title: kevent() reported about an closed connection error
body: <p>we are using FreeBSD, nginx, php-fpm in our server for php (yii) application. Sometimes </p>
  
  <pre><code>kevent() reported about an closed connection (54: Connection reset by peer) while  reading response header from upstream...
  </code></pre>
  
  <p>occured in server log file and website response reach time out. Service php-fpm restart solves the problem. Website is news website and new news (images, videos) add to website regularly. Always 150-250 visitors on website. Visits do not rise when down happen. Website database size is 3GB and size of files 3TB.  <br />
     What can cause this problem? What can best value be for buffer size, cache memory, request per second for config settings on this website? 
  Any suggestion can help</p>