dovecot - Oct 2006 - performance problems with rc10 and solaris 10

Hi,

i have 2 dovecot imap server running on solaris 10

The primary server with dovecot 1.0.alpha4 is running with best
performance on Sun Sparc E4k5 with 8x 450MHz

The secondary with rc10 has ugly performanceproblems on Sun E450 wth 4x
450MHz. Every new imap process takes permanent 25% cpu usage

List the folder and fetch message are both slowy!

Both servers are configred with ldap backend


preventive i deleted for rc10 the complet index and controlfiles,
because the spooldir is a sync from the masterserver with dovecot
alpha4. I thought its a little bit slowy because of my 30.000 mails.

the indexfiles are created now, but the still ugly slow ....

For debugging i compiled rc10 again --with-debug=yes and start dovecot
with solaris truss

truss tells nothing to explain this behavor
logentrys from dovecot has this warnings:

-->

dovecot: Oct 18 14:51:47 Warning: IMAP(saar): Growing pool 'storage'
with: 1024
dovecot: Oct 18 14:51:47 Info: IMAP(saar): dirsize quota limit 750000kB
dovecot: Oct 18 14:51:47 Warning: IMAP(saar): Growing data stack with:
32768
dovecot: Oct 18 14:51:47 Warning: IMAP(saar): Growing data stack with:
65536
dovecot: Oct 18 14:51:48 Warning: IMAP(saar): Growing data stack with:
131072
dovecot: Oct 18 14:51:48 Warning: IMAP(saar): Growing pool 'uidlist
record_pool' with: 32768

<--

also i compiled rc10 --with-notify=none, no result

to ensure it isn?t the solaris system, i compiled alpha4.
Result: good performance

Any ideas?

Cheers

Dominik

Hi,

I am running dovecot rc10 on a Sun E220R (sparc) for 3000 users with Solaris
10 version 6/06 plus current patches.  While the performance isn't great 
(it is a slow 2 cpu x 450 MHz box), it isn't bad either.

I use mbox format (/var/mail is NFS mounted) and ZFS for home directories.
Authentication is via PAM.  PAM uses kerberos to Active Directory.

I have the following in my /etc/system file for dovecot:

* double file descriptor limits for dovecot
set rlim_fd_cur = 65536
set rlim_fd_max = 131072

I also discovered that I need this setting in my dovecot.conf, or it
will fail over with the "shutting down too early/too many open files" 
problem that is often discussed on this list:

login_process_per_connection = no

Are you sure that your E450 isn't swapping?  The "growing data
stack"
sounds like lack of memory/swap issues.

Jeff Earickson
Colby College

On Thu, 19 Oct 2006, Dominik Saar wrote:
> Date: Thu, 19 Oct 2006 14:04:03 +0200
> From: Dominik Saar <dominik.saar at 1und1.de>
> To: dovecot at dovecot.org
> Subject: [Dovecot] performance problems with rc10 and solaris 10
> 
> Hi,
>
> i have 2 dovecot imap server running on solaris 10
>
> The primary server with dovecot 1.0.alpha4 is running with best
> performance on Sun Sparc E4k5 with 8x 450MHz
>
> The secondary with rc10 has ugly performanceproblems on Sun E450 wth 4x
> 450MHz. Every new imap process takes permanent 25% cpu usage
>
> List the folder and fetch message are both slowy!
>
> Both servers are configred with ldap backend
>
>
> preventive i deleted for rc10 the complet index and controlfiles,
> because the spooldir is a sync from the masterserver with dovecot
> alpha4. I thought its a little bit slowy because of my 30.000 mails.
>
> the indexfiles are created now, but the still ugly slow ....
>
> For debugging i compiled rc10 again --with-debug=yes and start dovecot
> with solaris truss
>
> truss tells nothing to explain this behavor
> logentrys from dovecot has this warnings:
>
> -->
>
> dovecot: Oct 18 14:51:47 Warning: IMAP(saar): Growing pool
'storage'
> with: 1024
> dovecot: Oct 18 14:51:47 Info: IMAP(saar): dirsize quota limit >
750000kB
> dovecot: Oct 18 14:51:47 Warning: IMAP(saar): Growing data stack with:
> 32768
> dovecot: Oct 18 14:51:47 Warning: IMAP(saar): Growing data stack with:
> 65536
> dovecot: Oct 18 14:51:48 Warning: IMAP(saar): Growing data stack with:
> 131072
> dovecot: Oct 18 14:51:48 Warning: IMAP(saar): Growing pool 'uidlist
> record_pool' with: 32768
>
> <--
>
> also i compiled rc10 --with-notify=none, no result
>
> to ensure it isn?t the solaris system, i compiled alpha4.
> Result: good performance
>
> Any ideas?
>
> Cheers
>
> Dominik
>
>

On Thu, 2006-10-19 at 14:04 +0200, Dominik Saar wrote:
> preventive i deleted for rc10 the complet index and controlfiles,
> because the spooldir is a sync from the masterserver with dovecot
> alpha4. I thought its a little bit slowy because of my 30.000 mails.
..
> dovecot: Oct 18 14:51:47 Info: IMAP(saar): dirsize quota limit >
750000kB
If you're using maildir, the dirsize quota backend REALLY sucks with it,
since it stat()s every single file it sees in the maildir. Use something
else.
> to ensure it isn?t the solaris system, i compiled alpha4.
> Result: good performance
With dirsize quota enabled with it too? I guess then it could be
something else..

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
URL:
<http://dovecot.org/pipermail/dovecot/attachments/20061023/f729d4a0/attachment.bin>