pg_stat_database: added support for active_time counter (#961)

* feat(pg_stat_database): active time metric

---------

Signed-off-by: Jiri Sveceny <jiri.sveceny@icloud.com>

collector/pg_stat_database.go

@@ -206,6 +206,15 @@ var (
 		[]string{"datid", "datname"},
 		prometheus.Labels{},
 	)
+	statDatabaseActiveTime = prometheus.NewDesc(prometheus.BuildFQName(
+		namespace,
+		statDatabaseSubsystem,
+		"active_time_seconds_total",
+	),
+		"Time spent executing SQL statements in this database, in seconds",
+		[]string{"datid", "datname"},
+		prometheus.Labels{},
+	)
 
 	statDatabaseQuery = `
 		SELECT
@@ -227,6 +236,7 @@ var (
 			,deadlocks
 			,blk_read_time
 			,blk_write_time
+		    ,active_time
 			,stats_reset
 		FROM pg_stat_database;
 	`
@@ -244,7 +254,7 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
 
 	for rows.Next() {
 		var datid, datname sql.NullString
-		var numBackends, xactCommit, xactRollback, blksRead, blksHit, tupReturned, tupFetched, tupInserted, tupUpdated, tupDeleted, conflicts, tempFiles, tempBytes, deadlocks, blkReadTime, blkWriteTime sql.NullFloat64
+		var numBackends, xactCommit, xactRollback, blksRead, blksHit, tupReturned, tupFetched, tupInserted, tupUpdated, tupDeleted, conflicts, tempFiles, tempBytes, deadlocks, blkReadTime, blkWriteTime, activeTime sql.NullFloat64
 		var statsReset sql.NullTime
 
 		err := rows.Scan(
@@ -266,6 +276,7 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
 			&deadlocks,
 			&blkReadTime,
 			&blkWriteTime,
+			&activeTime,
 			&statsReset,
 		)
 		if err != nil {
@@ -344,6 +355,10 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
 			level.Debug(c.log).Log("msg", "Skipping collecting metric because it has no blk_write_time")
 			continue
 		}
+		if !activeTime.Valid {
+			level.Debug(c.log).Log("msg", "Skipping collecting metric because it has no active_time")
+			continue
+		}
 
 		statsResetMetric := 0.0
 		if !statsReset.Valid {
@@ -467,6 +482,13 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
 			labels...,
 		)
 
+		ch <- prometheus.MustNewConstMetric(
+			statDatabaseActiveTime,
+			prometheus.CounterValue,
+			activeTime.Float64/1000.0,
+			labels...,
+		)
+
 		ch <- prometheus.MustNewConstMetric(
 			statDatabaseStatsReset,
 			prometheus.CounterValue,

collector/pg_stat_database_test.go

@@ -52,6 +52,7 @@ func TestPGStatDatabaseCollector(t *testing.T) {
 		"deadlocks",
 		"blk_read_time",
 		"blk_write_time",
+		"active_time",
 		"stats_reset",
 	}
 
@@ -80,6 +81,7 @@ func TestPGStatDatabaseCollector(t *testing.T) {
 			925,
 			16,
 			823,
+			33,
 			srT)
 
 	mock.ExpectQuery(sanitizeQuery(statDatabaseQuery)).WillReturnRows(rows)
@@ -113,6 +115,7 @@ func TestPGStatDatabaseCollector(t *testing.T) {
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 925},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 16},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 823},
+		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0.033},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 1685059842},
 	}
 
@@ -159,6 +162,7 @@ func TestPGStatDatabaseCollectorNullValues(t *testing.T) {
 		"deadlocks",
 		"blk_read_time",
 		"blk_write_time",
+		"active_time",
 		"stats_reset",
 	}
 
@@ -182,6 +186,7 @@ func TestPGStatDatabaseCollectorNullValues(t *testing.T) {
 			925,
 			16,
 			823,
+			32,
 			srT).
 		AddRow(
 			"pid",
@@ -202,6 +207,7 @@ func TestPGStatDatabaseCollectorNullValues(t *testing.T) {
 			925,
 			16,
 			823,
+			32,
 			srT)
 	mock.ExpectQuery(sanitizeQuery(statDatabaseQuery)).WillReturnRows(rows)
 
@@ -234,6 +240,7 @@ func TestPGStatDatabaseCollectorNullValues(t *testing.T) {
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 925},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 16},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 823},
+		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0.032},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 1685059842},
 	}
 
@@ -275,6 +282,7 @@ func TestPGStatDatabaseCollectorRowLeakTest(t *testing.T) {
 		"deadlocks",
 		"blk_read_time",
 		"blk_write_time",
+		"active_time",
 		"stats_reset",
 	}
 
@@ -303,6 +311,7 @@ func TestPGStatDatabaseCollectorRowLeakTest(t *testing.T) {
 			925,
 			16,
 			823,
+			14,
 			srT).
 		AddRow(
 			nil,
@@ -324,6 +333,7 @@ func TestPGStatDatabaseCollectorRowLeakTest(t *testing.T) {
 			nil,
 			nil,
 			nil,
+			nil,
 		).
 		AddRow(
 			"pid",
@@ -344,6 +354,7 @@ func TestPGStatDatabaseCollectorRowLeakTest(t *testing.T) {
 			926,
 			17,
 			824,
+			15,
 			srT)
 	mock.ExpectQuery(sanitizeQuery(statDatabaseQuery)).WillReturnRows(rows)
 
@@ -376,7 +387,9 @@ func TestPGStatDatabaseCollectorRowLeakTest(t *testing.T) {
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 925},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 16},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 823},
+		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0.014},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 1685059842},
+
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_GAUGE, value: 355},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 4946},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 289097745},
@@ -393,6 +406,7 @@ func TestPGStatDatabaseCollectorRowLeakTest(t *testing.T) {
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 926},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 17},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 824},
+		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0.015},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 1685059842},
 	}
 
@@ -435,6 +449,7 @@ func TestPGStatDatabaseCollectorTestNilStatReset(t *testing.T) {
 		"deadlocks",
 		"blk_read_time",
 		"blk_write_time",
+		"active_time",
 		"stats_reset",
 	}
 
@@ -458,6 +473,7 @@ func TestPGStatDatabaseCollectorTestNilStatReset(t *testing.T) {
 			925,
 			16,
 			823,
+			7,
 			nil)
 
 	mock.ExpectQuery(sanitizeQuery(statDatabaseQuery)).WillReturnRows(rows)
@@ -491,6 +507,7 @@ func TestPGStatDatabaseCollectorTestNilStatReset(t *testing.T) {
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 925},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 16},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 823},
+		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0.007},
 		{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0},
 	}