php-fpm returning empty response to nginx

Question

nginx is connecting to php-fpm over fastcgi, using the standard /etc/nginx/fastcgi_params in the location block.

When connecting to /.status (php-fpm.ini::ping.path) from the command line with cgi-fcgi -bind, the result comes back as expected (X-Powered-By set, response body, etc).

When requesting with nginx, the result comes back empty (X-Powered-By set, no body length or content). nginx returns 200, since it got a "valid" response.

Watching over tcpdump, I've isolated the requests to parity in their FCGI headers (minus user-related env variables still set by the shell.)

Answer 1

The standard factcgi_params file doesn't contain the key line for SCRIPT_FILENAME.

location ~ \.php$ { include fastcgi_params; fastcgi_split_path_info ^(.+\.php)(/.+)$; fastcgi_pass 127.0.0.1:9000; fastcgi_index index.php; fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name; } 

Add it and restart nginx.

Answer 2

Well, your question is a bit vague. A so called “white screen of death” (WSOD) might be triggered by an endless amount of things. But some things I do if I encounter this:

• Activate the following in your php.ini:

  display_errors = 1 display_startup_errors = 1 error_log = /path/to/file error_reporting = -1 ; (the -1 activates absolutely everything) log_errors = 1 

• Activate in your php-fpm.conf:

  error_log = /path/to/file 

• Activate for each php-fpm pool configuration:

  catch_workers_output = 1 

• Repeat your request and check all logs (incl. nginx error log)
• Increase logging level (e.g. debug on nginx)

If nothing of this helps you to pin-down the problem then please post your complete system information and configurations. Nobody is able to give you a precise answer without that.