[Beowulf] What services do you run on your cluster nodes?

[Perry E. Metzger]

Prentice Bisbal <prentice at ias.edu> writes:
> The more services you run on your cluster node (gmond, sendmail, etc.)
> the less performance is available for number crunching, but at the same
> time, administration difficulty increases. For example, if you turn off
> postfix/sendmail, you'll no longer get automated e-mails from your
> system to alert you to a problem.

If a machine isn't sending out more than, say, 20,000 email
messages an hour, you won't notice the additional load Postfix puts on
a modern machine with any reasonable measurement tool.

FYI, a modern box running postfix can handle millions of messages per
hour before it starts getting into trouble.

> My question is this: how extreme do you go in disabling non-essential
> services on your cluster nodes? Do you turn off *everything* that's not
> absolutely necessary, do you leave somethings running to make
> administration easier?

In general, one should turn off anything one isn't using, and leave on
anything one is, in fact, using. That probably means things like print
daemons are not appropriate, and things like nagios monitoring daemons
are.

Perry
-- 
Perry E. Metzger		perry at piermont.com