Identifying stored data slices during a slice migration activity in a dispersed storage network

• US 10,430,107 B2
• Filed: 01/13/2017
• Issued: 10/01/2019
• Est. Priority Date: 05/29/2015
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Khadiwala, Ravi V., Motwani, Manish, Resch, Jason K.
• Primary Examiner(s): Schell, Joseph O
• Application Number:
  US15/405,811
• Publication Number:
  US 20170123717A1
• Time in Patent Office: 991 Days
• CPC Class Codes: G06F 11/0727 in a storage system, e.g. in a DASD or network based storage system drivers for digital recording or reproducing units G06F3/06; circuits for error detection or correction within digital recording or reproducing units G11B20/18; for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS], H04L67/1097
• CPC Class Codes: G06F 11/073 in a memory management context, e.g. virtual memory or cache management memory management G06F12/00; testing of static memory units G11C29/00
• CPC Class Codes: G06F 11/0787 Storage of error reports, e.g. persistent data storage, storage using memory protection
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1088 Reconstruction on already foreseen single or plurality of spare disks
• CPC Class Codes: G06F 11/1612 where the redundant component is persistent storage
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 2211/1035 Keeping track, i.e. keeping track of data and parity changes
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0647 Migration 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: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/3761 using code combining, i.e. using combining of codeword portions which may have been transmitted separately, e.g. Digital Fountain codes, Raptor codes or Luby Transform [LT] codes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A method for execution by a dispersed storage and task (DST) execution unit includes obtaining a list slice request. At least one other storage unit affiliated with a DSN address range of the list slice request is identified and at least one proxied list slice request is issued to the at least one other storage unit. At least one received proxied list slice response associated with the list slice request is selected, and a list slice response is issued to the requesting entity based on the at least one selected proxied list slice response and locally stored encoded data slices associated with the list slice request.

Claims

1. A method for execution by a dispersed storage and task (DST) execution unit that includes a processor, the method comprises:

obtaining a first request that includes a slice name range;

identifying at least one storage unit affiliated with the slice name range of the first request;

issuing at least one second request to the at least one storage unit that includes a dispersed storage network (DSN) address range associated with the slice name range;

receiving at least one first response from the at least one storage unit in response to the at least one second request, wherein the at least one first response includes a list of slice names associated with the DSN address range;

selecting at least one selected first response from the at least one first response based on the slice name range of the first request; and

issuing a second response to a requesting entity that includes slice names of a list of slice names included in the at least one selected first response that are associated with the slice name range of the first request, and that further includes slice names of locally stored encoded data slices that are associated with the slice name range of the first request.

2. The method of claim 1, wherein the first request is received from an integrity processing unit via a network.

3. The method of claim 2, wherein the integrity processing unit issues the first request in response to determining that the slice name range of the first request is associated with a first storage unit set involved in an ongoing slice migration activity, and wherein the ongoing slice migration activity includes an ongoing transfer of encoded slices from the first storage unit set to a second storage unit set.

4. The method of claim 3, wherein the ongoing slice migration activity corresponds to a pending change of weighting factors of a decentralized agreement protocol function.

5. The method of claim 3, wherein the at least one storage unit is identified in response to determining that it is associated with the ongoing slice migration activity.

6. The method of claim 1, wherein the at least one storage unit is identified by performing a decentralized agreement protocol on a DSN address indicated in the slice name range of the first request based on pending weighting factors.

7. The method of claim 1, further comprising:

generating the at least one second request including the DSN address range based on at least one of;

the first request or a DSN address range affiliated with pending weighting factors.

8. The method of claim 1, further comprising:

receiving a plurality of first responses that include a plurality of lists of slice names; and

generating a plurality of scores corresponding to the plurality of first responses by performing a decentralized agreement protocol function on the plurality of slice names by utilizing current weighting factors;

wherein the at least one selected first response is selected based on the plurality of scores.

9. The method of claim 8, further comprising:

identifying a highest score of the plurality of scores, wherein the at least one selected first response corresponds to the highest score.

10. The method of claim 1, further comprising:

generating the second response including the slice names of the locally stored encoded data slices and the slice names of the at least one selected first response.

11. A processing system of a dispersed storage and task (DST) execution unit comprises:

at least one processor; and

a memory that stores operational instructions, that when executed by the at least one processor cause the processing system to;

obtain a first request that includes a slice name range;

identify at least one storage unit affiliated with the slice name range of the first request;

issue at least one second request to the at least one storage unit that includes a dispersed storage network (DSN) address range associated with the slice name range;

receive at least one first response from the at least one storage unit in response to the at least one second request, wherein the at least one first response includes a list of slice names associated with the DSN address range;

select at least one selected first response from the at least one first response based on the slice name range of the first request; and

issue a second response to a requesting entity that includes slice names of a list of slice names included in the at least one selected first response that are associated with the slice name range of the first request, and that further includes slice names of locally stored encoded data slices that are associated with the slice name range of the first request.

12. The processing system of claim 11, wherein the first request is received from an integrity processing unit via a network.

13. The processing system of claim 12, wherein the integrity processing unit issues the first request in response to determining that the slice name range of the first request is associated with a first storage unit set involved in an ongoing slice migration activity, and wherein the ongoing slice migration activity includes an ongoing transfer of encoded slices from the first storage unit set to a second storage unit set.

14. The processing system of claim 13, wherein the ongoing slice migration activity corresponds to a pending change of weighting factors of a decentralized agreement protocol function.

15. The processing system of claim 13, wherein the at least one storage unit is identified in response to determining that it is associated with the ongoing slice migration activity.

16. The processing system of claim 11, wherein the at least one storage unit is identified by performing a decentralized agreement protocol on a DSN address indicated in the slice name range of the first request based on pending weighting factors.

17. The processing system of claim 11, wherein the operational instructions, when executed by the at least one processor, further cause the processing system to:

generate the at least one second request including the DSN address range based on at least one of;

the first request or a DSN address range affiliated with pending weighting factors.

18. The processing system of claim 11, wherein the operational instructions, when executed by the at least one processor, further cause the processing system to:

receive a plurality of first responses that include a plurality of lists of slice names; and

generate a plurality of scores corresponding to the plurality of first responses by performing a decentralized agreement protocol function on the plurality of slice names by utilizing current weighting factors;

wherein the at least one selected first response is selected based on the plurality of scores.

19. The processing system of claim 18, wherein the operational instructions, when executed by the at least one processor, further cause the processing system to:

identify a highest score of the plurality of scores, wherein the at least one selected first response corresponds to the highest score.

20. A non-transitory computer readable storage medium comprises:

at least one memory section that stores operational instructions that, when executed by a processing system of a dispersed storage network (DSN) that includes a processor and a memory, causes the processing system to;

obtain a first request that includes a slice name range;

identify at least one storage unit affiliated with the slice name range of the first request;

issue at least one second request to the at least one storage unit that includes a DSN address range associated with the slice name range;

receive at least one first response from the at least one storage unit in response to the at least one second request, wherein the at least one first response includes a list of slice names associated with the DSN address range;

select at least one selected first response from the at least one first response based on the slice name range of the first request; and

issue a second response to a requesting entity that includes slice names of a list of slice names included in the at least one selected first response that are associated with the slice name range of the first request, and that further includes slice names of locally stored encoded data slices that are associated with the slice name range of the first request.