%0 Journal Article %T Data Synchronization and Resynchronization for Heterogeneous Databases Replication in Middleware¨Cbased Architecture %A Guoqiong Liao %J Journal of Networks %D 2012 %I Academy Publisher %R 10.4304/jnw.7.1.210-217 %X Currently more and more web applications and telecommunication applications are required to be separation with database layer. A general solution is to employ a middleware-based architecture, including an application client tier, a database front end (DB-FE) tier, also called middleware tier, and a database backend (DBBE) tier. This paper mainly focuses on the issues of data synchronization and resynchronization in the case of failures for the architecture. Firstly, a synchronous update everywhere replication model and a replication 2-phase commit protocol (R2PC) are discussed, which can increase update success ratio of replication transactions through relaxing the commit constraints, and enhance DB-BEs¡¯ availability using transaction retry and discard mechanisms. Then, a novel method using request logs is suggested for data resynchronization. The method only records the missing transaction requests for the unavailable DB-BEs in the DB-FEs and links the logs belonging to a site together, to reduce the resynchronization time. Moreover, the method doesn¡¯t interrupt the normal transaction processing in the DB-BEs, so system throughput using request logs is higher than using transaction logs. Experiences validate that the suggested methods have better performance. %K synchronization replication %K data resynchronization %K heterogeneous databases %K middlewarebased architecture %U http://ojs.academypublisher.com/index.php/jnw/article/view/6652