Scheduling algorithm for workflow-based applications in optical grid

Grid is evolving to a more efficient global computing infrastructure by introducing optical network technology to support the advanced data-intensive distributed applications. Scheduling such data-intensive applications includes assigning tasks on computational resources, routing lightpaths, and assigning wavelength channels for data communication. The scheduling problem is NP-hard in the traditional grid system, and in optical grids, it is more complicated due to the character of optical networks. In this paper, we formulate the scheduling problem in optical grids and propose a novel scheduling algorithm which modifies the scheduling order according to actual importance of each task to search for a better solution. We call it the scheduled critical path (SCP) algorithm. We compare the scheduling results obtained by the SCP algorithm with the optimal results calculated by OPL studio software on a 3-node optical grid. To evaluate the performance of the proposed algorithm on more complicated systems, we construct a simulator which is able to schedule the application to the optical grid according to a certain scheduling algorithm. The simulation results prove the efficiency of the SCP algorithm.