Improving Performance in Replicated Databases through Relaxed Coherency

Applications in finance and telecommunications (intelligent network, network management, mobile computing) cause renewed interest in distributed and replicated data management. Since synchronous update of replicated data is experienced to degrade distributed systems performance substantially, relaxing the requirement of coherency (mutual consistency) hasbecomeafavorable approachto achievehigh performance in replicated databases. In this paper we present formal conceptsfor specifying relaxed coherency which allows to calculate an independent measure of relaxation, called + coherencyindex. We incorporate this metric into a detailed analytical queueing model which emphasizes on the quality of replication to evaluatethe impact of relaxed coherencyon the performanceof replicated databases.The model considers responsetime, throughput, scalability andnetwork traffic asperformancecriteria. As it turns out, performance improvements through relaxed coherency depend significantly on various syst...

• Type: Conference
• Year: 1995
• Where: VLDB
• Authors: Rainer Gallersdörfer, Matthias Nicola
• Keywords: Analytical Queueing Model, Coherency Depend, Database, Mutual Consistency, VLDB 1995