Method for facilitating access to remote files

• US 6,847,968 B2
• Filed: 02/08/2002
• Issued: 01/25/2005
• Est. Priority Date: 02/08/2002
• Status: Active Grant

• Current Assignee: William M. Pitts
• Original Assignee: William M. Pitts
• Inventors: Pitts, William M.
• Primary Examiner(s): LE, UYEN T
• Application Number:
  US10/466,968
• Publication Number:
  US 20040054681A1
• Time in Patent Office: 1,082 Days
• Field of Search: 707/1, 707/2, 707/9, 707/10, 707/100, 707/101, 707/104.1, 709/213, 709/216, 709/217, 709/218, 709/219, 711/117, 711/118
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: Y10S 707/99939 Privileged access

Abstract

A method for facilitating access to a file in a networked multiprocessor computer system including establishing a hierarchical distributed data service (DDS) domain tree (200) that encompasses all computers in the network, grafting onto the tree the file system trees (198) that are exported from one or more Network Distributed Caches (NDC) (50). An arbitrarily chosen name assigned to each DDS domain (206) respectively identifies roots (208) of the hierarchical DDS domain tree (200) and of each of the DDS sub-domain trees (202).

Claims

1. A method for facilitating access by a first digital computer to a file that is stored in a local file system tree of a second digital computer, both the first and the second digital computers being included in a network of digital computers;

the first digital computer being adapted for retrieving from the second digital computer and for storing a cached image of the file, the method comprising the steps of;

a) initially establishing a single, hierarchical domain tree that encompasses digital computers in the network of digital computers including the second digital computer by;

i) digital computers in the network of digital computers exporting at least a root of a domain tree that is used in exporting files from digital computers; and

ii) digital computers in the network of digital computers that have been previously designated as domain managers for a group of digital computers in the network of digital computers;

1) receiving exported roots for domain trees; and

2) grafting onto a domain root of the domain manager the exported roots received from digital computers that belong to the group assigned to the domain manager; and

b;

the first digital computer retrieving from the domain manager the domain root for the hierarchical domain tree.

2. The method of claim 1 wherein individual digital computers export the root for the domain tree responsive to a request therefor.

3. The method of claim 1 wherein individual digital computer export the root for the domain tree by advertising the root to other digital computers included in the network of digital computers.

4. The method of claim 1:

wherein the network of digital computers includes at least a third digital computer that has been designated as the domain manager for a group of digital computers which includes a fourth digital computer that has also been designated as a domain manager; and

wherein during establishment of the hierarchical domain tree the fourth digital computer exports at least the domain root onto which the fourth digital computer grafts roots received from digital computers for which the fourth digital computer is the domain manager;

the method comprising the further steps of the third digital computer;

receiving the domain root exported by the fourth digital computer; and

grafting onto the domain root for the third digital computer the domain root exported by the fourth digital computer.

5. The method of claim 1:

wherein a request by the first digital computer for access to the file stored at the second digital computer must traverse a domain manager for the second digital computer before arriving at the second digital computer; and

wherein the domain manager that the request from the first digital computer for access to the file at the second digital computer must traverse has received from the second digital computer policy data specifying how access to files stored in the local domain tree of the second digital computer is to be administered;

the method comprising the further step of the domain manager forwarding onto the second digital computer the request by the first digital computer for access to the file stored at the second digital computer only if the policy data received by the domain manager permits access by the first digital computer to the file stored at the second digital computer.