Gitlab Collector: Activity Summary Collector

collector/pg_stat_activity_summary.go

@@ -0,0 +1,152 @@
+// Copyright 2023 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package collector
+
+import (
+	"context"
+	"database/sql"
+
+	"github.com/go-kit/log"
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const statActivitySummarySubsystem = "stat_activity_summary"
+
+func init() {
+	registerCollector(statActivitySummarySubsystem, defaultEnabled, NewPGStatActivitySummaryCollector)
+}
+
+type PGStatActivitySummaryCollector struct {
+	log log.Logger
+}
+
+func NewPGStatActivitySummaryCollector(config collectorConfig) (Collector, error) {
+	return &PGStatActivitySummaryCollector{log: config.logger}, nil
+}
+
+var (
+	statActivitySummaryActiveCount = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, statActivitySummarySubsystem, "active"),
+		"Number of active queries at time of sample",
+		[]string{"usename", "application", "endpoint", "command", "state", "wait_event", "wait_event_type"},
+		prometheus.Labels{},
+	)
+	statActivitySummaryMaxTxAgeInSeconds = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, statActivitySummarySubsystem, "max_tx_age_in_seconds"),
+		"Number of active queries at time of sample",
+		[]string{"usename", "application", "endpoint", "command", "state", "wait_event", "wait_event_type"},
+		prometheus.Labels{},
+	)
+
+	statActivitySummaryQuery = `
+	SELECT
+		usename AS usename,
+		a.matches[1] AS application,
+		a.matches[2] AS endpoint,
+		a.matches[3] AS command,
+		a.state AS state,
+		a.wait_event AS wait_event,
+		a.wait_event_type AS wait_event_type,
+		COUNT(*) active_count,
+		MAX(age_in_seconds) AS max_tx_age_in_seconds
+	FROM (
+		SELECT
+			usename,
+			regexp_matches(query, '^\s*(?:\/\*(?:application:(\w+),?)?(?:correlation_id:\w+,?)?(?:jid:\w+,?)?(?:endpoint_id:([\w/\-\.:\#\s]+),?)?.*?\*\/)?\s*(\w+)') AS matches,
+			state,
+			wait_event,
+			wait_event_type,
+			EXTRACT(EPOCH FROM (clock_timestamp() - xact_start)) AS age_in_seconds
+			FROM
+			pg_catalog.pg_stat_activity
+		) a
+	GROUP BY usename, application, endpoint, command, state, wait_event, wait_event_type
+	ORDER BY active_count DESC
+	`
+)
+
+func (PGStatActivitySummaryCollector) Update(ctx context.Context, instance *instance, ch chan<- prometheus.Metric) error {
+	db := instance.getDB()
+	rows, err := db.QueryContext(ctx,
+		statActivitySummaryQuery)
+
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var usename, application, endpoint, command, state, waitEvent, waitEventType sql.NullString
+		var count, maxTxAge sql.NullFloat64
+
+		if err := rows.Scan(&usename, &application, &endpoint, &command, &state, &waitEvent, &waitEventType, &count, &maxTxAge); err != nil {
+			return err
+		}
+		usenameLabel := "unknown"
+		if usename.Valid {
+			usenameLabel = usename.String
+		}
+		applicationLabel := "unknown"
+		if application.Valid {
+			applicationLabel = application.String
+		}
+		endpointLabel := "unknown"
+		if endpoint.Valid {
+			endpointLabel = endpoint.String
+		}
+		commandLabel := "unknown"
+		if command.Valid {
+			commandLabel = command.String
+		}
+		stateLabel := "unknown"
+		if state.Valid {
+			stateLabel = state.String
+		}
+		waitEventLabel := "unknown"
+		if waitEvent.Valid {
+			waitEventLabel = waitEvent.String
+		}
+		waitEventTypeLabel := "unknown"
+		if waitEventType.Valid {
+			waitEventTypeLabel = waitEventType.String
+		}
+		labels := []string{usenameLabel, applicationLabel, endpointLabel, commandLabel, stateLabel, waitEventLabel, waitEventTypeLabel}
+
+		countMetric := 0.0
+		if count.Valid {
+			countMetric = count.Float64
+		}
+		ch <- prometheus.MustNewConstMetric(
+			statActivitySummaryActiveCount,
+			prometheus.GaugeValue,
+			countMetric,
+			labels...,
+		)
+
+		maxTxAgeMetric := 0.0
+		if maxTxAge.Valid {
+			maxTxAgeMetric = maxTxAge.Float64
+		}
+		ch <- prometheus.MustNewConstMetric(
+			statActivitySummaryMaxTxAgeInSeconds,
+			prometheus.GaugeValue,
+			maxTxAgeMetric,
+			labels...,
+		)
+	}
+	if err := rows.Err(); err != nil {
+		return err
+	}
+	return nil
+}