On 26.4.2013, at 11.57, Christian Balzer <ch...@gol.com> wrote: > Apr 25 17:19:09 pp11 dovecot: auth: Warning: > proxy(redac...@gol.com,xx.xx.xx.xx,<26hUEivbfQBlMrMS>): DNS lookup for > mb04.dentaku.gol.com took 5.002 s > --- > > Now this machine at that time was handling a load of about 2 logins per > second, about 20% of what it previously handled with perdition w/o a > hiccup. > It also runs a local caching nameserver and the A record for the mailbox > server in question was most definitely cached at the time (verified via > TTL). > The machine in question was very bored and certainly capable of handling > hundreds if not thousands of DNS queries per second at that moment. > > In short, I can't see any reason how the lookup could have taken so long, so > my guess is there are some issues with the dns-helper (locking, stepping on > each others feet, not being spawned fast enough) causing this.
No idea. > Some general remarks, dovecot as proxy feels "heavier" than perdition. > > In the CPU area that's probably a more subjective impression, because all > the little helper processes make it clear what's going on where. > Though the "config" process being rather active is something that perdition > definitely doesn't do, it reads the config once at start time and that's > it. > All the IPC and central processes of course also make dovecot rather > file handle hungry. > > Memory wise it's about 35% bigger than perdition and that's not subjective > at all. ^o^ > About one MB per proxy process/connection for dovecot in my case. > Caveat emptor. ^o^ You could also switch to high-performance mode: http://wiki2.dovecot.org/LoginProcess
