1. 1 Formal Models for Transactions: BizTalk as ZSN Roberto Bruni Dipartimento di Informatica Università di Pisa Models and Languages for Coordination and Orchestration IMT- Institutions Markets Technologies - Alti Studi Lucca

2. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 2 Models and Languages for Coordination and Orchestration Contents Orchestration with Petri Nets Transactions with Zero Safe Nets From BizTalk to Zero Safe Nets

3. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 3 Models and Languages for Coordination and Orchestration Microsoft© BizTalk Orchestration Visual Designer Commercial Workflow Management System Designed for business process orchestration DTC for handling distributed business processes in asynchronous environment BizTalk includes a graphical environment Three different views integrated Flowchart view Implementation view Data flow view We focus on the flowchart view

4. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 4 Models and Languages for Coordination and Orchestration Workflows Coordinated execution of multiple tasks following a schedule Transactional mechanisms guarantee “correct” executions Correctness does not imply serializability Independent applications and DBs Coordination of applications, not just DBMS

5. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 5 Models and Languages for Coordination and Orchestration Transactional Workflows Biztalk process as flowcharts graphical environment short, timed, long transactions unique entry point unique exit point DTC for 2PC: BizTalk Server on-failure processes compensations SHAPES begin / end action decision while fork join transaction abort

6. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 6 Models and Languages for Coordination and Orchestration Transactional Workflows F 1,C 1 F 2,C 2 begin end Biztalk process as flowcharts graphical environment short, timed, long transactions unique entry point unique exit point DTC for 2PC: BizTalk Server on-failure processes compensations

7. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 7 Models and Languages for Coordination and Orchestration From BizTalk to Zero-Safe Nets Zero-Safe nets offer a suitable semantic framework for interpreting BizTalk diagrams for short transactions BizTalk diagrams (no nesting) can be easily translated in ZSN The translation suggests that the limitation of unique entry / exit point can be relaxed Multiple entry / exit points Multiway transactions

8. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 8 Models and Languages for Coordination and Orchestration BizTalk Graphical Environment SHAPES begin / end action decision while fork join transaction abort begin compute end send a (v) v a receive b (x) x b a flowchart begin send a (v) receive b (x) compute end v a x b a transaction

9. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 9 Models and Languages for Coordination and Orchestration A Rendez-Vous in BizTalk begin send a (v) receive b (x) compute end v a x b begin receive a (y) send b (u) compute end y u AB a,b transactional channels makes DTC aware of the cooperation A and B must commit / abort together (logically belong to the same transaction)

10. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 10 Models and Languages for Coordination and Orchestration BizTalk Without (Transaction) Boxes begin send a (v) receive b (x) compute end v a x b begin receive a (y) send b (u) compute end y u AB Colour shapes within the same box with a distinguished colour Shapes outside boxes stay the same

11. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 11 Models and Languages for Coordination and Orchestration BizTalk Without (Transaction) Boxes but With Places begin send a (v) receive b (x) compute end v a x b begin receive a (y) send b (u) compute end y u AB Small circles are addedd: between arrows connecting shapes of the same color and for representing transactional channels Large circles are added: between arrows connecting shapes of different colours and for representing non-transactional channels

12. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 12 Models and Languages for Coordination and Orchestration Multiway transaction BizTalk via Zero-Safe Nets Stable places: Large circles begin / end shapes Zero places: Small circles Transitions: Action shapes begin send a (v) receive b (x) compute end v a x b begin receive a (y) send b (u) compute end y u AB

13. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 13 Models and Languages for Coordination and Orchestration Recap Flowchart view of BizTalk Encoding BizTalk graphs in ZSN Handling multiway transactions is natural Dynamic boundaries of transactions Formal semantics Abstract / refined view

14. Roberto Bruni @ IMT Lucca 13 April 2005 Institutions Markets Technologies IMT 14 Models and Languages for Coordination and Orchestration References Orchestrating transactions in join calculus (Proc. CONCUR 2002, LNCS 2421, pp. 321- 336) R. Bruni, C. Laneve, U. Montanari