Lock-based concurrency control in distributed real-time database systems

Abstract

A real-time database system (RTDBS) is designed to provide timely response to the transactions of data-intensive applications. The transactions processed in a RTDBS are associated with real-time constraints typically in the form of deadlines. With the current database technology it is extremely difficult to provide schedules guaranteeing transaction deadlines. This difficulty comes from the unpredictability of transaction response times. Efficient resource scheduling algorithms and concurrency control protocols are required to schedule RTDB transactions so as to maximize the number of satisfied deadlines. In this paper, we describe several distributed, lock-based, real-time concurrency control protocols and report on the relative performance of the protocols in a distributed database environment. The protocols are different in the way real-time constraints of transactions are involved in controlling concurrent accesses to shared data. A detailed performance model of a distributed RTDBS was employed in the evaluation of concurrency control protocols.