基于瓦片寿命和访问热度的海量空间数据缓存置换策略  

Massive Spatial Data Cache Replacement Policy Based on Tile Lifetime and Popularity

作　　者：王浩[1] 喻占武[2] 曾武[2] 潘少明[2] 

机构地区：[1]武汉大学电子信息学院,武汉市珞喻路129号430079 [2]武汉大学测绘遥感信息工程国家重点实验室,武汉市珞喻路129号430079

出　　处：《武汉大学学报（信息科学版）》2009年第6期667-670,共4页Geomatics and Information Science of Wuhan University

基　　金：国家973计划资助项目(2004CB318206);武汉大学测绘遥感信息工程国家重点实验室专项科研经费资助项目

摘　　要：针对空间信息服务中所能支持的并发用户数有限、瓦片响应时间过长等问题,在客户端建立缓存机制。分析了空间数据瓦片的缓存索引,提出了适合于空间数据的缓存置换策略TCLEPR。实验结果表明,TCLEPR可以提高瓦片缓存的请求命中率和字节命中率,缩短瓦片的响应时间,并支持更多的并发用户数。Challenges such as limited simultaneous users and long tile request response times, exist in spatial information services. Cache mechanism is deployed in the services＇client. The establishment, query and update of cache index for spatial data tile are analyzed. Tile cache lifetime excess and popularity replacement （TCLEPR） policy is proposed. In TCLEPR, cache tile has a longest lifetime excess, which is current cache life subtracted by average cache life, and the lowest popularity is replaced by new requested tile. Simulation results show that TCLEPR can improve tile request cache hit ratioes and byte hit ratioes, which in return shortens tile request response times and support more simultaneous users.

关 键 词：空间数据缓存 瓦片寿命 瓦片热度 地形漫游 

分 类 号：P208[天文地球—地图制图学与地理信息工程]