Inventors:
James Allan Scott - Brighton MA
Jeffrey J. Vroom - Jamaica Plain MA
Assignee:
Art Technology Group, Inc. - Cambridge MA
International Classification:
G06F 900
Abstract:
A computer system for a web site uses load balancing of new sessions based on measurements and estimates of past, present, and future performance, using the average time each application server takes to respond to a request (the latency) and the number of active sessions on each application server. Generally, once assigned to a session, an application server handles all future requests relating to that session. However, if the load or performance of an application server becomes sufficiently degraded, a failover mechanism causes future requests to be handled by a different application server until the performance improves. Under extreme circumstances, an application server will be restarted. If a web or HTTP server is unable to have requests served by any application server, future requests may be redirected to another web server.