TRANSPARENT REDIRECTION AND LOAD-BALANCING IN A STORAGE NETWORK

• US 20070022121A1
• Filed: 07/25/2006
• Published: 01/25/2007
• Est. Priority Date: 07/25/2005
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Parascale Incorporated (Hitachi, Ltd.)
• Inventors: Nalam, Naveen, Oskouy, Rasoul, Bahar, Cameron, Hopfield, Joseph, Zafman, David
• Granted Patent: US 7,599,941 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• CPC Class Codes: G06F 2209/508 Monitor
• CPC Class Codes: G06F 9/5011 the resources being hardware resources other than CPUs, Servers and Terminals
• CPC Class Codes: G06F 9/5016 the resource being the memory
• CPC Class Codes: H04L 61/50 Address allocation
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• 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]
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: Y10S 707/99931 Database or file accessing
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A storage system includes a plurality of storage servers that store a plurality of files, a monitor module, and a redirector module. The monitor module monitors usage information associated with the plurality of storage servers. The redirector module determines, based on the monitored usage information, a storage server in the plurality of storage servers to service a session from a client. The redirector module then instructs the client to establish the session with the determined storage server.

Claims

1. A method of managing client requests to a file system distributed among a plurality of storage servers, the method comprising:

initiating client sessions for accessing one or more files in the file system by connecting to a virtual IP address associated with a master server;

generating a client to storage server binding decision based on file system to storage sever mappings and statistics collected by the plurality of storage servers; and

redirecting the client sessions to one of the plurality of storage servers based on the generated binding decision so as to efficiently distribute the client sessions among the plurality of storage servers.

2. The method of claim 1 wherein the statistics collected by the plurality of storage servers includes one or more of server statistics, client statistics, and storage statistics.

3. The method of claim 1 further comprising:

providing network file system (NFS) access and achieving the client session redirection by manufacturing an appropriate symbolic link and forcing the clients automounter to establish a connection to the selected storage server.

4. The method of claim 1 further comprising:

providing common internet file system (CIFS) access and achieving the client session redirection by masquerading as a Windows distributed file system (DFS) root server and returning a DFS junction redirect forcing the client to establish a connection to the selected storage server.

5. The method in claim 1 further comprising:

providing hypertext transfer protocol (HTTP) access and achieving the client session redirection by returning an HTTP redirect forcing the client to establish a connection to the selected storage server.

6. A storage system comprising:

a file system distributed among a plurality of storage servers;

a monitor module associated with each storage server, each monitor module being configured to collect statistics;

a redirector module configured to redirect a client session to one of the plurality of storage servers based on the collected statistics and file system to storage server mappings so as to efficiently distribute the client sessions among the plurality of storage servers.

7. The storage system of claim 6 wherein each monitor module is further configured to communicate the collected statistics to a master server.

8. The storage system of claim 6 wherein the statistics collected by each monitor module includes one or more of server statistics, client statistics, and storage statistics.