dovecot - Oct 2010 - migration 1.2.5 -> 2.0.5 load increased dramatically

During norml operation this morning we're seeing a significantly
increased load on the IMAP server (factor 5, from 5 to 25).

Does dovecot need to rebuild index files or perform other IO intensive
operations after the upgrade?

We're using Maildir

Our monitoring shows increased "system" time. We're runnign fewer
processes, the IO rate ist identical to yesterday, memory usage is
identical.

-- 
Ralf Hildebrandt
  Gesch?ftsbereich IT | Abteilung Netzwerk
  Charit? - Universit?tsmedizin 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

* Ralf Hildebrandt <Ralf.Hildebrandt at
charite.de>:
> During norml operation this morning we're seeing a significantly
> increased load on the IMAP server (factor 5, from 5 to 25).
> 
> Does dovecot need to rebuild index files or perform other IO intensive
> operations after the upgrade?
> 
> We're using Maildir
> 
> Our monitoring shows increased "system" time. We're runnign
fewer
> processes, the IO rate ist identical to yesterday, memory usage is
> identical.
I found the reason: My excessive number of ca-certificates!

dovecot-lda invoke doveconf, which in turn needs a whooping 1.2s
wallclock time to parse the config!

I pruned the ca-certificates file and removed ALL ca-certificates but
the ones that belong to the certificate chain for postamt.charite.de

-- 
Ralf Hildebrandt
  Gesch?ftsbereich IT | Abteilung Netzwerk
  Charit? - Universit?tsmedizin 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

* Ralf Hildebrandt <Ralf.Hildebrandt at charite.de>:
> dovecot-lda invoke doveconf, which in turn needs a whooping 1.2s
> wallclock time to parse the config!
strace -c  /usr/dovecot-2/bin/doveconf

reports:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 91.02    0.504031      504031         1           wait4
  3.61    0.020001         833        24           brk
  2.17    0.012001       12001         1           execve
  1.44    0.008001        8001         1           clone
  0.80    0.004443         114        39        27 open
  0.69    0.003833         348        11           read
  0.27    0.001471         134        11           fstat64
  0.00    0.000000           0        60           write
  0.00    0.000000           0        17           close
...

So what is doveconf waiting for?

-- 
Ralf Hildebrandt
  Gesch?ftsbereich IT | Abteilung Netzwerk
  Charit? - Universit?tsmedizin 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