Over vacation I read Pat Helland's "Life Beyond Transactions" (yes, vacation was that good :). To sum it up briefly, it advocates limiting the scope of transactions to a single entity and then using groups of "activities" that have the ability to update the entity or cancel a task anytime a change takes place that would make that task invalid.
(E.g. Shipping Order A requires some amount of Item 1. The Shipping Orders and Items are stored as entities and have their own activities. Shipping Order B ships with the last of Item 1 before A finishes. The activity for Item 1 cancels Shipping Order A.)
I had thought I was printing out the Dynamo paper, so forgive me if I conflate the two here. I've seen quite a few "NoSQL" projects influenced by Dynamo and BigTable, particularly in how they address entities by keys and partition data. I was wondering if this Entity-Message-Activity model has influenced any of them?
Or, to put it in more concrete terms, if I have an operation in HBase, Cassandra, Riak, etc. that spans multiple entities, do I need to implement an Activity all by myself (as more of a design pattern in the application), or is there some kind of existing framework? Or do they do something else completely that renders this entire question moot?
Thanks!