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.
But to concentrate on performance. The old IMP hopped along nicely on three load balanced x86 servers, with 2-4 cores at 2,3 GHz and 2-4 GB RAM, running Linux - the load was negligible (actually, the server with 4 cores and 4GB could handle all the load if need be). And the load on the database server was negligible. Now, we have three xen virtual servers, each with 4 cores @ 2,3 GHz (64 bit) and 6 GB memory, and they tend to choke at peak load - during the day, the load is always noticeable, it takes a couple seconds for each request to complete. Also, the mysql server tends to run with the mysqld process occupying one processor completely and hogging all the memory it can get (2GB, the server running on a 32 bit system). We had to disable Kronolith, Nag and Mnemo completely, because they just completely choked the mysql server. We are using all kinds of performance tweaks we could find information on, we are using a php cache (apc) and so on, but still the problems persist... So I was wondering if there are other people using a new Horde Webmail Edition in a similar setting: a university, ~50k accounts (including students & staff), peak concurrent users ~5000, peak logins/minute ~160. If anyone is, we'd like to hear about your performance experiences and also, what kind of hardware / OS you are running. Also, if there were any specific tricks that helped you reduce the server load, we'd love to hear about them. Thanks for any answers. --Janne Peltonen University of Helsinki -- Janne Peltonen <[email protected]> PGP Key ID: 0x9CFAC88B Please consider membership of the Hospitality Club (http://www.hospitalityclub.org) -- IMP mailing list - Join the hunt: http://horde.org/bounties/#imp Frequently Asked Questions: http://horde.org/faq/ To unsubscribe, mail: [email protected]
