Autor: Daniel Tiefnig Data: A: exim-users Assumpte: Re: [exim] High Perf server - was (exim allowed someone to slam my
mailserver for 3 hours)
Tony Finch wrote: > On Wed, 29 Jun 2005, Daniel Tiefnig wrote:
>> Hmm, I don't know much about that, but the other processes would
>> also access the cached files in RAM, wouldn't they? So a sync
>> wouldn't change anything in that respect. It just ensures the data
>> is consistent after a crash.
>
> If the db is on disk then the fsync makes each process spend much
> longer dealing with the hints, so you get fewer processes able to do
> things each second.
Sure, but the question is: Does it make sense to sync the hints DB to
disk at all? Or can we avoid it? At least GDBM supports a SYNC option, I
haven't checked exims source, whether it uses it or not. GDBM defaults
to non-sync mode since awhile. Besides that I fear GDBM does a sync in
any case when a writer process closes the DB file, and exim does that
really often. (Practically each time after a write?)
