too may ram usage when lost connection about mysql

[methane]

Don't use defer in a loop.
Just call cancel() after PingContext returns.

[methane]

It is unlimited by default. So increasing context timeout also increase timeout to get connection from pool.

[methane]

I can't compile jpeg.
Post a runnable source code.

[parsibox]

func mysql_check_connection() {
	logger.Info("mysql_check_connection call")
	//db.Execute("select 42")
	for {
		var errMy error
		ctx, _ := context.WithTimeout(context.Background(), 40*time.Second)
		errMy = db.PingContext(ctx)
		if errMy != nil {
			stats := db.Stats()
			fields := logrus.Fields{
				"MaxOpenConnections": stats.MaxOpenConnections,
				"OpenConnections":    stats.OpenConnections,
				"InUse":              stats.InUse,
				"Idle":               stats.Idle,
				"WaitCount":          stats.WaitCount,
				"WaitDuration":       stats.WaitDuration.String(),
				"MaxIdleClosed":      stats.MaxIdleClosed,
				"MaxLifetimeClosed":  stats.MaxLifetimeClosed,
				"err":                errMy,
			}
			logger.ErrorWithFields(fields, "ConMysql error on mysql_check_connection Err : ")
			Heartbeat = false
			//fmt.Println(" Heartbeat change to false :", Heartbeat)
			/**/
			mutex.Lock()
			db.Close()
			start()
			mutex.Unlock()

			//go start()
			return

		}
		Heartbeat = true
		time.Sleep(3 * time.Second)
	}
}

[parsibox]

how can increase total time blocked waiting for a new connection?

[methane]

Oh! You don't call cancel func.
You are leaking many contexts.

[parsibox]

do you mean this change?

		ctx, cancel := context.WithTimeout(context.Background(), 40*time.Second)
		defer cancel() // Call cancel function to release resources when the function returns

[parsibox]

i change it

		ctx, cancel := context.WithTimeout(context.Background(), 40*time.Second)
		errMy = db.PingContext(ctx)
		cancel()

how can increase total time blocked waiting for a new connection?

[methane]

I cannot understand what you mean.
If you want to be blocked long time, set max open connection to 1 and query "SELECT SLEEP(100)" from 100 goroutines.
99 goroutines need to wait 100 sec.
98 goroutines need to wait another 100 sec.
...

[parsibox]

no please see this db stat

{
    "Idle": 0,
    "InUse": 15,
    "MaxIdleClosed": 0,
    "MaxLifetimeClosed": 57,
    "MaxOpenConnections": 15,
    "OpenConnections": 15,
    "WaitCount": 141,
    "WaitDuration": "2m39.604195004s",
}

my MaxOpenConnections was equaled to OpenConnections and WaitDuration is 2m39
how can i increase WaitDuration to 10 m ?

[methane]

Maybe, you misunderstand it.
Wait duration in db stat is what I said.
Total time for waiting connection from pool.

[parsibox]

ok but is there any time limit for waiting connection from pool?

[methane]

Anyway, here is issue tracker, not user forum.