Breaking OpenNMS metric collection with SNMP
The most common question I get about OpenNMS at scale is some version of this: I have a lot of network equipment, I want SNMP performance data from all of it, how big does the box need to be? The honest answer used to be “it depends”, followed by a shrug about agent behavior.
What I reached for in those situations was the instrumentation log reader. It tells you two things about a running system: how long it takes to collect metrics from your agents, and how long it takes to persist them. The node inventory matters just as much. It tells you the node-to-interface ratio and how the metric collection is composed in your environment.
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