Patent ID: 7974186
Filing Date: 2011-07-05
Classification: G06F,H04L

Abstract:
1. A connection recovery device for a redundant system in which apparatuses having a communication processing unit are redundantly configured, the connection recovery device being provided for each of the apparatuses and performing connection recovery processing when communication processing is switched between the apparatuses, the connection recovery device comprising: a connection information storing unit which stores connection information identifying a connection and a transmission sequence number appended to each data transmitted on the connection and indicates sequentiality of sending and receiving data; a connection information takeover unit which performs, if a local apparatus is in active state in which communication processing is being performed, processing that sends to the other apparatus in standby state in which communication processing is being waited connection information of a connection when the connection is established and sends the transmission sequence number appended to each data to the other apparatus when data transmission is performed on the connection and, if the local apparatus is in the standby state, processing that receives the connection information and the transmission sequence number to store in the connection information storing unit and notifies the communication processing unit of the local apparatus that the connection is established in accordance with the connection information; a dummy data sending unit which, when the local apparatus is notified of switching from the standby state to the active state, creates dummy data in accordance with connection information in the connection information storing unit and sends the dummy data to the other side of the connection; and a connection continuity determining unit which, when the local apparatus is notified of switching from the standby state to the active state, receives reply data for the dummy data sent, acquires a transmission sequence number appended to the reply data, and notifies the communication processing unit of the local apparatus that connection can be continued if the transmission sequence number of the reply data matches with the latest transmission sequence number stored in the connection information storing unit.