1. Performance Analysis and Simulation of Service Based Applications Rajapaksage Jayampathi DM Rasanjalee Himali Instructor: Dr Xaolin Hu CSC 8350

2. Outline SOA Mapping SOA Elements to DEVS Elements Software and Hardware Models  Primitive Services  Composite Services  Generic Messages Case Study and Simulation Experimental Results

3. Service Oriented Architecture (SOA) SOA is an architectural style for building software applications that use services available in a network such as the web. Applications in SOA are built based on services. Services:  Well defined interfaces/ implementation independent  Self Contained  Loosely coupled  Can be dynamically discovered  New services can be created from an existing IT infrastructure of systems. SOA's Find-Bind-Execute Paradigm

4. Mapping SOA Elements to DEVS Elements SOA Model ElementDEVS Model Element services (service provider, service client, service broker) atomic models (service provider, service client, service broker) service descriptionentity (service-information) messagesentity (service-lookup and service-call) messaging frameworkports and couplings composition of servicescoupled models (service providers)

5. Software and Hardware Models Primitive Services Composite Services Communication of Messages

6. Software and Hardware Models [Contd.] Service Broker Simulation Model  modeled with service registry feature  Service provider publish services  Service Broker store received service-info messages  Service Consumer find services  Service broker return matching service-info to consumer

7. Software and Hardware Models [Contd.] Service Client Simulation Model  modeled with two behaviors such as looking up the service broker and invoking service provides.  service client simulation model looks up the service broker using a desired endpoint along with the service name  If the service client simulation model receives the service-info message from the service broker, then invoke the service provider; otherwise it may continue to look up the service broker for a given number.

8. Software and Hardware Models [Contd.] Service Provider Simulation Model  modeled with its own performService() function that fulfills a set of specific services  The service provider simulation model publishes its input ports as endpoints at the given time.  It should be able to handle multiple requests and service them simultaneously.  Accessing information is supported by coupling and ports

9. Primitive Service

10. Generic Messages Three principal usages of messages:  publication, lookup, and subscription

11. Composite Service Simulation Model Service composition information should be defined in the service- information message model as binding information. Each primitive service provider in the composite model does not know the order of invocation.

12. Case Study Simulation we describe two WS processes which provide the same required functionality. Both WS Process 1 and 2 (WSP1, WSP2), ensure on-line books acquisition. WSP 1WSP 2

13. Results of DEVS Simulation

14. References A SIMULATION FRAMEWORK FOR SERVICE-ORIENTED COMPUTING SYSTEMS, Hessam Sarjoughian, Sungung Kim Muthukumar Ramaswamy, Stephen Yau, 2008 Winter Simulation Conference, 2008 A Discrete-Event Simulation Approach for Evaluation of Service-Based Applications, Maha Driss1,2, Yassine Jamoussi,IEEE ECOWS.2008