Amazon.com, Inc.
Load balancing based on randomized selection of a load value based on a load probability distribution

Abstract:

Request routing in a network of computing devices. Back-end nodes associated with a request router send load reports to the request router that makes routing determinations for request from clients based on the reports. To select a back-end node for processing a request, a request router determines, based on the reports and one or more factors, load probability distributions for each of a group of back-end nodes selected from available back-end nodes. A load value is then randomly selected for each back-end node in the group, based on the node's probability distribution. The node in the group with the least randomly-selected value is chosen to process the request.