From eba572ffa54551d124e68952ed618e6c7ef7e4bc Mon Sep 17 00:00:00 2001
From: Felix Yuan <felix.yuan@reddit.com>
Date: Wed, 28 Jun 2023 10:49:11 -0700
Subject: [PATCH] Long Running Transactions summary collector
Signed-off-by: Felix Yuan <felix.yuan@reddit.com>
---
.../pg_long_running_transactions_summary.go | 109 ++++++++++++++++++
1 file changed, 109 insertions(+)
create mode 100644 collector/pg_long_running_transactions_summary.go
diff --git a/collector/pg_long_running_transactions_summary.go b/collector/pg_long_running_transactions_summary.go
new file mode 100644
index 00000000..0fb70c71
--- /dev/null
+++ b/collector/pg_long_running_transactions_summary.go
@@ -0,0 +1,109 @@
+// 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 longRunningTransactionsSummarySubsystem = "long_running_transactions_summary"
+
+func init() {
+ registerCollector(longRunningTransactionsSummarySubsystem, defaultDisabled, NewPGLongRunningTransactionsSummaryCollector)
+}
+
+type PGLongRunningTransactionsSummaryCollector struct {
+ log log.Logger
+}
+
+func NewPGLongRunningTransactionsSummaryCollector(config collectorConfig) (Collector, error) {
+ return &PGLongRunningTransactionsSummaryCollector{log: config.logger}, nil
+}
+
+var (
+ longRunningTransactionsSummaryMaxAgeInSeconds = prometheus.NewDesc(
+ prometheus.BuildFQName(namespace, longRunningTransactionsSummarySubsystem, "max_age_in_seconds"),
+ "The current maximum transaction age in seconds",
+ []string{"application", "endpoint"},
+ prometheus.Labels{},
+ )
+
+ longRunningTransactionsSummaryQuery = `
+ SELECT
+ activity.matches[1] AS application,
+ activity.matches[2] AS endpoint,
+ MAX(age_in_seconds) AS max_age_in_seconds
+ FROM (
+ SELECT
+ regexp_matches(query, '^\s*(?:\/\*(?:application:(\w+),?)?(?:correlation_id:\w+,?)?(?:jid:\w+,?)?(?:endpoint_id:([\w/\-\.:\#\s]+),?)?.*?\*\/)?\s*(\w+)') AS matches,
+ EXTRACT(EPOCH FROM (clock_timestamp() - xact_start)) AS age_in_seconds
+ FROM
+ pg_catalog.pg_stat_activity
+ WHERE state <> 'idle'
+ AND (clock_timestamp() - xact_start) > '30 seconds'::interval
+ AND query NOT LIKE 'autovacuum:%'
+ ) activity
+ GROUP BY application, endpoint
+ ORDER BY max_age_in_seconds DESC
+ `
+)
+
+func (PGLongRunningTransactionsSummaryCollector) Update(ctx context.Context, instance *instance, ch chan<- prometheus.Metric) error {
+ db := instance.getDB()
+ rows, err := db.QueryContext(ctx,
+ longRunningTransactionsSummaryQuery)
+
+ if err != nil {
+ return err
+ }
+ defer rows.Close()
+
+ for rows.Next() {
+ var application, endpoint sql.NullString
+ var maxAgeInSeconds sql.NullFloat64
+
+ if err := rows.Scan(&application, &endpoint, &maxAgeInSeconds); err != nil {
+ return err
+ }
+
+ applicationLabel := "unknown"
+ if application.Valid {
+ applicationLabel = application.String
+ }
+ endpointLabel := "unknown"
+ if endpoint.Valid {
+ endpointLabel = endpoint.String
+ }
+ labels := []string{applicationLabel, endpointLabel}
+
+ maxAgeInSecondsMetric := 0.0
+ if maxAgeInSeconds.Valid {
+ maxAgeInSecondsMetric = maxAgeInSeconds.Float64
+ }
+ ch <- prometheus.MustNewConstMetric(
+ longRunningTransactionsSummaryMaxAgeInSeconds,
+ prometheus.GaugeValue,
+ maxAgeInSecondsMetric,
+ labels...,
+ )
+ }
+ if err := rows.Err(); err != nil {
+ return err
+ }
+ return nil
+}