In second case, you have to use datastore only to store lock entity and perform transactions. If there are lots of threads waiting for lock to be free (polling datastore), there will be lots of unnecessary datastored reads. If the thread which acquires/releases the lock, update the lock entity in memecache also and waiting threads check lock entity from memcache and then check datastore (if cache entity says that the lock is not taken), lots of datastore reads can be saved.
-- Prashant http://code.google.com/p/claymus/ -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
