How to resolve the issue of custom nginx variables not taking effect?

If nginx custom variables are not working, it may be due to the following reasons:

1. Configuration file error: Please check if custom variables are correctly set in the nginx configuration file and properly called where custom variables are needed.
2. Module support: Some nginx modules may not support custom variables, so it is important to verify if the module being used is compatible.
3. Restart nginx: Make sure to reload or restart the nginx server after modifying the configuration file to apply the changes.
4. Version issue: Some Nginx versions may have bugs or not support certain custom variable features, it is recommended to update to the latest Nginx version.
5. Grammar error: Check if the syntax used in defining custom variables is correct, for example if the correct syntax and brackets are used.

If none of the above methods can solve the problem, it is recommended to check the nginx log files for any related error messages to better locate and resolve the issue.