Preferential load balancing for distributed Internet servers

We describe a preferential admission control and load balancing algorithm for distributed Internet server clusters. Clients initiate sessions consisting of a series of transactions. The clients may be aware of the various clusters of the distributed server and have preferences as to which cluster should process their session request. The scheme consists of a dispatcher which receives session requests and either admits or rejects those requests. Admitted requests are routed to their preferred cluster when the cluster is not congested. The algorithm also handles the case where a number of clients served have no cluster preference. We describe simulation results which demonstrate that the algorithm provides effective session admission control and load balancing, while maximizing the number of clients preferred by their most preferred cluster