Patent ID: 7895375

Claim:
A data transfer apparatus comprising each of a plurality of channel adapters for issuing a read request to read data and a cache controller for returning data in response to the read request: said channel adapters each including a controller that controls data transfer by issuing the read request, a monitor that monitors a response time at the time of data transfer controlled by the controller, a measuring unit that measures throughput of data sent and received between the each of the channel adapters and the cache controller, a notification unit that sends the cache controller information of the throughput measured by the measuring unit when the response time monitored by the monitor exceeds a predetermined time or when a request of the information of the throughput from the cache controller is received, and a suppression unit that suppresses the issuance of the read request in the controller upon receiving a suppression instruction to suppress the issuance of the read request from the cache controller after the notification unit sends the information of the throughput, the suppression unit including a counting unit that counts the number of the suppression instructions received from the cache controller and suppressing the issuance of the read request for a waiting time corresponding to the number of the suppression instructions counted, the waiting time being obtained by multiplying a predetermined unit of time by the number of the suppression instructions, the cache controller including a receiving unit that receives the information of the throughput sent from each of the channel adapters, a determining unit that determines a channel adapter having the throughput that is equal to or more than a predetermined threshold value on the basis of the information of the throughput received by the receiving unit, and a sending unit that sends the channel adapter determined by the determining unit the suppression instruction to suppress the issuance of the read request.