title: app engine dynamic backend doesn't act as expected in dev mode
body: <p>This issue was tested, and occurs, in the dev mode (Eclipse...).</p>
  
  <p>I have one configured backend (in backends.xml):</p>
  
  <pre><code>&lt;backends&gt;
      &lt;backend name="example"&gt;
          &lt;class&gt;B8&lt;/class&gt;
          &lt;options&gt;
              &lt;instances&gt;1&lt;/instances&gt;
              &lt;public&gt;false&lt;/public&gt;
              &lt;dynamic&gt;true&lt;/dynamic&gt;
          &lt;/options&gt;
      &lt;/backend&gt;
  &lt;/backends&gt;
  </code></pre>
  
  <p>As you see it's explicitly set to be 'dynamic'.</p>
  
  <p>This is my web.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
      version="2.5"&gt;
  
      &lt;servlet&gt;
          &lt;servlet-name&gt;backend_test&lt;/servlet-name&gt;
          &lt;servlet-class&gt;BackendTest&lt;/servlet-class&gt;
      &lt;/servlet&gt;
      &lt;servlet-mapping&gt;
          &lt;servlet-name&gt;backend_test&lt;/servlet-name&gt;
          &lt;url-pattern&gt;/_ah/start&lt;/url-pattern&gt;
      &lt;/servlet-mapping&gt;
  
  &lt;/web-app&gt;
  </code></pre>
  
  <p>.. just a regular servlet entry-point to the backend.</p>
  
  <p>And here's the backend's Java code:</p>
  
  <pre><code>import java.io.IOException;
  
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  @SuppressWarnings("serial")
  public class BackendTest extends HttpServlet
  {
  
      @Override
      public void doGet(HttpServletRequest req, HttpServletResponse res)
              throws ServletException, IOException
      {
          System.out.println("Backend started!");
  
          // ............
  
          System.out.println("Backend terminating!");
      }
  }
  </code></pre>
  
  <p>Now, when I hit F11 and start debugging the app, this is the output in the console:</p>
  
  <pre><code>INFO: The server is running at http://localhost:8888/
  Backend started!
  Backend terminating!
  </code></pre>
  
  <p>If I understand <a href="http://code.google.com/appengine/docs/java/backends/overview.html#Startup" rel="nofollow">this doc line</a> correctly it shouldn't start, until I request <code>/_ah/start</code> (http).
  It clearly says:</p>
  
  <blockquote>
    <p>When you start a dynamic backend, App Engine allows it to accept
    traffic, but the /_ah/start request is not sent to an instance until
    it receives its first user request.</p>
  </blockquote>
  
  <p>Another side-effect, related to this issue, is that the backend seem to never be "stopped", I mean it remains in the "running" state (as I see in the admin area at <a href="http://127.0.0.1:8888/_ah/admin/backends" rel="nofollow">http://127.0.0.1:8888/_ah/admin/backends</a> ).<br>
  After it was terminated (in the code above, as it clearly printed out in the console), shouldn't it be shutdown after a few minutes? (I'm waiting about 20min).</p>
  
  <p>What am I doing wrong?</p>
  
  <p>By the way, my final goal is to run some code within a "Backend" context, just like running a "Task". I want a "Backend" because of the CPU/RAM power and the no-time-limit.</p>
  
  <p>Please enlighten me.
  Thanks!</p>