Nginx – Broken pipe on nginx

The set_time_limit() function and the configuration directive max_execution_time only affect the execution time of the script itself. Any time spent on activity that happens outside the execution of the script such as system calls using system(), stream operations, database queries, etc. is not included when determining the maximum time that the script has been running. This is not true on Windows where the measured time is real.

You are probably falling on stream operations when using file_get_contents.

Try with:

while (1) { ;; }

First step: ensure you have error logging enabled in php.ini and check the log entries.

From your log entry:

WARNING: [pool www] child 920 said into stderr: "NOTICE: PHP message: PHP Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 39277825 bytes) in Unknown on line 0"

It appears PHP has run out of memory processing the uploaded file. You will need to increase the memory_limit parameter. Further information on upload tuning can be found at the PHP web site.