Method for bulk deletion through segmented files

• US 20060288047A1
• Filed: 06/20/2005
• Published: 12/21/2006
• Est. Priority Date: 09/17/2004
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Chron, Edward Gustav, Douglis, Frederick, Morgan, Stephen Paul
• Granted Patent: US 8,914,330 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/162 Delete operations erasing in storage systems G06F3/0652

Abstract

A mechanism is provided that aggregates data in a way that permits data to be deleted efficiently, while minimizing the overhead necessary to support bulk deletion of data. A request is received for automatic deletion of segments in a container and a waterline is determined for the container. A determination is made if at least one segment in the container falls below the waterline. Finally, in response to one segment falling below the waterline, the segment from the container is deleted. Each object has an associated creation time, initial retention value, and retention decay curve (also known as a retention curve). At any point, based on these values and the current time, the object'"'"'s current retention value may be computed. The container system continually maintains a time-varying waterline: at any point, objects with a retention value below the waterline may be deleted.

Claims

1. A method for bulk deletion through segmented files, the method comprising:

receiving a request for automatic deletion of segments in a container;

determining a waterline for the container;

determining if at least one segment within a plurality of segments in the container falls below the waterline; and

in response to the at least one segment falling below the waterline, deleting the at least one segment from the container.

2. The method of claim 1, wherein the waterline is set to a segment retention value, wherein the segment retention value is a function of information within the given segment and is a minimum value to retain the given segment.

3. The method of claim 2, wherein the minimum value is determined by at least one of the creation date of the given segment, the retention decay curve of the given segment, the initial retention value of the given segment, the current time or a date for deletion of the given segment.

4. The method of claim 1, wherein the waterline is a value determined by a function, wherein the function is determined by a retention decay curve of a given segment, and wherein determining if the at least one segment within the plurality of segments in the container falls below the waterline further comprises:

identifying the at least one segment within the plurality of segments in the container whose value is below the waterline to form an identified segment; and

deleting the identified segment from the container.

5. The method of claim 4, wherein segments that are not identified for deletion are not contiguous.

6. The method of claim 4, wherein segments that are not identified for deletion are contiguous.

7. The method of claim 1, wherein the waterline is a value determined by a function that converts a creation date of a given segment to the value and wherein determining if the at least one segment within the plurality of segments in the container falls below the waterline further comprises:

scanning the plurality of segments in the container from a beginning of the container in ascending date order for the least one segment whose value is above the waterline; and

deleting the at least one segment from the beginning of the container up to the segment whose value is above the waterline.

8. The method of claim 1, wherein deleting the at least one segment from the container is performed by unmapping individual file blocks associated with the at least one segment.

9. A data processing system comprising:

a bus system;

a communications system connected to the bus system;

a memory connected to the bus system, wherein the memory includes a set of instructions; and

a processing unit connected to the bus system, wherein the processing unit executes the set of instructions to receive a request for automatic deletion of segments in a container;

determine a waterline for the container;

determine if at least one segment within a plurality of segments in the container falls below the waterline; and

delete the at least one segment from the container in response to the at least one segment falling below the waterline.

10. The data processing system of claim 9, wherein the waterline is set to a segment retention value, wherein the segment retention value is a function of information within the given segment and is a minimum value to retain the given segment.

11. The data processing system of claim 10, wherein the minimum value is determined by at least one of the creation date of the given segment, the retention decay curve of the given segment, the initial retention value of the given segment, the current time or a date for deletion of the given segment.

12. The data processing system of claim 9, wherein the waterline is a value determined by a function, wherein the function is determined by a retention decay curve of a given segment, and wherein the set of instructions to determine if the at least one segment within the plurality of segments in the container falls below the waterline further comprises:

a set of instructions to identify the at least one segment within the plurality of segments in the container whose value is below the waterline to form an identified segment; and

delete the identified segment from the container.

13. The data processing system of claim 12, wherein segments that are not identified for deletion are not contiguous.

14. The data processing system of claim 12, wherein segments that are not identified for deletion are contiguous.

15. The data processing system of claim 9, wherein the waterline is a value determined by a function that converts a creation date of a given segment to the value and wherein the set of instructions to determine if the at least one segment within the plurality of segments in the container falls below the waterline further comprises:

a set of instructions to scan the plurality of segments in the container from a beginning of the container in ascending date order for the least one segment whose value is above the waterline; and

delete the at least one segment from the beginning of the container up to the segment whose value is above the waterline.

16. The data processing system of claim 9, wherein the set of instructions to delete the at least one segment from the container is performed by a set of instructions to unmap individual file blocks associated with the at least one segment.

17. A computer program product comprising:

a computer usable medium including computer usable program code for bulk deletion through segmented files, the computer program product including;

computer usable program code for receiving a request for automatic deletion of segments in a container;

computer usable program code for determining a waterline for the container;

computer usable program code for determining if at least one segment within a plurality of segments in the container falls below the waterline; and

computer usable program code for deleting the at least one segment from the container in response to the at least one segment falling below the waterline.

18. The computer program product of claim 17, wherein the waterline is set to a segment retention value, wherein the segment retention value is a function of information within the given segment and is a minimum value to retain the given segment.

19. The computer program product of claim 18, wherein the minimum value is determined by at least one of the creation date of the given segment, the retention decay curve of the given segment, the initial retention value of the given segment, the current time or a date for deletion of the given segment.

20. The computer program product of claim 17, wherein the waterline is a value determined by a function, wherein the function is determined by a retention decay curve of a given segment, and wherein the computer usable program code for determining if the at least one segment within the plurality of segments in the container falls below the waterline further comprises:

computer usable program code for identifying the at least one segment within the plurality of segments in the container whose value is below the waterline to form an identified segment; and

computer usable program code for deleting the identified segment from the container.

21. The computer program product of claim 20, wherein segments that are not identified for deletion are not contiguous.

22. The computer program product of claim 20, wherein segments that are not identified for deletion are contiguous.

23. The computer program product of claim 17, wherein the waterline is a value determined by a function that converts a creation date of a given segment to the value and wherein the computer usable program code for determining if the at least one segment within the plurality of segments in the container falls below the waterline further comprises:

computer usable program code for scanning the plurality of segments in the container from a beginning of the container in ascending date order for the least one segment whose value is above the waterline; and

computer usable program code for deleting the at least one segment from the beginning of the container up to the segment whose value is above the waterline.

24. The computer program product of claim 17, wherein deleting the at least one segment from the container is performed by unmapping individual file blocks associated with the at least one segment.