title: enabling xdebug remote debug makes apache server very slow
body: <p>If I enable xdebug by settting <code>xdebug.remote_enable=1</code>, the apache server becomes very slow; once I change the setting to <code>0</code>, it's normal.</p>
  
  <p>I found a same question here: <a href="https://stackoverflow.com/questions/8677388/xdebug-really-slow">XDebug really slow</a>, but the answer isn't helpful. I didn't enable profiling:</p>
  
  <pre><code>xdebug.profiler_enable=0
  xdebug.auto_trace = 0
  xdebug.trace_output_dir = /tmp/xdebug
  xdebug.trace_output_name = trace.%c
  </code></pre>
  
  <p>I checked there's nothing under /tmp/xdebug folder.</p>
  
  <p>When xdebug remote debug is enabled and I enable debug listening in PHPStorm, it takes a short while to stop at the breakpoint, but not as slow as disabling phpstorm debug listening.</p>
  
  <p>My environment is: <strong><em>php + apache + xdebug</em></strong> on local centos VM, my mysql db and PHPStorm are on Windows desktop for development. MySQL is not slow.</p>
  
  <p>Appreciate for help.</p>