Re: Quality Assurance of mailserver?
lør, 14 05 2011 kl. 12:11 -0300, skrev Henrique de Moraes Holschuh:
> On Sat, 14 May 2011, Camaleón wrote:
> > > I am running a mailserver with exim, courier-pop, courier-imap and
> > > squirrelmail. I has been running "fine" for about 18 months now. But how
> > > can I assure my self and my customers that I deliver a good quality
> > > mail-server?
> >
> > You can endorse a SLA (Service Level Agreement) that ensures and metrics
> > some basic aspects of your service.
>
> Yes. Assuming you're going to do it professionaly (and not
> semi-professionaly, or whatever):
>
> 1. Measure the *SERVICE*, which OUGHT to be different from measuring a
> server (because really, you need at least two in active/active or
> active/passive servers in an high-availability cluster to deliver something
> worth paying for).
>
> 2. Measure the standard metrics:
> a) service uptime (pingdom.com, custom scripts)
> - this is not just SERVER uptime.
> - service availability
> b) service performance metrics
> - delivery latency (incoming and outgoing. Outliers are not
> a problem. Average delay to deliver 90% of the email, is).
> - rejects (incoming and outgoing)
> - spam/virii blocking
>
> 3. Measure per-user metrics
> a) incoming/outgoing bandwitdh usage
> b) storage quota
>
> 4. Have a data recovery and backup strategy, provide an "undelete" service
> (your users will demand it), and test them often (or you're toast at the
> first failure).
>
> 5. Use the high-availability cluster capabilities to do rolling upgrades, an
> outdated server is a compromised server... and this also makes sure the
> HA is working well (which also means you NEED to do the fail over in a
> monitored way to make sure it won't go up in flames if it fails. E.g.
> whatever you do, don't use a filesystem that will not tolerate
> active/active usage even if normally you prefer to operate in
> active/passive mode.
>
> You will need scripts. munim, nagios, cacti, net-snmp can help you a lot to
> monitor the servers. queuegraph and mailgraph can help you monitor the MTA
> performance. You will have to write scripts to monitor service latency
> (send email, measure time until it is delivered to a system pop account,
> measure time until it is delivered at a remote account in gmail, hotmail,
> yahoo, other providers).
>
> You will need to enroll on yahoo/hotmail/etc spam feedback loops, and keep
> strict monitoring of all RBLs, and take a lot of care with the reputation of
> your outgoing servers and email domain. You will need a way to temporarily
> switch the outgoing server to a different IP if you get blacklisted (but do
> so only after you *HAVE* fixed the issue that resulted in the blacklisting).
>
> The list goes on and on. SPAM, and the "email attestation" industry
> fomented by the big email services like hotmail and yahoo, are causing a big
> problem.
>
> --
> "One disk to rule them all, One disk to find them. One disk to bring
> them all and in the darkness grind them. In the Land of Redmond
> where the shadows lie." -- The Silicon Valley Tarot
> Henrique Holschuh
>
>
Hi all,
Thank you for you fine answers. I got a lot of inspiration. I know now
that some kind of HA cluster is my target, but the first steps will be
more monitoring with nagios, munin and pingdom. Also I will write some
kind of SLA that my users can use to track my level of service.
Thanks again, and more suggestions are always welcome! :-)
Regards
Lars Nielsen
www.lfweb.dk
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