Nagios Support Forum

Nagios XI graph templates use RRDTool, with a setup that is only really suited to graph time-series data. If you're looking to use RRDTool to generate visualizations of this data, you would most likely need to roll your own solution, however RRDTool may not be the best tool for your use case. Regardless, I don't believe this is functionality that is supported by Nagios XI.

I've spoken with our Support team about this request, and have an update for you @sirine707:

It sounds like the graph templates you're attempting to customize are not used by Highcharts, which is what Performance graphs use for rendering. You should be able to get graphs using your custom graph template by reverting to the older style of graphing which is not default in XI but is still supported.

In XI go to the Admin > System Config> System Settings > Theme & Display Tab -- and uncheck this box:
"Use Highcharts for Performance graphs page and host/service detail pages (host/service popup graph always uses Highcharts)"

This will revert you to our "old" style of graphs for status details, which should let you get the graph you're looking for on the service using your custom plugin.

If your goal is to create custom graphs beyond what Nagios XI offers, you might consider:
Grafana: Can pull data from RRDTool or other sources like InfluxDB, Prometheus, or MySQL for more flexible and dynamic visualizations.
PNP4Nagios: A common add-on for Nagios that enhances graphing capabilities. block blast unblocked
Custom Scripts: Exporting RRD data to CSV or another format and using Python (Matplotlib) or JavaScript (D3.js) for visualization.