1. Click to edit Master title style Composite Applications: Can We Learn from Web Service Composition? Ian Jones – Chair OASIS ebXML Messaging Services TC

2. 2 Outline n Introduction n History n What we did? n What are the issues? n What are we doing next? n What we learned? n Questions

3. 3 Introduction n Chair OASIS ebXML Messaging Services TC n Day Job - Web Services, B2B & SOA International Standards Manager for BT n Almost 20 years in B2B l EDI – EDIFACT & ANSI X.12 l E-Commerce, Internet technology, EAI l ebXML from the beginning l Web services → SOA

4. 4 History n ebXML Messaging Version 1 l proprietary except SOAP 1.1 / SWA n ebXML Messaging Version 2 l Used XMLDSIG for security l Not WS* compatible and no SOAP 1.2 n Make V3 WS friendly, work with other WS-specs and support simple clients +++

5. 5 What We Did n WS-Security 1.0 & 1.1 n WS-Reliability n WS-Reliable Messaging n Not forgetting l SOAP 1.1 & SOAP 1.2 l WSI –Attachments Profile & Basic Security profile n All the other underlying technology!

6. 6 Issues …

7. 7 Issues … Baggage n The extra bits you get for free! n Ignore some! Optional? n Address some! Mandatory? n Dependencies and sub specifications! n Versioning – stability & upgrades n Support – Specification and software n You have to Profile !

8. 8 Issues … Leftovers n The bits you still need that did not fit! n Custom build the bits? n Ask your supplier to build? n Where do they fit? l Extend an existing component l Stand alone n Versioning & change

9. 9 Next!! n Adding extra functionality l Custom extension – large payload handling l Bundling messages l More transports n Extending functionality l Reliable delivery via intermediaries

10. 10 What we learned n Architecture & design l Pipeline (SOAP Processing model) l Embedded l Black box n Package / Component compatibility – what “flavour” do they implement n Unavailable header Data – someone else used it!

11. 11 The most important lesson n Compromise And / Or n Change

12. 12 What applies to Composite Applications? n Due diligence – functionality, interface and scope of component n Cost – time, effort, money – building the “glue” n Error handling n Test n Fault fixing – non trivial if component error

13. 13 Consider - 1 n “just because something can be done does not mean it should be done” n You will probably be the first person assembling this collections of components n Management – development / delivery /operational n Expect the unexpected

14. 14 The Spanish Inquisition

15. 15 Consider - 2 n Sceptics and cynics are not always wrong! n Don’t believe everything you read or are told – CHECK the documentation

16. 16 Final thoughts n Moving data between applications takes time n Distributed components could move l Servers l Continents l What if it is outsourced? n SLA for the component n Complexity are you reducing it?

17. 17 Questions / Comments / Discussion n Yes the last 10% takes 90% of the time!