Error: ER_NOT_SUPPORTED_AUTH_MODE

Introduction

This error occurs when the MySQL client tries to connect to a MySQL server with an unsupported authentication protocol. The error message suggests upgrading the MySQL client to resolve the issue.

Error Message

Error: ER_NOT_SUPPORTED_AUTH_MODE: The client doesn't support the authentication protocol requested by the server; consider upgrading MySQL client - SQL

Cause

The MySQL server is configured to use an authentication protocol that is not supported by the MySQL client being used. This is commonly seen when the MySQL server is using the caching_sha2_password authentication plugin, introduced in MySQL 8.0, while the client being used is an older version that does not support this new authentication protocol.

Solution

To resolve this error, you can perform one of the following solutions:

1. Upgrade MySQL Client

Upgrade the MySQL client to a version that supports the authentication protocol used by the MySQL server. If the server is using caching_sha2_password authentication plugin, consider upgrading the client to at least MySQL 8.0 or higher.

2. Change MySQL Server's Authentication Plugin

If you cannot upgrade the MySQL client, you can change the authentication plugin used by the MySQL server to one that is supported by the client. This can be done by modifying the server's configuration file (my.cnf or my.ini).

Here are the general steps to change the authentication plugin:

1. Open the MySQL server's configuration file.
2. Locate the [mysqld] section.
3. Add or modify the line default_authentication_plugin to specify the desired authentication plugin. For example, you can set it to mysql_native_password plugin.
4. Save the configuration file and restart the MySQL server for the changes to take effect.

Note: Changing the server's authentication plugin may affect the compatibility with other clients, so it is recommended to ensure all clients support the new authentication plugin before making this change.

Example

### Error

Error: ER_NOT_SUPPORTED_AUTH_MODE: The client doesn't support the authentication protocol requested by the server; consider upgrading MySQL client - SQL

### Solution
If you are using an older version of the MySQL client (e.g., 5.x) and the server is using the `caching_sha2_password` authentication plugin, you need to upgrade the client to at least MySQL 8.0 or higher. Alternatively, you can change the server's authentication plugin to `mysql_native_password` by modifying the server's configuration file.

To change the server's authentication plugin to `mysql_native_password`, follow these steps:

1. Open the MySQL server's configuration file (`my.cnf` or `my.ini`).
2. Locate the `[mysqld]` section.
3. Add or modify the line `default_authentication_plugin=mysql_native_password`.
4. Save the configuration file and restart the MySQL server.

After making these changes, the error should be resolved and the client will be able to connect to the MySQL server successfully.

Remember to choose the appropriate solution based on your specific scenario and requirements.

Note: Keep in mind that this error can also occur due to other reasons, such as incorrect credentials or network connectivity issues. So, it is essential to verify the configuration and troubleshoot any other potential causes if the provided solutions don't resolve the error.