Add collector for database/sql#DBStats (#866)

* Add collector for database/sql#DBStats

Signed-off-by: Mitsuo Heijo <mitsuo.heijo@gmail.com>
This commit is contained in:
Mitsuo Heijo 2021-05-21 05:22:17 +09:00 committed by GitHub
parent b89620c491
commit a66da1df4a
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4 changed files with 283 additions and 0 deletions

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// Copyright 2021 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 collectors
import (
"database/sql"
"github.com/prometheus/client_golang/prometheus"
)
type dbStatsCollector struct {
db *sql.DB
maxOpenConnections *prometheus.Desc
openConnections *prometheus.Desc
inUseConnections *prometheus.Desc
idleConnections *prometheus.Desc
waitCount *prometheus.Desc
waitDuration *prometheus.Desc
maxIdleClosed *prometheus.Desc
maxIdleTimeClosed *prometheus.Desc
maxLifetimeClosed *prometheus.Desc
}
// NewDBStatsCollector returns a collector that exports metrics about the given *sql.DB.
// See https://golang.org/pkg/database/sql/#DBStats for more information on stats.
func NewDBStatsCollector(db *sql.DB, dbName string) prometheus.Collector {
fqName := func(name string) string {
return "go_sql_" + name
}
return &dbStatsCollector{
db: db,
maxOpenConnections: prometheus.NewDesc(
fqName("max_open_connections"),
"Maximum number of open connections to the database.",
nil, prometheus.Labels{"db_name": dbName},
),
openConnections: prometheus.NewDesc(
fqName("open_connections"),
"The number of established connections both in use and idle.",
nil, prometheus.Labels{"db_name": dbName},
),
inUseConnections: prometheus.NewDesc(
fqName("in_use_connections"),
"The number of connections currently in use.",
nil, prometheus.Labels{"db_name": dbName},
),
idleConnections: prometheus.NewDesc(
fqName("idle_connections"),
"The number of idle connections.",
nil, prometheus.Labels{"db_name": dbName},
),
waitCount: prometheus.NewDesc(
fqName("wait_count_total"),
"The total number of connections waited for.",
nil, prometheus.Labels{"db_name": dbName},
),
waitDuration: prometheus.NewDesc(
fqName("wait_duration_seconds_total"),
"The total time blocked waiting for a new connection.",
nil, prometheus.Labels{"db_name": dbName},
),
maxIdleClosed: prometheus.NewDesc(
fqName("max_idle_closed_total"),
"The total number of connections closed due to SetMaxIdleConns.",
nil, prometheus.Labels{"db_name": dbName},
),
maxIdleTimeClosed: prometheus.NewDesc(
fqName("max_idle_time_closed_total"),
"The total number of connections closed due to SetConnMaxIdleTime.",
nil, prometheus.Labels{"db_name": dbName},
),
maxLifetimeClosed: prometheus.NewDesc(
fqName("max_lifetime_closed_total"),
"The total number of connections closed due to SetConnMaxLifetime.",
nil, prometheus.Labels{"db_name": dbName},
),
}
}
// Describe implements Collector.
func (c *dbStatsCollector) Describe(ch chan<- *prometheus.Desc) {
c.describe(ch)
}
// Collect implements Collector.
func (c *dbStatsCollector) Collect(ch chan<- prometheus.Metric) {
c.collect(ch)
}

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// Copyright 2021 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.
// +build go1.15
package collectors
import "github.com/prometheus/client_golang/prometheus"
func (c *dbStatsCollector) describe(ch chan<- *prometheus.Desc) {
ch <- c.maxOpenConnections
ch <- c.openConnections
ch <- c.inUseConnections
ch <- c.idleConnections
ch <- c.waitCount
ch <- c.waitDuration
ch <- c.maxIdleClosed
ch <- c.maxIdleTimeClosed
ch <- c.maxLifetimeClosed
}
func (c *dbStatsCollector) collect(ch chan<- prometheus.Metric) {
stats := c.db.Stats()
ch <- prometheus.MustNewConstMetric(c.maxOpenConnections, prometheus.GaugeValue, float64(stats.MaxOpenConnections))
ch <- prometheus.MustNewConstMetric(c.openConnections, prometheus.GaugeValue, float64(stats.OpenConnections))
ch <- prometheus.MustNewConstMetric(c.inUseConnections, prometheus.GaugeValue, float64(stats.InUse))
ch <- prometheus.MustNewConstMetric(c.idleConnections, prometheus.GaugeValue, float64(stats.Idle))
ch <- prometheus.MustNewConstMetric(c.waitCount, prometheus.CounterValue, float64(stats.WaitCount))
ch <- prometheus.MustNewConstMetric(c.waitDuration, prometheus.CounterValue, stats.WaitDuration.Seconds())
ch <- prometheus.MustNewConstMetric(c.maxIdleClosed, prometheus.CounterValue, float64(stats.MaxIdleClosed))
ch <- prometheus.MustNewConstMetric(c.maxIdleTimeClosed, prometheus.CounterValue, float64(stats.MaxIdleTimeClosed))
ch <- prometheus.MustNewConstMetric(c.maxLifetimeClosed, prometheus.CounterValue, float64(stats.MaxLifetimeClosed))
}

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// Copyright 2021 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.
// +build !go1.15
package collectors
import "github.com/prometheus/client_golang/prometheus"
func (c *dbStatsCollector) describe(ch chan<- *prometheus.Desc) {
ch <- c.maxOpenConnections
ch <- c.openConnections
ch <- c.inUseConnections
ch <- c.idleConnections
ch <- c.waitCount
ch <- c.waitDuration
ch <- c.maxIdleClosed
ch <- c.maxLifetimeClosed
}
func (c *dbStatsCollector) collect(ch chan<- prometheus.Metric) {
stats := c.db.Stats()
ch <- prometheus.MustNewConstMetric(c.maxOpenConnections, prometheus.GaugeValue, float64(stats.MaxOpenConnections))
ch <- prometheus.MustNewConstMetric(c.openConnections, prometheus.GaugeValue, float64(stats.OpenConnections))
ch <- prometheus.MustNewConstMetric(c.inUseConnections, prometheus.GaugeValue, float64(stats.InUse))
ch <- prometheus.MustNewConstMetric(c.idleConnections, prometheus.GaugeValue, float64(stats.Idle))
ch <- prometheus.MustNewConstMetric(c.waitCount, prometheus.CounterValue, float64(stats.WaitCount))
ch <- prometheus.MustNewConstMetric(c.waitDuration, prometheus.CounterValue, stats.WaitDuration.Seconds())
ch <- prometheus.MustNewConstMetric(c.maxIdleClosed, prometheus.CounterValue, float64(stats.MaxIdleClosed))
ch <- prometheus.MustNewConstMetric(c.maxLifetimeClosed, prometheus.CounterValue, float64(stats.MaxLifetimeClosed))
}

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// Copyright 2021 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 collectors
import (
"database/sql"
"runtime"
"testing"
"github.com/prometheus/client_golang/prometheus"
)
func TestDBStatsCollector(t *testing.T) {
reg := prometheus.NewRegistry()
{
db := new(sql.DB)
if err := reg.Register(NewDBStatsCollector(db, "db_A")); err != nil {
t.Fatal(err)
}
}
{
db := new(sql.DB)
if err := reg.Register(NewDBStatsCollector(db, "db_B")); err != nil {
t.Fatal(err)
}
}
mfs, err := reg.Gather()
if err != nil {
t.Fatal(err)
}
names := []string{
"go_sql_max_open_connections",
"go_sql_open_connections",
"go_sql_in_use_connections",
"go_sql_idle_connections",
"go_sql_wait_count_total",
"go_sql_wait_duration_seconds_total",
"go_sql_max_idle_closed_total",
"go_sql_max_lifetime_closed_total",
}
if runtime.Version() >= "go1.15" {
names = append(names, "go_sql_max_idle_time_closed_total")
}
type result struct {
found bool
}
results := make(map[string]result)
for _, name := range names {
results[name] = result{found: false}
}
for _, mf := range mfs {
m := mf.GetMetric()
if len(m) != 2 {
t.Errorf("expected 2 metrics bug got %d", len(m))
}
labelA := m[0].GetLabel()[0]
if name := labelA.GetName(); name != "db_name" {
t.Errorf("expected to get label \"db_name\" but got %s", name)
}
if value := labelA.GetValue(); value != "db_A" {
t.Errorf("expected to get value \"db_A\" but got %s", value)
}
labelB := m[1].GetLabel()[0]
if name := labelB.GetName(); name != "db_name" {
t.Errorf("expected to get label \"db_name\" but got %s", name)
}
if value := labelB.GetValue(); value != "db_B" {
t.Errorf("expected to get value \"db_B\" but got %s", value)
}
for _, name := range names {
if name == mf.GetName() {
results[name] = result{found: true}
break
}
}
}
for name, result := range results {
if !result.found {
t.Errorf("%s not found", name)
}
}
}