STEP: A Concomitant Protocol for Real Time Applications

Abstract

In distributed real-time database system, utilizing a priority inheritance mechanism may help in reducing the priority inversion duration of a conflicting (and waiting) high priority transaction. However, mere integration of the priority inheritance scheme with classic 2PC is not enough and may lead to performance degradation. The two main problems that arise because of such integration are considerably longer ‘Priority-Inherit’ message dissemination time and extra message overhead. In addition, the explosion of priority inheritance events in the system might lead to the increased miss percentage for high-priority transactions. To address the above-mentioned problems, a Sophisticated Time and message utilization centered Priority inheritance (STEP) concomitant protocol is designed which brings down the overhead (time & message) by simply requiring of single round intelligent message transfer and eliminates priority de-boosting part of the general priority inheritance mechanism. Moreover, it also keeps a check on the no. of priority inheritance events occurrences with the help of real-time monitoring of priority inversions’ percentage in the system and thereby makes sure that high priority transaction miss percentage does not increase in an uncontrolled manner. The extensive performance study suggests that STEP protocol performs considerably well compared to the existing state-of-the-art protocols. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.