Arrangement for a distributed file system having data objects mapped independent of any data object attribute

• US 20060179037A1
• Filed: 02/07/2005
• Published: 08/10/2006
• Est. Priority Date: 02/07/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Toebes, John, Walker, Douglas Jay, Turner, Bryan C.
• Granted Patent: US 8,229,985 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers
• CPC Class Codes: G06F 16/1844 Management specifically adapted to replicated file systems
• CPC Class Codes: Y10S 707/959 Network
• CPC Class Codes: Y10S 707/96 Object-relational

Abstract

Each data file of a distributed file system is identified by a corresponding globally-unique object identifier that is independent of any attribute of the data file. A node in the distributed file system has a file system that includes a plurality of directory entries, where each directory entry has a file name field, an attributes field, and an object identifier field configured for specifying a globally-unique object identifier. The globally-unique object identifier is universally reachable by any node of the distributed file system and uniquely identifies the data file, enabling the data file to be universally identifiable by any node based on the corresponding object identifier. The data file can be stored independently of a device file system based on providing a resolution between the data file name and its object identifier, followed by a resolution between the object identifier and a selected location for the data file.

Claims

1. A method in a node, the method comprising:

identifying a data object;

determining for the data object a unique object identifier that is assigned to the data object and having a value that is independent of any attribute of the data object; and

obtaining a storage location for the data object based on sending a query specifying the unique object identifier, and obtaining a resolution that specifies the storage location based on the unique object identifier.

2. The method of claim 1, wherein the determining includes:

sending a query that specifies a name of the data object to a destination; and

receiving a response to the query that specifies the name of the data object and the corresponding unique object identifier.

3. The method of claim 2, wherein the obtaining includes:

sending a second query that specifies the unique object identifier for the resolution specifying the storage location; and

receiving a second response to the second query that specifies the unique object identifier and the storage location for the corresponding data object.

4. The method of claim 3, further comprising caching the name, the corresponding unique object identifier, and the corresponding storage location in a directory entry.

5. The method of claim 4, wherein the node is within a distributed file system, the storage location specifying a location on a second node within the distributed file system.

6. The method of claim 1, wherein the data object identifies one of a data file and a directory.

7. The method of claim 6, wherein the data object identifies a root directory as said directory.

8. A method in a node of a distributed file system, the method comprising:

receiving by the node, from a second node in the distributed file system, a request for a unique object identifier assigned to a data object, the distributed file system configured for storing the data object at a storage location; and

outputting to the second node, by the node, a response to the request that specifies the unique object identifier, the unique object identifier having a value that is independent of any attribute of the data object, the storage location identifiable by the second node based on the unique object identifier.

9. The method of claim 8, wherein:

the request specifies that the data object is a new data object;

the outputting includes selecting a new identifier as the unique object identifier, and storing in a table an entry that specifies the unique object identifier for the new data object.

10. The method of claim 9, further comprising:

storing in a second table at least one entry specifying the unique object identifier and a corresponding location as the storage location for the data object;

receiving a query from a node specifying the unique object identifier and requesting the storage location for the unique object identifier; and

selectively supplying to the node the location specified in the at least one entry based on the unique object identifier and determined attributes.

11. The method of claim 10, wherein the data object specifies a root directory for use by the second node, the storage location storing a root attribute information file for the root directory for use by the second node.

12. A distributed file system comprising:

storage devices distributed throughout the distributed file system, each configured for storing data objects at respective storage locations;

a service node configured for providing resolutions to queries for unique object identifiers assigned to the data objects, respectively, each unique object identifier assigned to the corresponding data object having a value that is independent of any storage address on any of the storage devices; and

a node configured for determining the unique object identifier for a corresponding one of the data objects based on outputting the corresponding query into the distributed file system and receiving the corresponding resolution, the node further configured for obtaining a second resolution, that specifies the corresponding storage location of the one data object, based on the corresponding unique object identifier.

13. The file system of claim 12, wherein the node is configured for supplying in the query a name of the one data object, and the service node is configured for providing the corresponding resolution that specifies the name of the one data object in the corresponding unique object identifier.

14. The file system of claim 13, wherein the node is configured for obtaining the second resolution based on sending a second query that specifies the unique object identifier for the corresponding one data object, the service node configured for providing the second resolution, specifying the corresponding unique object identifier and the corresponding storage location of the one data object, based on the corresponding unique object identifier and determined attributes relevant to the node.

15. The file system of claim 14, wherein the one data object identifies one of a data file and a directory.

16. The file system of claim 15, wherein the one data object identifies a root directory as said directory, the corresponding unique object identifier being used by the node to obtain the corresponding storage location for retrieval of a root attribute information file for use of the root directory by the second node.

17. A node comprising:

a device file system configured for identifying a data object having been requested for one of a read operation and a write operation; and

a network-based query resource configured for determining for the data object a unique object identifier that is assigned to the data object, the unique object identifier having a value that is independent of any attribute of the data object, the network-based query resource further configured for obtaining a storage location for the data object based on sending a query specifying the unique object identifier, and obtaining a resolution that specifies the storage location based on the unique object identifier.

18. The node of claim 17, wherein the network-based query resource is configured for:

sending a query that specifies a name of the data object to a destination; and

receiving a response to the query that specifies the name of the data object and the corresponding unique object identifier.

19. The node of claim 18, wherein the network-based query resource is further configured for:

sending a second query that specifies the unique object identifier for the resolution specifying the storage location; and

receiving a second response to the second query that specifies the unique object identifier and the storage location for the corresponding data object.

20. The node of claim 19, wherein the device file system is configured for caching the name, the corresponding unique object identifier, and the corresponding storage location in a directory entry.

21. The node of claim 20, wherein the node is within a distributed file system, the storage location specifying a location on a second node within the distributed file system.

22. The node of claim 17, wherein the data object identifies a root directory.

23. A node of a distributed file system, the node comprising:

a network interface configured for receiving, from a second node in the distributed file system, a request for a unique object identifier assigned to a data object, the distributed file system configured for storing the data object at a storage location; and

a resolution resource configured for outputting to the second node a response to the request that specifies the unique object identifier, the unique object identifier having a value that is independent of any attribute of the data object, the storage location identifiable by the second node based on the unique object identifier.

24. The node of claim 23, further comprising a table configured for storing an entry, wherein:

the request specifies that the data object is a new data object; and

the resolution resource is configured for selecting a new identifier as the unique object identifier, and storing in the table said entry specifying the unique object identifier for the new data object.

25. The node of claim 24, further comprising a second table, wherein:

the resolution resource is configured for storing in the second table at least one entry specifying the unique object identifier and a corresponding location as the storage location for the data object;

in response to the network interface receiving a query from a node specifying the unique object identifier and requesting the storage location for the unique object identifier, the resolution resource is configured for selectively supplying to the node the location specified in the at least one entry based on the unique object identifier and determined attributes.

26. The node of claim 25, wherein the data object specifies a root directory for use by the second node, the storage location storing a root attribute information file for the root directory for use by the second node.

27. A node comprising:

means for identifying a data object; and

means for determining for the data object a unique object identifier that is assigned to the data object and having a value that is independent of any attribute of the data object, the means for determining configured for obtaining a storage location for the data object based on sending a query specifying the unique object identifier, and obtaining a resolution that specifies the storage location based on the unique object identifier.

28. The node of claim 27, wherein the means for determining is configured for:

sending a query that specifies a name of the data object to a destination; and

receiving a response to the query that specifies the name of the data object and the corresponding unique object identifier.

29. The node of claim 28, wherein the means for determining is further configured for:

sending a second query that specifies the unique object identifier for the resolution specifying the storage location; and

receiving a second response to the second query that specifies the unique object identifier and the storage location for the corresponding data object.

30. The node of claim 29, wherein the means for identifying is configured for caching the name, the corresponding unique object identifier, and the corresponding storage location in a directory entry.

31. The node of claim 30, wherein the node is within a distributed file system, the storage location specifying a location on a second node within the distributed file system.

32. The node of claim 27, wherein the data object identifies a root directory as said directory.

33. A node of a distributed file system, the node comprising:

means for receiving, from a second node in the distributed file system, a request for a unique object identifier assigned to a data object, the distributed file system configured for storing the data object at a storage location; and

means for outputting to the second node a response to the request that specifies the unique object identifier, the unique object identifier having a value that is independent of any attribute of the data object, the storage location identifiable by the second node based on the unique object identifier.

34. The node of claim 33, wherein:

the request specifies that the data object is a new data object;

the means for outputting configured for selecting a new identifier as the unique object identifier, and storing in a table an entry that specifies the unique object identifier for the new data object.

35. The node of claim 34, wherein the means for outputting is configured for:

storing in a second table at least one entry specifying the unique object identifier and a corresponding location as the storage location for the data object;

in response to the means for receiving having received a query from a node specifying the unique object identifier and requesting the storage location for the unique object identifier, the means for outputting selectively supplying to the node the location specified in the at least one entry based on the unique object identifier and determined attributes.

36. The node of claim 35, wherein the data object specifies a root directory for use by the second node, the storage location storing a root attribute information file for the root directory for use by the second node.