From 299ac3feab2f62ccee95a217dc423f3ad2bc9841 Mon Sep 17 00:00:00 2001 From: Michael Todorovic Date: Fri, 4 Oct 2024 15:55:13 +0200 Subject: [PATCH] feat: add support for pg_stat_user_indexes --- README.md | 3 + collector/pg_stat_user_indexes.go | 192 +++++++++++++++++++++++++ collector/pg_stat_user_indexes_test.go | 81 +++++++++++ 3 files changed, 276 insertions(+) create mode 100644 collector/pg_stat_user_indexes.go create mode 100644 collector/pg_stat_user_indexes_test.go diff --git a/README.md b/README.md index 4c464e210..53c85c303 100644 --- a/README.md +++ b/README.md @@ -147,6 +147,9 @@ This will build the docker image as `prometheuscommunity/postgres_exporter:${bra * `[no-]collector.stat_statements` Enable the `stat_statements` collector (default: disabled). +* `[no-]collector.stat_user_indexes` + Enable the `stat_user_indexes` collector (default: disabled). + * `[no-]collector.stat_user_tables` Enable the `stat_user_tables` collector (default: enabled). diff --git a/collector/pg_stat_user_indexes.go b/collector/pg_stat_user_indexes.go new file mode 100644 index 000000000..29a315db8 --- /dev/null +++ b/collector/pg_stat_user_indexes.go @@ -0,0 +1,192 @@ +// 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" + "fmt" + "strings" + + "github.com/blang/semver/v4" + "github.com/go-kit/log" + "github.com/go-kit/log/level" + "github.com/prometheus/client_golang/prometheus" +) + +func init() { + registerCollector(statUserIndexesSubsystem, defaultDisabled, NewPGStatUserIndexesCollector) +} + +type PGStatUserIndexesCollector struct { + log log.Logger +} + +const statUserIndexesSubsystem = "stat_user_indexes" + +func NewPGStatUserIndexesCollector(config collectorConfig) (Collector, error) { + return &PGStatUserIndexesCollector{log: config.logger}, nil +} + +var ( + statUserIndexesIdxScan = prometheus.NewDesc( + prometheus.BuildFQName(namespace, statUserIndexesSubsystem, "idx_scan_total"), + "Number of scans for this index", + []string{"datname", "schemaname", "relname", "indexrelname"}, + prometheus.Labels{}, + ) + + statUserIndexesLastIdxScan = prometheus.NewDesc( + prometheus.BuildFQName(namespace, statUserIndexesSubsystem, "last_idx_scan_time"), + "Last timestamp of scan for this index", + []string{"datname", "schemaname", "relname", "indexrelname"}, + prometheus.Labels{}, + ) + + statUserIndexesIdxTupRead = prometheus.NewDesc( + prometheus.BuildFQName(namespace, statUserIndexesSubsystem, "idx_tup_read"), + "Number of tuples read for this index", + []string{"datname", "schemaname", "relname", "indexrelname"}, + prometheus.Labels{}, + ) + + statUserIndexesIdxTupFetch = prometheus.NewDesc( + prometheus.BuildFQName(namespace, statUserIndexesSubsystem, "idx_tup_fetch"), + "Number of tuples fetch for this index", + []string{"datname", "schemaname", "relname", "indexrelname"}, + prometheus.Labels{}, + ) +) + +func statUserIndexesQuery(columns []string) string { + return fmt.Sprintf("SELECT %s FROM pg_stat_user_indexes;", strings.Join(columns, ",")) +} + +func (c *PGStatUserIndexesCollector) Update(ctx context.Context, instance *instance, ch chan<- prometheus.Metric) error { + db := instance.getDB() + + columns := []string{ + "current_database() datname", + "schemaname", + "relname", + "indexrelname", + "idx_scan", + "idx_tup_read", + "idx_tup_fetch", + } + + lastIdxScanAvail := instance.version.GTE(semver.MustParse("16.0.0")) + if lastIdxScanAvail { + columns = append(columns, "date_part('epoch', last_idx_scan) as last_idx_scan") + } + + rows, err := db.QueryContext(ctx, + statUserIndexesQuery(columns), + ) + + if err != nil { + return err + } + defer rows.Close() + for rows.Next() { + var datname, schemaname, relname, indexrelname sql.NullString + var idxScan, lastIdxScan, idxTupRead, idxTupFetch sql.NullFloat64 + + r := []any{ + &datname, + &schemaname, + &relname, + &indexrelname, + &idxScan, + &idxTupRead, + &idxTupFetch, + } + + if lastIdxScanAvail { + r = append(r, &lastIdxScan) + } + + if err := rows.Scan(r...); err != nil { + return err + } + datnameLabel := "unknown" + if datname.Valid { + datnameLabel = datname.String + } + schemanameLabel := "unknown" + if schemaname.Valid { + schemanameLabel = schemaname.String + } + relnameLabel := "unknown" + if relname.Valid { + relnameLabel = relname.String + } + indexrelnameLabel := "unknown" + if indexrelname.Valid { + indexrelnameLabel = indexrelname.String + } + + if lastIdxScanAvail && !lastIdxScan.Valid { + level.Debug(c.log).Log("msg", "Skipping collecting metric because it has no active_time") + continue + } + + labels := []string{datnameLabel, schemanameLabel, relnameLabel, indexrelnameLabel} + + idxScanMetric := 0.0 + if idxScan.Valid { + idxScanMetric = idxScan.Float64 + } + ch <- prometheus.MustNewConstMetric( + statUserIndexesIdxScan, + prometheus.CounterValue, + idxScanMetric, + labels..., + ) + + idxTupReadMetric := 0.0 + if idxTupRead.Valid { + idxTupReadMetric = idxTupRead.Float64 + } + ch <- prometheus.MustNewConstMetric( + statUserIndexesIdxTupRead, + prometheus.CounterValue, + idxTupReadMetric, + labels..., + ) + + idxTupFetchMetric := 0.0 + if idxTupFetch.Valid { + idxTupFetchMetric = idxTupFetch.Float64 + } + ch <- prometheus.MustNewConstMetric( + statUserIndexesIdxTupFetch, + prometheus.CounterValue, + idxTupFetchMetric, + labels..., + ) + + if lastIdxScanAvail { + ch <- prometheus.MustNewConstMetric( + statUserIndexesLastIdxScan, + prometheus.CounterValue, + lastIdxScan.Float64, + labels..., + ) + } + } + if err := rows.Err(); err != nil { + return err + } + return nil +} diff --git a/collector/pg_stat_user_indexes_test.go b/collector/pg_stat_user_indexes_test.go new file mode 100644 index 000000000..c30914e44 --- /dev/null +++ b/collector/pg_stat_user_indexes_test.go @@ -0,0 +1,81 @@ +// 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" + "testing" + + "github.com/DATA-DOG/go-sqlmock" + "github.com/prometheus/client_golang/prometheus" + dto "github.com/prometheus/client_model/go" + "github.com/smartystreets/goconvey/convey" +) + +func TestPgStatUserIndexesCollector(t *testing.T) { + db, mock, err := sqlmock.New() + if err != nil { + t.Fatalf("Error opening a stub db connection: %s", err) + } + defer db.Close() + inst := &instance{db: db} + + columns := []string{ + "datname", + "schemaname", + "relname", + "indexrelname", + "idx_scan", + "idx_tup_read", + "idx_tup_fetch", + } + rows := sqlmock.NewRows(columns). + AddRow("postgres", "public", "pgtest_accounts", "pgtest_accounts_pkey", "8", "9", "5") + + cols := []string{ + "current_database() datname", + "schemaname", + "relname", + "indexrelname", + "idx_scan", + "idx_tup_read", + "idx_tup_fetch", + } + + mock.ExpectQuery(sanitizeQuery(statUserIndexesQuery(cols))).WillReturnRows(rows) + + ch := make(chan prometheus.Metric) + go func() { + defer close(ch) + c := PGStatUserIndexesCollector{} + + if err := c.Update(context.Background(), inst, ch); err != nil { + t.Errorf("Error calling PGStatUserIndexesCollector.Update: %s", err) + } + }() + + expected := []MetricResult{ + {labels: labelMap{"datname": "postgres", "indexrelname": "pgtest_accounts_pkey", "schemaname": "public", "relname": "pgtest_accounts"}, value: 8, metricType: dto.MetricType_COUNTER}, + {labels: labelMap{"datname": "postgres", "indexrelname": "pgtest_accounts_pkey", "schemaname": "public", "relname": "pgtest_accounts"}, value: 9, metricType: dto.MetricType_COUNTER}, + {labels: labelMap{"datname": "postgres", "indexrelname": "pgtest_accounts_pkey", "schemaname": "public", "relname": "pgtest_accounts"}, value: 5, metricType: dto.MetricType_COUNTER}, + } + convey.Convey("Metrics comparison", t, func() { + for _, expect := range expected { + m := readMetric(<-ch) + convey.So(expect, convey.ShouldResemble, m) + } + }) + if err := mock.ExpectationsWereMet(); err != nil { + t.Errorf("there were unfulfilled exceptions: %s", err) + } +}