pgx conn pool metrics

metrics.go

package db

import (
	"github.com/prometheus/client_golang/prometheus"
	"github.com/prometheus/client_golang/prometheus/promauto"
)

const (
	clientNamespace   = "db_client"
	querySubsystem    = "query"
	connPoolSubsystem = "conn_pool"
	connSubsystem     = "conn"
)

var (
	labels = []string{
		"method",
	}
	queryTime = promauto.NewHistogramVec(
		prometheus.HistogramOpts{
			Namespace: clientNamespace,
			Subsystem: querySubsystem,
			Name:      "execution_time",
			Help:      "The query execution time",
		},
		labels,
	)
	acquireConnTime = promauto.NewHistogramVec(
		prometheus.HistogramOpts{
			Namespace: clientNamespace,
			Subsystem: connSubsystem,
			Name:      "acquire_time",
			Help:      "The query execution time",
		},
		labels,
	)
	releaseConnTime = promauto.NewHistogramVec(
		prometheus.HistogramOpts{
			Namespace: clientNamespace,
			Subsystem: connSubsystem,
			Name:      "release_time",
			Help:      "The query execution time",
		},
		labels,
	)
)

// DB conn pool metrics.
var (
	acquireCount = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "acquire",
			Help:      "The cumulative count of successful acquires from the pool",
		},
	)
	acquiredCount = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "acquired",
			Help:      "The number of currently acquired connections in the pool",
		},
	)
	canceledAcquireCount = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "canceled_acquire_count",
			Help:      "The cumulative count of acquires from the pool that were canceled by a context",
		},
	)
	constructingConns = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "constructing",
			Help:      "The number of conns with construction in progress in the pool",
		},
	)
	emptyAcquireCount = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "empty_acquire_count",
			Help: "The cumulative count of successful acquires from the pool that waited for a resource to be " +
				"released or constructed because the pool was empty",
		},
	)
	idleConns = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "idle_conns",
			Help:      "The number of currently idle conns in the pool",
		},
	)
	maxConns = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "max_conns",
			Help:      "The maximum size of the pool",
		},
	)
	newConnsCount = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "new_conns_count",
			Help:      "The cumulative count of new connections opened",
		},
	)
	maxLifetimeDestroyCount = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "max_lifetime_destroy_count",
			Help:      "The cumulative count of connections destroyed because they exceeded MaxConnLifetime",
		},
	)
	maxIdleDestroyCount = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "max_idle_destroy_count",
			Help:      "The cumulative count of connections destroyed because they exceeded MaxConnIdleTime",
		},
	)
	totalConns = promauto.NewGauge(
		prometheus.GaugeOpts{
			Namespace: clientNamespace,
			Subsystem: connPoolSubsystem,
			Name:      "total_conns",
			Help:      "The total number of resources currently in the pool",
		},
	)
)

func queryTimeObserver(method string) prometheus.Observer {
	return queryTime.WithLabelValues(method)
}

func acquireConnTimeObserver(method string) prometheus.Observer {
	return acquireConnTime.WithLabelValues(method)
}

func releaseConnTimeObserver(method string) prometheus.Observer {
	return releaseConnTime.WithLabelValues(method)
}