title: How to share APC cache between several PHP processes when running under FastCGI?
body: <p>I'm currently running several copies of PHP/FastCGI, with APC enabled (under Apache+mod_fastcgi, if that matters).  Can I share cache between the processes?  How can I check if it's shared already?  (I think the <code>apc.mmap_file_mask</code> ini setting might be involved, but I don't know how to use it.)</p>
  
  <p>(One of the reasons I think its <em>not</em> shared at the moment is that the <code>apc.mmap_file_mask</code>, as reported by the apc.php web interface flips between about 3 different values as I reload.)</p>