1// Copyright 2021 The Prometheus Authors
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14package collectors
15
16import (
17	"database/sql"
18
19	"github.com/prometheus/client_golang/prometheus"
20)
21
22type dbStatsCollector struct {
23	db *sql.DB
24
25	maxOpenConnections *prometheus.Desc
26
27	openConnections  *prometheus.Desc
28	inUseConnections *prometheus.Desc
29	idleConnections  *prometheus.Desc
30
31	waitCount         *prometheus.Desc
32	waitDuration      *prometheus.Desc
33	maxIdleClosed     *prometheus.Desc
34	maxIdleTimeClosed *prometheus.Desc
35	maxLifetimeClosed *prometheus.Desc
36}
37
38// NewDBStatsCollector returns a collector that exports metrics about the given *sql.DB.
39// See https://golang.org/pkg/database/sql/#DBStats for more information on stats.
40func NewDBStatsCollector(db *sql.DB, dbName string) prometheus.Collector {
41	fqName := func(name string) string {
42		return "go_sql_" + name
43	}
44	return &dbStatsCollector{
45		db: db,
46		maxOpenConnections: prometheus.NewDesc(
47			fqName("max_open_connections"),
48			"Maximum number of open connections to the database.",
49			nil, prometheus.Labels{"db_name": dbName},
50		),
51		openConnections: prometheus.NewDesc(
52			fqName("open_connections"),
53			"The number of established connections both in use and idle.",
54			nil, prometheus.Labels{"db_name": dbName},
55		),
56		inUseConnections: prometheus.NewDesc(
57			fqName("in_use_connections"),
58			"The number of connections currently in use.",
59			nil, prometheus.Labels{"db_name": dbName},
60		),
61		idleConnections: prometheus.NewDesc(
62			fqName("idle_connections"),
63			"The number of idle connections.",
64			nil, prometheus.Labels{"db_name": dbName},
65		),
66		waitCount: prometheus.NewDesc(
67			fqName("wait_count_total"),
68			"The total number of connections waited for.",
69			nil, prometheus.Labels{"db_name": dbName},
70		),
71		waitDuration: prometheus.NewDesc(
72			fqName("wait_duration_seconds_total"),
73			"The total time blocked waiting for a new connection.",
74			nil, prometheus.Labels{"db_name": dbName},
75		),
76		maxIdleClosed: prometheus.NewDesc(
77			fqName("max_idle_closed_total"),
78			"The total number of connections closed due to SetMaxIdleConns.",
79			nil, prometheus.Labels{"db_name": dbName},
80		),
81		maxIdleTimeClosed: prometheus.NewDesc(
82			fqName("max_idle_time_closed_total"),
83			"The total number of connections closed due to SetConnMaxIdleTime.",
84			nil, prometheus.Labels{"db_name": dbName},
85		),
86		maxLifetimeClosed: prometheus.NewDesc(
87			fqName("max_lifetime_closed_total"),
88			"The total number of connections closed due to SetConnMaxLifetime.",
89			nil, prometheus.Labels{"db_name": dbName},
90		),
91	}
92}
93
94// Describe implements Collector.
95func (c *dbStatsCollector) Describe(ch chan<- *prometheus.Desc) {
96	ch <- c.maxOpenConnections
97	ch <- c.openConnections
98	ch <- c.inUseConnections
99	ch <- c.idleConnections
100	ch <- c.waitCount
101	ch <- c.waitDuration
102	ch <- c.maxIdleClosed
103	ch <- c.maxLifetimeClosed
104	c.describeNewInGo115(ch)
105}
106
107// Collect implements Collector.
108func (c *dbStatsCollector) Collect(ch chan<- prometheus.Metric) {
109	stats := c.db.Stats()
110	ch <- prometheus.MustNewConstMetric(c.maxOpenConnections, prometheus.GaugeValue, float64(stats.MaxOpenConnections))
111	ch <- prometheus.MustNewConstMetric(c.openConnections, prometheus.GaugeValue, float64(stats.OpenConnections))
112	ch <- prometheus.MustNewConstMetric(c.inUseConnections, prometheus.GaugeValue, float64(stats.InUse))
113	ch <- prometheus.MustNewConstMetric(c.idleConnections, prometheus.GaugeValue, float64(stats.Idle))
114	ch <- prometheus.MustNewConstMetric(c.waitCount, prometheus.CounterValue, float64(stats.WaitCount))
115	ch <- prometheus.MustNewConstMetric(c.waitDuration, prometheus.CounterValue, stats.WaitDuration.Seconds())
116	ch <- prometheus.MustNewConstMetric(c.maxIdleClosed, prometheus.CounterValue, float64(stats.MaxIdleClosed))
117	ch <- prometheus.MustNewConstMetric(c.maxLifetimeClosed, prometheus.CounterValue, float64(stats.MaxLifetimeClosed))
118	c.collectNewInGo115(ch, stats)
119}
120