Disaster Recovery for Transaction Processing Systems (Thesis)
Report ID: TR-371-92Author: Polyzois, Christos A.
Date: 1992-06-00
Pages: 110
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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 usually log--based and can be classified as either 2--safe or 1--safe, depending on whether transactions commit at both sites simultaneously or the commit first at the primary and are then propagated to the backup. This thesis describes the 1--safe algorithms that can exploit multiple log streans to propagate information from the primary to the backup. An experimental distributed database system is used to evaluate the performance of these algorithms and compare the 1--safe with the 2--safe approach under various conditions. Techniques for processing read--only queries at the backup are also presented.