System support for object groups

ABSTRACT

This paper draws several observations from our experiences in building support for object groups. These observations actually go beyond our experiences and may apply to many other developments of object based distributed systems.Our first experience aimed at building support for Smalltalk object replication using the Isis process group toolkit. It was quite easy to achieve group transparency but we were confronted with a strong mismatch between the rigidity of the process group model and the flexible nature of object interactions. Consequently, we decided to build our own object oriented protocol framework, specifically dedicated to support object groups (instead of using a process group toolkit). We built our framework in such a way that basic distributed protocols, such as failure detection and multicasts, are considered as first class entities, directly accessible to the programmers. To achieve flexible and dynamic protocol composition, we had to go beyond inheritance and objectify distributed algorithms.Our second experience consisted in building a CORBA service aimed at managing group of objects written on different languages and running on different platforms. This experience revealed a mismatch between the asynchrony of group protocols and the synchrony of standard CORBA interaction mechanisms, which limited the portability of our CORBA object group service. We restricted the impact of this mismatch by encapsulating asynchrony issues inside a specific messaging sub-service.We dissect the cost of object group transparency in our various implementations, and we point out the recurrent sources of overheads, namely message indirection, marshaling/unmarshaling and strong consistency.

REFERENCES

• 1: G. Agha and R. Guerraoui (guest editors). Theory and Practice of Object Systems, John Wiley and Sons, Inc. Special issue on High Availability in CORBA, 1998, 4 (2),
• 2: Philip A. Bernstein , Vassco Hadzilacos , Nathan Goodman, Concurrency control and recovery in database systems, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1987
• 3: Andrew D. Birrell , Bruce Jay Nelson, Implementing remote procedure calls, ACM Transactions on Computer Systems (TOCS), v.2 n.1, p.39-59, February 1984 [doi>10.1145/2080.357392]
• 4: Jean-Pierre Briot , Rachid Guerraoui , Klaus-Peter Lohr, Concurrency and distribution in object-oriented programming, ACM Computing Surveys (CSUR), v.30 n.3, p.291-329, Sept. 1998 [doi>10.1145/292469.292470]
• 5: Kenneth P. Birman , Robbert Van Renesse, Reliable Distributed Computing with the ISIS Toolkit, IEEE Computer Society Press, Los Alamitos, CA, 1993
• 6: Andrew P. Black , Mark P. Immel, Encapsulating Plurality, Proceedings of the 7th European Conference on Object-Oriented Programming, p.57-79, July 26-30, 1993
• 7: N. Brown and C. Kindel. Distributed Component Object Model Protocol. DCOM, http://www.microsoft.com/oledev/olecom.
• 8: Tushar Deepak Chandra , Sam Toueg, Unreliable failure detectors for reliable distributed systems, Journal of the ACM (JACM), v.43 n.2, p.225-267, March 1996 [doi>10.1145/226643.226647]
• 9: David R. Cheriton , Dale Skeen, Understanding the limitations of causally and totally ordered communication, Proceedings of the fourteenth ACM symposium on Operating systems principles, p.44-57, December 05-08, 1993, Asheville, North Carolina, United States
• 10: E. Elnozahy, V. Ratan, and M. Segal. Experiences Using DCE and CORBA to Build Tools .for Creating Highly-Available Distributed Systems. IEEE Symposium on Fault-Tolerant Computing Systems, 1996.
• 11: P. Felber , B. Garbinato , R. Guerraoui, The design of a CORBA group communication service, Proceedings of the 15th Symposium on Reliable Distributed Systems (SRDS '96), p.150, October 23-25, 1996
• 12: P. Felber , R. Guerraoui , A. Schiper, Replicating objects using the CORBA Event Service?, Proceedings of the 6th IEEE Workshop on Future Trends of Distributed Computing Systems (FTDCS '97), p.14, October 29-31, 1997
• 13: Pascal Felber , Rachid Guerraoui , André Schiper, The implementation of a CORBA object group service, Theory and Practice of Object Systems, v.4 n.2, p.93-105, April 1998 [doi>10.1002/(SICI)1096-9942(1998)4:2<93::AID-TAPO4>3.3.CO;2-E]
• 14: Erich Gamma , Richard Helm , Ralph Johnson , John Vlissides, Design patterns: elements of reusable object-oriented software, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1995
• 15: Benoît Garbinato , Rachid Guerraoui , Karim Mazouni, Distributed Programming in GARF, Proceedings of the Workshop on Object-Based Distributed Programming, p.225-239, July 26-27, 1993
• 16: B. Gaxbinato, R. Guerraoui, and K. Mazouni. Implementation of the GARF Replicated Objects Plateform. Distributed Systems Engineering Journal, 1 (2), 1995, 14-27.
• 17: Benoît Garbinato , Pascal Felber , Rachid Guerraoui, Protocol Classes for Designing Reliable Distributed Environments, Proceedings of the 10th European Conference on Object-Oriented Programming, p.316-343, July 08-12, 1996
• 18: B. Garbinato and R. Guerraoui. Using the strategy design pattern to compose reliable distributed protocols. Usenix Conference on Object-Oriented Technologies and Systems, 1997, 221-232.
• 19: Benoit Garbinato , Rachid Guerraoui, Flexible Protocol Composition in Bast, Proceedings of the The 18th International Conference on Distributed Computing Systems, p.22, May 26-29, 1998
• 20: Adele Goldberg , David Robson, Smalltalk-80: the language and its implementation, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1983
• 21: Rachid Guerraoui , André Schiper, Transaction Model vs. Virtual Synchrony Model: Bridging the Gap, Selected Papers from the International Workshop on Theory and Practice in Distributed Systems, p.121-132, September 05-09, 1994
• 22: Rachid Guerraoui , Rui Oliveira , André Schiper, Atomic Updates of Replicated Data, Proceedings of the Second European Dependable Computing Conference on Dependable Computing, p.365-382, October 02-04, 1996
• 23: Rachid Guerraoui , André Schiper, Software-Based Replication for Fault Tolerance, Computer, v.30 n.4, p.68-74, April 1997 [doi>10.1109/2.585156]
• 24: Rachid Guerraoui , Benoît Garbinato , Karim Mazouni, Garf: A Tool for Programming Reliable Distributed Applications, IEEE Parallel & Distributed Technology: Systems & Technology, v.5 n.4, p.32-39, October 1997
• 25: Elliotte Rusty Harold, Java network programming, O'Reilly & Associates, Inc., Sebastopol, CA, 1997
• 26: Hermann Hüni , Ralph Johnson , Robert Engel, A framework for network protocol software, Proceedings of the tenth annual conference on Object-oriented programming systems, languages, and applications, p.358-369, October 15-19, 1995, Austin, Texas, United States
• 27: IONA. OrbixTalk Programming Guide. IONA Technologies Ltd, 1996.
• 28: IONA. Orbix 2.2 Programming Guide. IONA Technologies Ltd, 1997.
• 29: IONA and Isis. An Introduction to Orbix+Isis. IONA Technologies Ltd. and Isis Distributed Systems, inc, 1994.
• 30: Isis. Object Groups: A response to the ORB 2.0 RFI. Isis Distributed Systems, Inc, 1993.
• 31: Gregor Kiczales , Jim des Rivières , Daniel G. Bobrow, The art of metaobject protocol, MIT Press, Cambridge, MA, 1991
• 32: Mark C. Little , Santosh K. Shrivastava, Object Replication in Arjuna, University of Bologna, 1994
• 33: S. Maffeis. Run-Time Support for Object-Oriented Distributed Programming. PhD thesis, University of Zurich, 1995.
• 34: Filtering Duplicated Invocations Using Symmetric Proxies, Proceedings of the 4th International Workshop on Object-Orientation in Operating Systems, p.118, August 14-15, 1995
• 35: S. Mishra, L. Peterson, and R. Schlichting. Implementing Fault-Tolerant Replicated Objects Using Psync. IEEE Symposium on Reliable Distributed Systems, 1989.
• 36: P. Narasimhan, L. Moser, and M. Melliar-Smith. Exploiting the internet inter-ORB protocol to provide CORBA with fault-tolerance. Usenix Conference on Object-Oriented Technologies and Systems, 1997, 81-90.
• 37: OMG. The Common Object Request Broker Architec. ture: Architecture and Specification. OMG.
• 38: OMG. CORBAservices: Common Object Services Specifications. OMG.
• 39: L. Peterson , N. Hutchinson , S. O'Malley , M. Abbott, RPC in the x-Kernel: evaluating new design techniques, Proceedings of the twelfth ACM symposium on Operating systems principles, p.91-101, November 1989
• 40: David Powell, Group communication, Communications of the ACM, v.39 n.4, p.50-53, April 1996 [doi>10.1145/227210.227225]
• 41: L. Rodrigues , K. Guo , A. Sargento , R. van Renesse , B. Glade , P. Verissimo , K. Birman, A transparent light-weight group service, Proceedings of the 15th Symposium on Reliable Distributed Systems (SRDS '96), p.130, October 23-25, 1996
• 42: Santosh K. Shrivastava , Graeme N. Dixon , Graham D. Parrington, An Overview of the Arjuna Distributed Programming System, IEEE Software, v.8 n.1, p.66-73, January 1991 [doi>10.1109/52.62934]
• 43: Visigenic. Visibroker C+4- 3. 0 Programmer's Guide. Visigenic Software, Inc., 1997.
• 44: M. Wood. Replicated RPC Using Amoeba Closed Group Communication. IEEE International Conference on Distributed Computing Systems, 1993.

INDEX TERMS

Primary Classification:
  D. Software
  D.2 SOFTWARE ENGINEERING

Additional Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS

  D. Software
  D.1 PROGRAMMING TECHNIQUES
  D.2 SOFTWARE ENGINEERING
  D.3 PROGRAMMING LANGUAGES

  H. Information Systems
  H.5 INFORMATION INTERFACES AND PRESENTATION (I.7)

General Terms:
Design, Languages, Measurement, Performance, Standardization, Theory