Design and Implementation of Job Scheduling of a Virtual Observatory Data Access System (VO-DAS)

In order to achieve integrated seamless access to massive allopatric and heterogeneous astronomical data resources,the China-VO team has designed and implemented a set of their own programs,the Virtual Observatory Data Access System(VO-DAS).This paper mainly presents the design of the job scheduling of this system, specifically in the aspects of work-flow,design-pattern,session-management,lifecycle,resource destruction,and exception-handling modules.The paper finally describes several applications of this system in astronomy.