adamrights / node-native-metrics

Optional native module for collecting low-level Node & V8 metrics

Native Metrics for New Relic Node Agent

This module provides hooks into the native layer of Node to provide metrics for the New Relic Node Agent. It gathers information that isn't available at the JS layer about the V8 virtual machine and the process health. It comes packaged with the New Relic Agent v2, and there is nothing that needs to be done. For Agent v1 you need only to install the module alongside newrelic.

Installation

npm install --save @newrelic/native-metrics

Note that this is a native module and thus must be compiled to function. Pre-built binaries are provided for Linux servers running supported versions of Node. If you are not using Linux or not using a supported version of Node, you will need to have a compiler installed on the machine where this is to be deployed. See node-gyp for more information on compiling native addons.

If you prepare and package deployments on one machine and install them on another, the two machines must have the same operating system and architecture. If they are not, you will need to re-build the native module after deploying in order to get the correct binaries.

Usage

var getMetricEmitter = require('@newrelic/native-metrics')

var emitter = getMetricEmitter()
if (emitter.gcEnabled) {
  emitter.on('gc', (gc) => console.log(gc.type + ': ' + gc.duration))
}
if (emitter.usageEnabled) {
  emitter.on('usage', (usage) => console.log(usage))
}
if (emitter.loopEnabled) {
  setInterval(() => {
    var loopMetrics = emitter.getLoopMetrics()
    console.log("Loop time:", loopMetrics.loop)
    console.log("IO wait time:", loopMetrics.ioWait)
  }, 1000)
}

The metric emitter keeps a referenced timer running for its periodic sampling events. For a graceful shutdown of the process call NativeMetricEmitter#unbind.

getMetricEmitter().unbind() // Process will now close gracefully.

If you would like to change the period of the sampling, simply unbind and then call NativeMetricEmitter#bind with the new period.

var emitter = getMetricEmitter({timeout: 15000})
emitter.unbind()
emitter.bind(10000) // Samples will now fire once every 10 seconds.

License

The New Relic native metrics module is free-to-use, proprietary software. Please see the full license (found in LICENSE) for details on its license and the licenses of its dependencies.