[Dovecot] Timeout Value

[JackyC at umac.mo]

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.

> 1) strace -tt -p <pid> output for a 10 lines or so.

Once I start 'strace' to monitor the "dovecot-auth -w", it will 
immediately eat 100% and the following is the last few lines of strace 
output.
I do have a ldap backend for authentication.

10:43:34.726512 time(NULL)              = 1270608214
10:43:34.726561 poll([{fd=5, events=POLLIN|POLLPRI|POLLERR|POLLHUP}, 
{fd=-1}, {fd=-1}, {fd=12, events=POLLIN|POLLPRI|POLLERR|POLLHUP}], 4, 
10000) = 1 ([{fd=12, revents=POLLIN}])
10:43:34.728355 read(12, "0\204\0\0\0\21\2\2", 8) = 8
10:43:34.728421 read(12, "\30pa\204\0\0\0\7\n\1\0\4\0\4\0", 15) = 15
10:43:34.728491 time(NULL)              = 1270608214
10:43:34.728542 time(NULL)              = 1270608214
10:43:34.728594 write(12, 
"0\201\376\2\2\30oc\201\367\4'CN=Configuration,DC="..., 257) = 257
10:43:34.728673 time(NULL)              = 1270608214
10:43:34.728723 poll([{fd=5, events=POLLIN|POLLPRI|POLLERR|POLLHUP}, 
{fd=-1}, {fd=-1}, {fd=12, events=POLLIN|POLLPRI|POLLERR|POLLHUP}], 4, 
120000) = 1 ([{fd=12, revents=POLLIN}])
10:43:34.729401 read(12, "0\204\0\0\0R\2\2", 8) = 8
10:43:34.729465 read(12, "\30os\204\0\0\0H\4Fldap://xxx.xxx.xxx/C"..., 80) 
= 80

> 2) dovecot --build-options output
Build options: ioloop=epoll notify=inotify ipv6 openssl
Mail storages: cydir dbox maildir mbox raw shared
SQL drivers:
Passdb: checkpassword pam passwd passwd-file shadow
Userdb: nss passwd passwd-file prefetch static

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 10:36
Subject:
Re: [Dovecot] Timeout Value



On Tue, 2010-04-06 at 12:13 +0800, JackyC at umac.mo wrote:
> Dear All,
> 
> I constantly encounter 'dovecot-auth', 'login-imap', 'login-pop3' and 
> 'imap' processes consume 100% CPU.
> I run 'ps' and found those hanged up processes were running for a long 
> time.
> I am wondering whether dovecot.conf has some configuration parameters 
that 
> timeout those processes (or kill those after certain period of time).
> I am using dovecot 1.2.11 on RHEL 5.3.

There is no timeout value, because those processes just shouldn't be
eating 100% CPU. Strange that all of your processes are eating 100% CPU.
You do mean all dovecot processes eat 100% CPU, right? And it happens
immediately after they start up? I guess there's something really wrong
in your installation. A few things that might show something useful:

1) strace -tt -p <pid> output for a 10 lines or so.

2) dovecot --build-options output

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