Network System, Server, Data Processing Method and Program

Abstract

A front-end server for temporarily holding an operation request for a NAS server, which is sent from a predetermined client, is interposed between the NAS server and clients on a network. This front-end server holds information concerning a correlation among data files stored in the NAS server, optimizes the operation request received from the client based on the information, and transmits the operation request to the NAS server.

1 . A front-end server comprising:
 a cache memory for holding at least one operation request directed from a client device to a NAS (Network Attached Storage) server, the client device and the NAS server being coupled via the front-end server;   a client operation processing unit for receiving said at least one operation request from the client device, the client operation processing unit also being capable of performing an operation based on said at least one operation request by using cache data stored in the cache memory; and   a data change reflection processing unit for creating at least one operation sequence, the created at least one operation sequence being a result of an operation performed by the client operation processing unit in response to the received at least one operation request from the client device, the data change reflection processing unit also being capable of transmitting the created at least one operation sequence to the NAS server;   wherein, in response to a determination that multiple operation requests from the client device are compatible for merging, the client operation processing unit synthesizes a plurality of the operation requests received from the client device into one combined operation request, and the client operation processing unit executes the combined operation request using the cache data in the front-end server to create the created at least one operation sequence.   
   
   
       2 . The front-end server of  claim 1 , wherein the created at least one operation sequence sent to the NAS server is a directive to directly change data stored in the NAS server, the directive based on results of the client operation processing unit executing the combined operation request using data in the cache memory in the front-end server. 
   
   
       3 . The front-end server of  claim 1 , wherein in response to a determination that multiple operation requests from the client device are compatible for merging, the client operation processing unit synthesizes a plurality of the operation requests received from the client device into one combined operation request, and wherein the created operation sequence sent to the NAS server is the combined operation request to be executed by the NAS server using data stored in the NAS server. 
   
   
       4 . The front-end server of  claim 4 , wherein the series of instructions are pipelined when sent to the NAS server for parallel execution. 
   
   
       5 . The front-end server of  claim 1 , wherein the cache memory is a non-volatile recording medium. 
   
   
       6 . The front-end server of  claim 1 , wherein the front-end server is one of a plurality of front-end servers coupled to the NAS server via the Network File System (NFS) protocol.