Add sharding support for EventStorageEngine to shard by aggregate type

[jayhuanggz]

I am new to Axon, as far as I know, currently all events are stored in a single table or document and there is no event archiving mechanism, size of events will grow indefinitely over time. It would be nice to be able to store events in different table(document) each aggregate type, I suggest:

1. add a "aggregateType" param to EventStorageEngine read methods, callers need to change to supply this param as well

2. Add a "DestinationResolver" that resolves event storage destination by aggregateType and aggregateIdentifier(in case of further sharding by identifier)

3. change implementations of EventStorageEngine to use the resolved event destination, if null, use default(the current one)

Please share your opinions. Thank you.

[jayhuanggz]

any comment please?

[smcvb]

@abuijze do you have an opinion about this?
I'd argue that we'd still prefer a single event store, as that simplifies reading the entire event stream as it as. Added, a regular RDBMS typically does more than fine for an extended period of time.

[abuijze]

Hi @jayhuanggz,
we have decided not to implement this feature in Axon. A project-specific workaround for this is relatively easy to build, and there doesn't seem to be sufficient demand for a generic solution.