NAS load balancing system

• US 20050223096A1
• Filed: 04/26/2005
• Published: 10/06/2005
• Est. Priority Date: 12/05/2002
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Shinkai, Yoshitake
• Granted Patent: US 8,578,053 B2
• Time in Patent Office: Days
• US Class Current: 709/225
• CPC Class Codes: H04L 61/103 across network layers, e.g. resolution of network layer into physical layer addresses or address resolution protocol [ARP]
• CPC Class Codes: H04L 61/5007 Internet protocol [IP] addresses
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A NAS load balancing system for distributing NAS loads of a NAS unit including a plurality of nodes and accessed via a network by multiple NAS clients is disclosed. In the NAS load balancing system, the NAS unit has multiple virtual IP addresses.

Claims

1. A NAS load balancing system for distributing NAS loads of a NAS unit including a plurality of nodes and accessed via a network by multiple NAS clients, wherein:

the NAS unit has a plurality of virtual IP addresses.

2. The NAS load balancing system as claimed in claim 1, comprising:

a part statically assigning each of the NAS clients one of the virtual IP addresses.

3. The NAS load balancing system as claimed in claim 2, wherein the NAS unit includes a part allowing each of the NAS clients to transmit a file operation request to the one of the virtual IP addresses.

4. The NAS load balancing system as claimed in claim 1, wherein:

the NAS unit has a plurality of logical IP addresses; and

the NAS load balancing system comprises a part distributing the NAS loads based on file access locality of the NAS clients by causing each of the NAS clients to select one of the logical IP addresses of the NAS unit.

5. The NAS load balancing system as claimed in claim 1, wherein the NAS unit includes an IP address conversion part dynamically converting one of the virtual IP addresses to a corresponding one of real IP addresses corresponding to the nodes.

6. The NAS load balancing system as claimed in claim 5, wherein the NAS unit includes a part collecting statistical information of accessed files with respect to each of the NAS clients accessing the NAS unit.

7. The NAS load balancing system as claimed in claim 6, wherein the IP address conversion part performs optimization based on the file access locality of the NAS clients using the collected statistical information, and converts the one of the virtual IP addresses to the real IP address of an optimum one of the nodes.

8. The NAS load balancing system as claimed in claim 7, wherein the one of the virtual IP addresses is directly switched to the real IP address of one of the nodes having high file access locality in accordance with an access pattern of the NAS clients.

9. The NAS load balancing system as claimed in claim 7, wherein when the conversion of the one of the virtual IP addresses to the corresponding real IP address is required, a TCP/IP session whose operation is to be changed by the conversion is disconnected, and reconnected from a corresponding one of the NAS clients.

10. The NAS load balancing system as claimed in claim 1, wherein:

the NAS unit comprises a part collecting statistical information of accessed files with respect to each of the NAS clients accessing the NAS unit.