NetFlix Use Case Comparisons

Adrian Cockcroft of NetFlix proposed in a post last week the following use case:

A TV based device calls the API to add a movie to its favorites list (like the Netflix instant queue, but I have simplified the concept here), then reads back the entire list to ensure it is showing the current state. The API does not use cookies, and the load balancer (Amazon Elastic Load Balancer) is round robin, so the second request goes to a different API server, that happens to be in a different Amazon Availability Zone, and needs to respond with the modified list.

He then posed several questions related to the use case and asked the NoSQL folks to answer how their database would solve the problem. 10Gen makers of MongoDB and Riptano commercial support organization for Cassandra responded.

Cockcroft's original post: Comparing NoSQL Availability Models
10Gen's Reply (via Roger Bodamer): NoSQL Netflix Use Case Comparison for MongoDB
Riptano's Reply (via Jonathan Ellis): NoSQL Netflix Use Case Comparison for Cassandra