 <p>If you are running Apache with mod_php, you will not see a separate PHP process since the script is actually running inside an Apache process. If you are running as FastCGI, you also might not see a distinguishable PHP process for the actual script execution, though I have no experience with PHP/FastCGI and might be wrong on this.</p> <p>You can set the <a href="http://www.php.net/manual/en/info.configuration.php#ini.max-execution-time" rel="nofollow"><code>max_execution_time</code></a> option, but it is overridable at run time by calling <a href="http://www.php.net/manual/en/function.set-time-limit.php" rel="nofollow"><code>set_time_limit()</code></a> unless you run in <a href="http://www.php.net/manual/en/ini.sect.safe-mode.php#ini.safe-mode" rel="nofollow">Safe Mode</a>. Safe mode, however, has been deprecated in PHP 5.3 and <em>removed</em> in 5.4, so you cannot rely on it if you are on 5.4 or plan to upgrade.</p> <p>If you can manage it with your existing customers (since in some cases it requires non-trivial changes to PHP code), <a href="http://www.php.net/manual/en/install.unix.commandline.php" rel="nofollow">running PHP as CGI</a> should allow you to monitor the actual script execution, as each CGI request will spawn a separate PHP interpreter process and you should be able to distinguish between the scripts they are executing. Note, however, that CGI is the least effective setup (the others being mod_php and FastCGI).</p>