sqlstats
A Go library for collecting sql.DBStats and exporting them in Prometheus format.
A sql.DB object represents a pool of zero or more underlying connections that get created and freed automatically. Connections in the pool may also be idle. There are a few settings (SetMaxOpenConns(), SetMaxIdleConns() and SetConnMaxLifetime()) that can be used to control the pool of connections. This library exposes stats about this pool in Prometheus format, to aid with understanding of the pool.
Installation
go get github.com/dlmiddlecote/sqlstats
Example
package main
import (
"database/sql"
"net/http"
_ "github.com/lib/pq"
"github.com/dlmiddlecote/sqlstats"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
func main() {
if err := run(); err != nil {
panic(err)
}
}
func run() error {
// Open connection to a DB (could also use the https://github.com/jmoiron/sqlx library)
db, err := sql.Open("postgres", "postgres://postgres:postgres@localhost:5432/postgres")
if err != nil {
return err
}
// Create a new collector, the name will be used as a label on the metrics
collector := sqlstats.NewStatsCollector("db_name", db)
// Register it with Prometheus
prometheus.MustRegister(collector)
// Register the metrics handler
http.Handle("/metrics", promhttp.Handler())
// Run the web server
return http.ListenAndServe(":8080", nil)
}
Exposed Metrics
| Name | Description | Labels | Go Version |
|---|---|---|---|
| go_sql_stats_connections_max_open | Maximum number of open connections to the database. | db_name | 1.11+ |
| go_sql_stats_connections_open | The number of established connections both in use and idle. | db_name | 1.11+ |
| go_sql_stats_connections_in_use | The number of connections currently in use. | db_name | 1.11+ |
| go_sql_stats_connections_idle | The number of idle connections. | db_name | 1.11+ |
| go_sql_stats_connections_waited_for | The total number of connections waited for. | db_name | 1.11+ |
| go_sql_stats_connections_blocked_seconds | The total time blocked waiting for a new connection. | db_name | 1.11+ |
| go_sql_stats_connections_closed_max_idle | The total number of connections closed due to SetMaxIdleConns. | db_name | 1.11+ |
| go_sql_stats_connections_closed_max_lifetime | The total number of connections closed due to SetConnMaxLifetime. | db_name | 1.11+ |
| go_sql_stats_connections_closed_max_idle_time | The total number of connections closed due to SetConnMaxIdleTime. | db_name | 1.15+ |
