Before revision: Database replication is difficult but indispensable. We report on our experiences building and deploying middleware-based replication systems both as commercial products and research systems. We identify gaps that still separate academic research from industrial practiceand thus thwart potential technology transfer from academia to the field. We structure our analysis along three axes -- performance, availability and management -- and outline unmet database replication challenges at several levels.
After revision: The need for high availability and performance in data management systems has been fueling a long running interest in database replication from both academia and industry. However, academic groups often attack replication problems in isolation, overlooking the need for completeness in their solutions, while commercial teams take a holistic approach that often misses opportunities for fundamental innovation. This has created over time a gap between academic research and industrial practice. This paper aims to characterize the gap along three axes -- performance, availability and management -- and outline unmet database replication challenges at several levels.