[Lustre-discuss] Lustre SNMP module

[Brian J. Murrell]

On Mon, 2008-03-10 at 13:11 -0700, Kilian CAVALOTTI wrote:
> I think it would also be useful to get "activity metrics", the same kind 
> of information which is in /proc/fs/lustre/llite/*/stats on clients (so 
> we can see reads/writes and fs operations rates), 
> in /proc/fs/lustre/obdfilter/*/stats on OSSes and 
> in /proc/fs/lustre/mds/*/stats on MDSes.

I can't disagree with that, especially as Lustre installations get
bigger and bigger.  Apart from writing custom monitoring tools, there's
not a lot of "pre-emptive" monitoring options available.  There are a
few tools out there like collectl (never seen it, just heard about it)
and LLNL have one on sourceforge, but I can certainly see the attraction
at being able to monitor Lustre on your servers with the same tools as
you are using to monitor the servers' health themselves.

> Actually, all the /proc/fs/lustre/*/**/stats could be useful, but I 
> guess what precise metric is the most useful heavily depends on what 
> you want to see. :)

This could wind becoming a lustre-devel@ discussion, but for now, it
would be interesting to extend the interface(s) we use to
introduce /proc (and what will soon be it's replacement/augmentation)
stats files so that they are automagically provided via SNMP.

You know, given the discussion in this thread:
http://lists.lustre.org/pipermail/lustre-devel/2008-January/001475.html
now would be a good time for the the community (that perhaps might want
to contribute) desiring SNMP access to get their foot in the door.
Ideally, you get SNMP into the generic interface and then SNMP access to
all current and future variables comes more or less free.

That all said, there are some /proc files which provide a copious amount
of information, like brw_stats for instance.  I don't know how well that
sort of thing maps to SNMP, but having an SNMP manager watching
something as useful as brw_stats for trends over time could be quite
interesting.

b.