title: Apache, PHP Invalid Content Length
body: <p>I have a PHP (PHP 5.3.2) application running on Apache (2.2.14) on Linux server. More then once in its history user started to see in their browsers the following message: "Request entity too large". 
  First google search suggested that it happens when an uploaded file is too big or when cookies are too big. But it is not happening on file upload, only at logging in and always at the login page. User enters this page just through a normal POST form on a page. And the cookies are only containing session id.</p>
  
  <p>Furthermore, apache is logging "Invalid Content-Length". This is being logged before any of my code executes. $_POST is empty despite it should contain some data. When I added the following line:</p>
  
  <pre><code>error_log("Content-Length: ".$_SERVER['CONTENT_LENGTH']);
  </code></pre>
  
  <p>it says</p>
  
  <pre><code>Content-Length: 32, 32
  </code></pre>
  
  <p>which seems to be indeed invalid. Changing browser or resetting user PC does not seem to help. Everything just started to work the next day.</p>
  
  <p>Where can the problem lay? Is it something with Apache, PHP, user's network settings? If I need to add some more information, please let me know.</p>