SOA Patterns > Service Governance Patterns > Version Identification
Version Identification (Orchard, Riley)
How can consumers be made aware of service contract version information?
![Version Identification Version Identification](https://patterns.arcitura.com/wp-content/uploads/2018/09/version_identification.png)
Problem
When an already-published service contract is changed, unaware consumers will miss the opportunity to leverage the change or may be negatively impacted by the change.
Solution
Versioning information pertaining to compatible and incompatible changes can be expressed as part of the service contract, both for communication and enforcement purposes.
Application
With Web service contracts, version numbers can be incorporated into namespace values and as annotations.
Impacts
This pattern may require that version information be expressed with a proprietary vocabulary that needs to be understood by consumer designers in advance.
Principles
Architecture
Service
![Version Identification: Because the service contracts express versioning information, Consumer A can proceed to invoke version 3 of the service contract because it was designed to be compatible with that specific version. Version Identification: Because the service contracts express versioning information, Consumer A can proceed to invoke version 3 of the service contract because it was designed to be compatible with that specific version.](https://patterns.arcitura.com/wp-content/uploads/2018/09/fig1-113.png)
Because the service contracts express versioning information, Consumer A can proceed to invoke version 3 of the service contract because it was designed to be compatible with that specific version.
Related Patterns in This Catalog
Canonical Versioning, Compatible Change
Related Patterns in Other Catalogs
Related Service-Oriented Computing Goals
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.
This page contains excerpts from:
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
For more information about this book, visit www.arcitura.com/books.