The specific moments are at about 9:40 am and 2:30 pm. Exactly when I have most of my users connecting simultaneously (when they arrive in the morning and back from lunch break). At these exact moments, dovecot hangs.
Anyways, I took a look at http://wiki.dovecot.org/LoginProcess. I increased the default login_max_processes_count from 128 to 256 and restarted dovecot. Right before doing this (2:24pm, at this time, imap was getting slow already and dovecot was about to hang) I checked my processes every second: ps -ef | grep imap-login | grep dovecot | wc -l and the results varied from 149 to 152. After setting login_max_processes_count to 256, I hope the problem is fixed. I didn't do anything related to open file descriptors. Mario On Fri, Jan 8, 2010 at 11:36 AM, Steffen Kaiser < skdove...@smail.inf.fh-brs.de> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On Fri, 8 Jan 2010, Mario Gomide wrote: > > Then I commented the listen line, and things got better, but not good >> enough >> yet. Strange, uh? >> > > I never tried that. > > > Just for the record: My mail server is running super fast! The problem >> happens only at specific moments, twice a day, only. >> > > specific moments? Which and what are the spesifics? > > If I remember correctly, I made logs of the number of file descriptors of > the "dovecot" process; each time the number _almost_ reached the max (say > one or two are not allocated yet), I saw the stalls _and_ when I manually > logged off users (kill -15 imap-process) the number did not decreased. Well, > not much anyway. > Sort of, it looked like a fd leak. > > Since I have ulimit -n in my init.d, no such problem came up again. The > previous ulimit was lower than the max Dovecot could handle. > > > Regards, > > - -- Steffen Kaiser > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.6 (GNU/Linux) > > iQEVAwUBS0c0yb+Vh58GPL/cAQKYTQf/RRDR9hgWhjjO2hivS/Lncm1fO5cNVnqZ > 6dTT4Z70M+kgC/yPgGbWEMjEPthDORGeIFMBQof2XdBYAlc/B9TiPH4gmhvkhesU > sv5V8Rq9f02LPWmYAAwiCa4BZ+zQDBPQDfBajJhrhUsYfvrSwEW7Jgb9QUXl/00G > h4s1S2ptrg/3NzKFctyUgkxEyDRLEa+eqCNXNUBwakRfb+4dvkjcaKPCclA9bw51 > CxxtffJNR8oDxQoFCe+tXZDc5FWOxUAffkEDft1Qg9rabqMupfKw45Lecg8rtsgN > vU7D0Fxb18OF7p2JOelYA8sfeCCOLMXj91utH87/VK7Jy7IO2keSUw== > =n6J7 > -----END PGP SIGNATURE----- >
