MySQL server has gone away - How to solve MySQL error: MySQL server connection is disconnected

MySQL server has gone away - How to solve MySQL error: MySQL server connection is disconnected, specific code examples are needed

1. Introduction

MySQL is a popular open source relational database management system that is widely used for back-end data storage and management of websites and applications. However, when using MySQL, you sometimes encounter the "MySQL server has gone away" error, which means that the connection between the MySQL server and the client has been disconnected. This article explains how to solve this problem, including specific code examples.

2. Cause analysis

When the connection between the MySQL server and the client is disconnected, there may be the following reasons:

2.1 Connection timeout: When MySQL When the server does not receive any data from the client within the set time range, it will automatically close the connection. This could be due to a network issue or a connection timeout caused by high server load.

2.2 Data is too large: If the amount of data to be transferred exceeds the maximum limit allowed by the MySQL server, the MySQL server may actively close the connection.

2.3 Server configuration issues: Certain configuration parameters of the MySQL server may cause the connection to be closed, for example, the max_allowed_packet parameter is too small.

3. Solution

In order to solve the "MySQL server has gone away" error, we can take the following measures:

3.1 Increase the timeout: You can pass Modify the MySQL server and client configuration files to increase the timeout. For example, in the configuration file my.cnf of the MySQL server, increase the value of the wait_timeout parameter to a larger value, in seconds.

3.2 Increase the value of the max_allowed_packet parameter: If the data is too large and the connection is closed, it can be solved by increasing the value of the max_allowed_packet parameter. In the configuration file my.cnf of the MySQL server, increase the value of the max_allowed_packet parameter to the appropriate size, such as 100M.

3.3 Regular heartbeat detection: In order to keep the long-term connection active, heartbeat messages can be sent to the MySQL server regularly. The following is a sample code written in Python:

import mysql.connector

config = {
  'user': 'username',
  'password': 'password',
  'host': 'localhost',
  'database': 'database_name',
  'raise_on_warnings': True,
}

cnx = mysql.connector.connect(**config)
cursor = cnx.cursor()

# 执行心跳查询
query = "SELECT 1"
cursor.execute(query)

# 关闭游标和连接
cursor.close()
cnx.close()

The above code uses the mysql.connector module to connect to the MySQL server and issue a simple query to keep the connection to the server active.

3.4 Check the server load: If the connection timeout is caused by high server load, you can consider optimizing the query and index, or use a distributed database solution.

4. Summary

When using MySQL, you may encounter the "MySQL server has gone away" error, including connection timeout, excessive data, and server configuration issues. . In order to solve this error, we can increase the timeout, adjust the max_allowed_packet parameter value, perform regular heartbeat detection, and optimize the server load. We hope that the solutions and code examples provided in this article can help readers solve the problem of MySQL connection disconnection.

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