使用Ping找出数据库连接在Golang中是否仍然存在

Question

Is it safe to just ping the database to check if my golang app is still connected or is there a better solution than this? I've read somewhere that we should not use .ping() to determine a connection loss.

Thanks.

Answer 1

I would say Ping() is the way to do it if you need to test the connection separate of running queries probably at program start only.

Normally I just trust in the fact that database/sql will automatically try to reconnect in case if you are executing queries against DB and connection fails. So you could just use Open to check DB connection args are correct and trust query to return an error in case connection is lost.

People say Ping() can cause race conditions but cannot demonstrate me how or provide a suitable alternative where connection test needed.

This is how Gorm (widely used Golang ORM project) does it:

// Send a ping to make sure the database connection is alive.
    if d, ok := dbSQL.(*sql.DB); ok {
        if err = d.Ping(); err != nil {
            d.Close()
        }
    }
    return

https://github.com/jinzhu/gorm