metrics

README

Task Metrics using Prometheus in Go

Table of Contents

• Introduction
• Features
• Code Structure
• Metrics Collectors
  • Counter
  • Gauge
  • Histogram
• Usage
  • Starting the Server
  • Registering Metrics
  • Updating Metrics

Introduction

This project provides a comprehensive metrics collection and reporting framework integrated with Prometheus for Go applications.

Features

• Different types of metrics collectors including Counter, Gauge, and Histogram.
• Built-in Prometheus server.
• Strong typing to prevent metrics misuse.
• Error handling and logging integrated with Uber's Zap library.
• Support for custom labels.
• Thread-safe metric updates with read-write mutexes.
• Auto-registering of metrics based on type.

Code Structure

• /metrics/collectors/: Contains the implementation of various metrics collectors (Counter, Gauge, Histogram).
• /metrics/handler.go: Contains the MetricHandler interface and taskMetrics UpdateMetric, IncrementMetric, and DecrementMetric methods for updating metrics.
• /metrics/prometheus.go: Defines the Prometheus server.
• /metrics/register.go: Responsible for registering metrics with the Prometheus server.

Metrics Collectors

Counter

• File: /metrics/collectors/counter.go
• Methods: Update
• Usage: Counters are cumulative metrics that can only increase.

Gauge

• File: /metrics/collectors/gauge.go
• Methods: Update, Inc, Dec
• Usage: Gauges are metrics that can arbitrarily go up and down.

Histogram

• File: /metrics/collectors/histogram.go
• Methods: Update
• Usage: Histograms count observations (like request durations or response sizes) and place them in configurable buckets.

Usage

Starting the Server

metricsServer := metrics.NewTaskMetrics("/metrics", "9090")
err := metricsServer.Start()
if err != nil {
    log.Fatal(err)
}

Registering Metrics

// Without labels
err = metricsServer.RegisterMetric("my_counter", "This is a counter metric", nil, &collectors.Counter{})

// With labels
err = metricsServer.RegisterMetric("my_counter_with_labels", "This is a counter metric with labels", []string{"label1", "label2"}, &collectors.Counter{})

// Register a gauge
err = metricsServer.RegisterMetric("my_gauge", "This is a gauge metric", nil, &collectors.Gauge{})

Updating Metrics

// Without labels
metricsServer.UpdateMetric("my_counter", 1)

// With labels
metricsServer.UpdateMetric("my_counter_with_labels", 1, "label1_value", "label2_value")

// Increment a gauge
metricsServer.IncrementMetric("my_gauge")

// Decrement a gauge
metricsServer.DecrementMetric("my_gauge")

Documentation

Index

• type IncrementDecrementHandler
• type MetricDetail
• type MetricHandler
• type TaskMetrics
  • func NewTaskMetrics(path string, port string) TaskMetrics

Types

type IncrementDecrementHandler

type IncrementDecrementHandler interface {
	MetricHandler
	Inc(collector prometheus.Collector, labels ...string) error
	Dec(collector prometheus.Collector, labels ...string) error
}

type MetricDetail

type MetricDetail struct {
	Collector prometheus.Collector
	Handler   MetricHandler
}

type MetricHandler

type MetricHandler interface {
	Update(collector prometheus.Collector, value float64, labels ...string) error
	Type() string
}

type TaskMetrics

type TaskMetrics interface {
	Start() error
	RegisterMetric(name string, help string, labels []string, handler MetricHandler) error
	UpdateMetric(name string, value float64, labels ...string) error
	IncrementMetric(name string, labels ...string) error
	DecrementMetric(name string, labels ...string) error
	Name() string
	Stop() error
}

func NewTaskMetrics

func NewTaskMetrics(path string, port string) TaskMetrics