title: Mysql show processlist lists many processes sleep and info = null?
body: <p>I'm injecting a stress test into my web app that connects to a mysql server and I'm monitoring the show processlist of mysql.</p>
  
  <p>When the load is high (high swap i/o) I get many processes like that:</p>
  
  <pre><code>| 97535 | db| localhost | userA | Sleep   |  515 |         | NULL 
  | 97536 | db| localhost | userA | Sleep   |  516 |         | NULL 
  | 97786 | db| localhost | userA | Sleep   |  343 |         | NULL 
  | 97889 | db| localhost | userA | Sleep   |  310 |         | NULL 
  </code></pre>
  
  <p>But I can't understand why are they still there and are not killed? This eventually leads to my app using all max_connections and stop processing incoming requests...</p>
  
  <p>Any idea what are those processes and what are they doing there :) ?</p>