Coordinated retrieval of data from a dispersed storage network

• US 8,892,598 B2
• Filed: 06/07/2011
• Issued: 11/18/2014
• Est. Priority Date: 06/22/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Motwani, Manish
• Primary Examiner(s): Alam, Hosain
• Assistant Examiner(s): JOHNSON, JOHNESE T
• Application Number:
  US13/154,744
• Publication Number:
  US 20110314058A1
• Time in Patent Office: 1,260 Days
• Field of Search: 707/770
• US Class Current: 707/770
• 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 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G06F 11/141 for bus or memory accesses
• CPC Class Codes: G06F 11/167 Error detection by comparing the memory output
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: H04L 2209/043 of tables, e.g. lookup, substitution or mapping
• CPC Class Codes: H04L 2209/30 Compression, e.g. Merkle-Damgard construction
• CPC Class Codes: H04L 2209/34 Encoding or coding, e.g. Huffman coding or error correction
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/0428 wherein the data content is protected, e.g. by encrypting or encapsulating the payload
• CPC Class Codes: H04L 63/06 for supporting key management in a packet data network cryptographic mechanisms or cryptographic arrangements for key management H04L9/08
• CPC Class Codes: H04L 63/12 Applying verification of the received information cryptographic mechanisms or cryptographic arrangements for data integrity or data verification H04L9/32
• 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 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04L 9/3247 : involving digital signatures
• CPC Class Codes: H04L 9/3263 : involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04L 9/3271 : using challenge-response
• CPC Class Codes: H04W 12/041 : Key generation or derivation
• CPC Class Codes: H04W 12/0431 : Key distribution or pre-distribution; Key agreement
• CPC Class Codes: H04W 12/10 : Integrity
• CPC Class Codes: H04W 12/35 : Protecting application or service provisioning, e.g. securing SIM application provisioning

Abstract

A method begins by a processing module determining to retrieve a dispersed error encoded file from a dispersed storage network wherein the dispersed error encoded file is stored as a plurality of sets of encoded data slices. The method continues with the processing module determining whether a neighboring device has a desire to retrieve the dispersed error encoded file and when the neighboring device has a desire to retrieve the dispersed error encoded file, coordinating retrieving of the dispersed error encoded file such that, collectively, the device and the neighboring device receive at least a decode threshold number of encoded data slices of a first set of encoded data slices and at least the decode threshold number of encoded data slices of a second set of encoded data slices.

Claims

1. A method for execution by a user device, the method comprises:

determining, by the user device, to retrieve a dispersed error encoded file from a dispersed storage network (DSN), wherein the dispersed error encoded file is stored as a plurality of sets of encoded data slices and wherein a data segment of the file is encoded into a set of encoded data slices of the plurality of sets of encoded data slices;

determining, by the user device, whether a neighboring user device also has a desire to retrieve the dispersed error encoded file; and

when the neighboring user device has a desire to retrieve the dispersed error encoded file, coordinating, by the user device with the neighboring user device, retrieving of the dispersed error encoded file such that, collectively, the user device and the neighboring user device receive;

at least a decode threshold number of encoded data slices of a first set of encoded data slices; and

at least the decode threshold number of encoded data slices of a second set of encoded data slices; and

coordinating, by the user device with the neighboring user device, exchanging the at least a decode threshold number of encoded data slices of the first and second sets of encoded data slices such that each of the user device and neighboring user device separately dispersed storage error decodes the at least a decode threshold number of encoded data slices of the first and second sets of encoded data to recover first and second data segments of the file.

2. The method of claim 1, wherein the coordinating retrieving of the dispersed error encoded file comprises:

the user device retrieving a first portion of each of the at least the decode threshold number of encoded data slices of the first and second sets of encoded data slices; and

the neighboring user device retrieving a second portion of each of the at least the decode threshold number of encoded data slices of the first and second sets of encoded data slices.

3. The method of claim 1, wherein the coordinating retrieving of the dispersed error encoded file comprises:

the user device retrieving the at least the decode threshold number of encoded data slices of the first set of encoded data slices; and

the neighboring user device retrieving the at least the decode threshold number of encoded data slices of the second set of encoded data slices.

4. The method of claim 1, wherein the coordinating retrieving of the dispersed error encoded file comprises:

the user device retrieving the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices; and

the user device forwarding the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices to the neighboring user device.

5. The method of claim 1 further comprises:

storing the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices.

6. The method of claim 1 further comprises:

transcoding the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices from a first set of dispersed storage error coding parameters to a second set of dispersed storage error coding parameters to produce transcoded sets of encoded data slices; and

storing the transcoded sets of encoded data slices.

7. The method of claim 1, wherein the determining whether a neighboring user device has a desire to retrieve the dispersed error encoded file comprises at least one of:

querying the neighboring user device;

receiving a dispersed error encoded file retrieval request from the neighboring user device;

accessing a neighboring user device preference indicator;

accessing a look up table; and

determining that the neighboring user device is affiliated with a user group of the user device.

8. A user device comprises:

an interface;

a memory; and

a processing module operable to;

determine to retrieve a dispersed error encoded file from a dispersed storage network (DSN), wherein the dispersed error encoded file is stored as a plurality of sets of encoded data slices and wherein a data segment of the file is encoded into a set of encoded data slices of the plurality of sets of encoded data slices;

determine whether a neighboring user device has a desire to retrieve the dispersed error encoded file; and

when the neighboring user device has a desire to retrieve the dispersed error encoded file, coordinate retrieving of the dispersed error encoded file such that, collectively, the user device and the neighboring user device receive;

at least a decode threshold number of encoded data slices of a first set of encoded data slices; and

at least the decode threshold number of encoded data slices of a second set of encoded data slices; and

coordinate, by the user device with the neighboring user device, exchanging the at least a decode threshold number of encoded data slices of the first and second sets of encoded data slices such that each of the user device and neighboring user device separately dispersed storage error decodes the at least a decode threshold number of encoded data slices of the first and second sets of encoded data to recover first and second data segments of the file.

9. The device of claim 8, wherein the processing module further functions to coordinate retrieving of the dispersed error encoded file by:

the user device retrieving, via the interface, a first portion of each of the at least the decode threshold number of encoded data slices of the first and second sets of encoded data slices; and

the neighboring user device retrieving a second portion of each of the at least the decode threshold number of encoded data slices of the first and second sets of encoded data slices.

10. The device of claim 8, wherein the processing module further functions to coordinate retrieving of the dispersed error encoded file by:

the user device retrieving, via the interface, the at least the decode threshold number of encoded data slices of the first set of encoded data slices; and

the neighboring user device retrieving the at least the decode threshold number of encoded data slices of the second set of encoded data slices.

11. The device of claim 8, wherein the processing module further functions to coordinate retrieving of the dispersed error encoded file by:

the user device retrieving, via the interface, the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices; and

the user device forwarding, via the interface, the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices to the neighboring user device.

12. The device of claim 8, wherein the processing module further functions to:

store, in the memory, the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices.

13. The device of claim 8, wherein the processing module further functions to:

transcode the at least the decode threshold number of encoded data slices of the first set and second set of encoded data slices from a first set of dispersed storage error coding parameters to a second set of dispersed storage error coding parameters to produce transcoded sets of encoded data slices; and

storing the transcoded sets of encoded data slices.

14. The device of claim 8, wherein the processing module functions to determine whether a neighboring user device has a desire to retrieve the dispersed error encoded file by at least one of:

querying, via the interface, the neighboring user device;

receiving, via the interface, a dispersed error encoded file retrieval request from the neighboring user device;

accessing a neighboring user device preference indicator;

accessing a look up table; and

determining that the neighboring user device is affiliated with a user group of the user device.