Building Composite Grid tasks using STROLL File-system

Despite availability of a range of Grid computing platforms, domain specialists and scientists only rarely take advantage of these computing facilities. One reason for this is the complexity of Grid computing, and the need to learn a new programming environment to interact with the Grid. Moreover, users cannot easily deploy their compute tasks to multiple Grid platforms without rewriting their program to use different task submission interfaces. STROLL is a universal filesystem-based interface for seamless task submission to one or more Grid facilities. Users interact with the Grid through simple read and write filesystem commands. STROLL supports simple, i.e. single and batch, and composite, i.e. work-flow tasks. This paper describes how to build composite STROLL tasks in the form of filesystem directory structures. A R code example is described as a use-case, and evaluating the CPU consumption of the user machine shows that implementing a composite task can fairly reduce the computation overhead.