dovecot - Jul 2017 - weakforced

I've been playing with weakforced, so it fills in the 'fail2ban across a
cluster' niche (not to mention RBLs). It seems to work well, once you've
actually read the docs :)

I was curious if anyone had played with it and was *very* curious if anyone
was using it in high traffic production. Getting things to 'work' versus
getting them to work *and* handle a couple hundred dovecot servers is a
very wide margin. I realize this is not a weakforced mailing list (there
doesn't appear to be one anyway), but the users here are some of the
likeliest candidates for having tried it out.

Mainly I'm curious if weakforced can handle serious concurrency and whether
the cluster really works under load.

On 19.07.2017 02:38, Mark Moseley wrote:
> I've been playing with weakforced, so it fills in the 'fail2ban
across a
> cluster' niche (not to mention RBLs). It seems to work well, once
you've
> actually read the docs :)
>
> I was curious if anyone had played with it and was *very* curious if anyone
> was using it in high traffic production. Getting things to 'work'
versus
> getting them to work *and* handle a couple hundred dovecot servers is a
> very wide margin. I realize this is not a weakforced mailing list (there
> doesn't appear to be one anyway), but the users here are some of the
> likeliest candidates for having tried it out.
>
> Mainly I'm curious if weakforced can handle serious concurrency and
whether
> the cluster really works under load.
Hi!

Weakforced is used by some of our customers in quite large
installations, and performs quite nicely.

Aki

On Tue, Jul 18, 2017 at 10:40 PM, Aki Tuomi <aki.tuomi at dovecot.fi>
wrote:
>
>
> On 19.07.2017 02:38, Mark Moseley wrote:
> > I've been playing with weakforced, so it fills in the
'fail2ban across a
> > cluster' niche (not to mention RBLs). It seems to work well, once
you've
> > actually read the docs :)
> >
> > I was curious if anyone had played with it and was *very* curious if
> anyone
> > was using it in high traffic production. Getting things to
'work' versus
> > getting them to work *and* handle a couple hundred dovecot servers is
a
> > very wide margin. I realize this is not a weakforced mailing list
(there
> > doesn't appear to be one anyway), but the users here are some of
the
> > likeliest candidates for having tried it out.
> >
> > Mainly I'm curious if weakforced can handle serious concurrency
and
> whether
> > the cluster really works under load.
>
> Hi!
>
> Weakforced is used by some of our customers in quite large
> installations, and performs quite nicely.
>
>
>
Cool, good to know.

Do you have any hints/tips/guidelines for things like sizing, both in a
per-server sense (memory, mostly) and in a cluster-sense (logins per sec ::
node ratio)? I'm curious too how large is quite large. Not looking for
details but just a ballpark figure. My largest install would have about 4
million mailboxes to handle, which I'm guessing falls well below 'quite
large'. Looking at stats, our peak would be around 2000 logins/sec.

I'm also curious if -- assuming they're well north of 2000 logins/sec --
the replication protocol begins to overwhelm the daemon at very high
concurrency.

Any rules of thumb on things like "For each additional 1000 logins/sec, add
another # to setNumSiblingThreads and another # to setNumWorkerThreads"
would be super appreciated too.

Thanks! And again, feel free to point me elsewhere if there's a better
place to ask. For a young project, the docs are actually quite good.