Adaptive Load Sharing Based on a Broker Module

This paper describes a dynamic, symmetrically-initiated load sharing scheme which adapts to changing load condition by varying the algorithm's dependency on system's status information. The scheme is hybrid in that it relies on a a fully distributed algorithm when the system is heavily loaded, but resorts to a centrally coordinated location policy when parts of the system become idle. The simplicity of the algorithms proposed makes it possible to use a centralized component without int incurring in scalability problems and presenting instabilities. Both algorithms are very lightweight and do not need any tuning of parameters, so that they are extremely easy to implement to the point that an inexpensive hardware implementation of the centralized component is capable of handling millions of requests per second. Simulations show that the hybrid approach outperforms existing dynamic algorithms under all load conditions and task generation patterns, it is weakly sensitive to processing overhead and communication delays, and scales well (to hundreds of nodes) despite the use of a centralized component.

ICSI Technical Report TR-96-036

Technical Report