面向航天器综合测试系统的Web缓存替换策略

航天器一般为复杂系统，其作为典型安全苛刻系统，在综合测试过程中会产生大量测试数据。在查询这些测试数据时，现有的B/S数据查询技术，每次查询时采用从数据库服务器中获取数据的方式，极大地消耗了数据库服务器的资源，占用了大量的网络带宽，导致系统的整体性能下降，用户体验不佳。通过对安全苛刻系统综合测试数据特点和用户查询特征的分析，基于经典Web缓存替换算法GDSF，提出一种适用于B/S数据查询系统的Web缓存替换算法GDSF-STW。该算法是在GDSF算法的基础上，引入了数据流挖掘中的时间衰减模型，并采用滑动时间窗口的思想，提高缓存命中率，从而提高系统的性能，改善用户体验。通过GDSF-STW与LRU、LFU、LFU-DA、GDSF等经典算法进行实验对比，结果表明，GDSF-STW算法具有更好的缓存命中率。

A Web cache replacement strategy for spacecraft comprehensive testing system

As a typical safety critical system, spacecraft is generally a complex system, which could produce a large amount of test data during the comprehensive testing process.When querying these test data, the existing B/S data query technology obtains data from the database server for each query, which greatly consumes the database server resources, takes up a lot of network bandwidth, and results in pooroverall performance of the system and poor user experience.Based on the classical Web cache replacement algorithm GDSF, this paper proposes a Web cache replacement algorithm GDSF-STW which is suitable for B/S architecture data query system by analyzing the characteristics of test data of the safety critical system and the behavior of user query.Based on the classical Web cache replacement algorithm GDSF, this algorithm introduces the time decay model in data mining and adopts the idea of sliding time window to improve the cache hit rate, system performance, and user experience. Finally, the experimental results show that the GDSF-STW has a better hit rate by comparing the GDSF-STW with the classical algorithms such as LRU, LFU, LFU-DA and GDSF.