Select a Pattern Agnostic Capability Agnostic Context Agnostic Sub-Controller Asynchronous Queuing Atomic Service Transaction Brokered Authentication Canonical Expression Canonical Protocol Canonical Resources Canonical Schema Canonical Schema Bus Canonical Versioning Capability Composition Capability Recomposition Compatible Change Compensating Service Transaction Composition Autonomy Concurrent Contracts Contract Centralization Contract Denormalization Cross-Domain Utility Layer Data Confidentiality Data Format Transformation Data Model Transformation Data Origin Authentication Decomposed Capability Decoupled Contract Direct Authentication Distributed Capability Domain Inventory Dual Protocols Enterprise Inventory Enterprise Service Bus Entity Abstraction Event-Driven Messaging Exception Shielding Federated Endpoint Layer File Gateway Functional Decomposition Intermediate Routing Inventory Endpoint Legacy Wrapper Logic Centralization Message Screening Messaging Metadata Metadata Centralization Multi-Channel Endpoint Non-Agnostic Context Official Endpoint Orchestration Partial State Deferral Partial Validation Policy Centralization Process Abstraction Process Centralization Protocol Bridging Proxy Capability Redundant Implementation Reliable Messaging Rules Centralization Schema Centralization Service Agent Service Broker Service Callback Service Data Replication Service Decomposition Service Encapsulation Service Facade Service Grid Service Instance Routing Service Layers Service Messaging Service Normalization Service Perimeter Guard Service Refactoring State Messaging State Repository Stateful Services Termination Notification Three-Layer Inventory Trusted Subsystem UI Mediator Utility Abstraction Validation Abstraction Version Identification Overview     History     Acknowledgements     Podcasts     Notification Form     Feedback Form     Press Release #1     Press Release #2     Press Release #3 Master SOA Design Pattern Catalog     Master Pattern List (alphabetical)     Master Pattern List (by category)     Master Pattern List with Page Numbers (PDF)     Master Pattern List (Text)     Pattern Notation     Pattern Profiles     Symbol Legend     Pattern Contribution Form SOA Candidate Patterns     SOA Patterns Review Committee     Candidate Patterns Overview     Candidate Patterns List     Candidate Pattern Contribution Form     Candidate Pattern Feedback Form     SOA Pattern Template Design Pattern Basics     What's a Design Pattern?     What's a Design Pattern Language?     What's a Compound Pattern? Supplemental     SOA Patterns and Application Technologies     SOA Design Patterns Historical Influences     SOA Design Patterns and Design Principles     SOA Design Patterns and Design Granularity     Legal Resources     Design Patterns Publications     Reference Posters     SOAPrinciples.com     WhatIsSOA.com     SOA Visio Stencil Contract Centralization (Erl) Home > Service Contract Design Patterns > Contract Centralization How can direct consumer-to-implementation coupling be avoided?   Problem Consumer programs can be designed to access underlying service resources using different entry points, resulting in different forms of implementation dependencies that inhibit the service from evolving in response to change. Solution Access to service logic is limited to the service contract, forcing consumers to avoid implementation coupling. Application This pattern is realized through formal enterprise design standards and the targeted application of the Service Abstraction design principle. Impacts Forcing consumer programs to access service capabilities and resources via a central contract can impose performance overhead and requires on-going standardization effort. Principles Standardized Service Contract, Service Loose Coupling, Service Abstraction Architecture Composition, Service   Through Contract Centralization we place the service contract front and center within a service architecture. This is why much of service-orientation is focused on contract design. Audio Podcast This pattern is discussed as part of the audio podcast: Service Contract-Related SOA Design Patterns   Related Patterns in This Catalog Agnostic Sub-Controller (Erl), Canonical Expression (Erl), Decoupled Contract (Erl), Distributed Capability (Erl), Domain Inventory (Erl), Dual Protocols (Erl), Enterprise Inventory (Erl), Inventory Endpoint (Erl), Logic Centralization (Erl), Metadata Centralization (Erl), Multi-Channel Endpoint (Roy), Policy Centralization (Erl), Schema Centralization (Erl), Service Normalization (Erl), Service Refactoring (Erl), Trusted Subsystem (Hogg, Smith, Chong, Hollander, Kozaczynski, Brader, Delgado, Taylor, Wall, Slater, Imran, Cibraro, Cunningham) Related Service-Oriented Computing Goals Increased Intrinsic Interoperability, Increased Federation, Reduced IT Burden This page contains excerpts from: SOA Design Patterns by Thomas Erl Foreword by Grady Booch With contributions from David Chappell, Jason Hogg, Anish Karmarkar, Mark Little, David Orchard, Satadru Roy, Thomas Rischbeck, Arnaud Simon, Clemens Utschig, Dennis Wisnosky, and others. (ISBN: 0136135161, Hardcover, Full-Color, 400+ Illustrations, 865 pages) For more information about this book, visit www.soabooks.com. This pattern is also discussed in the following title: Web Service Contract Design and Versioning for SOA by Thomas Erl, Anish Karmarkar, Priscilla Walmsley, Hugo Haas, Umit Yalcinalp, Canyang Kevin Liu, David Orchard, Andre Tost, James Pasley Foreword by David Chappell (ISBN: 013613517X, Hardcover, 826 pages) For more information about this book, visit www.soabooks.com.

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