Thank you, I switched from a member variable to the datastore and it
solved the problem.
There is one thing that is not clear yet:
I've overridden the init() and destroy() methods of the servlet and
added a log printout in each one of them. I can see that the init()
method is called from time to ti
It's generally a bad idea to store data in member variables because
containers can create and destroy servlet instances depending on the
situation (load, idle time, etc).
http://en.wikipedia.org/wiki/Java_Servlet#Lifecycle_of_a_servlet
A better idea would be to persist the data in the datastore.
