title: What are "many successive interrupted connection requests" in MySQL?
body: <p>I regularly have the following error:</p>
  
  <p><em>PHP Fatal error:  Uncaught exception 'PDOException' with message 'SQLSTATE[HY000] [1129] Host 'MY SERVER' is blocked because of many connection errors; unblock with 'mysqladmin flush-hosts'</em></p>
  
  <p>It is easy to solve the problem with a regular (like crontab) <em>mysqladmin flush-hosts</em> command or increasing the max_connect_errors system variable, as written <a href="http://dev.mysql.com/doc/refman/5.1/en/blocked-host.html" rel="nofollow">here</a>. </p>
  
  <p>BUT ! What are "<strong>many successive interrupted connection requests</strong>", why is this happening?</p>
  
  <p>I'd rather prevent the problem upstream, rather than correcting blocking.</p>
  
  <p>MySQL version : 5.5.12. I'm using Zend Framework 1.11.10 and Doctrine 2.1.6.</p>
  
  <p>There are no mysql_close() nor mysqli_close() in my PHP Code.</p>
  
  <p>max_connect_errors has the default value, 10, and I don't want to increase it yet, I want to understand why I've got the errors. I use a cron, every 5 minutes which does a mysqladmin flush-hosts command.</p>