The idea can be described using three things: entities, activities, and using workflows instead of transactions.
- entity is a single collection of data that lives within a single scope of serializability (e.g. cluster). Each entity has a unique key, and transactions cannot expand multiple entities.
- Activity is a relationship between two entities (holds all state about such a relationship).
- Finally, the key idea is that entities cope by not doing transactions with each other, but handling the uncertainty rise out of lack of transactions through a workflow.
- The author makes an interesting observation that normal world does not have transactions, but cope with uncertainties through time limits, compensations, cancellations etc., or in other words cope through a workflow. So he argues that activities should be carried out with tentative message, confirmation or cancellation model.
No comments:
Post a Comment