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Virtual Observatory Data Access Service (VO-DAS) (VO-DAS 1.0) |
Virtual Observatory Data Access Service (VO-DAS) is a data access software, which is developed by Chinese Virtual Observatory (China-VO) team, allowing the user to visit world-wide big volume data , to query the different types of astronomical data resources such as catalog, image, spectrum etc. The software provides graphic interface, asynchronous inquiry , real-time monitoring of query and plastic integration .VO-DAS is available in a java standalone application . a command lines and a simple previewer will be supported.
- Access distributed and heterogeneous astronomical databases
- Achieve automatic discovery data resources
- Support big volume data access
- Support cross-identification of astronomical data
- Query the different types : catalog, image, spectrum
- Java: Sun Microsystems JRE
- Container: Apache Tomcat 5.0 or later, which can
be downloaded here.
- Web Service: Globus Toolkis 4.0 Java WS Core, which can be downloaded here.
- Middleware: OGSA-DAI WSRF 2.2 or later ,which can be downloaded here.
- Database: MySQl/eXist/DB2/Oracle/Posgre SQL/SQL
Server
- Others: Apache Ant ,which
can be downloaded here.
- Coming soon
The VO-DAS System contains of several services including VO-DAS Server , Data Node , Client and VO registry . The installation of the system is how to deploy these interdependent services into a unified system.
- VO-DAS Server is mainly for the GAR package of DAS service and configuration file (das.xml) deployment. You can run ¡°globus-deploy-gar¡± command in GLOBUS directory to deploy the DAS service into the GLOBUS container.
- Data Node deployment only run the jar package of the data node resource configuration tool , which provides graphic interface to achieve data resource metadata configuration. The file (metadata.xml) is created after configuration operation.
- The URI of the above metadata.xml registry to the VO registry through the ASTROGRID registry.
- Storage Server support VOSpace
system provided by ASTROGRID while FTP and GridFTP
specified by user are also supported.
- Finally, running the client jar package
on Client can be access the VO-DAS server through graphic interface for
the user of GUI style.
Connection between Client and Server
Before user accessing the VO-DAS, the client must make with the designed VO-DAS server correct link .During the connection , user needs to provide the IP and port number of VO-DAS server. then you can connect the server and read some metadata of data node server specified by metadata.xml and display them in graphic interface.
After archiving, each metadata¡¯s
description will be show in ¡°description¡± while you click on metadata ¡®s tree, so you can know more information about it
and assist you editing the ADQL .
Submitting ADQL to Server
Synchronous query and asynchronous query in VO-DAS are supported:
- Synchronous query is that user can not simultaneously submit query jobs, but have been waiting the result of the one of submitted job . It meets the small volume data query .
- Asynchronous query allows user to submit a number of consecutive jobs without waiting for the result of query, which can be saved in URI specified by user. It meets the big volume data query.
Job Monitor
To allow user to know all the jobs of progress in VO-DAS server, VO-DAS provides Job Monitor which monitor the jobs and access and update detail information about jobs such as task name, job status, submit time, finish time, the URI etc.
- AS VO-DAS system is improving ,the more information about it will be added or updated by us .
Developers of
the tool include Chao LIU, Haijun
TIAN, Dan GAO Yang YANG , Yong LU and Chenzhou CUI. Suggestions and comments are sincerely
welcome, please send to Chenzhou Cui.
© 2007, China-VO