According to the documentation:
max_execution_time only affect the execution time of the script itself.
Any time spent on activity that happens outside the e
This is an old and answered question. But for the sake of helping others, I wanted to point out the request_terminate_timeout php-fpm option. If you're using PHP-FPM, it is most likely what you need.
If set, this option allows you to tell PHP-FPM to kill a request after N seconds, regardless of what PHP does.
See http://php.net/manual/en/install.fpm.configuration.php#request-terminate-timeout for details.