Add a gtid transaction counter based on the @@gtid_executed global variable

README.md

@@ -96,6 +96,7 @@ collect.engine_innodb_status                                 | 5.1           | C
 collect.engine_tokudb_status                                 | 5.6           | Collect from SHOW ENGINE TOKUDB STATUS.
 collect.global_status                                        | 5.1           | Collect from SHOW GLOBAL STATUS (Enabled by default)
 collect.global_variables                                     | 5.1           | Collect from SHOW GLOBAL VARIABLES (Enabled by default)
+collect.gtid_transactions                                    | 5.6           | Collect a transaction count from @gtid_executed.
 collect.heartbeat                                            | 5.1           | Collect from [heartbeat](#heartbeat).
 collect.heartbeat.database                                   | 5.1           | Database from where to collect heartbeat data. (default: heartbeat)
 collect.heartbeat.table                                      | 5.1           | Table from where to collect heartbeat data. (default: heartbeat)

collector/mysql_gtid.go

@@ -0,0 +1,87 @@
+// Copyright 2025 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.
+
+// Scrape a transaction counter from the gtid_executed
+
+package collector
+
+import (
+	"context"
+	"log/slog"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/sjmudd/mysqlgtid"
+)
+
+const (
+	// transactions is the Metric subsystem we use.
+	prometheusSubsystem = "gtid"
+	prometheusName      = "transactions"
+	// gtidTransactionCountQuery is the query used to fetch gtid_executed.
+	// With this value we can convert it to an incremental transaction counter.
+	gtidTransactionCountQuery = "SELECT @@gtid_executed"
+)
+
+var (
+	// Metric descriptors.
+	GtidTransactionCounterDesc = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, prometheusSubsystem, prometheusName),
+		"Number of GTID transactions",
+		[]string{}, nil,
+	)
+)
+
+// ScrapeGtidExecuted scrapes transaction count from @@gtid_executed.
+type ScrapeGtidExecuted struct{}
+
+// Name of the Scraper. Should be unique.
+func (ScrapeGtidExecuted) Name() string {
+	return "gtid_transactions"
+}
+
+// Help describes the role of the Scraper.
+func (ScrapeGtidExecuted) Help() string {
+	return "Number of GTID transactions"
+}
+
+// Version of MySQL from which scraper is available.
+func (ScrapeGtidExecuted) Version() float64 {
+	return 5.6
+}
+
+// Scrape collects data from database connection and sends it over channel as prometheus metric.
+func (ScrapeGtidExecuted) Scrape(ctx context.Context, instance *instance, ch chan<- prometheus.Metric, logger *slog.Logger) error {
+	var gtidExecuted string
+
+	db := instance.getDB()
+	if err := db.QueryRowContext(ctx, gtidTransactionCountQuery).Scan(&gtidExecuted); err != nil {
+		return err
+	}
+
+	// convert into a counter
+	gtidExecutedTransactionCounterIntVal, err := mysqlgtid.TransactionCount(gtidExecuted)
+	if err != nil {
+		return err
+	}
+
+	ch <- prometheus.MustNewConstMetric(
+		GtidTransactionCounterDesc,
+		prometheus.CounterValue,
+		float64(gtidExecutedTransactionCounterIntVal),
+	)
+
+	return nil
+}
+
+// check interface
+var _ Scraper = ScrapeGtidExecuted{}

collector/mysql_gtid_test.go

@@ -0,0 +1,90 @@
+// Copyright 2025 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/prometheus/common/promslog"
+	"github.com/smartystreets/goconvey/convey"
+)
+
+// TestScrapeGtidExecuted tests ScrapeGtidExecuted behaviour
+func TestScrapeGtidExecuted(t *testing.T) {
+
+	tests := []struct {
+		name     string
+		gtidSet  string
+		expected float64
+	}{
+		{"empty_set", "", 0},
+		{"single_uuid_and_range", `uuid1:1-1000`, 1000},
+		{"multiple_uuid_single_range", `uuid1:1-1000,
+	uuid1:1001-2000`, 2000},
+		{"single_uuid_with_ranges", `uuid1:1-1000,2001-4000`, 3000},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			db, mock, err := sqlmock.New()
+			if err != nil {
+				t.Fatalf("error opening a stub database connection: %s", err)
+			}
+			defer db.Close()
+
+			inst := &instance{db: db}
+
+			columns := []string{"@@gtid_executed"}
+			rows := sqlmock.NewRows(columns).
+				AddRow(test.gtidSet)
+			mock.ExpectQuery(gtidTransactionCountQuery).
+				WithArgs().
+				WillReturnRows(rows)
+
+			ch := make(chan prometheus.Metric)
+			go func() {
+				if err = (ScrapeGtidExecuted{}).Scrape(context.Background(), inst, ch, promslog.NewNopLogger()); err != nil {
+					t.Errorf("error calling function on test: %s", err)
+				}
+				close(ch)
+			}()
+
+			counterExpected := []MetricResult{
+				{
+					labels:     labelMap{},
+					value:      test.expected,
+					metricType: dto.MetricType_COUNTER,
+				},
+			}
+
+			convey.Convey("Metrics comparison", t, func() {
+				for _, expect := range counterExpected {
+					got := readMetric(<-ch)
+					convey.So(got, convey.ShouldResemble, expect)
+				}
+			})
+
+			// Ensure all SQL queries were executed
+			if err := mock.ExpectationsWereMet(); err != nil {
+				t.Errorf("there were unfulfilled expectations: %s", err)
+			}
+		})
+
+	}
+
+}

go.mod

@@ -1,6 +1,6 @@
 module github.com/prometheus/mysqld_exporter
 
-go 1.23.0
+go 1.23.3
 
 require (
 	github.com/DATA-DOG/go-sqlmock v1.5.2
@@ -13,6 +13,7 @@ require (
 	github.com/prometheus/client_model v0.6.2
 	github.com/prometheus/common v0.65.0
 	github.com/prometheus/exporter-toolkit v0.13.2
+	github.com/sjmudd/mysqlgtid v0.1.0
 	github.com/smartystreets/goconvey v1.8.1
 	gopkg.in/ini.v1 v1.67.0
 )

go.sum

@@ -61,6 +61,8 @@ github.com/prometheus/procfs v0.15.1 h1:YagwOFzUgYfKKHX6Dr+sHT7km/hxC76UB0leargg
 github.com/prometheus/procfs v0.15.1/go.mod h1:fB45yRUv8NstnjriLhBQLuOUt+WW4BsoGhij/e3PBqk=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
+github.com/sjmudd/mysqlgtid v0.1.0 h1:L/jycKaCUcO0vGBT1UuUuuZR6XmN/3SQpbO7IarPVu0=
+github.com/sjmudd/mysqlgtid v0.1.0/go.mod h1:+guZnxmozw/hUgPZXSSryyRL2o3pBNC6aoVh1QlNg0E=
 github.com/smarty/assertions v1.15.0 h1:cR//PqUBUiQRakZWqBiFFQ9wb8emQGDb0HeGdqGByCY=
 github.com/smarty/assertions v1.15.0/go.mod h1:yABtdzeQs6l1brC900WlRNwj6ZR55d7B+E8C6HtKdec=
 github.com/smartystreets/goconvey v1.8.1 h1:qGjIddxOk4grTu9JPOU31tVfq3cNdBlNa5sSznIX1xY=

mysqld_exporter.go

@@ -105,6 +105,7 @@ var scrapers = map[collector.Scraper]bool{
 	collector.ScrapeSlaveHosts{}:                          false,
 	collector.ScrapeReplicaHost{}:                         false,
 	collector.ScrapeRocksDBPerfContext{}:                  false,
+	collector.ScrapeGtidExecuted{}:                        false,
 }
 
 func filterScrapers(scrapers []collector.Scraper, collectParams []string) []collector.Scraper {