1. www.edikt.org info@edikt.org Enterprise Java and Data Services Designing for Broadly Available Grid Data Access Services

2. www.edikt.org 2 Contents 1.Motivation, Issues and Solution 2.Web and Grid Services 3.J2EE and EJBs 4.Eldas 5.Further work and conclusions

3. www.edikt.org 3 Motivation DAIS-WG –Grid Data Service Specification –data: relational dbs; XML dbs; file systems Eldas (Enterprise Level Data Access Services) commercial quality product: –robust –well documented –easy to use –modular, extensible design

4. www.edikt.org 4 Problem: Data Access Issues Additional issues: 1.Machine/Database Independence 2.Dual Compatibility 3.Layered Services 4.Ease of Use

5. www.edikt.org 5 Solution: Eldas 1.Machine/Database Independence 2.Dual Compatibility 3.Layered Services 4.Ease of Use

6. www.edikt.org 6 Web Services –services exposed via platform and language independent interfaces –interface described using WSDL –communication via SOAP/HTTP

7. www.edikt.org 7 Web Services and Grid Services Web Services –WSDL interface –static –container lifetime –stateless Grid Services –G-WSDL interface –dynamic –distinct lifetime –stateful

8. www.edikt.org 8 Current J2EE Grid Services Application Server Client Web Container JAX-RPC GDSF GDS SOAP Data (RDBMS, XML DB, File System) both presentation and business logic in web container (presentation layer)

9. www.edikt.org 9 J2EE for Web and Grid Services Separate Presentation, Business and Data layers Presentation Layer JSP/ Servlets Data Layer Typically RDBMS Application or Business Layer Beans, EJB Scalable, available, reliable, secure, transactional, distributed (Web Container)(EJB Container)(External Data)

10. www.edikt.org 10 EJB Features J2EE component for multi-tier, distributed applications –server side –business logic only –EJB container manages system level services –benefits of component based engineering

11. www.edikt.org 11 EJBs and Web Services Server Client (command line, browser, GUI) Data (RDBMS, XML DB, File System) Web Container (e.g. Tomcat ) JAX-RPC HTTP/SOAP Web Service Bean EJB Container Session EJB Entity EJB Presentation layer Business layer Web Services API in presentation layer Business logic in business layer Client-server objects passed with HTTP/SOAP

12. www.edikt.org 12 Grid Services GDS Database GDSF Client SOAP / HTTP Service Creation API Interactions create

13. www.edikt.org 13 Application Server EJB Grid Services Client Web Container JAX-RPC SOAP Data PROXYPROXY EJB Container EJB GDSF GDS Data Access Component

14. www.edikt.org 14 Eldas Design Considerations established patterns used throughout –e.g Business Delegate, Data Access Object, Singleton GDS is stateful session EJB –one bean per client session –maintains conversational state with client entity EJBs not used –replaced by DAC

15. www.edikt.org 15 DEMO Demo –Shows Eldas service created –Query a database in Edinburgh –Display the results Xml Excel format

16. www.edikt.org 16 e-Science Applications Overview Plug and Play Concept –Clearly defined interfaces OSAGE BPS BinX Others Eldas Core Eldas Bespoke Applications

17. www.edikt.org 17 Enhanced Data Services ELDAS Data Annotation Service Data Transform Service DB2 DBMySQL DBXindice DBOracle 9i DB Data Archiving Service Data Versioning Service Examples of Enhanced Data Services

18. www.edikt.org 18 BinX Binary XML Description Language Eldas XML JDBC File System BinX

19. www.edikt.org 19 Summary Eldas –commercial quality –machine and data independent –dual compatibility –extensible core allowing bespoke services –easy to use (even our boss managed to install and use it!) Future work with e-Science customers –Enhanced Services –BinX