Patent ID: 7475108

Claim:
A load balancing method for use in a data processing system with a distributed architecture including a plurality of servers and a plurality of clients, the method comprising for at least one client the steps of: associating the client with a preferred one of the servers, the preferred server storing specific information for the client; detecting an indication of a workload and an indication of a response time of each server; selecting an eligible one of the servers according to the workload and the response time of each server, wherein the step of selecting the eligible server includes: (1) establishing an acceptable range of the response times, wherein the step of establishing the acceptable range includes setting a lower limit of the acceptable range to a lowest response time of the servers and setting an upper limit of the acceptable range to the lowest response time multiplied by a predefined factor; (2) selecting a subset of the servers having the response time within the acceptable range; and (3) setting the eligible server to a server of the subset having a lowest workload; calculating at least one comparison parameter indicative of a performance difference between the preferred server and the eligible server; and switching the preferred server to the eligible server and transferring the specific information to the eligible server in response to the reaching of a predefined threshold by the at least one comparison parameter.