Design and implementation of database schema evolution for service continuity of web-based internet applications

Today, Internet services are utilized as major service platforms to provide business services. Web-based Internet applications that follow the multi-tier architecture are a well-accepted computation model when providing Internet services. Such a model suffers from interruption caused by software failures, hardware errors or software maintenance. The interruption may incur significant financial loss to Internet service providers. Thus, Service Continuity is one of the main challenges for Web-based Internet applications. Although several service continuity technologies have been developed, many of them focus on a single tier of the applications and do not guarantee end-to-end service continuity. In this paper, we describe the design, implementation, and performance evaluation of our proposed service continuity technology. This technology resolves the long time interruption problem caused by database schema evolution, handles software components upgrade, and achieves end-to-end Service Continuity. We propose a mechanism that contains multiple modules running interactively between each module. This approach only requires minimal amount of code rewriting and a small storage space. Comparing with existing approaches, our approach is more efficient with the least overhead.