How to debug: read data timeout / End of script

Question

On my site, after new user registration, a 500 server error occurs. The error log says:

mod_fcgid: read data timeout in 31 seconds, referer: https://mysite.com/login?view=registration End of script output before headers: index.php, referer: https://mysite.com/login?view=registration

There is no other indication where this error comes from. I have raised the max execution time to 300secons in php.ini, trying to see if there will be more information in the error log, however, the error still occurs after "31" seconds. Although the user is successfully created.

It is unlikely a server configuration error, my other sites on the same server are working well, one of them was cloned from the website in question about 1 month ago. During this month, I did make some change to the codes, but they are mostly made to some extensions. So I really can't think of any reason that may cause this issue.

Since the error occurs after the user is created, I have tried disabling all plugins in the user category, but the error still occurs.

Can someone point me to a right direction of how to debug this?

Answer 1

There's multiple settings in PHP and Apache that can cause timeouts.

From your error message, the issue is not the PHP Max Execution time, but with FastCGI. This is a programming interface on Apache web servers that is used to improve server performance.

The error is in your host's FastCGI configuration. Check the value for FcgidIOTimeout, which defaults to 40 seconds, but may be 30 seconds on your server (hence causing an error at 31 seconds).

The setting: http://httpd.apache.org/mod_fcgid/mod/mod_fcgid.html#fcgidiotimeout

The details on where to fix it (via Plesk support) https://support.plesk.com/hc/en-us/articles/213374769-Website-or-webmail-shows-500-internal-server-error-on-Plesk-mod-fcgid-read-data-timeout