title: Apache's mod_php OR FastCGI? Which is good for Wordpress?
body: <p>I have basic idea about running PHP in different configurations like mod_php, cgi, FastCGI, etc.</p>
  
  <p>In my findings and test I found FastCGI is slightly better. I like FastCGI's support for SuEXEC most. Wait I do not want to get into benchmarking business here again. If you surf web, you will find people proving one way is faster than another in terms of number of requests handled per second. Well its good metrics but I am interested in different factors and here are my questions...</p>
  
  <ol>
  <li>Which method of running PHP consumes less memory? </li>
  <li>Also which method consumes memory nearly constant. I see with mod_php my servers memory usage fluctuating between 300MB and 800MB, every few seconds.</li>
  <li>But with FastCGI, first response from server comes very late. I see with FastCGI there is an initial delay per webpage request. Once first response from server arrives, other items like images, css, js loads pretty faster.</li>
  <li>Is it OK to run mix of both? I have 5 sites on dedicated server. Is it ok if I run few with mod_php and rest with FastCGI?</li>
  <li>I am sure that my server goes down mostly because of improper memory usage by mod_php. I checked all scripts. Is there any way to make sure memory consumption on server remains nearly constant?</li>
  <li>Does complexity of .htaccess affects memory usage significantly? If yes, can it be a single reason to make server run out of memory?</li>
  <li>Does apache MPM prefork/worker settings affect memory consumption? Do they affect mod_php and FastCGI mode equally?</li>
  <li>When I run "top" command, I see apache (httpd) consuming memory around 40MB. There are many instances of httpd running. Also in addition to that FastCGI forks some processes of similar size. What is normal memory size for httpd process?</li>
  <li>As I am running Wordpress on all of our sites, which will be good way in that context?</li>
  <li>Does FastCGI/SuExec works fine with APC? Do I need to reconfigure APC to work with SuEXEC and FastCGI.</li>
  </ol>
  
  <p>Please note, I am less interested in surviving against DIGG or traffic spikes. I want a way which can make server stable and predictable.</p>
  
  <p>Sorry if I am confusing but I am really in mess. I have 512MB physical RAM, 400MB Swap and my server is running out of memory like crazy. Average memory requirement is around 350MB, it just memory usage spikes makes memory unavailable for few seconds and if few extra hits received in those few second window, apache crashed while mysql and all other fellas keep running fine.</p>
  
  <p>Please help me out guys. I am not gonna buy more RAM or hardware. I am damn sure that problem is in my configuration. Sorry if I sound arrogant or ignorant.</p>