[ On Wednesday, October 18, 2000 at 11:51:44 (-0400), Peter Radcliffe wrote: ]
> Subject: Re: [Exim] Failing behviour based on SMTP codes.
>
> "Greg A. Woods" <woods@???> probably said:
> > Those are good reasons for having parallel MXers. Only when the
> > "backup" server cannot handle 1/2 the load normally should it be given a
> > lower-priority MX.
>
> Actually usually in that situation I'd give the second box a lower MX
> if it could handle the load or otherwise. I dont want mail taking
> extra hops when it doesn't need to but it's useful when it does need
> to.
I wouldn't configure such parallel servers in a way that would require
extra hops from one or the other in the first place! :-)
That way you have an N+1 configuration and there's equal chance that
should any one of the machines be down that incoming e-mail will
immediately hit the remaining available host(s). This also means that
you have fewer problems in handling fail-over because there's
effectively no fail-over to do -- the down host(s) are simply not
available and the remaining host(s) continue to function normally.
Back-up and hot-standby servers are oxymorons in my dictionary.
> If you don't trust a secondary MX, don't use it, but if you trust them
> (my level of trust happens to be "I run it") I don't have a problem.
That should go without saying, though I'm not so sure many hostmasters
and postmasters understand what "trust" means in this situation.
> Backup MXes are very useful, they're just an overused tool in many
> situations where they may not be the most appropriate tool.
VERY over-used! :-)
--
Greg A. Woods
+1 416 218-0098 VE3TCP <gwoods@???> <robohack!woods>
Planix, Inc. <woods@???>; Secrets of the Weird <woods@???>
