Weird graph issue

[weetos]

Hi

I'm using cacti on a whole bunch of switches and routers (mostly HP and Cisco) and for a few servers as well - everything's perfect except for one thing :

I poll every ports of a HP ProCurve Switch 4104GL, one of them being an uplink to the internet access for this LAN. Every graph is ok except this one, showing a sawtooth kind of shape (Please have a look at the attachment)

Those ports are Gigabit-SX mini-Gbics.

I'm polling this device using SNMP V2c, and this switch is working fine

Anyone has a clue about what's going on ?

Thanks

[weetos]

*bump*

Anyone ?

[gandalf]

It is "possible", that the snmp daemon caches information you requested. This is at least known for net-snmp to occur.
If you manually snmpwalk those OIDs does a similar issue occur?
Reinhard

[weetos]

Sorry for this late reply

If you manually snmpwalk those OIDs does a similar issue occur?

Well I already tried, but it didn't occur at the time I did this test - it seems to happen only late at night (between 0:00am and 9:00am) - when there's much traffic goinf through the uplink.

I'll run a scripted snmpwalk at night for this OID and we'll see

Thanks Gandalf

[weetos]

Ok I made a script and configured my crontab so it runs every 5 minutes and inserts the In and Out statistics in a database

Here's the code, if anyone is interested :

Code: Select all

#!/bin/sh

InOctets=`snmpwalk -cCommunity -v2c switch_ip .1.3.6.1.2.1.2.2.1.10.1 | awk '{print $4}'`
OutOctets=`snmpwalk -cCommunity -v2c switch_ip .1.3.6.1.2.1.2.2.1.16.1 | awk '{print $4}'`

mysql -uDBUser debug_graph_DB -e"insert into data values(NOW(),$InOctets,$OutOctets)"

I used BIGINT datatype for in and out values

I hope the OIDs I poll are the right ones, though - those counters are 32bit, therefore their value is reset once they reach 4294967296

Is this the right method, Gandalf ?

[gandalf]

I'm polling this device using SNMP V2c, and this switch is working fine

I hope the OIDs I poll are the right ones, though - those counters are 32bit, therefore their value is reset once they reach 4294967296

This depends. If you're using the "normal" traffic graphs, they refer to those OIDs. The traffic shown on the graph is low, it would NOT require using the 64 bit counters (you may find them in ./resource/snmp_queries/interface.xml)
Reinhard

[weetos]

Ok I guess the 64 bit counter would not be required just as long as the traffic doesn't exceed 4294967296 bytes per polling interval (5 mins in this case)

I got no sawtooth last night, and the values in the database are ok - Maybe tonight :/

Thanks for the 64bit OIDs anyway, this may come in handy