Reusable Cost-Based Scheduling of Grid Workflows Operating on Higher-Order Components

Grid applications are increasingly being developed as workflows built of well-structured, reusable components. We develop a user-transparent scheduling approach for Higher-Order Components (HOCs) - parallel implementations of typical programming patterns, accessible and customizable via Web services. We introduce a set of cost functions for a reusable scheduling: when the workflow recurs, it is map ped to the same execution nodes, avoiding the need for a repeated scheduling phase. We prove the efficiency of ou r scheduling by implementing it within the KOALA scheduler and comparing it with KOALA's standard Close-to- File policy. Experiments on scheduling HOC-based applications achieve a 40% speedup in communication and a 100% throughput increase.