[Dovecot] Timeout Value

[JackyC at umac.mo]

Hi Timo,

> What about other processes than dovecot-auth -w? When do they start to 
eat 100% CPU?
Not certain, sometime when the system start doing backup, such process 
like 'imap', 'procmail' and even postfix's 'proxymap' and 'local' process.
The above process also depend on LDAP lookup.
Sometime when 2 'dovecot-auth -w' eat 100% CPU, dovecot will die sometime 
are not. 

> At least for dovecot-auth -w it looks like it's doing an LDAP lookup (or 
connect) in here. Maybe it keeps rapidly reconnecting to it all the 
time?.. Anything in Dovecot's error logs?
I think we don't have many massive connection between our LDAP server 
since we have NSCD to cache the LDAP lookup result in local server. 
I am not quite sure LDAP lookup can explain but the 'dovecot-auth -w' does 
eat 100% CPU when looking up LDAP at the last output of strace

I have been encountering this problem for a month, and I upgrade dovecot 
from 1.2.1 to 1.2.11 for that.
I may suspect is there any hardware problem such as disk, can a clean 
reboot help?

Yours Sincerely,
Jacky Chan

---------
CHAN Hoi Kei, Jacky
Technical and User Support Section
Information and Communication Technology Office
University of Macau
DL: (853) 8397 8629 | FAX: (853) 2883 5606



From:
Timo Sirainen <tss at iki.fi>
To:
JackyC at umac.mo
Cc:
dovecot at dovecot.org
Date:
07/04/2010 上午 11:03
Subject:
Re: [Dovecot] Timeout Value



On Wed, 2010-04-07 at 10:56 +0800, JackyC at umac.mo wrote:
> Hi Timo,
> 
> > You do mean all dovecot processes eat 100% CPU, right? And it happens 
> immediately after they start up?
> 
> Not all. For example, we have 2 "dovecot-auth -w". Suddenly one of them 
> will eat 100%. After a certain period of time (short/long, not a 
> constant), another will come up.
> They didn't eat 100% when they start up even.

What about other processes than dovecot-auth -w? When do they start to
eat 100% CPU?

> 10:43:34.728594 write(12, 
> "0\201\376\2\2\30oc\201\367\4'CN=Configuration,DC="..., 257) = 257

At least for dovecot-auth -w it looks like it's doing an LDAP lookup (or
connect) in here. Maybe it keeps rapidly reconnecting to it all the
time?.. Anything in Dovecot's error logs?
http://wiki.dovecot.org/Logging

But you said other processes also eat 100% CPU, and LDAP doesn't explain
that.

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