@pm2/node-runtime-stats

How does it work?

You can see most of the implementation details in src/nativeStats.cc. The plugin sets callbacks around GC invocations, and during the prepare and check phases of the event loop, tracks the amount of time spent in each.

Metrics collected

{
  "gc": {
    "collections": 0,
    "pause": 0,
    "oldCollections": 0,
    "oldPause": 0,
    "youngCollections": 0,
    "youngPause": 0
  },
  // duration of event loop tick
  "ticks": [
    20,
    10
  ]
}

Source

Inspired from https://github.com/heroku/heroku-nodejs-plugin