Miserable performance of cyrus-imapd 2.3.9 -- seems to be locking issues

[Kenneth Marshall]

On Fri, Feb 29, 2008 at 07:16:24AM +0100, Pascal Gienger wrote:
> Jeff Fookson <jfookson at as.arizona.edu> wrote:
> 
> > Databases are all skiplist.
> 
> As a rule of thumb, do not use skiplist for the duplicate delivery 
> suppression database (deliver.db). Even if everybody hates it, use 
> BerkeleyDB, Version 4.4.52 or higher. Give it a quite fair amount of shared 
> memory. And run cyr_expunge often to prune that database so that no entry 
> is older than - say - 3 days.
> 
> We have approx 10-15 messages/sec incoming on one node.

I would like to add that we use skiplist for the deliver.db here
with a hardware caching controller for a system with 7500 accounts
and have no performance problems. It is key to run cyr_expunge to
keep it pruned. Also, with your setup (software RAID + DRBD) you
would benefit from the in memory nature of the BerkeleyDB format.
That one change may make a significant improvement for your system.

Cheers,
Ken