A new CEP (Complex Event Processing) method that pushes negation operation into SSC (Sequence Scan and Construction) to address changes that a large number of commercial applications based on RFID (Radio Frequency IDentification) have time-critical requirements in the processing CEP while the existing CEP technology still has the disadvantages of inefficiency and poor real-time ca-pacity. The method adds negative status in the NFA (Non-deterministic Finite Automate) so as to push negation into SSC,which can re-move the inappropriate events dynamically in process of sequence scan. Consequently,it reduces the intermediate result sizes. Besides,it cuts down the cost of traversing back along AIS in the process of Sequence Construction (SC) to improve the throughput. The results of simulation experiments show that at maximum case,the proposal shows 20. 2 times higher throughout than the traditional method SASE, and the intermediate result sizes reduces to 1/20. So it's concluded that the method that pushes negation into SSC can significantly im-prove the performance in CEP.%针对许多基于无线射频识别的商业应用对复杂事件处理具有严格的实时性要求,而目前存在的复杂事件处理技术仍然存在处理效率不高、实时性差等问题,提出了一种前置非操作的复杂事件处理方法.该方法在构建非确定性有限自动机时加入消极事件对应的状态,用于把非操作前置到序列构建和扫描中,通过前置非操作来动态地去除序列扫描过程中不满足查询要求的原子事件,使得在平滑窗口内的事件数量大大减少,以此减少序列构建过程中的中间结果规模;并减少序列构建时回溯搜索的代价,以提高复杂事件处理的吞吐量.仿真实验结果表明,使用前置非操作方法后,复杂事件处理的吞吐量最高可提升约20.2倍,而中间结果规模在最好的情况下减少为原来的1/20.因此使用前置非操作方法可以有效地提高复杂事件处理的性能.
展开▼
