title: How/when the 'after_filter' works/runs?
body: <p>I am using Ruby on Rails 3.1 and I would like to know (for <em>performance</em> reasons) whether or not the <code>after_filter</code> runs after that view files are rendered. That is, when an user access a my application URL, the related view file that he/she should display is rendered before that the <code>after_filter</code> runs or the <code>after_filter</code> runs before that the view file is rendered?</p>
  
  <p><em>In other words</em>, <strong>the application <em>server</em> starts to send the rendered view data to the user before to run the <code>after_filter</code> or it waits to run the <code>after_filter</code> method and only then it sends that view data?</strong></p>
  
  <p><em>P.S.</em>: I opened this question because I would like to run some system updates (<em>note</em>: these updates doesn't affect the view output data and are not "used by"/"necessary to" the view at all) without impact on the end user experience (for example: slow loading of my application Web pages).</p>