Using vault to track reception of slices

• US 10,157,018 B2
• Filed: 08/26/2016
• Issued: 12/18/2018
• Est. Priority Date: 09/24/2015
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Kazi, Asimuddin, Khadiwala, Ravi V., Resch, Jason K.
• Primary Examiner(s): Alphonse, Fritz
• Application Number:
  US15/248,493
• Publication Number:
  US 20170091035A1
• Time in Patent Office: 844 Days
• Field of Search: 714764, 714767, 714770, 714773
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 3/0611 in relation to response time
• 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 3/064 Management of blocks
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• 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 8/65 Updates security arrangements therefor G06F21/57
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/154 Error and erasure correction, e.g. by using the error and erasure locator or Forney polynomial
• 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 63/061 for key exchange, e.g. in peer-to-peer networks cryptographic mechanisms or cryptographic arrangements for key agreement H04L9/0838
• CPC Class Codes: H04L 67/01 Protocols
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• 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]
• CPC Class Codes: H04L 67/34 involving the movement of software or configuration parameters network booting or remote initial program loading [RIPL] G06F9/4416
• CPC Class Codes: H04L 67/60 Scheduling or organising the servicing of application requests, e.g. requests for application data transmissions using the analysis and optimisation of the required network resources admission control or resource allocation H04L47/70

Abstract

A method for execution by one or more processing modules of one or more computing devices of a dispersed storage network (DSN) begins by detecting, by an access module, a write failure of an encoded data slice to a storage unit of a set of DSN storage units. The method continues when detecting the write failure, by adding by the access module, an error entry to an error list. The method continues by recovering, by an integrity module, the error entry from the error list. The method continues by generating, by the integrity module, a rebuilt encoded data slice for the encoded data slice of the write failure. The method continues by facilitating storage of the rebuilt encoded data slice in the storage unit associated with the write failure.

Claims

1. A method for execution by one or more processing modules of one or more computing devices of a dispersed storage network (DSN), the method comprises:

detecting, by an access module of the one or more processing modules, a write failure of an encoded data slice to a storage unit of a set of DSN storage units;

when detecting the write failure, generating, by the access module, an error entry;

updating, by the access module, an error list to include the error entry;

recovering, by an integrity module of the one or more processing modules, the error entry from the error list;

generating, by the integrity module, a rebuilt encoded data slice for the encoded data slice of the write failure; and

facilitating storage of the rebuilt encoded data slice in the storage unit associated with the write failure.

2. The method of claim 1, wherein detecting the write failure includes the access module dispersed storage error encoding a data object to produce a plurality of sets of encoded data slices, issuing read slice requests to the storage unit of the storage set, and interpreting write slice responses to identify the write failure.

3. The method of claim 1, wherein the error entry list is stored in any of:

a dispersed data structure, a Dispersed Lockless Concurrent Index (DLCI), a queue, or a dedicated storage vault.

4. The method of claim 1, wherein the write failure is detected by any of:

receiving no response from the storage unit within a storage time frame or receiving an unfavorable response from the storage unit.

5. The method of claim 1, wherein the generating the error entry includes the access module generating a new error entry that includes one or more of:

a slice name associated with the write failure, an encoded data slice associated with the write failure, or an identifier of the storage unit.

6. The method of claim 1, wherein the recovering includes:

a dispersed storage error encoding a new entry to produce a set of error entry slices, issuing write slice requests to the set of DSN storage units, where the write slice requests includes the set of error entry slices; and

updating an entry of a dispersed hierarchical index.

7. The method of claim 1, wherein the recovering includes the integrity module issuing read slice requests to the set of DSN storage units, receiving read slice responses that include at least a decode threshold number of the error entry slices, and dispersed storage error decoding the error entry slices to reproduce the error entry.

8. The method of claim 1, wherein the recovering includes the integrity module recovering a corresponding node of a dispersed hierarchical index and extracting the error entry from the recovered corresponding node.

9. The method of claim 1, wherein the generating includes the integrity module identifying the encoded data slice to be rebuilt by:

issuing read slice requests to the set of DSN storage units, receiving read slice responses that includes at least the decode threshold number of encoded data slices of a set of encoded data slices associated with the encoded data slice to be rebuilt, disperse storage error decoding the at least decode threshold number of received encoded data slices to reproduce a data segment, and disperse storage error encoding the reproduced data segment to produce the rebuilt encoded data slice.

10. The method of claim 1, wherein facilitating includes the integrity module issuing a write slice request to the storage unit, where the write slice request includes the rebuilt encoded data slice.

11. The method of claim 1, wherein facilitating further comprises deletion of the error entry from the error list when successfully facilitating the storage of the rebuilt encoded data slice.

12. The method of claim 11, wherein the deletion includes any of:

deleting encoded data slices of the error entry or deleting an entry of a node of a dispersed hierarchical index.

13. A processing unit within a dispersed storage network (DSN) comprises:

an interface;

a local memory; and

a processing module operably coupled to the interface and the local memory, wherein the processing module functions to;

detect, by an access module of the processing module, a write failure of an encoded data slice to a storage unit of a set of DSN storage units;

when detecting the write failure, generate, by the access module, an error entry;

update, by the access module, an error list to include the error entry;

recover, by an integrity module of the processing module, the error entry from the error list;

generate, by the integrity module, a rebuilt encoded data slice for the encoded data slice of the write failure; and

facilitate storage of the rebuilt encoded data slice in the storage unit associated with the write failure.

14. The processing unit of claim 13, wherein detecting the write failure includes the access module dispersed storage error encoding a data object to produce a plurality of sets of encoded data slices, issuing read slice requests to the storage unit of the storage set, and interpreting write slice responses to identify the write failure.

15. The processing unit of claim 13, wherein the generating the error entry includes the access module generating a new entry that includes one or more of:

a slice name associated with the write failure, an encoded data slice associated with the write failure, or an identifier of the storage unit.

16. The processing unit of claim 13, wherein the recovering includes:

a dispersed storage error encoding a new error entry to produce a set of error entry slices, issuing write slice requests to the set of DSN storage units, where the write slice requests includes the set of error entry slices; and

updating an entry of a dispersed hierarchical index.

17. The processing unit of claim 13, wherein the recovering includes the integrity module issuing read slice requests to the set of DSN storage units, receiving read slice responses that include at least a decode threshold number of the error entry slices, and dispersed storage error decoding the error entry slices to reproduce the error entry.

18. The processing unit of claim 13, wherein the recovering includes the integrity module recovering a corresponding node of a dispersed hierarchical index and extracting the error entry from the recovered corresponding node.

19. The processing unit of claim 13, wherein the generating includes the integrity module identifying the encoded data slice to be rebuilt by:

issuing read slice requests to the set of DSN storage units, receiving read slice responses that includes at least the decode threshold number of encoded data slices of a set of encoded data slices associated with the encoded data slice to be rebuilt, disperse storage error decoding the at least decode threshold number of received encoded data slices to reproduce a data segment, and disperse storage error encoding the reproduced data segment to produce the rebuilt encoded data slice.

20. The processing unit of claim 13, wherein the error entry list is stored in any of:

a dispersed data structure, a Dispersed Lockless Concurrent Index (DLCI), a queue, or a dedicated storage vault.