Chapter 22. Using the Network Weather Service

Table of Contents
Using NWS
NWS Components utilized in NetSolve
NetSolve agent and the NWS nameserver, memory and forecast
NetSolve server and the NWS sensor


In NetSolve, as in other metacomputing systems, the scheduling of tasks to available resources is difficult. NetSolve uses a limited load-balancing strategy to improve the utilization of computational resources. This load-balancing strategy takes into account the current workload of the computational resources available in the NetSolve system. In scheduling the client's requests over a network, the workload estimate should be ``forecast'' for when the computation will execute, and not a workload estimate obtained at a time prior to the request. There are also other characteristics of distributed metacomputing resources such as the CPU speed of the resource, the amount of physical memory of the resource, as well as the latency/bandwidth from the client to the computational resource, that can be effectively utilized in scheduling decisions for the computational resources.

The Network Weather Service (NWS) is a system which provides a way of forecasting dynamically changing performance characteristics, such as the workload, from distributed metacomputing resources. Integrating NWS into NetSolve improves the load-balancing strategy by taking into account the future load instead of the current load of the computational resources.