Causes, Effects, and Consequences of Priority Inversion in Transaction Processing

Abstract

The problem of priority inversion occurs when a high priority task is required to wait for completion of some other task with low priority as a result of conflict in accessing the shared system resource(s). This problem is discussed by many researchers covering a wide range of research areas. Some of the key research areas are real-time operating systems, real-time systems, real-time databases, and distributed real-time databases. Irrespective of the application area, however, the problem lies with the fact that priority inversion can only be controlled with no method available to eliminate it entirely. In this chapter, the priority inversion-related scheduling issues and research efforts in this direction are discussed. Different approaches and their effectiveness to resolve this problem are analytically compared. Finally, major research accomplishments to date have been summarized and several unanswered research questions have also been listed.