A One Phase Priority Inheritance Commit Protocol

Abstract

High priority two phase locking (HP2PL) concurrency control algorithm can be used for accessing of data items to resolve conflicts amongst the concurrently executing transactions. Inclusion of priority inversion and data inaccessibility are the most undesirable problems in transactions’ execution which seriously affect the system performance. Previously developed protocols for resolving such issues put a lot of messages and time overhead which is not desirable. In distributed real-time database system (DRTDBS), basic aim is to minimize the number of transactions missing their deadline. This can be achieved by minimizing commit time. In this paper, A One Phase Priority Inheritance Commit Protocol (OPPIC) has been proposed specifically reducing one round of message transfer among coordinator and participating cohorts’ sites in case of priority inversion problem at any of the cohort of low priority transaction. Focus of this protocol is to minimize the priority inversion duration that in turn minimizes commit time. A distributed database system is simulated for measuring the performance of this protocol with 2PC and PIC protocols. The results confirm the significant improvement in system performance with the OPPIC protocol.