Abstract: A client computer, a first server computer, and a second server computer are connected via a network. The client computer executes a transaction process with the first server computer at the normal time. When a fault occurring in the first server computer is detected, first, the client computer requests a connection to the first server computer. When the connection to the first server computer is failed, the client computer requests a connection to the second server computer. When the connection is established, a transaction process is started by the client computer and the second server computer.