Development of integrated Analysis System for Space and Astronomical Science combined with Mass Database

1.远程站点之间数据共享的技术评估我们比较了远程站点之间可以使用的各种文件共享方式。虽然SRFS(Shared Rapid File System，共享快速文件系统)能够高效地传输海量数据并保证数据的一致性，但当数据量太小时，性能会下降。对于较小的数据传输，NFS显示出更好的结果。尽管NFS不能保证数据的一致性，但我们发现可以避免ISAS(空间和宇航科学研究所)提供的文件的不一致性。源自网格的数据共享方法似乎与ISAS中使用的分析软件不兼容。2.集成分析环境我们构建了一个数据分析网络系统(DANS)，该系统使用了网络文件系统，并结合了SAN上的快速文件共享。我们与日本国家天文台(NAOJ)合作，将ISAS和NAOJ的数据库相互连接。我们与NAOJ的Smoka团队合作开发了jMAISON(基于Java的多波长天文图像在线服务)。JMAISON是www.WEB上为用户和多个远程天文数据(图像和星表)服务器提供的中间代理服务。我们在常用框架的基础上对数据存档和传输系统(DARTS)进行了改造，并为天文数据服务的国际标准虚拟天文台(VO)开发了接口。我们预计将在IAS和NAOJ分布一个数据处理环境。我们发现在常用的个人计算机上使用文件系统可以在ISA和NAOJ之间以300 Mbps或更高的速率传输文件，我们构建了一个集成的分析环境，提供了各种工具和一系列空间和天文科学数据。不仅是ISAS的几台计算机，而且外部机构的几台计算机也共享环境。该系统降低了管理成本，提高了工作效率。

1.Technical evaluation of data sharing among remote sitesWe compared various file sharing methods which can be used among remote sites. While SRFS (Shared Rapid File System) efficiently transfers mass data and guarantees the coherency of the data, the performance degrades when the data are so small. NFS shows better results for small data transfer. Though NFS does not guarantee the coherency of data, we found it possible to avoid the incoherency as for the files ISAS (Institute of Space and Astronautical Science) provides. Data sharing methods derived from GRID seems incompatible with analysis software used here in ISAS.2.Integrated Analysis EnvironmentWe constructed the Data Analysis Network System (DANS) using NFS in conjunction with rapid file sharing over SAN. We cooperate with National Astronomical Observatory Japan (NAOJ) to connect databases in ISAS and ones in NAOJ each other. We developed jMAISON (Java-based Multi-wavelength Astronomical Image Service ON-line) in collaboration with SMOKA team in NAOJ. jMAISON is an intermediate broker service for users and multiple remote-astronomical data (images and catalogs) servers on WWW.We rebuilt Data Archive and Transfer System (DARTS) on the basis of commonly used framework, and developed an interface for Virtual Observatory (VO), which is an international standard for astronomical data services.We estimated a data processing environment which will be distributed in ISAS and NAOJ. We found it possible to transfer files between ISAS and NAOJ at the rate of 300Mbps or more using NFS with commonly used personal computers.We constructed an integrated environment for analysis, which provides various tools together with a series of space and astronomical science data. Several computers not only is ISAS but also at external institutes share the environment. This system decreases a management cost, and improves a working efficiency.