We're implementing Logstash 5.6.3 (upgrading from ELK 2.x) and now that we have access to logstash's rest endpoints I'd like some rudimentary monitoring of how our logstash nodes perform.
Theres a ton of stuff to choose from, but the problem I'm having is that I can't really find any good documentation on what the various counters actually mean. The "duration in millis" counter for instance, seems promising but I can't find any info about it. Is it an average counter? Or a total one? (the number seems to rise steadily so I'm guessing the latter).
Is there any documentation (that I've missed) covering how to use the logstash rest api to set up some rudimentary perf monitoring and what the counters actually mean?