Add support for MariaDB GTID in slave status

Author: etam

collector/slave_status.go

@@ -20,6 +20,7 @@ import (
 	"database/sql"
 	"fmt"
 	"log/slog"
+	"strconv"
 	"strings"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -139,9 +140,46 @@ func (ScrapeSlaveStatus) Scrape(ctx context.Context, instance *instance, ch chan
 				)
 			}
 		}
+
+		ScrapeMariaDBGtid(scanArgs, slaveCols, "Gtid_IO_Pos", ch, masterHost, masterUUID, channelName, connectionName)
+		ScrapeMariaDBGtid(scanArgs, slaveCols, "Gtid_Slave_Pos", ch, masterHost, masterUUID, channelName, connectionName)
 	}
 	return nil
 }
 
+func ScrapeMariaDBGtid(scanArgs []interface{}, slaveCols []string, name string, ch chan<- prometheus.Metric, masterHost string, masterUUID string, channelName string, connectionName string) {
+	value := columnValue(scanArgs, slaveCols, name)
+	if value == "" {
+		return
+	}
+
+	for _, gtid := range strings.Split(value, ",") {
+		parts := strings.Split(gtid, "-")
+		if len(parts) != 3 {
+			continue
+		}
+
+		domainID := parts[0]
+		serverID := parts[1]
+
+		sequence_num, err := strconv.ParseUint(parts[2], 10, 64)
+		if err != nil {
+			continue
+		}
+
+		ch <- prometheus.MustNewConstMetric(
+			prometheus.NewDesc(
+				prometheus.BuildFQName(namespace, slaveStatus, strings.ToLower(name)),
+				fmt.Sprintf("%s metric from SHOW SLAVE STATUS.", name),
+				[]string{"master_host", "master_uuid", "channel_name", "connection_name", "domain_id", "server_id"},
+				nil,
+			),
+			prometheus.GaugeValue,
+			float64(sequence_num),
+			masterHost, masterUUID, channelName, connectionName, domainID, serverID,
+		)
+	}
+}
+
 // check interface
 var _ Scraper = ScrapeSlaveStatus{}

collector/slave_status_test.go

@@ -32,9 +32,9 @@ func TestScrapeSlaveStatus(t *testing.T) {
 	defer db.Close()
 	inst := &instance{db: db}
 
-	columns := []string{"Master_Host", "Read_Master_Log_Pos", "Slave_IO_Running", "Slave_SQL_Running", "Seconds_Behind_Master"}
+	columns := []string{"Master_Host", "Read_Master_Log_Pos", "Slave_IO_Running", "Slave_SQL_Running", "Seconds_Behind_Master", "Gtid_IO_Pos"}
 	rows := sqlmock.NewRows(columns).
-		AddRow("127.0.0.1", "1", "Connecting", "Yes", "2")
+		AddRow("127.0.0.1", "1", "Connecting", "Yes", "2", "0-1-2,3-4-5")
 	mock.ExpectQuery(sanitizeQuery("SHOW SLAVE STATUS")).WillReturnRows(rows)
 
 	ch := make(chan prometheus.Metric)
@@ -50,6 +50,8 @@ func TestScrapeSlaveStatus(t *testing.T) {
 		{labels: labelMap{"channel_name": "", "connection_name": "", "master_host": "127.0.0.1", "master_uuid": ""}, value: 0, metricType: dto.MetricType_UNTYPED},
 		{labels: labelMap{"channel_name": "", "connection_name": "", "master_host": "127.0.0.1", "master_uuid": ""}, value: 1, metricType: dto.MetricType_UNTYPED},
 		{labels: labelMap{"channel_name": "", "connection_name": "", "master_host": "127.0.0.1", "master_uuid": ""}, value: 2, metricType: dto.MetricType_UNTYPED},
+		{labels: labelMap{"channel_name": "", "connection_name": "", "master_host": "127.0.0.1", "master_uuid": "", "domain_id": "0", "server_id": "1"}, value: 2, metricType: dto.MetricType_GAUGE},
+		{labels: labelMap{"channel_name": "", "connection_name": "", "master_host": "127.0.0.1", "master_uuid": "", "domain_id": "3", "server_id": "4"}, value: 5, metricType: dto.MetricType_GAUGE},
 	}
 	convey.Convey("Metrics comparison", t, func() {
 		for _, expect := range counterExpected {