On the Use of Resource Reservation for Web Services Load Balancing

A key issue for good performance of worldwide distributed web services is the efficiency of the load balancing mechanism used to distribute client requests among the replicated servers. The load balancing solution allows providers to make better use of their resources, soften the need for over-provision, and help tolerate abrupt load peaks. In this paper, we propose a new load balancing solution that reduces service response times by applying a protocol for the reservation of remote resources. This protocol prevents the overload of remote servers by limiting the amount of load each server can redirect to the others. We describe a middleware that supports this protocol by managing the trade of resources among a set of servers, allowing them to share their spare capacity in a transparent way. We also present the results of a large set of simulations that encompass an exhaustive set of workload scenarios based on realistic internet traffic models.