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Collect idle_in_transaction_time from PG >= 15
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idle_in_transaction_time was added to pg_stat_database in pg 15

Signed-off-by: Alexander J. Maidak <amaidak@equinix.com>
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@ajmaidak
ajmaidak committed Oct 17, 2024
1 parent 3be4edc commit 69c4119
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Showing 2 changed files with 143 additions and 1 deletion.
34 changes: 33 additions & 1 deletion collector/pg_stat_database.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -218,6 +218,15 @@ var (
[]string{"datid", "datname"},
prometheus.Labels{},
)
statDatabaseIdleInTransaction = prometheus.NewDesc(prometheus.BuildFQName(
namespace,
statDatabaseSubsystem,
"idle_in_transaction_time_seconds_total",
),
"Time spent idling while in a transaction in this database, in seconds",
[]string{"datid", "datname"},
prometheus.Labels{},
)
)

func statDatabaseQuery(columns []string) string {
Expand Down Expand Up @@ -254,6 +263,11 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
columns = append(columns, "active_time")
}

idleInTransactionTimeAvail := instance.version.GTE(semver.MustParse("15.0.0"))
if idleInTransactionTimeAvail {
columns = append(columns, "idle_in_transaction_time")
}

rows, err := db.QueryContext(ctx,
statDatabaseQuery(columns),
)
Expand All @@ -264,7 +278,7 @@ 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, activeTime sql.NullFloat64
var numBackends, xactCommit, xactRollback, blksRead, blksHit, tupReturned, tupFetched, tupInserted, tupUpdated, tupDeleted, conflicts, tempFiles, tempBytes, deadlocks, blkReadTime, blkWriteTime, activeTime, idleInTransactionTime sql.NullFloat64
var statsReset sql.NullTime

r := []any{
Expand Down Expand Up @@ -293,6 +307,10 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
r = append(r, &activeTime)
}

if idleInTransactionTimeAvail {
r = append(r, &idleInTransactionTime)
}

err := rows.Scan(r...)
if err != nil {
return err
Expand Down Expand Up @@ -375,6 +393,11 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
continue
}

if idleInTransactionTimeAvail && !idleInTransactionTime.Valid {
level.Debug(c.log).Log("msg", "Skipping collecting metric because it has no idle_in_transaction_time")
continue
}

statsResetMetric := 0.0
if !statsReset.Valid {
level.Debug(c.log).Log("msg", "No metric for stats_reset, will collect 0 instead")
Expand Down Expand Up @@ -512,6 +535,15 @@ func (c *PGStatDatabaseCollector) Update(ctx context.Context, instance *instance
labels...,
)
}

if idleInTransactionTimeAvail {
ch <- prometheus.MustNewConstMetric(
statDatabaseIdleInTransaction,
prometheus.CounterValue,
idleInTransactionTime.Float64/1000.0,
labels...,
)
}
}
return nil
}
110 changes: 110 additions & 0 deletions collector/pg_stat_database_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -132,6 +132,116 @@ func TestPGStatDatabaseCollector(t *testing.T) {
}
}

func TestPGStatDatabaseCollectorCollectsIdleTime(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, version: semver.MustParse("15.0.0")}

columns := []string{
"datid",
"datname",
"numbackends",
"xact_commit",
"xact_rollback",
"blks_read",
"blks_hit",
"tup_returned",
"tup_fetched",
"tup_inserted",
"tup_updated",
"tup_deleted",
"conflicts",
"temp_files",
"temp_bytes",
"deadlocks",
"blk_read_time",
"blk_write_time",
"stats_reset",
"active_time",
"idle_in_transaction_time",
}

srT, err := time.Parse("2006-01-02 15:04:05.00000-07", "2023-05-25 17:10:42.81132-07")
if err != nil {
t.Fatalf("Error parsing time: %s", err)
}

rows := sqlmock.NewRows(columns).
AddRow(
"pid",
"postgres",
354,
4945,
289097744,
1242257,
int64(3275602074),
89320867,
450139,
2034563757,
0,
int64(2725688749),
23,
52,
74,
925,
16,
823,
srT,
33,
123,
)

mock.ExpectQuery(sanitizeQuery(statDatabaseQuery(columns))).WillReturnRows(rows)

ch := make(chan prometheus.Metric)
go func() {
defer close(ch)
c := PGStatDatabaseCollector{
log: log.With(log.NewNopLogger(), "collector", "pg_stat_database"),
}

if err := c.Update(context.Background(), inst, ch); err != nil {
t.Errorf("Error calling PGStatDatabaseCollector.Update: %s", err)
}
}()

expected := []MetricResult{
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_GAUGE, value: 354},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 4945},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 289097744},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 1242257},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 3275602074},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 89320867},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 450139},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 2034563757},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 2725688749},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 23},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 52},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 74},
{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: 1685059842},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0.033},
{labels: labelMap{"datid": "pid", "datname": "postgres"}, metricType: dto.MetricType_COUNTER, value: 0.123},
}

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 TestPGStatDatabaseCollectorNullValues(t *testing.T) {
db, mock, err := sqlmock.New()
if err != nil {
Expand Down

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