Introduction

Welcome Getting started Create CML Project Examples Usage as Library Frequently Asked Questions

Language Reference (Core)

CML Reference - Introduction Language Semantics Context Map Bounded Context Domain and Subdomain Domain Vision Statement Partnership Shared Kernel Customer/Supplier Conformist Open Host Service Anticorruption Layer Published Language Responsibility Layers Knowledge Level Aggregate Tactic DDD Syntax Application and Process Layer User Requirements Imports

Analysis and Design Transformations

Rapid Object-oriented Analysis and Design Story Splitting (PoC)

Architectural Refactorings (ARs)

Architectural Refactorings AR-1: Split Aggregate by Entities AR-2: Split Bounded Context by Features AR-3: Split Bounded Context by Owner AR-4: Extract Aggregates by Volatility AR-5: Extract Aggregates by Cohesion AR-6: Merge Aggregates AR-7: Merge Bounded Contexts AR-8: Extract Shared Kernel AR-9: Suspend Partnership AR-10: Change Shared Kernel to Partnership AR-11: Change Partnership to Shared Kernel

Service Cutter

Context Map Suggestions with Service Cutter Service Cutter Configuration File (.servicecutter.yml)

Reverse Engineering

Context Map Discovery

Generators

Generators Overview Context Map Generator PlantUML Generator BPMN Sketch Miner Generator MDSL (Micro-)Service Contracts Generator Service Cutter Generators Generic Generator (Templating)

Tutorials

Model Event Storming Results in Context Mapper Event Sourcing and CQRS Modeling in Context Mapper Generate Microservices From Context Map Using JHipster Systematic Service Decomposition with Context Mapper and Service Cutter Validating the Implementation against the Model (with ArchUnit)

IDE Plugins and Extensions

Visual Studio Code Extension Online IDE (via Gitpod) Eclipse Plugin Feature Support

AR-3: Split Bounded Context by Owner

Splits a bounded context by grouping those aggregates together into one bounded context which belong to the same team.

Hint: An aggregate in CML can belong to one owner/team (therefore the singular owner in the AR name).

Context & Rationales

By decomposing a system into multiple bounded contexts we aim for loose coupling between the bounded context and a high cohesion within them. One approach to achieve this and to decompose a system into components or (micro-) services is to split by owner (team).

See also:

Coupling criterion Shared Owner of ServiceCutter
Conway’s Law
“Bounded contexts decouple PARTS. Parts are code and teams.” by Nick Tune

In Context Mapper you can assign an aggregate the owning team. Consult our aggregate documentation page to see how this can be modeled in CML.

Goal

This Architectural Refactoring (AR) splits a bounded context by the owners of the aggregates. This means, it creates bounded contexts containing aggregates which all belong to the same team. It can be applied if your model exhibits a bounded contexts with aggregates which are owned by different teams.

Inverse AR’s:

AR-7: Merge Bounded Contexts

Preconditions

The bounded context must contain at least two aggregates.
The aggregates must be assigned to different teams.

Input

One bounded context.

Output

The AR creates multiple bounded contexts. Each bounded context contains one or more aggregates which are owned by the same team.

Example

The following example illustrates how this AR can be applied. The corresponding sources can be found in our examples repository.

Input

The examples bounded context contains two aggregates which belong to different teams. The AR is available on the bounded context:

Result

The resulting model contains two bounded context, one for each team:

Example Sources

You can find the CML sources for this AR example here.

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