Sample project demonstrating CQRS & Event Sourcing
The sample uses the following projects from Jonathan Oliver (https://github.com/joliver)
For more information on CQRS and Event Sourcing http://cqrsinfo.com/
To Run The Sample
- You need to create 3 databases in SQL Server 2008 express: Sample.Subscriptions Sample.EventStore Sample.ReadModel
On the Sample.Subscriptions table you need to run the lib\NanoMessageBus\SubscriptionStorage.sql to create the table in which NanoMessageBus will store the subscriptions.
- You need to create 4 transactional Queues in MSMQ: Sample.AppService Sample.Error Sample.Denormalizer Sample.Client
Description of the sample Domain Models implemented:
Simple domain consisting of a Person Aggregate Root and two value objects ( PersonName and Address ). The model allows the creation of a person, the MovePerson operation witch changes the address and the kill-ing of a person.
Sample domain with two ARs, Document and ShareClass and some VOs that demonstrates modeling many-to-many between aggregates. This domain is still work in progress.
A short description of the projects in the sample:
1. Sample.DomainModel - the domain model for the sample - this model is persisted using event sourcing and does not need to handle reads ( queries ) since they are done on the read side. - the resulting event stream is the "source of truth" data. 2. Sample.AppService - the handlers for the commands our domain knows to execute 3. Sample.AppServiceHost - infrastructure for wiring up the command handlers to NanoServiceBus - this is the actual instance of the service that needs to be running for the write side to process commands.
1. Sample.ReadModel - the read model on witch queries are executed - this model should be mapped as close as possible to the views - this model can be regenerated from the event stream 2. Sample.Denormalizer - the event handlers for the domain events that are published by the DomainModel on the WriteSide - this handlers keep the read model in sync with the event stream - a better name for it is welcome 3. Sample.DenormalizerHost - infrastructure for wiring up the event handlers to NanoServiceBus - this process needs to run for the read side to be updated.
1. Sample.Messages - definitions for commands and events that are handled or published by the Domain Model 2. Sample.Client.Web - ASP.NET MVC3 application that demonstrates how to integrate the WriteSide & the ReadSide in an application.
- Add more complex objects to the domain
- Review transaction management on integration points
- use ConfOrm for mapping the read model
- Add error handeling/reporting
- Create generic infrastructure to handle message/handler registration in nano message bus
- Add js pooling sample to handle eventual consistency
- Add more inter aggregate communication/operations
This sample's primary purpose is for me to gain experience with Autofac, NanoMessageBus, EventStore and all the other projects involved.