that IMP tends to request specific detailed
> information about every mail item in the inbox at logon.  When you have
> 1000's of messages and if your IMAP server is not local or is not super
> fast, this results in the slow login problem reported here.  My solution to
> this was to set the $conf[server][sort_limit] variable (IMP configuration,
> Server tab) to a small number and basically turn off sorting if there are
> too many messages in a  mailbox.  Doing this, resulted in eliminating the
> massive request at login.
>
> What would be nice is if IMP only requested specifics about messages that
> appear in the current window rather than ask for every message in the
> mailbox.  The problem is that if a user selects any sort field other than by
> arrival order, then at login, IMP asks for detailed information about every
> mail item in the mailbox, slowing down login to a crawl.

Sorting other than arrival *may* be done in the client (IMP) and  
therefore IMP request all the information needed for sorting. If your  
server had some index on the fields to sort for and announce sort  
capabilities it *may* be better, but i'm not sure how complete the  
server side sorting capabilities of IMP are. So your best bet is to  
disable sorting if your IMAP server is not able to handle the load  
imposed or limit sorting for smaller mailboxes.

Regards

Andreas

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