Metadata structures and related locking techniques to improve performance and scalability in a cluster file system

• US 7,487,228 B1
• Filed: 12/30/2004
• Issued: 02/03/2009
• Est. Priority Date: 01/30/2003
• Status: Active Grant

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Inventors: O'Keefe, Matthew, Declerck, Michael J., Preslan, Kenneth
• Primary Examiner(s): PEIKARI, BEHZAD
• Application Number:
  US11/026,270
• Time in Patent Office: 1,496 Days
• Field of Search: 711/150, 711/163, 709/203, 707/8, 707/10, 707/201
• US Class Current: 709/219
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/1774 Locking methods, e.g. locking methods for file systems allowing shared and concurrent access to files
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1031 Controlling of the operation of servers by a load balancer, e.g. adding or removing servers that serve requests
• 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: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

A cluster file system is disclosed. A plurality of disk servers, operating as a single distributed disk server layer, are connected to the one or more physical disks. Each disk server stores metadata for each of the files. A plurality of lock servers, having one or more locks for each file and associated file system metadata operates as a single centralized distributed lock server to coordinate access to the files stored by the disk server layer. A plurality of asynchronous file servers, operating as a single distributed file server layer in response to a request for a file from a user program: (i) retrieves the requested file from the disk server layer and at least one lock, associated with the retrieved file, from the lock server, and (ii) retrieves metadata for at least one file that is related to the requested files, and at least one lock, for each file that has had its metadata retrieved.

Claims

1. A file system distributed over a plurality of computers connected by a network, the plurality of computers executing user programs, and the user programs accessing files stored on one or more physical disks connected to the plurality of computers, comprising:

a plurality of disk servers operating as a single distributed disk server layer and connected to the one or more physical disks, each disk server storing metadata for each of the files stored on the one or more disks;

a plurality of lock servers, having at least one or more read locks and one or more write locks for each file stored on the one or more physical disks, said lock servers operating as a single distributed lock server to coordinate access to the files stored by the disk server layer,

a plurality of asynchronous file servers, each having a memory, operating as a single distributed file server layer so that in response to a request for a file from a user program, the file system is configured to maintain at least one quota file and a quota change tag associated with a transaction, the at least one quota file configured to maintain quota values for each identification number, wherein the quota change tag is accumulated in a journal and periodically updated to the at least one quota file.

2. The file system of claim 1, further comprising Lock Value Blocks, the Lock Value Blocks caching recent quota file data, whereby global contention for the at least one quota file is avoided.