From 704dabf908195d4583d28b522e717ffc986ada8a Mon Sep 17 00:00:00 2001 From: Felix Yuan Date: Wed, 28 Jun 2023 11:15:12 -0700 Subject: [PATCH] Total relation size collector and test Signed-off-by: Felix Yuan --- collector/pg_total_relation_size.go | 98 +++++++++++++++++++++ collector/pg_total_relation_size_test.go | 103 +++++++++++++++++++++++ 2 files changed, 201 insertions(+) create mode 100644 collector/pg_total_relation_size.go create mode 100644 collector/pg_total_relation_size_test.go diff --git a/collector/pg_total_relation_size.go b/collector/pg_total_relation_size.go new file mode 100644 index 000000000..b9024833e --- /dev/null +++ b/collector/pg_total_relation_size.go @@ -0,0 +1,98 @@ +// 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 totalRelationSizeSubsystem = "total_relation_size" + +func init() { + registerCollector(totalRelationSizeSubsystem, defaultDisabled, NewPGTotalRelationSizeCollector) +} + +type PGTotalRelationSizeCollector struct { + log log.Logger +} + +func NewPGTotalRelationSizeCollector(config collectorConfig) (Collector, error) { + return &PGTotalRelationSizeCollector{log: config.logger}, nil +} + +var ( + totalRelationSizeBytes = prometheus.NewDesc( + prometheus.BuildFQName(namespace, totalRelationSizeSubsystem, "bytes"), + "total disk space usage for the specified table and associated indexes", + []string{"schemaname", "relname"}, + prometheus.Labels{}, + ) + + totalRelationSizeQuery = ` + SELECT + relnamespace::regnamespace as schemaname, + relname as relname, + pg_total_relation_size(oid) bytes + FROM pg_class + WHERE relkind = 'r'; + ` +) + +func (PGTotalRelationSizeCollector) Update(ctx context.Context, instance *instance, ch chan<- prometheus.Metric) error { + db := instance.getDB() + rows, err := db.QueryContext(ctx, + totalRelationSizeQuery) + + if err != nil { + return err + } + defer rows.Close() + + for rows.Next() { + var schemaname, relname sql.NullString + var bytes sql.NullFloat64 + + if err := rows.Scan(&schemaname, &relname, &bytes); err != nil { + return err + } + schemanameLabel := "unknown" + if schemaname.Valid { + schemanameLabel = schemaname.String + } + relnameLabel := "unknown" + if relname.Valid { + relnameLabel = relname.String + } + labels := []string{schemanameLabel, relnameLabel} + + bytesMetric := 0.0 + if bytes.Valid { + bytesMetric = bytes.Float64 + } + ch <- prometheus.MustNewConstMetric( + totalRelationSizeBytes, + prometheus.GaugeValue, + bytesMetric, + labels..., + ) + } + if err := rows.Err(); err != nil { + return err + } + return nil +} diff --git a/collector/pg_total_relation_size_test.go b/collector/pg_total_relation_size_test.go new file mode 100644 index 000000000..c13bd8045 --- /dev/null +++ b/collector/pg_total_relation_size_test.go @@ -0,0 +1,103 @@ +// 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 TestPgTotalRelationSizeCollector(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{ + "schemaname", + "relname", + "bytes", + } + rows := sqlmock.NewRows(columns). + AddRow("public", "bar", 200) + + mock.ExpectQuery(sanitizeQuery(totalRelationSizeQuery)).WillReturnRows(rows) + + ch := make(chan prometheus.Metric) + go func() { + defer close(ch) + c := PGTotalRelationSizeCollector{} + + if err := c.Update(context.Background(), inst, ch); err != nil { + t.Errorf("Error calling PGTotalRelationSizeCollector.Update: %s", err) + } + }() + expected := []MetricResult{ + {labels: labelMap{"schemaname": "public", "relname": "bar"}, value: 200, metricType: dto.MetricType_GAUGE}, + } + 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) + } +} + +func TestPgTotalRelationSizeCollectorNull(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{ + "schemaname", + "relname", + "bytes", + } + rows := sqlmock.NewRows(columns). + AddRow(nil, nil, nil) + + mock.ExpectQuery(sanitizeQuery(totalRelationSizeQuery)).WillReturnRows(rows) + + ch := make(chan prometheus.Metric) + go func() { + defer close(ch) + c := PGTotalRelationSizeCollector{} + + if err := c.Update(context.Background(), inst, ch); err != nil { + t.Errorf("Error calling PGTotalRelationSizeCollector.Update: %s", err) + } + }() + expected := []MetricResult{ + {labels: labelMap{"schemaname": "unknown", "relname": "unknown"}, value: 0, metricType: dto.MetricType_GAUGE}, + } + 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) + } +}