1. Zoltán Mann: Tracing CORBA applications 1/22 Tracing CORBA applications using interceptors Zoltán Mann Supervisor: Dr. Károly Kondorosi Budapest University of Technology and Economics Department of Control Engineering and Information Technology

2. Zoltán Mann: Tracing CORBA applications 2/22 Contents 1. Motivation 2. Tracing in general 3. Interceptors 4. Tracing using interceptors 5. Conclusion

3. Zoltán Mann: Tracing CORBA applications 3/22 Motivation 1. Technical development: Distributed, heterogeneous environment Object-oriented integration  CORBA

4. Zoltán Mann: Tracing CORBA applications 4/22 Motivation 2. Applications: e-Business Embedded systems

5. Zoltán Mann: Tracing CORBA applications 5/22 Motivation 3. Growing competition: Functional and reliability requirements Time-to-market pressure

6. Zoltán Mann: Tracing CORBA applications 6/22 Contents 1. Motivation 2. Tracing in general 3. Interceptors 4. Tracing using interceptors 5. Conclusion

7. Zoltán Mann: Tracing CORBA applications 7/22 Tracing vs. debugging

8. Zoltán Mann: Tracing CORBA applications 8/22 Aims of tracing (use cases) 1. Checking correct behaviour 2. Locating bugs 3. Better understanding of how the system works 5. Automatic documentation extraction 6. Performance analysis, identifying bottlenecks 4. Monitoring crucial applications

9. Zoltán Mann: Tracing CORBA applications 9/22 Current tracing mechanisms Current solutions are bound to particular programming languages. Synchronization, lack of global clock etc. Heterogeneity Collecting information from different namespaces Problems with distributed systems:

10. Zoltán Mann: Tracing CORBA applications 10/22 Current tracing mechanisms State of the art in distributed systems: + Central tracer – Manual instrumentation – Extra programming work – Prone to errors

11. Zoltán Mann: Tracing CORBA applications 11/22 Contents 1. Motivation 2. Tracing in general 3. Interceptors 4. Tracing using interceptors 5. Conclusion

12. Zoltán Mann: Tracing CORBA applications 12/22 CORBA interceptor An object implementing the interceptor interface without actually modifying the ORB using callback methods extending the functionality of the ORB

13. Zoltán Mann: Tracing CORBA applications 13/22 Callback methods ClientProxySkeletonServant Server Request Interceptor receive_request() send_reply() Client Request Interceptor send_request() receive_reply() methodX() Client Server

14. Zoltán Mann: Tracing CORBA applications 14/22 Definitions & implementations First definition: CORBA 2.3 Incompatible implementations September 1998: OMG RFP December 1999: Joint Submission March 2000: CORBA 3.0 Working Draft The used implementation: TAO 1.1 and 1.1.9 beta

15. Zoltán Mann: Tracing CORBA applications 15/22 Other possible solutions Smart proxies Servant managers Pluggable protocols ORB event handlers …

16. Zoltán Mann: Tracing CORBA applications 16/22 Contents 1. Motivation 2. Tracing in general 3. Interceptors 4. Tracing using interceptors 5. Conclusion

17. Zoltán Mann: Tracing CORBA applications 17/22 Tracing using interceptors ClientServerTracer send_request() receive_request() send_reply() receive_reply()

18. Zoltán Mann: Tracing CORBA applications 18/22 The resulting architecture Automatic instrumentation Open system Until then: a slight modification of the ORB With the standard registration mechanism of interceptors, even that could be avoided One single line of initialization code per name space

19. Zoltán Mann: Tracing CORBA applications 19/22 Overhead In interactive mode: ~ 500 % communication overhead In local mode: ~ 15 %

20. Zoltán Mann: Tracing CORBA applications 20/22 Contents 1. Motivation 2. Tracing in general 3. Interceptors 4. Tracing using interceptors 5. Conclusion

21. Zoltán Mann: Tracing CORBA applications 21/22 Results A tracing architecture satisfying the previously defined requirements A tool for documenting and interactive tracing of CORBA applications The solution works in a distributed and heterogeneous environment Prototype of a future product

22. Zoltán Mann: Tracing CORBA applications 22/22 Future plans Improving interoperability Extending the architecture for other middleware systems, such as DCOM Improving user interface, with the inclusion of possible users Making the tracer persistent …

23. Zoltán Mann: Tracing CORBA applications 23/22 Tracing CORBA applications using interceptors Zoltán Mann Supervisor: Dr. Károly Kondorosi Budapest University of Technology and Economics Department of Control Engineering and Information Technology