2005/06/14 by Yi Lin, Bettina Kemme, Marta Patiño-Martı́nez +1 · 2 citations
Computer Science · #Advanced Data Storage Technologies #Cloud Computing and Resource Management #Distributed systems and fault tolerance
paper · doi:10.1145/1066157.1066205
openalex publication_date 2005/06/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Many cluster based replication solutions have been proposed providing scalability and fault-tolerance. Many of these solutions perform replica control in a middleware on top of the database replicas. In such a setting concurrency control is a challenge and is often performed on a table basis. Additionally, some systems put severe requirements on transaction programs (e.g., to declare all objects to be accessed in advance). This paper addresses these issues and presents a middleware-based replication scheme which provides the popular snapshot isolation level at the same tuple-level granularity as database systems like PostgreSQL and Oracle, without any need to declare transaction properties in advance. Both read-only and update transactions can be executed at any replica while providing data consistency at all times. Our approach provides what we call "1-copy-snapshot-isolation" as long as the underlying database replicas provide snapshot isolation. We have implemented our approach as a replicated middleware on top of PostgreSQL replicas. By providing a standard JDBC interface, the middleware is completely transparent to the client program. Fault-tolerance is provided by automatically reconnecting clients in case of crashes. Our middleware shows good performance in terms of response times and scalability.