Resource Selection and Ranking

Surfer is an extensible framework for selecting and ranking grid resources. A resource is defined as anything that needs selecting such as compute resources, storage resources, and data resources. The user specifies the set of resource types desired, the constraints that must hold over all the resources, and the ranking function to be used to order the resources. For each request received, Surfer returns a set of resource tuples, where each tuple contains a resource instance for each resource type requested, each tuple satisfies the specified constraints, and tuples are ordered by descending values of the given ranking function. Constraints and ranking functions are Boolean and numeric expressions, respectively, using a set of built-in arithmetic, Boolean and relational operators, and a set of functions supplied by information providers, which are implemented independently of the framework and integrated into the system using a single configuration line.