[solved]Problem with SNMP-generic oid template

[wjemail]

I am testing to monitor the memory usage of the linux machine. From the output of snmpwalk, the value of the OID is:
[root@nms rra]# snmpwalk -v1 -cfaplpublic localhost .1.3.6.1.4.1.2021.51.101.1
UCD-SNMP-MIB::ucdavis.51.101.1 = STRING: "15"
It is confirmed the value should be around 15.

However, when I create a graph by use of this OID, the value on the diagram is around 4. I have attached the screenshot of my configuration and the diagram. During the configuration, I did not change any default value except the title, OID...

It is highly appreciated if anyone could help. Thanks!

Wang Jun

[gandalf]

Please visit the Graph at Graph management, switch to debug and post the resulting rrdtool graph statement. Looking for a CDEF ...
Reinhard

[wjemail]

I have attached the rrdtool and cdef.
1. I never manually edit anything in the cdef ;
2. the graphs of other monitoring targets (like real memory, cpu) are ok except this generic OID.

Thanks,

Wang Jun

[gandalf]

Well, that's indeed fine.
Now, please see 2nd link of my sig to learn how to use DEBUG mode for the poller. Then, please find the result of your script in the cacti.log. Please post this along with the "rrdtool update" command for that rrd file.
Reinhard

[wjemail]

Sorry I don't know which post I should refer to. Anyway, is the information below helpful?

[root@nms log]# cat cacti.log | grep -i snmp_oid
12/08/2008 06:05:02 PM - CMDPHP: Poller[0] Host[2] DS[141] SNMP: v1: 127.0.0.1, dsname: snmp_oid, oid: .1.3.6.1.4.1.2021.51.101.1, output: 6
12/08/2008 06:05:02 PM - CMDPHP: Poller[0] DEBUG: SQL Exec: "insert into poller_output (local_data_id, rrd_name, time, output) values (141, 'snmp_oid', '2008-12-08 18:05:02', '6')"
12/08/2008 06:05:02 PM - CMDPHP: Poller[0] DEBUG: SQL Exec: "delete from poller_output where local_data_id='141' and rrd_name='snmp_oid' and time='2008-12-08 18:05:02'"
12/08/2008 06:05:02 PM - POLLER: Poller[0] CACTI2RRD: /usr/bin/rrdtool update /var/www/html/cacti/rra/nms_snmp_oid_141.rrd --template snmp_oid 1228730702:6
12/08/2008 06:10:02 PM - CMDPHP: Poller[0] Host[2] DS[141] SNMP: v1: 127.0.0.1, dsname: snmp_oid, oid: .1.3.6.1.4.1.2021.51.101.1, output: 6
12/08/2008 06:10:02 PM - CMDPHP: Poller[0] DEBUG: SQL Exec: "insert into poller_output (local_data_id, rrd_name, time, output) values (141, 'snmp_oid', '2008-12-08 18:10:02', '6')"
12/08/2008 06:10:03 PM - CMDPHP: Poller[0] DEBUG: SQL Exec: "delete from poller_output where local_data_id='141' and rrd_name='snmp_oid' and time='2008-12-08 18:10:02'"
12/08/2008 06:10:03 PM - POLLER: Poller[0] CACTI2RRD: /usr/bin/rrdtool update /var/www/html/cacti/rra/nms_snmp_oid_141.rrd --template snmp_oid 1228731002:6


[root@nms log]# snmpwalk -v1 -cfaplpublic localhost .1.3.6.1.4.1.2021.51.101.1
UCD-SNMP-MIB::ucdavis.51.101.1 = STRING: "20"

Thanks and Regards,

Wang Jun

[gandalf]

12/08/2008 06:05:02 PM - CMDPHP: Poller[0] Host[2] DS[141] SNMP: v1: 127.0.0.1, dsname: snmp_oid, oid: .1.3.6.1.4.1.2021.51.101.1, output: 6

This shows that a value of "6" is retrieved. The rrdtool update command stores this value. All seems fine. Is the graph showing the number of "6"?
Reinhard

[wjemail]

Actually, the graph matches the output from the poller. However, as shown in my former post, for the OID .1.3.6.1.4.1.2021.51.101.1:
the value retrieved via Cacti Poller:
dsname: snmp_oid, oid: .1.3.6.1.4.1.2021.51.101.1, output: 6

but the value retrieved via snmpwalk
[root@nms log]# snmpwalk -v1 -cfaplpublic localhost .1.3.6.1.4.1.2021.51.101.1
UCD-SNMP-MIB::ucdavis.51.101.1 = STRING: "20"


I am not sure why the value is different.

Thanks and Regards,

Wang Jun

[wjemail]

Is it possible the string OID type issus?

Thanks and Regards,

Wang Jun

[gandalf]

Is it possible the string OID type issus?

Thanks and Regards,

Wang Jun

No, that shouldn't matter.
Reinhard

[wjemail]

You are right !
I wrote another script to monitor the SNMP OID by snmpwalk. I found the value of the OID reduced a lot at the instance of each polling. So, there's no mismatch between the value retrieved by Cacti and the value retrieved by snmpwalk.

Thanks for your help!

Wang Jun