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Re: router daemons

> > What I need to consider when one wants to configure the number of router
> > daemons to run simultaneously? One, two...?
>    Usually *one*.
> If you accumulate lots of queue which takes long time; there
> are at least two possible reasons:
>      - you absolutely run out of horse-power (router process(es) are
>        running all the time at 30-50% cpu share)
>        At a N-CPU system you could run up to N parallel routers,
>        or perhaps a few short, if you have *lots* of processors..
>        At a quad cpu system: 2-3 routers, no reason to have more
>        than 4 routers; leave something for the scheduler and
>        transport programs.)
>      - your router script is doing some DNS lookups which don't
>        resolve immediately, rather they time out (cpu share 1-2%)
>        for this second case running more parallel routers can help,
>        although fixing the script so that router does not do DNS
>        lookups could be more productive.

I'd like to add that on a comparatively big relay the second case is
quite common.  There are a lot of places on the Net with slow DNSes.
Here, we process 25,000+ messages per day, and *sometimes* four
routers are all busy doing lookups.  I am running 8 and that's enough.
On a home or small office machine, one router should suffice.