Client server system, fault tolerant and process to operate the same

摘要

"Client server system, fault tolerant and process to operate the same. A client server system has a primary fault tolerant server; and a client.The client transmits a request to the primary server, which receives and processes the request, and transmitting the response to the client.Independently of any processing of backup copy. The response includes state information of the primary server.The primary server also performs processing for backup which includes periodically transmitting the state information from the primary server to the backup server.The client receives the response from the primary server, and sends the state information of the primary server to the backup server.The state information from the primary server includes all the pairs of request response to the primary server has processed since a most recent transmission of state information of aRvidor primary server to backup copy.The devices of the primary server to execute processing of backup copy may be activated periodically based on a predetermined time interval.Alternatively, they can be activated when the memory of the primary server for storing the state information of the primary host is completed in predetermined proportion.