System of and method for transparent management of data objects in containers across distributed heterogenous resources

• US 20040133609A1
• Filed: 10/24/2003
• Published: 07/08/2004
• Est. Priority Date: 04/27/2000
• Status: Active Grant

• Current Assignee: General Atomics, Inc.
• Original Assignee: General Atomics, Inc.
• Inventors: Rajasekar, Arcot, Moore, Reagan W., Wan, Michael Y.
• Granted Patent: US 7,269,604 B2
• Time in Patent Office: Days
• US Class Current: 707/200
• CPC Class Codes: G06F 16/188 Virtual file systems
• CPC Class Codes: G06F 16/256 in federated or virtual databases
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 16/273 Asynchronous replication or reconciliation
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

A system of and method for maintaining data objects in containers across a network of distributed heterogeneous resources in a manner which is transparent to a client. A client request pertaining to containers is resolved by querying meta data for the container, processing the request through one or more copies of the container maintained on the system, updating the meta data for the container to reflect any changes made to the container as a result processing the re quest, and, if a copy of the container has changed, changing the status of the copy to indicate dirty status or synchronizing the copy to one or more other copies that may be present on the system.

Claims

1. A method of creating a logical resource comprising the steps of:

associating one or more physical resources with the logical resource;

for each physical resource, specifying a type thereof from the group comprising an archive, a cache, a primary archive, and a primary cache; and

for each physical resource, also specifying size, access control, and optionally other relevant meta-information.

10. The method of claim 1 wherein the at least one physical resources are located in a distributed system.

11. The method of claim 1 wherein the at least one physical resources are heterogenous.

2. A method of creating a container comprising the steps of:

specifying, in response to a client request, a name of a container and a logical resource to be allocated to the container, the logical resource being associated with one or more physical resources, including at least one archive and at least one cache;

creating meta-data for the container, including meta-data specifying the container name and the logical resource to be allocated to the container;

storing the meta-data for the container in a meta-data catalog; and

reserving one or more of the resources allocated to the container.

3. A method of importing a data object into a container comprising the steps of:

specifying the container;

querying meta data for the container, including a next available offset;

locating on or staging to a selected resource a copy of the container;

writing the data object into the copy at the next available offset;

updating meta-data for the copy to reflect the write operation; and

marking the copy as dirty or synchronizing the copy with any other copies.

4. The method of claim 3 wherein the selected resource is cache resource.

5. The method of claim 4 wherein the cache resource is a principal cache resource.

6. A method of synchronizing a plurality of copies of a container comprising the steps of:

if no copies of the container are marked as dirty, ending the method;

if a cache copy of the container is marked as dirty, synchronizing such to one or more archival copies that are not marked as dirty;

if all archival copies are thereby written over, resetting the dirty flags of all such archival copies; and

if one or more but not all archival copies are thereby written over, setting the dirty flags of the one or more archives that are written over.

7. A method of reading a data object from a container comprising the steps of:

querying meta data for the container, including an offset within the container where the object is stored;

locating on or staging to a selected resource a copy of the container; and

using the offset to retrieve the data object from the copy of the container.

8. The method of claim 7 wherein the selected resource is a cache resource.

9. The method of claim 7 wherein the selected resource is a principal cache resource.

12. The methods of any of claims 7, 8, and 9, wherein the client is a user on a remote system.

13. The methods of any of claims 7, 8, and 9, wherein the client is a program on a local server.

14. The methods of any of claims 7, 8, and 9, wherein the client is a program on a remote server.

15. The method of any of claims 7, 8, and 9, wherein the client is a program on a remote client.