Load Balanced Parallel Simulated Annealing on a Cluster of SMP Nodes

Abstract. The paper focuses on a parallel implementation of a simulated annealing algorithm. In order to take advantage of the properties of modern clustered SMP architectures a hybrid method using a combination of OpenMP nested in MPI is advocated. The development of the reference implementation is proposed. Furthermore, a few load balancing strategies are introduced: time scheduling at the annealing process level, clustering at the basic annealing step level and suspending—inside of the basic annealing step. The application of the algorithm to VRPTW—a generally accepted benchmark problem—is used to illustrate their positive influence on execution time and the quality of results. Key words: Simulated annealing, parallel processing, load balancing, MPI, OpenMP, hybrid parallelization