Introduction to Service-Oriented Architecture

Outline Definition Features Examples of SOA Web Service Standards Example Pros and Cons Integration with Previous Works Issues

Definition A service is a unit of work done by a service provider to achieve desired end results for a service consumer Results of a service are usually the change of state for the consumer or the provider Let experts (providers) do the work for us (consumers) Providers Different quality of service Consumer

Definition (cont.) Webopedia: “ An application architecture in which all functions, or services, are defined using a description language and have invokable interfaces that are called to perform business processes ” Webopedia SOA is an architectural style whose goal is to achieve loose coupling among interacting software agents

Features Distributed Components are distributed in the network Loosely coupled We can switch components according to our need as long as they implement the same interface Open standard Web Service standard Easy integration even if implemented in different platforms Process centric Analysis the process of a specific task Divide it to service interfaces

Examples of SOA CORBA? CORBA software from different vendors may not always interoperate at all levels DCOM? Windows-based solution only Web Service? XML-based protocols that are lightweight and simple

Web Service Standards XML Document format HTTP Transport layer protocol SOAP For message exchange WSDL Interface description UDDI Registration and discovery

WSDL Example

K2 Fatbob SOAP Messages Chris Englesmann SOAP resquest SOAP response

Pros And Cons of Web Service Programming Model Pros Standard-based Loose coupling leads to increased modularity and flexibility Reduces integration costs Cons Immature Some vendor solutions are single-vendor approaches which conflict with the open standards- based vision of Web Services

Integration with Our Previous Work Accounting Service Security Services Dfdf H.264 RMI Roaming RMI Streaming Task Switching MPEGIIVoIP Video Streaming IP Phone … Web Service Interface APPs 3 rd Party Services SW/HW Components Logging Service To make integration easier

Integration Issues Programming Model Previous works are based on Java Client applications should interoperate with our services through web service interfaces Performance SOAP message serialization downgrades performance

Future Work Model Definition RMI Roaming + RMI Streaming Integration with other works Any possibilities?