Missing Queryable Part

[beachwalker]

Hi,

I don't see the projection (building the read model) part of CQRS in the example. Do I missed some lines or is this not included?

I think this should propagate the event to some kind of EventBus in the AggregateRoot here
https://github.com/Horusiath/AkkaCQRS/blob/master/CSharp/Akkme.Shared/Infrastructure/Domain/AggregateRoot.cs#L37

[Horusiath]

@beachwalker this example is far from complete and probably outdated at this moment. Unfortunately I didn't have enough time to finish it. I'll try to do that in the future.

[beachwalker]

Thx for the reply. Do you know other resources to get and idea how to implement that part? I could create specific actors but so they are tightly coupled.
I have two things in my mind related to that topic: http://getakka.net/docs/persistence/persistence-query for the "event handlers" of the readmodel projection
and http://getakka.net/docs/clustering/distributed-publish-subscribe for the event bus.

[Horusiath]

Persistence query would be a way to go here. I'm not even sure if you will need distributed pub/sub here, as you'd need to manually acknowledge incoming events (so you don't accidentally loose single event over the network). You could just spawn live query from read journal on each machine, that needs that data - while this introduces a little more burden on your database (i.e. SQL journals periodically send a query to pull new events from db), I think it's easier to sync that way.

[lessismore1]

I would appreciate a Query Side implementation as well - looking for a template to use.
Akka Streams implementation using Persistence Query as source seems intuitively correct.

Have found one "framework" - https://github.com/evendotnet/Even - so far, but he is not using Akka Persistence or Persistence Query...