The configuration of the docker/go-metrics module allows for effective use of metrics collection in Go applications. Below are the detailed options and step-by-step instructions for configuring the module in a development environment.

Step 1: Importing the Module

To use the go-metrics package in a Go project, ensure the module is imported at the top of your Go file:

import "github.com/docker/go-metrics"

Step 2: Initialize the Metrics Collector

Begin by creating a metrics registry. This registry will be used to collect and store metrics.

registry := metrics.NewRegistry()

Step 3: Choosing a Metrics Reporter

You can report metrics to multiple back-end systems. Below is an example of using a StatsD reporter, which is commonly used for sending metrics.

Example: StatsD Reporter

First, you must install the go-metrics/statsd package:

go get github.com/docker/go-metrics/statsd

Next, initialize the StatsD reporter:

statsdAddr := "localhost:8125"
reporter, err := statsd.New(statsdAddr, registry)
if err != nil {
    log.Fatalf("Failed to create StatsD reporter: %v", err)
}

// Start the reporter
go reporter.Report()

Step 4: Creating Metrics

You can now create different types of metrics. Here are some common metrics that can be defined:

Counter

A counter is a metric that represents a single numerical value that only ever goes up. It’s useful for counting events.

counter := metrics.NewCounter()
registry.Register("my_counter", counter)
counter.Inc(1) // Increment the counter by 1

Gauge

A gauge is a metric that represents a single numerical value that can arbitrarily go up and down.

gauge := metrics.NewGauge()
registry.Register("my_gauge", gauge)
gauge.Update(10) // Set the gauge to 10

Histogram

A histogram samples observations and counts them in configurable buckets.

histogram := metrics.NewHistogram(metrics.NewUniformSample(1028))
registry.Register("my_histogram", histogram)
histogram.Update(5) // Record value 5

Step 5: Handling Metrics in Application Logic

Integrate metric recordings into your application’s flow. For example, you may want to record the duration of certain operations.

startTime := time.Now()

// Some operation
time.Sleep(2 * time.Second)

duration := time.Since(startTime)
histogram.Update(int64(duration.Seconds() * 1000)) // Record the duration in milliseconds

Step 6: Reporting

Ensure that your metrics are being reported correctly by checking the output in your chosen backend (e.g., StatsD). This step is crucial to validate that the metrics collection is functioning as expected.

Conclusion

By following this configuration guide, metrics will be effectively collected from your application for analysis and monitoring. Adjust the configuration according to your specific project requirements.

Source: GitHub repository for docker/go-metrics