[Dovecot] distributed mdbox

[Timo Sirainen]

On 23.3.2012, at 19.43, <list at airstreamcomm.net> <list at airstreamcomm.net> wrote:

>> Have you tried stress testing it with imaptest? Run in parallel for both
>> servers:
> I did stress test it, but we have developed a "mail bot net" tool for the
> purpose.  I should mention this was tested using dovecot 1.2, as this is
> our current production version (hopefully will be upgrading soon).  Its
> comprised of a control server that starts a bot network of client machines
> that creates pop/imap connections (smtp as well) on our test cluster of
> dovecot (and postfix) servers.  In my test I distributed the load across a
> two node dovecot (/postfix) cluster back ended by glusterfs, which has SAN
> storage attached to it.  I actually didn't change my configuration from
> when I had a test NFS server connected to the test servers (mmap disabled,
> fcntl locking, etc), because glusterfs was an afterthought when we were
> stress testing our new netapp system using NFS.  We have everything in
> VMware, including the glusterfs servers.  Using five bot servers and
> connecting 7 times a second from each server (35 connections per second)
> for both pop and imap (70 total connections per second) split between two
> dovecot servers I was not seeing any big issues.  The load average was low,
> and there were no errors to speak of in dovecot (or postfix).  I was
> mounting the storage with the glusterfs native client, not using NFS (which
> I have not tested).  I would like to do a more thorough test of glusterfs
> using Dovecot 2.0 on some dedicated hardware and see how much further I can
> push the system.

What did the bots do? Add messages and delete messages as fast as they could? I guess that's mostly enough to see if things work. imaptest anyway hammers the server as fast as it can with all kinds of commands.