Data store page recovery

• US 9,009,428 B2
• Filed: 07/08/2011
• Issued: 04/14/2015
• Est. Priority Date: 07/08/2011
• Status: Expired due to Fees

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Graefe, Goetz, Kuno, Harumi
• Primary Examiner(s): Bansal, Gurtej
• Application Number:
  US13/179,261
• Publication Number:
  US 20130013874A1
• Time in Patent Office: 1,376 Days
• Field of Search: 711/161, 711/162
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery

Abstract

In one implementation, a data store page recovery process includes selecting a page reference and an update record reference at a page recovery mapping based on a page identifier, accessing a backup page via the page reference, accessing an update record via the update record reference, and modifying the backup page according to the update record. The page reference is associated with the update record reference at the page recovery mapping.

Claims

1. A non-transitory machine-readable storage medium storing code representing instructions to cause a processor to perform a data store page recovery process, the process comprising:

selecting a page reference and an update record reference at a page recovery mapping based on a page identifier, the page reference associated with the update record reference at the page recovery mapping;

accessing a backup page via the page reference, wherein the backup page is a first backup page and the page reference is a first page reference;

accessing an update record via the update record reference;

modifying the backup page according to the update record;

marking the backup page to prevent deletion of the backup page;

selecting a second backup page;

after selecting the second backup page, marking the first backup page to allow deletion of the first backup page; and

replacing the first page reference with a second page reference at the page recovery mapping, the second page reference associated with the second backup page.

2. The non-transitory machine-readable storage medium of claim 1, wherein the page reference and the update record reference are associated at the page recovery mapping with a failed page of a data store, the process further comprising:

replacing the failed page of the data store with the backup page after the modifying, the data store being online during the selecting, the accessing the backup page, the accessing the update record, the modifying, and the replacing.

3. The non-transitory machine-readable storage medium of claim 1, the process further comprising:

recursively accessing a plurality of update records from the update record; and

modifying the backup page according to the plurality of update records.

4. The non-transitory machine-readable storage medium of claim 1, the process further comprising:

accessing a plurality of update records from the update record;

applying update record analysis to the plurality of update records; and

modifying the backup page based on the plurality of update records and the update record analysis.

5. The non-transitory machine-readable storage medium of claim 1, the process further comprising:

accessing a first plurality of update records from the update record;

disregarding a second plurality of update records from the first plurality of update records to define a third plurality of update records;

an

modifying the backup page according to the third plurality of update records.

6. A data store page recovery system, comprising:

a record module to store an update record associated with a page of a data store, the update record describing an update to the page; and

a page recovery module to

store a reference to the update record at a portion of a page recovery mapping associated with the page, the portion of the page recovery mapping including a reference to a backup page associated with the page,

replace the reference to the update record with a second reference to a second update record associated with the page at the page recovery mapping; and

storing the reference to the update record at the second update record.

7. The system of claim 6, wherein:

the reference to the backup page is a first backup page;

the page recovery module is configured to replace the reference to the first backup page with a reference to a second backup page in response to the page being written to a storage medium; and

the second backup page is the page at the storage medium.

8. The system of claim 6, further comprising:

a first memory to include a page buffer pool and the page recovery mapping, the page stored at the page buffer pool; and

a second memory to include the backup page, the page recovery module configured to store the reference to the update record at the portion of the page recovery mapping associated with the page in response to eviction of the page from the page buffer pool.

9. The system of claim 6, further comprising:

a first memory to include a page buffer pool, the page stored at the page buffer pool; and

a second memory to include the backup page and the page recovery mapping, the page recovery module configured to store the reference to the update record at the portion of the page recovery mapping associated with the page in response to eviction of the page from the page buffer pool.

10. The system of claim 6, wherein the backup page is a first backup page, the system further comprising:

a backup page selection module to select the first backup page at a first time, to select a second backup page associated with the page at a second time, and to discard the first backup page after the second time, the page recovery module configured to replace the reference to the first backup page at the portion of the page recovery mapping with a reference to the second backup page.

11. The system of claim 6, wherein the backup page is a first backup page, the system further comprising:

a backup page selection module to select the first backup page at a first time, to mark the first backup page to prevent deletion of the first backup page after the first time, to select a second backup page associated with the page at a second time, and to mark the first backup page to allow deletion of the first backup page after the second time, the page recovery module configured to replace the reference to the first backup page at the portion of the page recovery mapping with a reference to the second backup page.

12. A non-transitory machine-readable storage medium storing code representing instructions to cause a processor to perform a data store page recovery process, the process comprising:

defining a backup page based on a valid page;

storing a reference to the backup page at a page recovery mapping;

storing a reference to an update record associated with the valid page at the page recovery mapping, the reference to the backup page associated with the reference to the update page at the page recovery mapping, the update record comprising a first update record associated with the valid page; and

replacing the reference to the first update record with a reference to a second update record associated with the valid page at the page recovery mapping; and

storing a reference to the first update record at the second update record.

13. The non-transitory machine-readable storage medium of claim 12, the process further comprising:

accessing a plurality of update records from the update record;

applying update record analysis to the plurality of update records; and

modifying the backup page based on the plurality of update records and the update record analysis.

14. The non-transitory machine-readable storage medium of claim 12, the process further comprising:

accessing a first plurality of update records from the update record;

disregarding a second plurality of update records from the first plurality of update records to define a third plurality of update records; and

modifying the backup page according to the third plurality of update records.

15. The non-transitory machine-readable storage medium of claim 12, the process further comprising:

selecting the reference to the backup page and the reference to the update record at the page recovery mapping based on an identifier of the valid page;

accessing the backup page via the reference to the backup page;

accessing the update record via the reference to the update record; and

modifying the backup page according to the update record.

16. The non-transitory machine-readable storage medium of claim 12, the process further comprising:

selecting the reference to the backup page and the reference to the update record at the page recovery mapping based on a page identifier associated with the valid page;

accessing the backup page via the reference to the backup page;

accessing a plurality of update records via the reference to the update record, the plurality of update records including the update record; and

modifying the backup page according to the plurality of update records.