面向分布式GIS空间数据的Key-value缓存  

Key-value Caching of Geospatial Data for Distributed GIS

作　　者：涂振发[1] 孟令奎[1] 张文[1] 黄长青[1] 

机构地区：[1]武汉大学遥感信息工程学院,武汉市珞喻路129号430079

出　　处：《武汉大学学报（信息科学版）》2013年第11期1339-1343,共5页Geomatics and Information Science of Wuhan University

基　　金：水利部公益性行业科研专项经费资助项目(201001046);国家科技支撑计划资助项目(2011BAH16B08)

摘　　要：设计了一种基于Key-value结构的缓存KV-cache,旨在简化数据结构,高效管理缓存数据。KV-cache由Mem-cache和F-cache构成。其中,Mem-cache为第一级缓存,并采用缓存回写机制以异步方式将数据写入F-cache进行持久化存储。F-cache使用大文件存储数据,并构建了基于B树的缓存索引以加快检索速度。数据写入F-cache的位置由基于B树的空闲空间管理器进行分配。在100 Mbps局域网内测试KV-cache读写性能。实验表明,KV-cache读写性能优于传统文件目录方式的缓存,能够安全、高效地管理所缓存的各种空间数据。The access and network transmission costs for geospatial data in distributed GIS are important factors effecting performance. The cache is one of the effective measures to solve performance problems. In this paper, we designed a cache named KV-cache based on Key-value structure to manage geospatial data efficiently with a simple data structure. A KV-cache consists of a memory cache called Mem cache and a file cache called F-cache. Mem- cache is the first level cache, the cache write back mechanism guarantees that data is being written to the F-cache asynchronously. The F-cache is created by a single large file, while a cache indexer based on B-tree, is built to speed up the query. A free space manager which is also based on B-tree is used to allocate the data storage address for F cache. Experiments compare the read/write performance of KV-cache with the traditional file cache in the 100 Mbps LAN. The experiments show that the read/write performance of KV cache is much better than file cache, thus managing geospatial data more securely and efficiently.

关 键 词：分布式GIS 缓存 KV cache Key—value存储 空闲空间管理 

分 类 号：P208[天文地球—地图制图学与地理信息工程] TP311.13[天文地球—测绘科学与技术]