Nagios Support Forum

Hey there I have a problem with our performance graphs.
They are not updating in case the number of lines change.

We are monitoring a set of applications which are distributed over several servers. They are doing the same but they are in a stateful construction so that only one of em can be active while all other are passiv.
We are prompting that application for a lIst of metrics and we can only get that list back from the application that is curently active. All passive ones return just a state of passivness as a numbered perfdata and nothing else.

However when an application gets active that was passive before (only 1 line in the graph) the graph does not print the now updated number of metrics. Instead it just shows the one line of passiv status the application returns when it runs passiv. In the advanced Tab I can see all perfdata, so the plugin returns those correct. Why cant Nagios update the number of lines?

I hope you can follow the description...

Is that a general Problem?

If I'm understanding you properly (correct me if I'm wrong), the performance data is stored in RRD files, the RRDs expect the same number of metrics from the time of creation in order to insert data into them. So if you create a service with 4 metrics then change it to return 5 metrics the data will not be inserted into the RRD file because the RRD file doesn't know how to handle it (trying to insert 5 metrics into a 4 metric RRD file) and it will essentially stop graphing.

You would need to do this to add another datasource to the RRD so it will graph:

https://support.nagios.com/kb/article/n ... g-149.html

If you remove a metric, you would need to do this:

https://support.nagios.com/kb/article/n ... e-497.html

Development intends to move away from RRDs in the future but that's currently the way it works.

Additionally, if the metric count doesn't change and it stops graphing, you can follow this guide to troubleshoot:

https://support.nagios.com/kb/article.php?id=9

Thank you for your reply.

first: your assumption of my problem is correct.
Also I am glad to read that you have seen the problem and that you gonna change the system to smth more suited to adaptation.

I have used the mentioned script to add datasources to the rrd's. If I understand correctly this this will lead to my graphs not updating while we only get a single datasource in, but they will be updating once the ativ/passiv state shifts and the monitored application gets active sending in all datasources in that the rrd knows.

that is enough for now. I hope that you can switch from rrd soon!

Yes, they should start graphing after the number of datasources match and more results come in. Do you see them graphing now?

If they don't, send me the RRD and XML file for one of the services from:

It's allright for now, thx! You can lock the thread.

gomatze wrote:It's allright for now, thx! You can lock the thread.

Locking thread