Event Driven Architecture (EDA) // Command Request Separation (CQRS) differences

[Space Borg]

Hi

In various sources presenting EDA and CQRS, it's said quite often that
CQRS and EDA significantly differs. While I agree they don't cover
exactly the same functionalities/aims, I find them pretty close.

So why is it everyone takes all this pain to distinguish between
them ?

My rough understanding of the differences:
- CQRS doesn't dictate that the state can be rebuild through the
commands/events
- EDA dictates the state rebuild, hence as well persistent events.

Apart from that...

thanks in advance once more

[√iktor Klang]

On Fri, Mar 4, 2011 at 1:51 PM, Space Borg <space.bo...@gmail.com> wrote:

Hi

In various sources presenting EDA and CQRS, it's said quite often that
CQRS and EDA significantly differs. While I agree they don't cover
exactly the same functionalities/aims, I find them pretty close.

CQRS and EDA are as ketchup is to hot dogs, a good combination, but can work outside of that, and they are definitely not the same thing.

CQRS is about the segregation of reads and writes (do not query the write model, and do not use the readmodel for the writes.)

So why is it everyone takes all this pain to distinguish between
them ?

My rough understanding of the differences:
- CQRS doesn't dictate that the state can be rebuild through the
commands/events

CQRS are not about commands and events, but when combined with DDD (DDDD) you have that (Domain Events and Commands using Aggregate Roots as the consistency boundraries)
 

- EDA dictates the state rebuild, hence as well persistent events.

EDA is about modelling architectures around events, producing, publishing and consuming events.
For example, Java Swing is an EDA, but is most definitely not a "CQRS API".

Makes sense?

Cheers!
 

Apart from that...

thanks in advance once more

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[Space Borg]

hi

Up to now I've heard of EDA only in the context of CQRS, hence my
confusion. Your clarification makes sense, thx a lot :)

On Mar 4, 3:36 pm, √iktor Klang <viktor.kl...@gmail.com> wrote:

> Work:   Scalable Solutions <http://www.scalablesolutions.se>