On 09 Mar 2011, at 20:16, Timo Sirainen wrote:
On 8.3.2011, at 19.42, Thierry de Montaudry wrote:
So... if the httpd process is the one consuming all of the CPU, doesn't it stand to reason that it might be something to do with one of your web apps, and not dovecot?
But then why was it fine with 1.1.13, which never had once this problem in 2 years? or is 2.0.9 slower, or consuming more resources to create the problem?
One possibility is that maybe v2.0 works a bit differently.. Maybe it causes webmail to use a new feature that wasn't yet in v1.1, which causes more CPU? Yes, possibly. I will investigate the features that the webmail might use now that it was not previously.
I also just heard that apparently this "Resource temporarily unavailable" can happen if service imap/pop3-login's client_limit is too large. I'm not really sure why, but you could try reducing them to e.g. 50. I reduced the limits with process_limit. I'm wondering if I should use the client_limit as well, but couldn't find much documentation, would you have any light on that?
Do you remember how high the CPU usage was at peak times in v1.1? Has that changed? Is the problem maybe that v2.0 just fails in a different way by logging these failures, where v1.1 wouldn't even accept as many incoming connections? v1.1 was about the same as current, load avg between 3 and 4 from 9pm to 4am, no change on that side. It looks like it's just when there is spikes, the new version is reaching some limit.