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Questions tagged [dddd]

Distributed domain driven design deals with DDD in a distributed environment and how to integrate the different contexts.

45 questions
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Using Kafka as a (CQRS) Eventstore. Good idea?

Although I've come across Kafka before, I just recently realized Kafka may perhaps be used as (the basis of) a CQRS, eventstore. One of the main points that Kafka supports: Event capturing/storing, all HA of course. Pub/sub architecture Ability to…
Geert-Jan
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Alternatives to many-to-many relationships with CQRS

How do we model classic many-to-many relationships with CQRS/DDD? I know that both DDD and CQRS implementations and solutions tend to be domain-specific, so it may be difficult to come up with a general answer to this question. However, let's assume…
Mark Seemann
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4 answers

Should Value Objects Contain Technical Validation For Input Parameters?

As DDD practitioner advise, business rule's validations must be implemented inside domain objects (Entities, Value Objects and Domain Services) and follow their own context also somewhere i've read that we should put technical validations (such as…
Masoud Sedghi
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3 answers

Can we use REST + Event Sourcing + CQRS together

I understand the basics of REST + Event Sourcing. I never worked on a strict RESTful API and not either in any Event Sourcing project. Can someone explain if both can be used together? As in event sourcing, the client send events, does this mean…
Sebastien Lorber
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15
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5 answers

Naming Convention for Commands & Events

I'm just getting into event-driven architectures and would like to know what the convention is for naming commands and events. I know this much: Commands should be in the form DoSomething while events should be in the form SomethingHappened. What I…
Tolu
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Implementing set-based constraints in CQRS

I'm still struggling with what must be basic (and resolved) issues related to CQRS style architecture: How do we implement business rules that rely on a set of Aggregate Roots? Take, as an example, a booking application. It may enable you to book…
Mark Seemann
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1 answer

DDDD: Event data

I'm trying to get my head around DDDD in Greg Young's style. There is much talk about how to implement DDDD with CQRS+EventSourcing and there are some sample implementations ... and altogether it can be quite confusing... In Gregs view aggregates…
David Rettenbacher
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Distributed Domain Driven Design Resources

I am quite confident with developing DDD applications, but one area which is continuing to cause me problems is when two applications integrate with each other. I am struggling to find any useful books or resources on the subject. Books such as…
Paul T Davies
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CQRS + Event Sourcing: (is it correct that) Commands are generally communicated point-to-point, while Domain Events are communicated through pub/sub?

Didn't know how to shorten that title. I'm basically trying to wrap my head around the concept of CQRS (http://en.wikipedia.org/wiki/Command-query_separation) and related concepts. Although CQRS doesn't necessarily incorporate Messaging and Event…
Geert-Jan
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Concurrency with DDD + CRQS + ES

I've been studying DDD for a while, and stumbled into design patterns like CQRS, and Event sourcing (ES). These patterns can be used to help achieving some concepts of DDD with less effort. Then I started to develop a simple software to implement…
Rodrigo Riskalla Leal
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How entities covered with in an aggregate Root are saved in DDD?

After reading lot of posts, I realised if an aggregate root exists for a concept/context, we need to have a single repository for that whole concept/context. If thats the case, I see there won't be any repositories for the internal entities. If so,…
Ayyappa
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How to deal with updating Entity (CRUD) and Domain Events using DDD?

I know that DDD is good with a Task-Based UI, but I'm refactoring a legacy app, where I have Anemic Domain Model (many setters without business logic). One of the first steps was to make it reach model and add Domain Events. While adding events for…
borN_free
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DDD Domain Entity vs Persistence Entity

In DDD we say that the domain Entity is not a representation of the database model/entity. We also say that to correctly extract the domain model from the application, the domain model is not supposed to have any information about the way it is…
George
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What is the purpose of using both Application Service and Manager?

I'm not an experienced programmer. I always browse the source codes to learn some things. ASP.NET Boilerplate is my favorite one. Yesterday, I noticed there is friendship application service (in service/application layer) and friendship manager (in…
Taşyürek Gökşah
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EventSourcing inside and outside Bounded Contexts

I'm trying to implement an event sourced system with dddd. Currently I'm struggling how and where my events are crossing the boundaries of the bounded contexts. Imagine there are two bounded contexts: Product Management Logistics System Product…
trialgod
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