Granted Patent B1

US 10,896,132 · App. 15/980,770 · Granted Jan 19, 2021

Inventors: Jitendra Patidar (Pune, IN); Anindya Banerjee (Pune, IN)

Assignee: Veritas Technologies LLC

G06F12/0891G06F12/0895G06F2212/1044

Abstract

Claims (57)

1. A computer-implemented method for prioritizing cache objects for deletion, at least a portion of the method being performed by a computing device comprising at least one processor, the method comprising:

tracking, at the computing device, a respective time an externally-accessed object spends in an external cache;

queuing, when the externally-accessed object is purged from the external cache, the externally-accessed object in a first queue;

setting, when the externally-accessed object is purged, a respective unhold flag;

queuing, when an internally-accessed object is released, the internally-accessed object in a second queue;

setting, when the externally-accessed object in the first queue re-accessed internally, a respective hold flag;

transferring, when the externally-accessed object in the first queue having both a respective hold flag and a respective unhold flag set is released, the externally-accessed object to a third queue;

prioritizing objects within the first queue, based on a cache-defined internal age factor and on respective times the objects in the first queue spend in the external cache and respective times the objects in the first queue spend in an internal cache;

prioritizing objects within the second queue based on respective times the objects in the second queue spend in the internal cache;

prioritizing objects within the third queue based on respective times the objects in the third queue spend in the internal cache;

selecting an oldest object having a longest time in any of the first queue, the second queue, and the third queue; and

deleting the oldest object.

2. The computer-implemented method of claim 1 , further comprising:

setting the respective hold flag when the externally-accessed object is initially accessed externally; and

clearing, when the externally-accessed object is purged, the respective hold flag.

3. The computer-implemented method of claim 1 , wherein at least one of the externally-accessed object and the internally-accessed object is an inode data structure.

4. The computer-implemented method of claim 1 , wherein at least one of the internal cache and the external cache is an inode cache.

5. The computer-implemented method of claim 4 , wherein the inode cache is in a file system layer, an operating system layer, or a network file system layer.

6. The computer-implemented method of claim 1 , wherein the deleting is initiated by at least one of a system memory reaching maximum capacity and an in-core cache reaching maximum capacity.

7. A system for prioritizing cache objects for deletion, the system comprising:

a tracking module, stored in memory, that tracks a respective time an externally-accessed object spends in an external cache;

a first queuing module, stored in the memory, that queues, when the externally-accessed object is purged from the external cache, the externally-accessed object in a first queue;

a first setting module, stored in the memory, that sets, when the externally-accessed object is purged, a respective unhold flag;

a second queuing module, stored in the memory, that queues, when an internally-accessed object is released, the internally-accessed object in a second queue;

a second setting module, stored in the memory, that sets, when the externally-accessed object in the first queue re-accessed internally, a respective hold flag;

a transferring module, stored in the memory, that transfers, when the externally-accessed object in the first queue having both a respective hold flag and a respective unhold flag set is released, the externally-accessed object to a third queue;

a first prioritizing module, stored in the memory, that prioritizes objects within the first queue, based on a cache-defined internal age factor and on respective times the objects in the first queue spend in the external cache and respective times the objects in the first queue spend in an internal cache;

a second prioritizing module, stored in the memory, that prioritizes objects within the second queue based on respective times the objects in the second queue spend in the internal cache;

a third prioritizing module, stored in the memory, that prioritizes objects within the third queue based on respective times the objects in the third queue spend in the internal cache;

a selecting module, stored in the memory, that selects an oldest object having a longest time in any of the first queue, the second queue, and the third queue;

a deleting module, stored in the memory, that deletes the oldest object; and

at least one physical processor that executes the tracking module, the first queuing module, the first setting module, the second queuing module, the second setting module, the transferring module, the first prioritizing module, the second prioritizing module, the third prioritizing module, the selecting module, and the deleting module.

8. The system of claim 7 , further comprising:

a third setting module, stored in the memory, that sets the respective hold flag when the externally-accessed object is initially accessed externally; and

a clearing module, stored in the memory, that clears, when the externally-accessed object is purged, the respective hold flag.

9. The system of claim 7 , wherein at least one of the externally-accessed object and the internally-accessed object is an inode data structure.

10. The system of claim 7 , wherein at least one of the internal cache and the external cache is an inode cache.

11. The system of claim 10 , wherein the inode cache is in a file system layer, an operating system layer, or a network file system layer.

12. The system of claim 7 , wherein the deleting is initiated by at least one of a system memory reaching maximum capacity and an in-core cache reaching maximum capacity.

13. A non-transitory computer-readable medium comprising one or more computer-executable instructions that, when executed by at least one processor of a computing device, cause the computing device to:

track, at the computing device, a respective time an externally-accessed object spends in an external cache;

queue, when the externally-accessed object is purged from the external cache, the externally-accessed object in a first queue;

set, when the externally-accessed object is purged, a respective unhold flag;

queue, when an internally-accessed object is released, the internally-accessed object in a second queue;

set, when the externally-accessed object in the first queue re-accessed internally, a respective hold flag;

transfer, when the externally-accessed object in the first queue having both a respective hold flag and a respective unhold flag set is released, the externally-accessed object to a third queue;

prioritize objects within the first queue based on a cache-defined internal age factor and on respective times the objects in the first queue spend in the external cache and respective times the objects in the first queue spend in an internal cache;

prioritize objects within the second queue based on respective times the objects in the second queue spend in the internal cache;

prioritize objects within the third queue based on respective times the objects in the third queue spend in the internal cache;

select an oldest object having a longest time in any of the first queue, the second queue, and the third queue; and

delete the oldest object.

14. The non-transitory computer-readable medium of claim 13 , wherein the computer-executable instructions further comprise computer-executable instructions that cause the computing device to:

set the respective hold flag when the externally-accessed object is initially accessed externally; and

clear, when the externally-accessed object is purged, the respective hold flag.

15. The non-transitory computer-readable medium of claim 13 , wherein at least one of the externally-accessed object and the internally-accessed object is an inode data structure.

16. The non-transitory computer-readable medium of claim 13 , wherein at least one of the internal cache and the external cache is an inode cache.

17. The non-transitory computer-readable medium of claim 16 , wherein the inode cache is in a file system layer, an operating system layer, or a network file system layer.

Assignments (14)