A hierarchical load sharing policy for distributed systems

In dynamic load sharing policies, system state information can be collected in a distributed manner or by a single coordinator node. Two principal policies that belong to the distributed scheme are the sender-initiated and receiver-initiated policies. In the centralized scheme, a central coordinator node is responsible for collecting system state information. Distributed policies do not perform as well as the centralized policy. The performance of distributed policies is sensitive to the variance in job service times and inter-arrival times. Distributed policies, however, are scalable, whereas the centralized policy can cause bottlenecks and fault-tolerance problems for large systems. We propose a hierarchical load sharing policy that minimizes the drawbacks associated with the distributed and centralized policies while retaining their advantages.