Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In exist...Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In existing technologies,the efficiency of big data applications(BDAs)in distributed systems hinges on the stable-state and low-latency links between worker nodes.However,LMCNs with high-dynamic nodes and long-distance links can not provide the above conditions,which makes the performance of OBDP hard to be intuitively measured.To bridge this gap,a multidimensional simulation platform is indispensable that can simulate the network environment of LMCNs and put BDAs in it for performance testing.Using STK's APIs and parallel computing framework,we achieve real-time simulation for thousands of satellite nodes,which are mapped as application nodes through software defined network(SDN)and container technologies.We elaborate the architecture and mechanism of the simulation platform,and take the Starlink and Hadoop as realistic examples for simulations.The results indicate that LMCNs have dynamic end-to-end latency which fluctuates periodically with the constellation movement.Compared to ground data center networks(GDCNs),LMCNs deteriorate the computing and storage job throughput,which can be alleviated by the utilization of erasure codes and data flow scheduling of worker nodes.展开更多
为解决医疗数据的高效存储与处理分析等问题,设计并开发了医疗大数据平台。首先,搭建并部署了Hadoop分布式文件系统,设计基于Tomcat服务器搭建的网站平台。然后,通过编写Hadoop WEB API将WEB服务器与分布式文件系统相结合,设计数据处理...为解决医疗数据的高效存储与处理分析等问题,设计并开发了医疗大数据平台。首先,搭建并部署了Hadoop分布式文件系统,设计基于Tomcat服务器搭建的网站平台。然后,通过编写Hadoop WEB API将WEB服务器与分布式文件系统相结合,设计数据处理效率高的Python脚本程序读取并统计分析医疗数据。平台运行测试结果表明,该医疗大数据平台实现了数据存储、共享、可视化展示等预期功能。展开更多
基金supported by National Natural Sciences Foundation of China(No.62271165,62027802,62201307)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030297)+2 种基金the Shenzhen Science and Technology Program ZDSYS20210623091808025Stable Support Plan Program GXWD20231129102638002the Major Key Project of PCL(No.PCL2024A01)。
文摘Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In existing technologies,the efficiency of big data applications(BDAs)in distributed systems hinges on the stable-state and low-latency links between worker nodes.However,LMCNs with high-dynamic nodes and long-distance links can not provide the above conditions,which makes the performance of OBDP hard to be intuitively measured.To bridge this gap,a multidimensional simulation platform is indispensable that can simulate the network environment of LMCNs and put BDAs in it for performance testing.Using STK's APIs and parallel computing framework,we achieve real-time simulation for thousands of satellite nodes,which are mapped as application nodes through software defined network(SDN)and container technologies.We elaborate the architecture and mechanism of the simulation platform,and take the Starlink and Hadoop as realistic examples for simulations.The results indicate that LMCNs have dynamic end-to-end latency which fluctuates periodically with the constellation movement.Compared to ground data center networks(GDCNs),LMCNs deteriorate the computing and storage job throughput,which can be alleviated by the utilization of erasure codes and data flow scheduling of worker nodes.
文摘为解决医疗数据的高效存储与处理分析等问题,设计并开发了医疗大数据平台。首先,搭建并部署了Hadoop分布式文件系统,设计基于Tomcat服务器搭建的网站平台。然后,通过编写Hadoop WEB API将WEB服务器与分布式文件系统相结合,设计数据处理效率高的Python脚本程序读取并统计分析医疗数据。平台运行测试结果表明,该医疗大数据平台实现了数据存储、共享、可视化展示等预期功能。
