dovecot - Nov 2008 - Dovecot master process

We are running into a situation where Dovecot master is simply trying
to do too much.  It some situations, we are finding that there are
times in which it cannot service requests.  Restarting Dovecot seems
to help in these situations, possibly due to the fact that it no longer
has to manage its THOUSANDS of file descriptors for pipes to the many
imap/proxy processes that it uses for logging.  Is there a way to turn
off logging through the master process (in exchange for lesser security)?
If not, would it be easy to have the master process do its logging using
separate threads (which would help on some modern hardware)?  Finally,
would it be easy to delegate the task of logging to a dedicated process?

We are still running Dovecot 1.0.0 at this time, on Solaris 10 servers.

-- 

Steven F. Siirila			Office: WBOB, 621F
Internet Services			E-mail: sfs at umn.edu
Office of Information Technology	Voice: (612) 626-0244
University of Minnesota			Fax: (612) 626-7593

On Nov 12, 2008, at 12:34 AM, Steven F Siirila wrote:
> We are running into a situation where Dovecot master is simply trying
> to do too much.  It some situations, we are finding that there are
> times in which it cannot service requests.  Restarting Dovecot seems
> to help in these situations, possibly due to the fact that it no  
> longer
> has to manage its THOUSANDS of file descriptors for pipes to the many
> imap/proxy processes that it uses for logging.  Is there a way to turn
> off logging through the master process (in exchange for lesser  
> security)?
> If not, would it be easy to have the master process do its logging  
> using
> separate threads (which would help on some modern hardware)?  Finally,
> would it be easy to delegate the task of logging to a dedicated  
> process?

I was planning on using separate logger processes with v2.0. For now I  
guess you could make imap/pop3 processes log directly by changing  
mail_executable to a script that:

1) Unsets LOG_TO_MASTER environment
2) Sets USE_SYSLOG environment
3) Closes file descriptor 2 (stderr). I'm not actually sure if you can  
do this using a shell script, might need to use something else.
4) Executes the imap/pop3 binary.

http://wiki.dovecot.org/PostLoginScripting tells a bit more about  
using mail_executable.

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On Wed, 12 Nov 2008 00:41:36 +0200
Timo Sirainen <tss at iki.fi> wrote:
> On Nov 12, 2008, at 12:34 AM, Steven F Siirila wrote:
> 3) Closes file descriptor 2 (stderr). I'm not actually sure if you
> can do this using a shell script, might need to use something else.
With bash, you can close fd 2 with 'exec 2>&-'.

-- 
Ben Winslow <rain at bluecherry.net>