[imp] Horde/IMP performance and system requirements (50k+ accounts)

Michael M Slusarz slusarz at horde.org
Tue Mar 24 22:08:50 UTC 2009

Quoting Jie Gao <J.Gao at isu.usyd.edu.au>:

> * Janne Peltonen <janne.peltonen at helsinki.fi> wrote:
>> Hi!
>> We've been running IMP here at the University of Helsinki since 2001,
>> and performed a major upgrade last summer, straight into Horde Webmail
>> Edition 1.1.1. Since then, there has been no end of problems we've been
>> running into, most notably all kinds of performance problems
>> - so much so that we've been considering moving out of Horde/IMP
>> altogether. At least my boss is getting convinved that Horde just
>> doesn't work.
> We have 80k user accounts here. We tried to upgrade from 2.* to 3.*
> a few years ago and had to rollback due to a performance problem caused
> by a bad sql query in the code; adding more resources did not help.
> We tried again with Horde Webmail Edition a few weeks ago, and we had
> plenty of resources ready: 6 front-end redhat servers (in vmware - not
> my preference though), and a dual Quad-Core AMD Opteron redhat server
> (16GB mem) for the mysql database (it is used as a front-end server as
> well now).
> We immediately encountered performance problem, and found that it was
> caused by dynamic address matching in the compose window, and as it
> would match almost everything when you type in the first letter of an
> email address, our ldap server was brought to its knees!

See http://bugs.horde.org/ticket/7322 - the threshold for searching is  
now configurable in IMP.  Additionally, there is an option that when a  
compose window is opened, if a user has below a certain number of  
contacts all of those contacts are loaded into the browser and any  
autocomplete search is done entirely on the browser side.  This is  
only in IMP 5 however.

In IMP 4 this can be worked around by modifying imp/js/autocomplete.js  
- set 'minChars' to the number of characters desired before a search  
is triggered.


Michael Slusarz [slusarz at horde.org]

More information about the imp mailing list