Tham khảo tài liệu 'pro mysql experts voice in open source phần 10', công nghệ thông tin, cơ sở dữ liệu phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 20 TROUBLESHOOTING 661 Solutions The following are a few ways of discovering the cause of a broken MySQL connection To verify that it was a connection problem reconnect and issue the statement again. If the statement runs successfully you probably encountered a timeout. If the connection is broken when you run the query a second time check the value of your --max-allowed-packet setting. You can also look in the error log to see if a Packet too large message is logged. If so increase the --max-allowed-packet value. Check with your database administrator to see if he killed your connection. Note The database administrator should immediately contact users with a notification that their connection was causing a problem and was killed and help them work through the problem. If you don t have a problem with the packet size carefully examine the syntax of your query. MySQL will sometimes close the connection if the query syntax is incorrect. Make sure all of your join fields are specified. You may want to reduce the complexity of the query and gradually build it piece by piece to get back to the original complex query. If in building a query you find that some combination of valid SQL syntax generates this error you may have stumbled into a MySQL bug rare but possible . See the How to Report MySQL Bugs section later in this chapter for information about finding and reporting bugs to MySQL AB. For more information refer to http doc mysql en and http doc mysql en . Troubleshooting Start Restart and Shutdown Issues In this section we ll discuss common problems related to starting and shutting down the server properly including the following Determining whether the server crashed Problems starting the MySQL server Problems stopping the MySQL server Unexpected restarts Note While MySQL aims to make every server installation a bump-free and quick process you may run into trouble when installing or .
