DGL

Data Grid Language

The GriPhyN Data Grid Language developed by GriPhyN is an XML Schema based language that defines the format of gridflow requests and gridflow responses. DGL borrowed well-known computer science concepts in: Compiler Design (recursive grammar, scoped variables and execution stack management), Data Modeling (Schema definitions for all logical data types), Grid Computing (Fundamental data grid operations) and other features like XQuery to query the gridflow execution. DGL currently supports the following gridflow patterns:

• sequential flow, parallel flow,
• while loop, for loop,
• milestone execution,
• switch-by-context,
• concurrent parameter sweep, n of m execution

It allows description of pre-process and post-process rules to be executed, very similar to triggers in databases. Research prototype to compile DGL at runtime into a format is called DAX (DAG in XML). This format serves as input for the GriPhyN Pegasus Planner and can be used to start DGL computational processes in the grid using Condor-G. It is also a target workflow language for SDSC Matrix gridflow project.

Resources

• P.Avery, I.Foster: GriPhyN Annual Report for 2003-2004
• A.S.Jagatheesan: DGL: The Assembly Language for Grid Computing

Related

• SDSC Matrix
• Pegasus