unexpected EOF and busy buffer in (go-sql-driver/mysql) packets.go

Question

I am getting the unexpected EOF and busy buffer error in go-sql-driver/mysql despite after setting the SetConnMaxLifetime, SetMaxIdleConns and SetMaxOpenConns as suggested here. Can anyone tell me the proper solution of this issue nothing seems to work for me?

db, err := sql.Open("mysql", "USERNAME:PASSWORD@tcp(IP:PORT)/DB?charset=utf8")
checkErr(err)
db.SetConnMaxLifetime(time.Second * 5)
db.SetMaxIdleConns(0)
db.SetMaxOpenConns(151)

rows, err := db.Query("Select col1, col2, col3 from tbl")
checkErr(err)

for rows.Next() {
    var col1 string     
    var col2 int32
    var col3 uint64

    err = rows.Scan(&col1, &col2, &col3)
    checkErr(err)  
    Process(col1, col2, col3)

}

Answer 1

According to go-sql-driver/mysql/issues/314, bad_buffer could also happen when attempting to run multiple statements within a transaction while still having an open *sql.Rows.

Ensuring that all *sql.Rows were closed before running subsequent statements resolves the issue.

Before

rows, queryErr = tx.Query(selectQuery, queryArgs...)

// process rows.Next()

// Attempt to perform additional query
rows2, query2Err = tx.Query(selectQuery2, query2Args ...)

// Get bad_buffer error (from logs:)
// [mysql] {timestamp} packets.go:447: busy buffer
// [mysql] {timestamp} connection.go:173: bad connection

After

rows, queryErr = tx.Query(selectQuery, queryArgs...)

defer func(result *sql.Rows) {  
   _ = result.Close()  
}(rows)

// process rows.Next()

// Attempt to perform additional query
rows2, query2Err = tx.Query(selectQuery2, query2Args ...)

defer func(result *sql.Rows) {  
   _ = result.Close()  
}(rows2)

// No error