Abort-oriented concurrency control for real-time databases

There has been growing interest in the performance of transaction systems that have significant response time requirements. These requirements are usually specified as hard or soft deadlines on individual transactions and a concurrency control algorithm must attempt to meet the deadlines as well as preserve data consistency. This paper proposes a class of simple and efficient abort-oriented concurrency control algorithms in which the schedulability of a transaction system is improved by aborting transactions that introduce excessive blockings. We consider different levels of the aborting relationship among transactions and evaluate the impacts of the aborting relationship when the relationship is built in an online or offline fashion. We measure aborting overheads on a system running the LynxOS real time operating system. The strengths of the work are demonstrated by improving the worst-case schedulability of an avionics example [20]; a satellite control system [7], and randomly generated transaction sets.