A Real-Time Scheduling Strategy Based on Priority in Data Stream System

In this paper, some concepts of real-time system (e.g., dealine, slack and criticalness) are introduced into some high-critical specific applications of Data Stream Management System (DSMS). In light of the features of continuous queries in DSMS, they are given new meaning. According to these concepts, a real-time scheduling strategy based on priority is proposed. In this strategy, the earlier dealine is, the shorter slack is and the higher criticalness is, the higher priopirty of a query is. Meanwhile, a structure of priority tree is presented in order to realize the unique execution sequence of queries based on their priorities. The experimental results show that the Hit Value Ratio (HVR) is improved greatly by applying this strategy, and the successful possibility of continuous query scheduling is improved as well.