Workflow language definition and workflow handling in P-Grade Portal

Researchers and application developers have to create workflows and use workflow engines for their complex workflow applications to run them on the Distributed Computing Infrastructure (DCI) they have access to. The capabilities of the workflow language and the workflow engine determine heavily the range of solvable problems. This paper describes a P-GRADE Portal workflow language in details. The P-GRADE Portal (Parallel Grid Run-time and Application Development Environment) is a service-rich, workflow-oriented graphical environment. Nowadays large number of P-GRADE Portals are operating and serving numerous user communities of international multi-institutional grids and grid based virtual organizations as Portals or eScience Gateways in Europe and in the United States. In this paper we describe its high-level workflow language, give a historical background how this language evolved during time, enumerate available features of the language, and show examples how the language is used inside the P-GRADE Portal environment. With specification of the P-GRADE Portal’s workflow language we can gain more insight into the P-GRADE Portal workflow management system