System and method for accessing files in a network

• US 20040030731A1
• Filed: 04/03/2003
• Published: 02/12/2004
• Est. Priority Date: 04/03/2002
• Status: Abandoned Application

• Current Assignee: Ashok Arumugam, Liviu Iftode, Robert Sidie, Suresh Gopalakrishnan
• Original Assignee: Ashok Arumugam, Liviu Iftode, Robert Sidie, Suresh Gopalakrishnan
• Inventors: Gopalakrishnan, Suresh, Arumugam, Ashok, Sidie, Robert, Iftode, Liviu
• Application Number:
  US10/406,533
• Publication Number:
  US 20040030731A1
• Time in Patent Office: Days
• US Class Current: 707/205
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

A distributed file system architecture, characterized as a Federated File System (FedFS), is provided as a loose clustering of local file systems existing in a plurality of cluster nodes. The distributed file system architecture is established as an ad-hoc global file space to be used by a distributed application and a separate FedFS process is created for each application. Correspondingly, the lifetime of a FedFS process is limited to the lifetime of the distributed application for which it was created. File access for files in the node cluster is provided in a location-independent manner. FedFS also supports dynamic reconfiguration, file migration and file replication. FedFS further operates on top of, and without constraint on autonomous local file systems.

Claims

1. A distributed file system provided in a global file space to access local file systems established in a plurality of clustered nodes.

2. The distributed file system of claim 1 wherein a new file access process is established ad hoc for ones of applications served by the system.

3. The distributed file system of claim 1 wherein file pathnames in the global file space are independent of a location of a file designated by the pathname on ones of the clustered nodes.

4. The distributed file system of claim 1 wherein no change is required in a local file system for participation in the global file space file access process.

5. The distributed file system of claim 1 wherein virtual directories are created in the global file space as a union of local directories from participating nodes with the same pathname.

6. The distributed file system of claim 3 wherein the global pathnames are stored and maintained in volatile memory.

7. The distributed file system of claim 5 wherein the virtual directories are stored and maintained in volatile memory.

8. The distributed file system of claim 5 wherein a directory table is provided at ones of the nodes to store virtual directory entries for recent file accesses.

9. The distributed file system of claim 1 wherein directory tree summaries are generated for ones of the nodes in the node cluster.

10. The distributed file system of claim 9 wherein generation of the directory tree summaries is carried out using a Bloom filter.

11. The distributed file system of claim 1 further including the step of utilizing low-latency user level communication protocols.

12. A system for providing access from a global file space to local files distributed across a cluster of local nodes comprising:

creating separate instances of the file system for ones of applications served by the system; and

establishing, for each application, a virtual directory in the global file space as a merger of local file directory trees for participating nodes in the node cluster.

13. The file access system of claim 12 wherein a pathname in the virtual directory represents the union of local file directories from participating nodes with the same pathname.

14. The file access system of claim 12 wherein file pathnames in the global file space are independent of a location of a file designated by the pathname on ones of the clustered nodes.

15. The file access system of claim 12 wherein the virtual directories are stored and maintained in volatile memory.

16. The file access system of claim 12 wherein global pathnames are stored and maintained in volatile memory.

17. The file access system of claim 12 further comprising a directory table provided at ones of the nodes to store virtual directory entries for recent file accesses.

18. The file access system of claim 12 further comprising a generation of directory tree summaries for ones of the nodes in the node cluster.

19. The file access system of claim 18 wherein generation of the directory tree summaries is carried out using a Bloom filter.

20. The file access system of claim 12 further comprising low-latency user level communication protocols.