[Dovecot] Ongoing performance issues with 2.0.x

[Ralf Hildebrandt]

* Ralf Hildebrandt <Ralf.Hildebrandt at charite.de>:
> Due to the ongoing performance issues with 2.0.x I switched back to
> 1.2.15 yesterday evening, with no changes to the machine or my users.
> 
> (I migrated from 1.2.15 to 2.0.x by converting the existing config)
> 
> Today, we have MUCH LESS load, with the same number of logins/min.
> 
> I cannot say what exactly causes this immense increase in load, but one
> observation is that the time spent in system() has now dropped (user and
> iowait have stayed contant) to a third of the values I was seeing with
> 2.0.x.
> 
> This evening I'll post some graphs showing two comparable 24  hour
> ranges.

I uploaded a preliminary screenshot with comments:
http://www.arschkrebs.de/bugs/dovecot.png

During the night we're using clamdscan to scan mailboxes for viruses,
this results in the big block of system & user from 0:00 until about
08:00

-- 
Ralf Hildebrandt
  Geschäftsbereich IT | Abteilung Netzwerk
  Charité - Universitätsmedizin Berlin
  Campus Benjamin Franklin
  Hindenburgdamm 30 | D-12203 Berlin
  Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962
  ralf.hildebrandt at charite.de | http://www.charite.de