Dynamic transaction routing in distributed database systems

The authors investigate dynamic transaction routing strategies for locally distributed database systems in which the database is partitioned and distributed among multiple transaction-processing systems, and the incoming transactions are routed by a common front-end processor. If a transaction issues a database request referencing a nonlocal database partition, the request has to be shipped to the system owing the referenced partition for processing. Various dynamic strategies are studied. Their performance is compared with that of the optimal static strategy. A class of dynamic transaction routing strategies which take into account routing history and minimize the estimated response time of incoming transactions is proposed; they are found to provide a substantial improvement over the optimal static strategy. The robustness of the strategies is further studied through sensitivity analysis over various transaction loads, communication overheads, and database reference distributions