diff --git a/README.md b/README.md index 505d2a7e1..f8c99ecb9 100644 --- a/README.md +++ b/README.md @@ -56,15 +56,31 @@ Make sure [Git is installed](https://git-scm.com/downloads) on your machine and _Go MySQL Driver_ is an implementation of Go's `database/sql/driver` interface. You only need to import the driver and can use the full [`database/sql`](https://golang.org/pkg/database/sql/) API then. Use `mysql` as `driverName` and a valid [DSN](#dsn-data-source-name) as `dataSourceName`: + ```go import "database/sql" import _ "github.com/go-sql-driver/mysql" db, err := sql.Open("mysql", "user:password@/dbname") +if err != nil { + panic(err) +} +// See "Important settings" section. +db.SetConnMaxLifetime(time.Minute * 3) +db.SetMaxOpenConns(10) +db.SetMaxIdleConns(10) ``` [Examples are available in our Wiki](https://github.com/go-sql-driver/mysql/wiki/Examples "Go-MySQL-Driver Examples"). +### Important settings + +`db.SetConnMaxLifetime()` is required to ensure connections are closed by the driver safely before connection is closed by MySQL server, OS, or other middlewares. Since some middlewares close idle connections by 5 minutes, we recommend timeout shorter than 5 minutes. This setting helps load balancing and changing system variables too. + +`db.SetMaxOpenConns()` is highly recommended to limit the number of connection used by the application. There is no recommended limit number because it depends on application and MySQL server. + +`db.SetMaxIdleConns()` is recommended to be set same to (or greater than) `db.SetMaxOpenConns()`. When it is smaller than `SetMaxOpenConns()`, connections can be opened and closed very frequently than you expect. Idle connections can be closed by the `db.SetConnMaxLifetime()`. If you want to close idle connections more rapidly, you can use `db.SetConnMaxIdleTime()` since Go 1.15. + ### DSN (Data Source Name) @@ -498,4 +514,3 @@ Please read the [MPL 2.0 FAQ](https://www.mozilla.org/en-US/MPL/2.0/FAQ/) if you You can read the full terms here: [LICENSE](https://raw.github.com/go-sql-driver/mysql/master/LICENSE). ![Go Gopher and MySQL Dolphin](https://raw.github.com/wiki/go-sql-driver/mysql/go-mysql-driver_m.jpg "Golang Gopher transporting the MySQL Dolphin in a wheelbarrow") -