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CQRS

Identify Commands & Events

Once I started down the path of segregating commands and queries, I soon enough ran into a few issues that I needed to solve. Identifying Commands & Events Correlating Commands & Events Idempotent Commands Idempotent Events If you are familiar with CQRS, then you may have run into these issues as well.  If you are not completely familiar with CQRS but have heard of it, to be clear, I’m not talking about Event Sourcing, Domain Driven Design, or having multiple data stores or any of the overly complex version people think it is. I’m simply talking about splitting up incoming requests into commands and queries.… Read More »Identify Commands & Events

Thin Controllers with CQRS and MediatR

I’m not a fan of fat controllers. One of the reasons I dislike having my core application logic in controllers is because I like using the web frameworks for what they are good at in my context. My context is usually creating web api’s. For me I use web frameworks as infrastructure that handles HTTP routing and endpoints Deserialization of input payloads Serialization of output payloads HTTP Headers and Status Codes Web Stuff (eg File Uploads) You get the gist, I like using it for handling the web.  Not for containing my features. If you have any questions, please follow me on Twitter.… Read More »Thin Controllers with CQRS and MediatR

Event Store Persistent Subscriptions Demo

In my previous blog post, I talked about Catch-Up Subscriptions in-comparison to Persistent Subscriptions in Event Store. I’ve been meaning to create a little demo as I didn’t find very much in my limited searching. Specifically, I wanted to create a console app that would contain the subscription client  and another console app (event writer) that would write events to a stream. This way you could run the subscription client multiple times, then run the event writer and see how the events are only received from one subscription client. Source All the source code for this demo is available on GitHub.  Please… Read More »Event Store Persistent Subscriptions Demo