A server cluster (100) has a plurality of application servers (A-F). During failover of a failed application server of the application servers, right to use of an internet protocol (IP) address of the failed application server is transferred to a surviving application server of the server cluster (100) according to a failed-link index (132) of the failed application server, the total number of surviving application servers of the server cluster (100), and successful link indexes (122) of the surviving application servers.