Error 1158: Got an error reading communication packets

Possible Causes

This error tells us that the connection between the server and client was aborted. The most common cause is that the client hard-aborted the connection, without calling mysql_close(). It could also be a problem with the connection to the server, such as a wrong or lost package.

How to Find Out More

The error log may have more information about the cause of the error. Setting the MariaDB server option log_warnings to a value of 4 or above can generate more diagnostic warnings in the error log when there is a problem reading packages:

2024-04-19 17:02:11 20090 [Warning] mariadbd: Could not read packet: fd: 4575  state: 1  read_length: 4  errno: 104  vio_errno: 1158  length: -1

How to interpret the above:

• 20090 is the connection id that got the warning/error.
• fd: 4575 4575 is the file descriptor that had a problem.
• state: 1 shows that the file is open. Anything else means the file is not active. Note that in some cases MariaDB will try to abort a read on a file descriptor by closing it.
• read_length: 4 is how many characters the server tried to read from the file.
• errno 104 is the system error code (more below).
• vio_errno: 1158 is our internal error code from the vio library, which stands for ER_NET_READ_ERROR "Got an error reading communication packets".
• length: -1 is how many characters was reported to be read from the read() system call. -1 indicates failure. If length <= read_length then something broke in the communication.

You can use the perror utility to get a description of system and storage engine errors:

shell> perror 104
OS error code 104: Connection reset by peer

This means the connection was aborted by the application/user.

How to Fix

• Ensure you have a stable internet connection.
• Ensure that your applications calls mysql_close() for all open connections before exiting.

See Also

• perror Getting a description for an error number.