1. 1©2005 OnTapSolutions5 December 2005 Service Oriented Architecture with O.K.I. Tom Coppeto OnTapSolutions Stuart Sim Sun Microsystems 5 December 2005

2. 2©2005 OnTapSolutions5 December 2005 Service Oriented Architectures An architecture is a framework that defines an organization of system components SOA is an architecture organizing systems around services Each service is defined using a service interface Service implementation hidden from the interface consumer

3. 3©2005 OnTapSolutions5 December 2005 It’s About Integration Making applications work with IT infrastructures Making system components work with each other The interfaces define the integration points among disparate services, not the technologies or other service implementation details

4. 4©2005 OnTapSolutions5 December 2005 It’s About Software Some SOAs place the interface boundary on the wire We believe the interface boundary is better placed in the software consumer provider consumer provider

5. 5©2005 OnTapSolutions5 December 2005 O.K.I. Open Service Interface Definitions (OSIDs) O.K.I. is an SOA built on service definitions OSIDs define software interfaces The interface is a contract between a service consumer and a service provider OSIDs do not specify how a service works Different providers of the same OSID may do entirely different things

6. 6©2005 OnTapSolutions5 December 2005 OSID Specifications Repository Scheduling Assessment Course Management User Messaging Workflow www.okiproject.org Id Agent Authentication Authorization Logging SQL Filing

7. 7©2005 OnTapSolutions5 December 2005 OSID Providers O.K.I. does not specify what a provider implementation can do other than to implement the interface An Authorization provider that makes use of LDAP should work just as well as an Authorization provider that simply said yes –One may be a bit more useful than the other, however –Sometimes it’s useful to have a provider do nothing

8. 8©2005 OnTapSolutions5 December 2005 Old School Programming Send credential Send command Make server connection Get auth credential Core application read response Authentication configuration Authentication credential Server identity Connection handle Authentication credential command Data to be parsed status config APIs Log

9. 9©2005 OnTapSolutions5 December 2005 Interface Programming Core application authN log Service log Service Interface Service Implementation

10. 10©2005 OnTapSolutions5 December 2005 Software Design (the way not to look at OSIDs) Repository Application AUTHLOGGINGREPOSITORY

11. 11©2005 OnTapSolutions5 December 2005 Software Design (2) (better) Repository Application Repository Authentication Agent Logging LOGGING

12. 12©2005 OnTapSolutions5 December 2005 Software Design (3) Application Service Implementation Service Implementation Service Implementation (adapters)

13. 13©2005 OnTapSolutions5 December 2005 Software Design (4) IMPL Application Server Client Client/server systems begin with standalone impls

14. 14©2005 OnTapSolutions5 December 2005 What an Implementation Looks Like INTERFACE CONTRACT UTILITIES CLIENT PROTOCOLS OTHER IMPLEMENTATIONS REMOTE SERVER WIRE PROTOCOLS CONFIGURATION PROPERTIES TRANSACTION MANAGEMENT APPLICATION

15. 15©2005 OnTapSolutions5 December 2005 Pound Wise, Penny Foolish As software engineers, we get too caught up in reusing small amounts of code Instead of worrying about reusing a particular java class, we should worry about not replicating entire services

16. 16©2005 OnTapSolutions5 December 2005 Architectural Case Study Project Athena Student Services Alumni Atheltics Sloan Parking Libraries IST SloanSpace DSpace Techtime Parking Moira SIS Alumni Atheltics Data Warehouse

17. 17©2005 OnTapSolutions5 December 2005 Resulting System Architecture Agent Group Authentication Authorization Messaging Scheduling Course Mgmt Repository MoiraSISAlumniAthletics SloanSpace DSpaceTechtimeParking

18. 18©2005 OnTapSolutions5 December 2005 Taking The Red Pill Top-down organization of processes, services and utilities Technology specifics don’t matter to application code Consumers should not tell providers how to do their job, just that it needs to be done Services relying on data feeds need to be refactored www.okiproject.org