title: Long running progam times out to proxy error over DMZ
body: <p>I have set up a DMZ to run a web site.  Most of the code is on an application server running Debian Release 7.0 (wheezy) 64-bit.  I also have a web server running CentOS 6.5.  It acts as a proxy for the application server.  I have set up LAMP on both and my web pages are written in PHP.  A PHP script on the web server calls a PHP script on the application server.  The application server script calls a long running (> 1 minute) executable (that had been developed in C++).  After 60 seconds (timed by my watch), the script fails with the following message.</p>
  
  <pre><code>Proxy Error
  
  The proxy server received an invalid response from an upstream server.
  The proxy server could not handle the request POST /appServer/scriptName.php.
  
  Reason: Error reading from remote server
  
  Apache/2.2.15 (CentOS) Server at sitename.com Port 80
  </code></pre>
  
  <p>I commented out code in the application server PHP script and narrowed the problem down to the long-running C++ executable.  I also ran the executable in the shell without any problems.  So there is clearly a time-out issue and it seems to be associated with the web server.  I have only recently replaced an old version of Ubuntu, with Centos 6.5, on the web server and I did not have this problem before I did that.   Also, the PHP code is the same as before I made the switch and it did not give me this problem prior to that.  So I am convinced that the problem lies with something on the web server and one of the setting I have, with php or apache, on the new system.</p>
  
  <p>I edited /etc/php.ini, on the web server, and changed all of the uncommented-out 60 second time limits (max_input_time, default_socket_timeout, mysql.connect_timeout) from 60 seconds to 600 seconds.  I still get the above proxy error after 60 seconds.</p>