SOA Patterns > Capability Composition Patterns > Capability Composition
Capability Composition (Erl)
How can a service capability solve a problem that requires logic outside of the service boundary?
Problem
A capability may not be able to fulfill its processing requirements without adding logic that resides outside of its service’s functional context, thereby compromising the integrity of the service context and risking service denormalization.
Solution
When requiring access to logic that falls outside of a service’s boundary, capability logic within the service is designed to compose one or more capabilities in other services.
Application
The functionality encapsulated by a capability includes logic that can invoke other capabilities from other services.
Impacts
Carrying out composition logic requires external invocation, which adds performance overhead and decreases service autonomy.
Principles
Standardized Service Contract, Service Loose Coupling, Service Abstraction, Service Reusability, Service Autonomy, Service Statelessness, Service Discoverability, Service Composability
Architecture
Inventory, Composition, Service
The individual capabilities of services can be aggregated to collectively help solve the large problem from which they were originally derived.
Related Patterns in This Catalog
Agnostic Capability, Capability Recomposition, Logic Centralization, Non-Agnostic Context, Process Abstraction, Process Centralization, Service Normalization
Related Patterns in Other Catalogs
Related Service-Oriented Computing Goals
This pattern is covered in SOACP Module 4: Fundamental SOA Analysis & Modeling with Services & Microservices.
For more information regarding the SOA Certified Pofessional (SOACP) curriculum,
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This page contains excerpts from:
SOA Design Patterns by Thomas Erl
(ISBN: 0136135161, Hardcover, Full-Color, 400+ Illustrations, 865 pages)
For more information about this book, visit www.arcitura.com/books.