Consistency without ordering dependency

• US 9,430,160 B2
• Filed: 03/25/2015
• Issued: 08/30/2016
• Est. Priority Date: 12/11/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Miller, Thomas J., Cargille, Jonathan M., Tipton, William R., Verma, Surendra
• Primary Examiner(s): NGUYEN, THAN VINH
• Application Number:
  US14/668,628
• Publication Number:
  US 20150199143A1
• Time in Patent Office: 524 Days
• Field of Search: 711/161, 711/162
• US Class Current: 1/1
• CPC Class Codes: G06F 3/0614 Improving the reliability of storage systems
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 9/466 Transaction processing

Abstract

Aspects of the subject matter described herein relate to maintaining consistency in a storage system. In aspects, one or more objects may be updated in the context of a transaction. In conjunction with updating the objects, logical copies of the objects may be obtained and modified. A request to write the updated logical copies is sent to a storage controller. The logical copies do not overwrite the original copies. In conjunction with sending the request, a data structure is provided for the storage controller to store on the disk. The data structure indicates the one or more objects that were supposed to be written to disk and may include verification data to indicate the content that was supposed to be written to disk. During recovery, this data structure may be used to determine whether all of the object(s) were correctly written to disk.

Claims

1. A system comprising:

at least one processor;

memory; and

at least one program module comprising particular instructions via which the system is configured, based on execution by the at least one processor of at least a portion of the particular instructions, to;

copy each of a plurality of objects that are involved in a transaction, where the objects are copied from first locations on a data store at which the objects are stored;

create a write plan that defines an association between the copied objects; and

request that the copied objects and the write plan be written, according to the write plan, to the data store at second locations that are different than the first locations on the data store, where the copied objects and the write plan written at the second locations on the data store do not overwrite any portion of the corresponding objects stored at the first locations on the data store.

2. The system of claim 1 wherein the created association binds the copied objects in an atomic unit.

3. The system of claim 1 wherein the transaction involves a file system.

4. The system of claim 1 wherein one of the objects is a file and another of the objects is a directory that includes the file.

5. The system of claim 1 wherein the transaction comprises a modification to an aspect of at least one of the objects.

6. The system of claim 1 wherein a change to one of the plurality of objects according to the transaction has an effect on at least one other of the plurality of objects.

7. The system of claim 1 further configured, as part of the request that the copied objects and the created association be written to the data store at second locations, to maintain the plurality of objects stored at the first locations on the data store.

8. A method performed on a computing device that includes at least one processor and memory, the method comprising:

copying, by the computing device, each of a plurality of objects that are involved in a transaction, where the objects are copied from first locations on a data store at which the objects are stored;

creating, by the computing device, a write plan that defines an association between the copied objects; and

requesting, by the computing device, that the copied objects and the write plan be written, according to the write plan, to the data store at second locations that are different than the first locations on the data store, where the copied objects and the write plan written at the second locations on the data store do not overwrite any portion of the corresponding objects stored at the first locations on the data store.

9. The method of claim 8 wherein the created association binds the copied objects in an atomic unit.

10. The method of claim 8 wherein the transaction involves a file system.

11. The method of claim 8 wherein one of the objects is a file and another of the objects is a directory that includes the file.

12. The method of claim 8 wherein the transaction comprises a modification to an aspect of at least one of the objects.

13. The method of claim 8 wherein a change to one of the plurality of objects according to the transaction has an effect on at least one other of the plurality of objects.

14. The method of claim 8, the requesting comprising maintaining the plurality of objects stored at the first locations on the data store.

15. At least one computer-readable medium comprising:

memory that comprises at least one program module comprising particular instructions that, based on execution of at least a portion of the particular instructions by a computing device, configure the computing device to;

copy each of a plurality of objects that are involved in a transaction, where the objects are copied from first locations on a data store at which the objects are stored;

create a write plan that defines an association between the copied objects; and

request that the copied objects and the write plan be written, according to the write plan, to the data store at second locations that are different than the first locations on the data store, where the copied objects and the write plan written at the second locations on the data store do not overwrite any portion of the corresponding objects stored at the first locations on the data store.

16. The at least computer-readable medium of claim 15 wherein the created association binds the copied objects in an atomic unit.

17. The at least one computer-readable medium of claim 15 wherein one of the objects is a file and another of the objects is a directory that includes the file.

18. The at least one computer-readable medium of claim 15 wherein the transaction comprises a modification to an aspect of at least one of the objects.

19. The at least one computer-readable medium of claim 15 wherein a change to one of the plurality of objects according to the transaction has an effect on at least one other of the plurality of objects.

20. The at least one computer-readable medium of claim 15 wherein the particular instructions further configure the computing device, as part of the request that the copied objects and the created association be written to the data store at second locations, to maintain the plurality of objects stored at the first locations on the data store.