Efficient trigger-broadcasting in heterogeneous clusters

Abstract

Broadcasts in parallel computing environments are often used to trigger “personal” computations at the processors (or, nodes) that comprise the system. (The qualifier “personal” means that the triggered computations may differ in type and complexity at each node.) We present an algorithm for trigger-broadcasting in a node-heterogeneous cluster of workstations, which comes predictably close to minimizing the time for completing both the broadcast and the computations it triggers. The algorithm orchestrates its broadcast taking account of: the speeds of the cluster's constituent workstations, the speed of the cluster's network, and the complexities of the computations that the broadcast triggers. The algorithm is within a constant factor of optimal when the speeds of the cluster's workstations and of its network are independent of the number of workstations. The algorithm is exactly optimal when the cluster is homogeneous—no matter how diverse the “personal” computations are.