Graphing unusual devices with cacti.

[Andy Davidson <adavidson@ebuyer.com>]

Hi, guys --

A plea for help if I may - I am trying to graph various pieces of data
which can be retrieved from a Redline Networks load balancer with Cacti.

Various nuggets of management information can be obtained from these
devices using SNMP, e.g. :


orwell:~# snmpget -v 2c -c *** rl1.local .1.3.6.1.4.1.6213.2.4.1.1.2.0
REDLINE-STATS-MIB::sessTotal.0 = Counter64: 4569634


I'd like to graph this data using cacti, using the template system (so
that we can graph many of these devices without having to build graphs
by hand for each one.)

If we manage to get this working, I'm happy then to put working configs
online for other folk to find with google and somesuch.

I'm following some advice on the cacti forums, which I'll summarise
here.


 1 - create an xml 'control' file explaining where the data lives.

Note that the OID in the example above is the same as the one in the
file below.

There isn't actually an index for this data (this may therefore be the
problem), but cacti dies with an error along the lines of 'oid_index is
a required parameter' if I miss it out.

===
<interface>
        <name>Get Redline Active Sessions</name>
        <oid_index>.1.3.6.1.4.1.6213.2.4.1.1.2.0</oid_index>

        <fields>
                <rlActiveSessions>
                        <name>Sessions</name>
                        <method>walk</method>
                        <source>value</source>
                        <direction>input</direction>
                        <oid>.1.3.6.1.4.1.6213.2.4.1.1.2.0</oid>
                </rlActiveSessions>
        </fields>
</interface>
===


 2 - Create a data query in Cacti

Pointed the xml path to the correct xml file, selected 'Get SNMP data
(indexed) as the data input method (no 'unindexed' options are made
available)

 3 - Create a data template
 4 - Create a graph template

Nothing remarkable here.

 5 - Create a host template

I already have a host template, and am graphing interface stats, so I'll
simply add this new graph as an 'Associated Data Query'

 6 - Associate graph template to Data Query

Done...


Now, when I click on 'Devices', select the device, and add the new Data
Query I created, and 'None' as the re-index method.



Clicking 'Verbose Query' for this new data query shows this
information :

====
+ Running data query [16].
+ Found type = '3' [snmp query].
+ Found data query XML file at
'/usr/share/cacti/resource/snmp_queries/redline_active_sessions.xml'
+ XML file parsed ok.
+ Executing SNMP walk for list of indexes @
'.1.3.6.1.4.1.6213.2.4.1.1.2.0'
+ No SNMP data returned
+ Found data query XML file at
'/usr/share/cacti/resource/snmp_queries/redline_active_sessions.xml'
+ Found data query XML file at
'/usr/share/cacti/resource/snmp_queries/redline_active_sessions.xml'
+ Found data query XML file at
'/usr/share/cacti/resource/snmp_queries/redline_active_sessions.xml'
====

I think the key line is the 'No SMNP data returned' line.

I'm guessing the problem is that the data which is returned at
'.1.3.6.1.4.1.6213.2.4.1.1.2.0' is not an index - it's the result that I
really want to graph.  

I can't use the generic SNMP OID graphing template as suggested at :
   http://www.cacti.net/downloads/docs/html/how_to.html#GRAPH_SNMP_OID

.. since you only seem to be able to use the SNMP - Generic OID Template
once per host, and I want to graph lots of this data (the debugging
options also seem a lot better if you make a data query, as you get the
'Verbose Query' option.

Running the snmpget command at the top of this email as the user
'nobody' works fine, so it suggests that it's not a user-specific
environment setting (in fact, the mib location and names are specified
as environment variables in the system-wide /etc/profile)


Any ideas ?


-- 

Andy Davidson
Systems Administrator
Ebuyer UK Ltd., 201 Woodbourn Road, Sheffield, S9 3LR