Github user HeartSaVioR commented on a diff in the pull request: https://github.com/apache/storm/pull/2628#discussion_r180614324 --- Diff: docs/metrics_v2.md --- @@ -0,0 +1,149 @@ +--- +title: Metrics Reporting API v2 +layout: documentation +documentation: true +--- +Apache Storm version 1.2 introduced a new metrics system for reporting +internal statistics (e.g. acked, failed, emitted, transferred, disruptor queue metrics, etc.) as well as a +new API for user defined metrics. + +The new metrics system is based on [Dropwizard Metrics](http://metrics.dropwizard.io). + + +## User Defined Metrics +To allow users to define custom metrics, the following methods have been added to the `TopologyContext` +class, an instance of which is passed to spout's `open()` method and bolt's `prepare()` method: + + public Timer registerTimer(String name) + + public Histogram registerHistogram(String name) + + public Meter registerMeter(String name) + + public Counter registerCounter(String name) + + public Gauge registerGauge(String name, Gauge gauge) + +API documentation: [Timer](http://metrics.dropwizard.io/4.0.0/apidocs/com/codahale/metrics/Timer.html), +[Histogram](http://metrics.dropwizard.io/4.0.0/apidocs/com/codahale/metrics/Histogram.html), +[Meter](http://metrics.dropwizard.io/4.0.0/apidocs/com/codahale/metrics/Meter.html), +[Counter](http://metrics.dropwizard.io/4.0.0/apidocs/com/codahale/metrics/Counter.html), +[Guage](http://metrics.dropwizard.io/4.0.0/apidocs/com/codahale/metrics/Gauge.html) --- End diff -- nit: Guage -> Gauge. Missed spot while reviewing 1.x doc. Could you also please raise a patch for 1.x version too?