Methods for host-side caching and application consistent writeback restore and devices thereof

• US 9,852,072 B2
• Filed: 07/02/2015
• Issued: 12/26/2017
• Est. Priority Date: 07/02/2015
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Sehgal, Priya, Basu, Sourav
• Primary Examiner(s): Rojas, Midys
• Assistant Examiner(s): Doan, Khoa D
• Application Number:
  US14/790,701
• Publication Number:
  US 20170004082A1
• Time in Patent Office: 908 Days
• CPC Class Codes: G06F 11/14 Error detection or correction of the data by redundancy in operation G06F11/16 takes precedence
• CPC Class Codes: G06F 11/1446 Point-in-time backing up or restoration of persistent data
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 2212/1016 Performance improvement
• CPC Class Codes: G06F 2212/154 Networked environment
• CPC Class Codes: G06F 2212/314 In storage network, e.g. network attached cache
• CPC Class Codes: G06F 2212/463 File
• CPC Class Codes: G06F 2212/466 Metadata, control data
• CPC Class Codes: G06F 2212/621 Coherency control relating to peripheral accessing, e.g. from DMA or I/O device
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

Abstract

A method, non-transitory computer readable medium, and device that assists with file-based host-side caching and application consistent write back includes receiving a write operation on a file from a client computing device. When the file for which the write operation has been received is determined when the file is present in the cache. An acknowledgement is sent back to the client computing device indicating the acceptance of the write operation when the file for which the write operation has been received is determined to be present within the cache. The write-back operation is completed for data present in the cache of the storage management computing device to one of the plurality of servers upon sending the acknowledgement.

Claims

1. A method comprising:

receiving, by a computing device, a first write operation having an offset and first data directed to a file from an application executing on a client computing device;

determining, by the computing device, when the file is present in a cache of the computing device;

sending, by the computing device, an acknowledgement of the first write operation to the client computing device, when the file is determined to be present in the cache and the first data is written to the file in the cache;

adding, by the computing device, the offset to a dirty list;

blocking processing, by the computing device, of a second write operation directed to the file and having second data received from the application executing on the client computing device;

write-protecting, by the computing device, the offset of the dirty list upon receiving the second write operation;

resuming processing, by the computing device, of the second write operation;

completing, by the computing device, a write-back operation for the first data present in the cache to a storage server upon sending the acknowledgement; and

write-unprotecting, by the computing device, the offset of the dirty list when the write-back operation is complete.

2. The method of claim 1 wherein determining when the file is present in the cache further comprises, obtaining and caching, by the computing device, the file from the storage server when the file is not determined to be present in the cache.

3. The method of claim 1 wherein completing the write-back operation further comprises:

determining, by the computing device, when a current memory size of the cache exceeds a threshold based on the second data being written to the file in the cache; and

determining, by the computing device, when a write-back timer has expired on the cache.

4. The method of claim 3 further comprising:

temporarily designating, by the computing device, a status of the application executing in the client computing device issuing the write operations directed to the file as inactive; and

in response to write-protecting the offset of the dirty list, changing, by the computing device the status of the application executing in the client computing device to active.

5. The method of claim 1 further comprising:

capturing, by the computing device, a snapshot of the file in the storage server upon the completion of the write-back operation.

6. The method of claim 5 further comprising:

determining, by the computing device, when there is a failure of the cache of the computing device; and

re-validating, by the computing device, the first data present in the failed cache using the captured snapshot.

19. The method of claim 1 wherein the first data is written to a first storage location and the second data is written to a second storage location different from the first storage location while the dirty list is write protected.

7. A non-transitory computer readable medium having stored thereon instructions including executable code configured to perform steps comprising:

receiving a first write operation having an offset and first data directed to a file from an application executing on a client computing device;

determining when the file is present in a cache of a computing device;

sending an acknowledgement of the first write operation to the client computing device, when the file is determined to be present in the cache and the first data is written to the file in the cache;

adding the offset to a dirty list;

blocking processing of a second write operation directed to the file and having second data received from the application executing on the client computing device;

write-protecting the offset of the dirty list upon receiving the second write operation;

resuming processing of the second write operation;

completing a write-back operation for the first data present in the cache to a storage server upon sending the acknowledgement; and

write-unprotecting the offset of the dirty list when the write-back operation is complete.

8. The non-transitory computer readable medium of claim 7 wherein the step of determining when the file is present in the cache further comprises, obtaining and caching the file from the storage server in the cache of the computing device when the file is not determined to be present in the cache.

9. The non-transitory computer readable medium of claim 7 wherein the step of completing the write-back operation further comprises:

determining when a current memory size of the cache exceeds a threshold based on the second data being written to the file in the cache; and

determining when a write-back timer has expired on the cache.

10. The non-transitory computer readable medium of claim 9 wherein the stored instructions are further configured to perform steps comprising:

temporarily designating a status of the application executing in the client computing device issuing the write operations directed to the file as inactive; and

in response to write protecting the offset of the dirty list, changing the status of the application executing in the client computing device to active.

11. The non-transitory computer readable medium of claim 7 wherein the stored instructions are further configured to perform a step comprising capturing a snapshot of the file in the storage server upon the completion of the write-back operation.

12. The non-transitory computer readable medium of claim 11 further comprising:

determining when there is a failure of the cache of the computing device; and

re-validating the first data present in the failed cache using the captured snapshot.

13. A computing device comprising:

a processor;

a memory coupled to the processor, the memory including programmed instructions configured to;

receive a first write operation having an offset and first data directed to a file from an application executing on a client computing device;

determine when the file is present in a cache of the computing device;

send an acknowledgement of the first write operation to the client computing device when the file is determined to be present in the cache and the first data is written to the file in the cache;

add the offset to a dirty list;

block processing of a second write operation directed to the file and having second data received from the application executing on the client computing device;

write-protect the offset of the dirty list upon receiving the second write operation;

resume processing of the second write operation;

complete a write-back operation for the first data present in the cache to a storage server upon sending the acknowledgement; and

write-unprotect the offset of the dirty list when the write-back operation is complete.

14. The computing device of claim 13 wherein the programmed instructions included in the memory are further configured to obtain and cache the file from the storage server to the cache of the computing device when the file is not determined to be present in the cache.

15. The computing device of claim 13 wherein the programmed instructions included in the memory configured to complete the write-back operation are further configured to:

determine when a current memory size of the cache exceeds a threshold based on the second data being written to the file in the cache; and

determine when a write-back timer has expired on the cache.

16. The computing device of claim 15 wherein the programmed instructions included in the memory are further configured to:

determine a status of the application executing in the client computing device issuing the write operation directed to the file to inactive;

complete the write-back operation by transferring the first data from the cache to the storage server; and

in response to write-protecting changes to the dirty list, change the status of the application executing in the client computing device to active upon the completion of the write-back operation.

17. The computing device of claim 13 wherein the programmed instructions included in the memory are further configured to capture a snapshot of the file in the storage server upon the completion of the write-back operation.

18. The computing device of claim 17 wherein the programmed instructions included in the memory are further configured to:

determine when there is a failure of the cache of the computing device; and

re-validate the first data present in the failed cache using the captured snapshot.

20. The computing device of claim 13 wherein the first data is written to a first storage location and the second data is written to a second storage location different from the first storage location while the dirty list is write protected.