Re: Documentation for Squids SNMP OIDs

Andreas Michligk wrote:

> the thing is that I have never really understood MIBs. Given, I have never
> REALLY loooked into it, either, but the short peeks I had revealed just
> cryptic information to me or better, I did not see how to use the given
> information for MRTG. But I shall try again ...

MRTG knows all the details of MIBs it needs. You do not need to worry
too much about these details.

From mrtg.conf your load the Squid mib.txt file using LoadMib (I think
it is called, see the MRTG docs), and then all the Squid OIDs are
available by name. The same can be repeated for most other SNMP enabled
products for which you have a MIB definition text file.

I don't know exactly how MRTG knows to find the correct OID from the
name, but somehow it magically works. It probably takes the first OID
found matching the requested name in the MIB .

For people actually caring about the numeric OIDs I think the MIB
definition is more than sufficient. However, it could use some more
explaining on what the value actually monitors, but this goes for
cachemgr output as well and is not isolated to SNMP monitoring of
Squid...

Hint for reading MIBs: They define a tree structure where each
definition adds more levels to a already defined OID.

nlanr OBJECT IDENTIFIER ::= { enterprises 3495 }

defines enterprises.nlanr to be the OID enterprises.3495
(I don't remember the full path or OID of enterprises, but it is defined
in the standard)

squid is then defined as { nlanr 1 }, which gives the OID
enterprises.3495.1
and so on, until you for example have

enterprises.nlanr.squid.cachePerf.cacheProtoStats.cacheProtoAggregateStats.cacheClientHttpRequests
which is the OID enterprises.3495.1.3.2.1.1

or in short cacheClientHttpRequests in MRTG with the Squid mib.txt file
loaded.

--
Henrik Nordstrom
Squid hacker