Evaluation of Remote Backup Algorithms for Transaction-Processing Systems

Abstract

A remote backup is a copy of a primary database maintained at a geographically separate location and is used to increase data availability. Remote backup systems are typically log-based and can be classified into 2-safe and 1-safe, depending on whether transactions commit at both sites simultaneously or first commit at the primary and are later propagated to the backup. We have built an experimental database system on which we evaluated the performance of the epoch and the dependency reconstruction algorithms, two 1-safe algorithms we have developed. We compared the 1-safe with the 2-safe approach under various conditions. © 1994, ACM. All rights reserved.