Enhancing availability in distributed real-time databases

ABSTRACT

One of the issues in distributed databases is to maintain the data consistency when a database is replicated for higher availability. In a real-time database system, availability may be more important than consistency since a result must be produced before a deadline. We propose techniques to increase the availability in a partitioned real-time database. We also suggest that a transaction may execute even when the most up-to-date information is not available or when a serializable execution cannot be guaranteed. As long as data integrity is maintained, serializable execution may not be necessary.

REFERENCES

• 1: Peter A. Alsberg , John D. Day, A principle for resilient sharing of distributed resources, Proceedings of the 2nd international conference on Software engineering, p.562-570, October 13-15, 1976, San Francisco, California, United States
• 2: Philip A. Bernstein , Nathan Goodman, Multiversion concurrency control—theory and algorithms, ACM Transactions on Database Systems (TODS), v.8 n.4, p.465-483, Dec. 1983 [doi>10.1145/319996.319998]
• 3: Philip A. Bernstein , Vassco Hadzilacos , Nathan Goodman, Concurrency control and recovery in database systems, Addison-Wesley Longman Publishing Co., Inc., Boston, MA, 1987
• 4: Susan B. Davidson, An optimistic protocol for partitioned distributed database systems, Princeton University, Princeton, NJ, 1982
• 5: Susan B. Davidson , Hector Garcia-Molina , Dale Skeen, Consistency in a partitioned network: a survey, ACM Computing Surveys (CSUR), v.17 n.3, p.341-370, Sept. 1985 [doi>10.1145/5505.5508]
• 6: Hector Garcia-Molina , Gio Wiederhold, Read-only transactions in a distributed database, ACM Transactions on Database Systems (TODS), v.7 n.2, p.209-234, June 1982 [doi>10.1145/319702.319704]
• 7: [Garcia et al. 83] Garcia-Molina, H., et al., "Data-Patch: Integrating inconsistent copies of a database after a partition," Proc. 3rd Symp. Reliability in Distributed Softw. and Database Systems, pp. 38- 48, Oct. 1983.
• 8: David K. Gifford, Weighted voting for replicated data, Proceedings of the seventh ACM symposium on Operating systems principles, p.150-162, December 10-12, 1979, Pacific Grove, California, United States [doi>10.1145/800215.806583]
• 9: [Minoura and Wiederhold 82] Minoura, T., and G. Wiederhold, "Resilient extended true-copy token scheme for a distributed database system," IEEE Trans. Softw. Eng., vol. SE-8, pp. 173-189, May 1982.
• 10: [Parker et al. 83] Parker, D. S., et al., "Detection of mutual inconsistency in distributed systems," IEEE Trans. Softw. Eng., vol. SE-9, pp. 240-247, May 1983.

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.3 SPECIAL-PURPOSE AND APPLICATION-BASED SYSTEMS
      Subjects: Real-time and embedded systems

Additional Classification:
  H. Information Systems
  H.2 DATABASE MANAGEMENT
      H.2.0 General
          Subjects: Security, integrity, and protection**
      H.2.4 Systems
          Subjects: Distributed databases

General Terms:
Algorithms, Design, Management, Performance