I am switching my entire code base from PHP to Go and during several processes that run, I randomly get this error:

[mysql] 2016/10/11 09:17:16 packets.go:33: unexpected EOF

Here is my db package that handles all connections to the database:

package db

import (

"database/sql"

_ "github.com/go-sql-driver/mysql"

"pkg/db"

)

var connection *sql.DB

var err error

func GetConnection() *sql.DB {

if connection != nil {

fmt.Println("********** CHECKING PING")

err = connection.Ping()

if err == nil {

fmt.Println("************ CONNECTION STILL ACTIVE")

return connection

} else {

fmt.Println("********** PING ERROR: " + err.Error())

}

}

connection, err = sql.Open("mysql", db.DEVUSER + ":" + db.DEVUSER_PASSWORD + "@tcp(localhost:3306)/main?parseTime=true")

if err != nil {

panic(err)

}

return connection

}

Is there anything I'm doing wrong with this db package that causes this error to be thrown? What exactly does this error mean? I make sure to return the current connection if there is one open so for multiple requests it uses the same connection object.

Here's an excerpt from the mysql packets.go:

// Read packet to buffer 'data'

func (mc *mysqlConn) readPacket() ([]byte, error) {

var payload []byte

for {

// Read packet header

data, err := mc.buf.readNext(4)

if err != nil {

errLog.Print(err)

mc.Close()

return nil, driver.ErrBadConn

}

// Packet Length [24 bit]

pktLen := int(uint32(data[0]) | uint32(data[1])<<8 | uint32(data[2])<<16)

if pktLen < 1 {

errLog.Print(ErrMalformPkt)

mc.Close()

return nil, driver.ErrBadConn

}

// Check Packet Sync [8 bit]

if data[3] != mc.sequence {

if data[3] > mc.sequence {

return nil, ErrPktSyncMul

}

return nil, ErrPktSync

}

mc.sequence++

// Read packet body [pktLen bytes]

data, err = mc.buf.readNext(pktLen)

if err != nil {

errLog.Print(err)

mc.Close()

return nil, driver.ErrBadConn

}

isLastPacket := (pktLen < maxPacketSize)

// Zero allocations for non-splitting packets

if isLastPacket && payload == nil {

return data, nil

}

payload = append(payload, data...)

if isLastPacket {

return payload, nil

}

}

}

The first "errLog.Print(err)" is line 33 in the "Read packet header" section.

Any help is greatly appreciated!

I added a few log.Println to the connection package and let the process run, and right where I get this error, this is what the console prints:

********** CHECKING PING

************ CONNECTION STILL ACTIVE

[mysql] 2016/10/11 11:57:27 packets.go:33: unexpected EOF

********** CHECKING PING

************ CONNECTION STILL ACTIVE

解决方案

Looks like the link to the github issue provided the fix. The fix, at least for my situation was setting the MaxIdleConnections to 0. I have kept a server up for 24 hours, running queries against it every several hours and have yet to reproduce the error.

Thanks to @city for the link.