Files
SG Command f69cbea49f
Integration Tests / integration-test (pull_request) Successful in 2m33s
feat: add prometheus metrics and dashboard
2026-09-19 05:12:04 +02:00

131 lines
4.5 KiB
Go

// Package metrics defines the broker's Prometheus collectors and a small
// embedded HTTP server that exposes them, both as the standard /metrics
// exposition endpoint and as a single-page HTML dashboard.
package metrics
import (
"strconv"
"time"
"github.com/prometheus/client_golang/prometheus"
)
// Metrics holds every Prometheus collector the broker exposes. It is safe
// for concurrent use, and a nil *Metrics is safe to call methods on (all
// recording methods become no-ops), so callers that construct a Broker
// without metrics enabled don't need to special-case it.
type Metrics struct {
Registry *prometheus.Registry
jobsCompleted *prometheus.CounterVec
jobsFailed *prometheus.CounterVec
jobsRequeued *prometheus.CounterVec
jobDuration *prometheus.HistogramVec
jobsQueued *prometheus.GaugeVec
databaseCount prometheus.Gauge
queueCount *prometheus.GaugeVec
}
// New creates a Metrics instance with a fresh (non-global) registry, so
// multiple brokers can coexist in the same process -- e.g. in tests --
// without colliding on prometheus.DefaultRegisterer.
func New() *Metrics {
registry := prometheus.NewRegistry()
m := &Metrics{
Registry: registry,
jobsCompleted: prometheus.NewCounterVec(prometheus.CounterOpts{
Name: "broker_jobs_completed_total",
Help: "Total number of jobs that completed successfully.",
}, []string{"database", "job_group", "job_name"}),
jobsFailed: prometheus.NewCounterVec(prometheus.CounterOpts{
Name: "broker_jobs_failed_total",
Help: "Total number of jobs that were dead-lettered after exhausting retries.",
}, []string{"database", "job_group", "job_name"}),
jobsRequeued: prometheus.NewCounterVec(prometheus.CounterOpts{
Name: "broker_jobs_requeued_total",
Help: "Total number of job attempts that failed and were requeued for retry.",
}, []string{"database", "job_group", "job_name"}),
jobDuration: prometheus.NewHistogramVec(prometheus.HistogramOpts{
Name: "broker_job_duration_seconds",
Help: "Job execution duration in seconds, by group and name.",
Buckets: prometheus.DefBuckets,
}, []string{"database", "job_group", "job_name"}),
jobsQueued: prometheus.NewGaugeVec(prometheus.GaugeOpts{
Name: "broker_jobs_queued",
Help: "Current number of pending (not yet claimed) jobs, by database and queue.",
}, []string{"database", "queue"}),
databaseCount: prometheus.NewGauge(prometheus.GaugeOpts{
Name: "broker_databases",
Help: "Number of database instances managed by this broker process.",
}),
queueCount: prometheus.NewGaugeVec(prometheus.GaugeOpts{
Name: "broker_queues",
Help: "Number of queues configured for a database instance.",
}, []string{"database"}),
}
registry.MustRegister(
m.jobsCompleted,
m.jobsFailed,
m.jobsRequeued,
m.jobDuration,
m.jobsQueued,
m.databaseCount,
m.queueCount,
)
return m
}
// RecordJobCompleted records a successfully completed job attempt.
func (m *Metrics) RecordJobCompleted(database, group, name string, duration time.Duration) {
if m == nil {
return
}
m.jobsCompleted.WithLabelValues(database, group, name).Inc()
m.jobDuration.WithLabelValues(database, group, name).Observe(duration.Seconds())
}
// RecordJobFailed records a job attempt that was dead-lettered (attempts exhausted).
func (m *Metrics) RecordJobFailed(database, group, name string, duration time.Duration) {
if m == nil {
return
}
m.jobsFailed.WithLabelValues(database, group, name).Inc()
m.jobDuration.WithLabelValues(database, group, name).Observe(duration.Seconds())
}
// RecordJobRequeued records a job attempt that failed but was requeued for retry.
func (m *Metrics) RecordJobRequeued(database, group, name string, duration time.Duration) {
if m == nil {
return
}
m.jobsRequeued.WithLabelValues(database, group, name).Inc()
m.jobDuration.WithLabelValues(database, group, name).Observe(duration.Seconds())
}
// SetJobsQueued sets the current pending job count for a database/queue pair.
func (m *Metrics) SetJobsQueued(database string, queue int, count float64) {
if m == nil {
return
}
m.jobsQueued.WithLabelValues(database, strconv.Itoa(queue)).Set(count)
}
// SetDatabaseCount sets the number of database instances managed by this process.
func (m *Metrics) SetDatabaseCount(n int) {
if m == nil {
return
}
m.databaseCount.Set(float64(n))
}
// SetQueueCount sets the number of queues configured for a database instance.
func (m *Metrics) SetQueueCount(database string, n int) {
if m == nil {
return
}
m.queueCount.WithLabelValues(database).Set(float64(n))
}