Advances in WS-Transaction and WS-Coordination

1. Advances inWS-Transaction andWS-Coordination William Cox, Ph.D. OASIS Symposium on Reliable Infrastructure New Orleans 26 April 2004

2. Outline • Motivation and History • The Specifications • Evolution • Specification Techniques • Comparisons • Standardization Issues • Future • Summary and References Cox OASIS Symposium 20040426

3. Disclaimer • All opinions are those of the individual author of this presentation, and do not necessarily reflect those of the companies or individuals who are the specification authors. • “My opinion, and welcome to it.” - apologies to James Thurber Cox OASIS Symposium 20040426

4. Motivations • Support Business process, legacy integration • Designed from the ground up as composableWeb services • Tailored to specific needs • WS-AT – tightly coupled, legacy integration, rollback semantics • WS-BA – loosely coupled, long running, compensation semantics • WS-C – Factoring of context management Cox OASIS Symposium 20040426

5. History • XA (X/Open) • OMG Object Transaction Service • And Extended Structures for OTS • XOCP, others • BTP (similar goals but more complex) • WS-CAF (overlapped completion of v1.1) Cox OASIS Symposium 20040426

6. Published Specifications • August 2002 Publications • WS-Coordination 1.0 • WS-Transaction 1.0 [WS-TX] • September 2003 Publications • WS-Coordination 1.1 [WS-C] • WS-AtomicTransaction [WS-AT] • January 2004 Publication • WS-BusinessActivity [WS-BA] • Abbreviations • WS-Transaction [WS-TX]refers to WS-AT+WS-BA Cox OASIS Symposium 20040426

7. Specification Relationships v1.1 v1.0 WS- AtomicTransaction WS- BusinessActivity WS-Transaction WS-Coordination WS-Coordination WS-Addressing Cox OASIS Symposium 20040426

8. Structural Evolution v1.0-v1.1 • WS-AtomicTransaction and WS-BusinessActivity are now separate specifications • Were subparts of WS-TX 1.0 • Use of WS-Addressing Endpoint Reference’s opaque ReferenceProperties throughout • Editorial and readability improvements • Separate publication of WS-AT and WS-BA Cox OASIS Symposium 20040426

9. Technical Evolution v1.0-v1.1 • General • Adopted opaque Endpoint Reference from WS-Addressing • v1.0 “roll your own” contributed to WS-Addressing requirements • Updated and enhanced security considerations, policy • WS-AT • Renamed to Volatile 2PC, Durable 2PC • Complete state tables • WS-BA • Named more consistently • BusinessActivityWithCoordinatorCompletion • BusinessActivityWithParticipantCompletion • Renamed some states • Complete state tables Cox OASIS Symposium 20040426

10. Specification Techniques • State reduction through simplification • Factored WS-Coordination • Didn’t try to view state of entire interaction • Only the coordinator and participant separate views • Some additional care for consistency designed in • Acknowledge then ignore “state smear” • Broad applicability for WS-Coordination • WS-AT, WS-BA, other coordinations Cox OASIS Symposium 20040426

11. Some Comparisons • WS-C/WS-TX • WS-Coordination specified as simple algorithm • WS-AT has 7 states • WS-BA has 8/9 states • BTP has 28 Superior, 36 Inferior states • But includes ~ WS-C x WS-BA states in one machine Cox OASIS Symposium 20040426

12. Some Comparisons (continued) • WS-CAF—Bookkeeping difficult • Builds on context mgt protocol WS-CTX, as does WS-TX • Atomic has 8 states and 14 messages • LRA has many sub-protocols (total of 40 messages) Cox OASIS Symposium 20040426

13. Another Comparison • Pages of specification • BTP: 188 pages • WS-CAF base docs 240 pages • WS-Coordination+WS-AT+WS-BA 59 pages • Does reflect time needed to read and understand Cox OASIS Symposium 20040426

14. Standardization Issues • Use of WS-Addressing requires standardization of at least Endpoint Reference • This is also an issue for the new WS-Resource Framework and WS-Notification TC base documents • Factoring useful if not overdone • WS-TX/WS-C factoring seems about right • Specify, demonstrate interoperability, iterate • Focus on interoperable implementations important • When and in which cycle? • More mature specs into standardization process vs buy-in Cox OASIS Symposium 20040426

15. The Future • Author companies have committed to submitting to a standards organization • Feedback meeting March 2004 • See references • Comment license required • So can maintain royalty-free approach to these specs • Interoperability event in planning Cox OASIS Symposium 20040426

16. Summary • WS-Transaction and WS-Coordination simple enough, rich enough • Composable web services target level • Specifications at the right level • Reasonable number of states • Reasonable number of protocols • Comparatively lower complexity than competing specs • Progressing to interoperability testing and submission to a standards organization Cox OASIS Symposium 20040426

17. References • WS-Coordination • WS-AtomicTransaction • WS-BusinessActivity • WS-Addressing • IBM Links http://www-106.ibm.com/developerworks/views/webservices/standards.jsp Alphabetization problems--some under “WS-”, some under “Web Services” • Microsoft Links http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnglobspec/html/wsatspecindex.asp • BEA Links http://dev2dev.bea.com/technologies/webservices/standards.jsp Interoperability and Feedback http://www-106.ibm.com/developerworks/offers/WS-Specworkshops/ws-tx200402post.html http://msdn.microsoft.com/webservices/community/workshops/transactionws032004.aspx Cox OASIS Symposium 20040426

18. References (continued) • WS-CAF (Arjuna, Fujitsu, Iona, Oracle, Sun) July 2003, OASIS TC • http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=ws-caf • BTP OASIS TC http://www.oasis-open.org/committees/tc_home.php?wg_abbrev=business-transaction • BTP 1.0 http://www.oasis-open.org/committees/download.php/1184/2002-06-03.BTP_cttee_spec_1.0.pdf • BTP Primer http://www.oasis-open.org/committees/download.php/2077/BTP_Primer_v1.0.20020605.pdf Cox OASIS Symposium 20040426