Display difference sins last poll...

[proohu01]

I am running a Perl script that returns an ever increasing number.

I am monitoring the Total SNMP sent items on an Exchange server. I don't want it to print a graph of the total SNMP messages sent.

I just want to see with how much the previous poll has increased.

So if the previous poll returned 100 and the current poll returns 112, I want it to graph 12 for the last 5 minutes.

I have read the Cacti user manual.... I am sad to say that it did not help me. Probably because I am to new with this kind of stuff.

Do I have to use CDEFs for this? Can anyone point me in the right direction please?

Thnx!

[jcaesar]

Yes, you will need to use a CDEF function to get what you want. It looks like the "Make per 5 Minute" CDEF function should put "12" on the graph (based on your example) instead of "12 / 300".

I've never used that CDEF function, but that is how I understand it to work. Someone can correct me if I'm wrong.

[rony]

Accually, RRD will do this for you, you just need to select the right type in the Data source. I don't recall off the top of my head, I will check when I get home.

[proohu01]

Thnx!

I think I know what you mean. I changed the data source type to DERIVE. I will have to wait a couple of hours to know if it is really working. Otherwise the option COUNTER looks promising.

[rony]

COUNTER is the one...

I just couldn't remember off the top of my head.