[Dovecot] Degeneration of CPU Performance

Thiago Monaco Papageorgiou thiago.monaco at corp.terra.com.br
Fri May 8 23:11:34 EEST 2009


hi Steffen, thanks for your reply. Below my replies:

Steffen Kaiser wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> v1.1.6 is pretty old, though.
Right! update is my next step
>
>
> What's hashdir? Maybe this is a performance killer?
This run in the mail process and it is killed after the end of session, 
so I don't think this could cause performance degeneration.
>
> Did you checked things like memory consumption and if there are 
> processes which do consume lots of CPU, e.g. via "top" or similiar 
> command. Maybe your server spends the time on the network?

We have monitoring memory, I/O, network consumption and everything seems 
to be fine.

This is a snapshot of a top :
 %CPU %MEM   
60.4  1.8 495:12.52 dovecot
4.2  0.6   0:27.53 dovecot-auth
1.0  0.0   2:04.48 pop3-login              <- lots of 
                                                                                   


After reboot:
4.9  2.8   2:20.13 
dovecot-auth                                                                                    

4.3  0.1   2:16.56 dovecot
1.0  0.0   0:00.03 pop3

This is a rough way to measure the consumption, but i think it still 
valid since we have a big difference. I will make some better measures 
of CPU usage and send here soon.

I was think if is there any kind of structure that dovecot keep in 
memory, it would have small growth rate and not make much difference to 
memory consumption, but makes dovecot process a lot more each day. Maybe 
a structure that needs upgrade after each access...

Thanks everyone! I really appreciate your help!

-- 
Thiago Monaco Papageorgiou <thiago.monaco at corp.terra.com.br>
________________________
Terra Networks Brasil S/A 
Tel: +55 (51) 3284-4274



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