Gitlab Collector: User Index io stats collector and test (#845)

* User Index io stats collector and test --------- Signed-off-by: Felix Yuan <felix.yuan@reddit.com>
2023-08-24 00:55:26 -07:00
parent 2402783205
commit ce74daee92
2 changed files with 227 additions and 0 deletions
--- a/collector/pg_statio_user_indexes.go
+++ b/collector/pg_statio_user_indexes.go
@@ -0,0 +1,118 @@
+// 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"
+)
+
+func init() {
+	registerCollector(statioUserIndexesSubsystem, defaultDisabled, NewPGStatioUserIndexesCollector)
+}
+
+type PGStatioUserIndexesCollector struct {
+	log log.Logger
+}
+
+const statioUserIndexesSubsystem = "statio_user_indexes"
+
+func NewPGStatioUserIndexesCollector(config collectorConfig) (Collector, error) {
+	return &PGStatioUserIndexesCollector{log: config.logger}, nil
+}
+
+var (
+	statioUserIndexesIdxBlksRead = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, statioUserIndexesSubsystem, "idx_blks_read_total"),
+		"Number of disk blocks read from this index",
+		[]string{"schemaname", "relname", "indexrelname"},
+		prometheus.Labels{},
+	)
+	statioUserIndexesIdxBlksHit = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, statioUserIndexesSubsystem, "idx_blks_hit_total"),
+		"Number of buffer hits in this index",
+		[]string{"schemaname", "relname", "indexrelname"},
+		prometheus.Labels{},
+	)
+
+	statioUserIndexesQuery = `
+	SELECT
+		schemaname,
+		relname,
+		indexrelname,
+		idx_blks_read,
+		idx_blks_hit
+	FROM pg_statio_user_indexes
+	`
+)
+
+func (c *PGStatioUserIndexesCollector) Update(ctx context.Context, instance *instance, ch chan<- prometheus.Metric) error {
+	db := instance.getDB()
+	rows, err := db.QueryContext(ctx,
+		statioUserIndexesQuery)
+
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var schemaname, relname, indexrelname sql.NullString
+		var idxBlksRead, idxBlksHit sql.NullFloat64
+
+		if err := rows.Scan(&schemaname, &relname, &indexrelname, &idxBlksRead, &idxBlksHit); err != nil {
+			return err
+		}
+		schemanameLabel := "unknown"
+		if schemaname.Valid {
+			schemanameLabel = schemaname.String
+		}
+		relnameLabel := "unknown"
+		if relname.Valid {
+			relnameLabel = relname.String
+		}
+		indexrelnameLabel := "unknown"
+		if indexrelname.Valid {
+			indexrelnameLabel = indexrelname.String
+		}
+		labels := []string{schemanameLabel, relnameLabel, indexrelnameLabel}
+
+		idxBlksReadMetric := 0.0
+		if idxBlksRead.Valid {
+			idxBlksReadMetric = idxBlksRead.Float64
+		}
+		ch <- prometheus.MustNewConstMetric(
+			statioUserIndexesIdxBlksRead,
+			prometheus.CounterValue,
+			idxBlksReadMetric,
+			labels...,
+		)
+
+		idxBlksHitMetric := 0.0
+		if idxBlksHit.Valid {
+			idxBlksHitMetric = idxBlksHit.Float64
+		}
+		ch <- prometheus.MustNewConstMetric(
+			statioUserIndexesIdxBlksHit,
+			prometheus.CounterValue,
+			idxBlksHitMetric,
+			labels...,
+		)
+	}
+	if err := rows.Err(); err != nil {
+		return err
+	}
+	return nil
+}