Real-time scheduling for continuous queries with deadlines

Abstract

Many stream-based applications have real-time performance requirements for continuous queries over time-varying data streams. In order to address this challenge, a real-time continuous query model is presented to handle multiple queries with timing constraints. In this model, the execution of one tuple passing through an operator path is modeled as a real-time task instance. A fine-grained scheduling strategy named OP-EDF is proposed for real-time scheduling, which schedules the operator path with the earliest deadline of the waiting tuples at any time slot. The experimental results show that the proposed continuous query model and scheduling algorithm are effective in real-time query processing for data streams with bursty arrival rates.