Err_connection_reset

[Administrator]

The `ERR_CONNECTION_RESET` error typically occurs when the connection between the client and the MySQL server is unexpectedly closed. Here are some common reasons and troubleshooting steps for this issue:

1. Network Issues:
- Check Network Connection: Ensure that the network connection between the client and the MySQL server is stable and has no interruptions.
- Firewall Settings: Make sure there are no firewalls blocking the connection. Both the client and the server should allow traffic on the MySQL port (default is 3306).

2. Server Configuration:
- MySQL Timeout Settings: Check the MySQL server's timeout settings, such as `wait_timeout` and `interactive_timeout`. These settings define the duration MySQL waits for activity on a non-interactive and interactive connection before closing it.

 sql
SHOW VARIABLES LIKE 'wait_timeout';
SHOW VARIABLES LIKE 'interactive_timeout';

- Max Connections: Ensure that the server's `max_connections` setting is not being exceeded.

SHOW VARIABLES LIKE 'max_connections';

3. Client Configuration:
- Client Timeout Settings: Some client applications have their own timeout settings. Ensure these settings are configured appropriately.

4. Server Performance:
- Server Load: High server load can cause the server to drop connections. Monitor server performance and ensure it is not under heavy load.
- Error Logs: Check MySQL error logs for any specific errors or issues that might indicate why connections are being reset.

5. Connection Pooling:
- If using a connection pool, ensure it is configured correctly and not exhausting available connections.

6. Version Compatibility:
- Ensure that the MySQL client and server versions are compatible. Incompatible versions might cause unexpected behavior.

### Steps to Diagnose and Fix the Issue

1. Check MySQL Server Logs:

 tail -f /var/log/mysql/error.log

Look for any errors or messages that might indicate the cause of the connection resets.

2. Verify Network Stability:
- Use tools like `ping` or `traceroute` to check the network path between the client and the server.

3. Adjust Timeout Settings:

SET GLOBAL wait_timeout = 28800;
SET GLOBAL interactive_timeout = 28800;

Adjust these values to be longer than the default to see if it resolves the issue.

4. Monitor Server Load:
- Use tools like `top`, `htop`, or MySQL's `SHOW PROCESSLIST` to monitor server load and active connections.

5. Update MySQL:
- Ensure both the client and server are updated to the latest versions to benefit from fixes and improvements.

By systematically checking and addressing these potential issues, you should be able to identify and resolve the cause of the `ERR_CONNECTION_RESET` error.