Symbio (Reactive Storage)
The VLINGO XOOM Reactive CQRS and Event Sourcing storage and projections.
The idea behind the name "symbio" is that there is a symbiotic relationship between domain models and persistence, and persistence and domain models. They depend on each other, but in a way that neither "life form" may be entirely conscious of the other. This is certainly true of the domain model more so than the data model.
The XOOM Symbio parent tool is a set of protocols and default in-memory implementations. The protocols are usable by concrete implementations. The in-memory implementations are useful for testing.
There are three primary kinds of storage mechanism protocols available:
StateStore(i.e. Key-Value and NoSQL), and
Journal. Among these there are a number of concrete implementations. For example, there are Postgres implementations of all three:
Each storage type is discussed in the following subsections. Additionally there is a separate useful discussion about Adapters, which are used to translate between application or service state and persistent state.