metrics

InfluxDB Metrics Reporter

Package metrics is based on github.com/rcrowley/go-metrics and loosely inspired by github.com/vrischmann/go-metrics-influxdb.

Why?

Why write a new package if there already is a influxDB reporter?

The main difference between this package and vrischmann/go-metrics-influxdb is the API. This API is based on the go-metrics api and separates the registry (built into the Reporter) from the measurement/metrics. This enables a global Reporter and the creation of independant metrics distributed across the codebase without passing the Reporter around. A reporter can however be injected into a metric if needed.

With vrischmann/go-metrics-influxdb a reporter can only handle one measurement, meaning a new reporter is needed per measurement. This entails more goroutines and more calls to the influxDB in larger applications with multiple measurements.

Metrics collection has been optimized in regards to memory allocations to be fast and have less impact on the GC.

Usage

Global Reporter, metrics accross the application

func main() {
	// Initialize reporter and set it as default (global).
	rep := metrics.NewReporter("http://localhost:8086", "metrics", metrics.Interval(1*time.Second))
	metrics.SetDefaultReporter(rep)

	// Start reporting all registered or to be registered metrics.
	go rep.Run()
}

This creates a new reporter, sets it as the default reporter and starts it. The reporter will then start a Timer with given interval (default: 10 seconds). It will collect and report data from all metrics registered to the default reporter.

To register a metric use the following code anywhere in your server:

func registerGauge() {
	// Create and register a new gauge metric.
	metric := metrics.NewGauge("MetricName", metrics.WithMeasurement("MeasurementName"))
}

To update the data of the metric:

// Update the gauge metric value.
metric.Update(n)

For working code see the simple-gauge example.

Without Global Reporter

Some might prefer to inject the reporter with the metric instead of using a global reporter. This is supported with the WithReporter option when creating a metric:

rep := metrics.NewReporter("http://localhost:8086", "metrics")

// inject the reporter to be registered to:
metric := metrics.NewGauge("MetricName", metrics.WithMeasurement("MeasurementName"), metrics.WithReporter(rep))

For working code see the multiple-reporters example.

⚠ When creating multiple repoters use the Registry option to supply a new registry to each reporter. If multiple reporters are created without this option, they will all use the default registry: all reporters will report data from all the metrics.

Metrics

New metrics can be created with the metrics.NewXY functions.

For more information on the different metric types see go-metrics. If a go-metrics metric is not implemented here, please open an issue.