海绵城市云空间数据库设计与实现

摘要

Building a cloud geodatabase for a sponge city is crucial to integrate the geospatial information dispersed in various departments for multi-user high concurrent access and retrieval, high scalability and availability, efficient storage and management. In this study, Hadoop distributed computing framework, including Hadoop distributed file system and MapReduce (mapper and reducer), is firstly designed with a parallel computing framework to process massive spatial data. Then, access control with a series of standard application programming interfaces for different functions is designed, including spatial data storage layer, cloud geodatabase access layer, spatial data access layer and spatial data analysis layer. Subsequently, a retrieval model is designed, including direct addressing via file name, three-level concurrent retrieval and block data retrieval strategies. Main functions are realised, including real-time concurrent access, high-performance computing, communication, massive data storage, efficient retrieval and scheduling decisions on the multi-scale, multi-source and massive spatial data. Finally, the performance of Hadoop cloud geodatabases is validated and compared with that of the Oracle database. The cloud geodatabase for the sponge city can avoid redundant configuration of personnel, hardware and software, support the data transfer, model debugging and application development, and provide accurate, real-time, virtual, intelligent, reliable, elastically scalable, dynamic and on-demand cloud services of the basic and thematic geographic information for the construction and management of the sponge city.%构建海绵城市云空间数据库可以整合不同管理部门分散的地理空间信息,实现海量数据的多用户高并发访问和检索、高可扩展性和可用性、高效存储和管理.为了处理海量空间数据,本研究首先利用并行计算技术设计了包括Hadoop分布式文件系统和MapReduce的Hadoop分布式计算框架.其次,用一系列标准API设计了访问控制模块,包括空间数据存储层、云空间数据库访问层、空间数据访问层和空间数据分析层.然后,设计了一个检索模型,包括利用文件名直接寻址、3层并行检索和数据块检索策略.实现了多尺度、多源和海量空间数据的实时并行访问,高性能计算、通讯、存储、高效检索和时序安排等功能.最后,通过与Oracle数据库的比较,验证了Hadoop云空间数据库的性能.海绵城市云空间数据库能避免人员、硬件和软件资源的冗余配置,支持数据传输、模型调试和应用开发,为海绵城市建设和管理提供基础和专题地理信息的精确、实时、虚拟、智能、可靠、动态、按需和弹性可扩展的云服务.