WEB SERVICESAN EVALUATION OF MODERN WEB SERVICE ARCHITECTURESGordon HewCOMS E6125 Web Information Management Systems

Agenda

Introduction Architectural Styles

Remote Procedure Call (RPC) Serviced Oriented Architecture (SOA) Representational State Transfer (REST)

Conclusion

Web Services & Architectural Styles What are Web Services? Why are they important? What are some examples? Why are Architectural Styles important? What criteria will be using to evaluate

these styles?

Remote Procedure Call (RPC) RPC

Client invocation of a local representation of a remote method

Remote Procedure Call (RPC) Example Technologies

XML-RPC RPC Style SOAP

Advantages Simple

Disadvantages Tightly Coupled Not Easily Scalable

Service Oriented Architecture (SOA) SOA Principles

Separation of concerns Service Orientation

Loosely Coupled Formal Contracts Abstract Logic Composable Reusable Autonomous Stateless Discoverable

Service Oriented Architecture (SOA) SOA Workflow

Service Oriented Architecture (SOA) Primary Technologies

Document-centric SOAP WSDL UDDI

Advantages Extensible Scalable

Disadvantages Excessive Configuration Reliance on Tools

Representational State Transfer (REST) REST Principles

Resource Oriented Uniquely Addressable Client-Server Stateless Cache Uniform Interface Layered System

Representational State Transfer (REST) REST Workflow

Representational State Transfer (REST) Example Framework

Restlet Advantages

Extensible Scalable Content Types

Disadvantages Data Size

Conclusion

REST is the best overall architecture style Not too complex Extensible Interoperable Scalable

Challenges to Adoption Benefits are not immediately recognizable Maturity Investment in SOA

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