Google App Engine Cache List in Session Variable

I have a question about Google App Engine java implem开发者_运维知识库entation. I have been trying to port over an application to google app engine from mysql/tomcat. I have changed and tested most of the code on the google app engine local environment. The application works on the local google app engine but when it is deployed it does not work. I have narrowed the problem down to a variable that caches information in a list that is stored in a session variable. Is this a prohibited action in Google app engine, and if so does anyone have a work around. I really don't want to be hitting the datastore unless this list is changed.

thanks,

I had the same problem, because sessions are backed by the datastore you need to call session.setAttribute everytime you change anything in the object.