## ''Work-Efficient Load Balancing''

### Gokarna Sharma

### Suresh Rai

### Costas Busch

### Jerry L. Trahan

### Ramachandran Vaidyanathan

*Proc. 10th International Workshop on Scheduling and Resource Management for
Parallel and Distributed Systems* (SRMPDS), pp. 27-36,
2014

#### Abstract:

Load balancing is the key to many parallel and
distributed applications. We consider the following load balancing
problem: given any undirected connected graph and an initial
weight distribution on the nodes, determine a schedule to move
weights across edges so as to have (almost) equal weights on
the nodes. Weights are moved across edges in rounds; and,
in a round, weights are moved between the adjacent nodes
exactly once. We study this problem in both static and dynamic
networks. Previously studied diffusion and dimension exchange
algorithms are slow in practice in the sense that they require
many rounds of weight exchanges. In this paper, we present a
class of algorithms that are work-efficient, i.e., they reduce the
number of rounds (i.e., iterations) of weight exchanges needed to
balance the load. In our algorithms, a node exchanges load with
its neighbors sequentially (one neighbor at a time) and the load
at that node is updated before subsequent exchanges with other
neighbors. Simulation results on six network topologies show that
our algorithms balance the load quite work-efficiently compared
to previous algorithms.