[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

[Michael M Slusarz]

Quoting lst_hoe02 at kwsoft.de:

> 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.

Unfortunately, this is a much too broad statement to pinpoint the  
issue.  I can vouch that if IMP is correctly configured that it can  
handle loads better than any other open-source webmail solution.  This  
is because IMP (and Horde in general) is designed to be  
ultra-configurable and has its sub-systems clearly separated to allow  
for optimization of each sub-system.

But making a broad guess on your issue - if not using an IMAP server  
that does server-side caching or server-side sorting, you will most  
likely see terrible performance if sorting large mailboxes by anything  
other than arrival time.  This is not an issue with IMP.  This is an  
issue with your setup.

michael

-- 
___________________________________
Michael Slusarz [slusarz at horde.org]