Re: [Devmon] Undocumented "<!--DEVMON RRD" graphing method?

[Buchan M. <bg...@st...>]

On Wednesday, 4 January 2012 04:10:58 Jeremy Laidman wrote:
> Hi
> 
> I've created a template for an Infoblox DNS appliance, and I'm trying
> to graph fan speed.  The OIDs are leaf nodes, and so I can't create a
> table to do this.

Are you *sure*? Can you provide the MIB file and a sample snmpwalk (preferably 
with the MIB known to snmpwalk)?

> Instead, I'm trying to fudge the equivalent output
> by hard-coding the output that devmon normally creates.
> 
> I can't find any doco on how to do this, and so I suspect it's
> undocumented.

The intention was really only to support table data, but I agree that it is 
sometimes useful to use it for leaf data too, if you are saddled with badly 
designed MIBs.

> So, my first question is, should I avoid this method?
> 
> The format appears to be this:
> 
> <!--DEVMON RRD: testname 0 0
> DS:ds0:GAUGE:600:0:U
> somename1 {value1}
> somename2 {value2}
> somename3 {value3}
> -->

Yes. Have a look at the data sent from some existing tests that have working 
graphs (e.g. if_load).

Can you provide the actual data you are sending? E.g. from:
bb localhost 'hobbitdlog hostname.testname'
(or the equivalent with xymon in place of bb/hobbit if you are on 4.3.x).

> >From the source (do_devmon.c) I can't tell what the "0 0" is for, or
> 
> even if it's necessary.

I think do_devmon.c should work fine without the '0 0', but all examples I 
have seen have had the '0 0'.

> The dm_tests.pm file shows these as "$dir
> $do_max" but I can't find what "dir" means - an RRD option that I
> can't find.

To be honest, I have no idea what either of these were for. "I found it like 
this". The majority of the perl/devmon portion of the RRD support was written 
by Eric Schwimmer, but with no implementation of the Hobbit/Xymon side, and 
very little documentation.

> The do_devmon.c file seems to not need it, and discards
> everything after the space before the "dir" field.

I wrote do_devmon.c, and I had no idea what to do with those ...

> Either way, I can't seem to get RRD files created, and I don't know
> where to look for parsing errors.  Xymon's rrd-status.log would seem
> to be the place, but nothing relevant is showing up there.  Any ideas?

You need to start hobbitd_rrd with debugging enabled, e.g. by adding the '--
debug' option to the CMD in the task definion for rrdstatus.

Regards,
Buchan