title: Should I use sessions in Google App Engine?
body: <p>I have just learned from  <a href="https://stackoverflow.com/questions/2675371/google-app-engine-sessions-now-supported">this questions</a> that Google app Engine now supports session.  I would like to be able to use them but am not sure whether I should just because I can.  Thanks to scalability issues.</p>
  
  <p>My questions are really,</p>
  
  <p>Where would I store the session information?  In the data store or would this take to long?  And surely far to costly?</p>
  
  <p>What about the mem cache?  I have only known of GAE for a few days and am still reading.  Is the Mem cache considered to be fast/scalable and does it cost?</p>
  
  <p>What is the best practice for scalability with sessions?</p>
  
  <p>Thanks a lot</p>