[Dovecot] Dovecot + OCFS2

Samuel HAMEAU samuel.hameau at opentrust.com
Thu Oct 4 13:36:40 EEST 2007


Hi,

The load reaches 20, which is not that far from your MAX_DAEMON_CHILDREN 
directive in sendmail.
You should try to find why the delivery processes are so slow to 
accomplish. Maybe it's a I/O backend problem. (I have experienced the 
same kind of problems with drbd writing, and slow hard disks)

For example, during a mailling delivery, check the wait (wa) state of 
your cpu with the command 'vmstat 1'. A high value reflect the cpu time 
spent in waiting for I/O.

Hope this helps,
sam


Jon Blazquez a écrit :
> Thank you for your response,
> With sendmail we have achieved to limit the load :
>
> define(`confMAX_DAEMON_CHILDREN', `15')
> define(`confCONNECTION_RATE_THROTTLE', `2')dnl
> define(`confQUEUE_LA', `5')dnl
> define(`confREFUSE_LA', `4')dnl
>
>
> With this configuration the LOAD only reaches 20 ;-) but it’s not the 
> solution.
> The cluster is formed by 3 nodes. The load balancer sends mails to a 
> node, when it's full (LOAD 4-5) it denies receiving more mails so the 
> load balancer sends them to the following node in the cluster and so 
> on...
> In the first node the load continues increasing until it reaches 
> roughly 20, then it falls down.
>
> This is a temporary solution but we don’t know where exactly the 
> problem is: dovecot’s deliver, ocfs2….
> Any help would be appreciated,
>
> Jon
>
>
>
>
> Tomi Hakala escribió:
>> Jon Blazquez wrote:
>>> The system works fine but when there are mailing lists the load 
>>> increases dramatically.
>>
>>> Any suggestions?
>>
>> First thing that I would do is to reduce number of concurrent deliver 
>> processes. I have no clue how this is done with Sendmail but with 
>> Postfix one could adjust deliver process "maxproc" value in master.cf.
>>
>> Tomi
>>
>



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