1. Why RESTafarians live shorter Lyntale Javazone 8. september 2010 André Wiik Seniorkonsulent Webstep AS

2. RESTafarian o Religious/fanatic believer in RESTful services o Web services = REST o SOA = REST / WOA Intro

3. REST principles o Identify resources (addressable via URIs) o Uniform Interface (GET, PUT, POST, DELETE) o Self-descriptive messages (MIME, XML Schema) o Hypermedia (links) to related resources (HATEOAS) REST constraints o Client / server o Stateless interaction (interaction state entirely on client) o Expressed cacheability o Layered system Intro

4. No consistent way to design RESTful applications o Parameters, collections, search Navigation and state in RESTful services can kill performance Asynchronous messaging Publish/subscribe No guaranteed delivery and/or single delivery of message High-volume and low-latency distributed messaging Distributed peer systems that might at times be disconnected RESTafarian death traps

5. Distributed transaction boundaries Shared resources + reservations (think mobile apps) Orchestration and service aggregation into services Restricted reusability because of HATEOAS RESTafarian death traps

6. RESTify DayTrader http://bitworking.org/news/201/RESTify-DayTrader Look at the comments and discussions Amazon S3 REST API http://docs.amazonwebservices.com/AmazonS3/2006-03-01/APIRest.html No simpler than SOAP I think: http://docs.amazonwebservices.com/AmazonS3/2006-03-01/APISoap.html Examples / links

7. Use REST on simple solutions Good for CRUD – limited for business services Consider RESTful services as client-aware proxies for SOA services Consider REST-style endpoints as candidates for SOA endpoints Don't be religous/fanatic, use the tools and architectures suited for the job! "The trade-off, though, is that a uniform interface degrades efficiency, since information is transferred in a standardized form rather than one which is specific to an application's needs." - Roy Fielding in his dissertation about REST Conclusion

8. Questions? Slides at: webstep.no/javazone Questions