Distributed sessions
Thursday, February 04, 2010
1:46 PM
Distributed sessions
Session information is stored in the cloud. 
No mechanism for using "the same server" for two sequential requests. Service switch can be "flowless". 
Each application instance must fetch session context from the cloud (slower). Thus there is at least one datastore transaction for every request. 
Very robust: virtually no impact from a server failure. 
This is the architecture of Google Appengine. 