[Dovecot] critical performance problem

[Rene Luria]

Ok, everything is about indexes.

What happens, as I thought, is that indexes get recomputed. Once per
account/login, of course, but with a high loaded system it just make the
situation unbearable in normal use.

There is then nothing wrong about upgrading, in terms of performance.
It's just that a high load is to be expected 'till indexes have been
recreated. (erasing them before won't help that much)

The only way to mitigate it in some way is to prevent concurrent intents
to recreate indexes.
pop3_lock_session can help then.

Thank you for your answers.

p.s. on a little less loaded server, load rised but then situation got
back to normal after an hour.