title: App Engine and creating a private cache (java)
body: <p>I'm aware that App Engine has memcache build it. I'm using objectify, so all I have to do it add an annotation to use it.</p>
  
  <p>I see one downside of the memcache solution and that is that Google have control. If they want to free up some memory on the server to supply another instance then they can empty my cache and I have to pay to refill it.</p>
  
  <p>For this reason I'm wondering about creating my own cache as a hashmap of instances of objectify entities but I have two concerns that I'm struggling to find information on.</p>
  
  <ol>
  <li><p>How can I monitor the memory usage of an instance to make sure I don't get too close to my 128mb limit?</p></li>
  <li><p>I understand that objectify caches properties rather than whole entities in memcache. Is there a technical reason as to why I can't cache instances objectify entities?</p></li>
  </ol>