Đang chuẩn bị liên kết để tải về tài liệu:
Epidemic Algorithms for Replicated Database Maintenance

Oracle Audit Vault is an enterprise-class audit consolidation and management solution that enables organizations to simplify compliance reporting, proactively detect threats, reduce costs, and secure audit data. Faced with numerous regulatory mandates and increasing concerns about insider threats, organizations are utilizing database audit data as an important security measure, enforcing the trust-but-verify principle. Oracle Audit Vault delivers an in-depth and comprehensive view of audit data pulled from the database, helps to ensure the integrity of this information, and can reduce the cost of compliance by making it easier for auditors and security personnel to manage and report on this data | Palo Alto Research Center Epidemic Algorithms for Replicated Database Maintenance Alan Demers Mark Gealy Dan Greene Carl Hauser Wes Irish John Larson Sue Manning Scott Shenker Howard Sturgis Dan Swinehart Doug Terry and Don Woods XEROX Epidemic Algorithms for Replicated Database Maintenance Alan Demers Mark Gealy Dan Greene Carl Hauser Wes Irish John Larson Sue Manning Scott Shenker Howard Sturgis Dan Swinehart Doug Terry and Don Woods CSL-89-1 January 1989 P89-00001 Copyright 1987 Association of Computing Machinery. Printed with permission. Abstract When a database is replicated at many sites maintaining mutual consistency among the sites in the face of updates is a significant problem. This paper describes several randomized algorithms for distributing updates and driving the replicas toward consistency. The algorithms are very simple and require few guarantees from the underlying communication system yet they ensure that the effect of every update is eventually reflected in all replicas. The cost and performance of the algorithms are tuned by choosing appropriate distributions in the randomization step. The algorithms are closely analogous to epidemics and the epidemiology literature aids in understanding their behavior. One of the algorithms has been implemented in the Clearinghouse servers of the Xerox Corporate Internet solving long-standing problems of high traffic and database inconsistency. An earlier version of this paper appeared in the Proceedings of the Sixth Annual ACM Symposium on Principles of Distributed Computing Vancouver August 1987 pages 1-12. CR Categories and Subject Descriptors c.2.4 Computer-Communication Networks Distributed Systems - distributed databases. General Terms Algorithms experimentation performance theory. Additional Keywords and Phrases Epidemiology rumors consistency name service electronic mail. XEROX Xerox Corporation Palo Alto Research Center 3333 Coyote Hill Road Palo Alto California .