Data distribution utilizing unique read parameters in a dispersed storage system

• US 9,049,463 B2
• Filed: 03/03/2014
• Issued: 06/02/2015
• Est. Priority Date: 10/29/2009
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Clevesafe Incorporated
• Inventors: Grube, Gary W., Markison, Timothy W.
• Primary Examiner(s): ABRAHAM, ESAW T
• Application Number:
  US14/194,961
• Publication Number:
  US 20140181619A1
• Time in Patent Office: 456 Days
• Field of Search: 714/763, 714/770
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1008 in individual solid state devices G06F11/1004 takes precedence
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/1092 Rebuilding, e.g. when physically replacing a failing disk
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/15 Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes H03M13/17 takes precedence
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/23 using convolutional codes, e.g. unit memory codes
• CPC Class Codes: H03M 13/356 Unequal error protection [UEP]
• CPC Class Codes: H04N 21/2181 comprising remotely distributed storage units, e.g. when movies are replicated over a plurality of video servers 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: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/2393 involving handling client requests scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/274 Storing end-user multimedia data in response to end-user request , e.g. network recorder
• CPC Class Codes: H04N 21/2747 Remote storage of video programs received via the downstream path, e.g. from the server
• CPC Class Codes: H04N 21/6587 Control parameters, e.g. trick play commands, viewpoint selection

Abstract

A method begins by storing, in response to storage requests, a single encoded copy of broadcast data as a plurality of sets of encoded data slices. The broadcast data is encoded in accordance with an error coding dispersal storage function to produce the plurality of sets of encoded data slices. The method continues by receiving a playback requests for the broadcast data. The method continues for each of the plurality of playback requests by retrieving, based on the error coding dispersal storage function, a unique combination of encoded data slices and sending the unique combination of encoded data slices to a requesting entity corresponding to one of the playback requests.

Claims

1. A memory comprises:

a first memory section that stores operational instructions that, when executed by a computing device, causes the computing device to store a broadcast of data in accordance with an error coding dispersal storage function, wherein the broadcast of data is stored as a plurality of sets of encoded data slices;

a second memory section that stores operational instructions that, when executed by the computing device, causes the computing device to receive a plurality of playback requests for the broadcast of data; and

a third memory section that stores operational instructions that, when executed by the computing device, causes the computing device to;

for a first playback request of the plurality of playback requests;

determine a first unique combination for retrieving the plurality of sets of encoded data slices;

retrieve, as a first unique copy of the broadcast data, encoded data slices of the plurality of sets of encoded data slices in accordance with the first unique combination; and

for a second playback request of the plurality of playback requests;

determine a second unique combination for retrieving the plurality of sets of encoded data slices; and

retrieve, as a second unique copy of the broadcast data, encoded data slices of the plurality of sets of encoded data slices in accordance with the second unique combination.

2. The memory of claim 1, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to:

generate the first unique combination when a storage request is received by a device sending the first playback request; and

store the first unique combination as part of the first unique copy of the broadcast data.

3. The memory of claim 1, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to:

generate the second unique combination when a storage request is received by a device sending the second playback request; and

store the second unique combination as part of the second unique copy of the broadcast data.

4. The memory of claim 1, wherein the broadcast of data comprises at least one of:

a cable television broadcast;

a satellite television broadcast; and

an internet broadcast.

5. The memory of claim 1, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to:

determine the first unique combination by identifying a first set of storage nodes of a plurality of storage nodes, wherein the plurality of storage nodes stores the plurality of sets of encoded data slices and wherein the first set of storage nodes stores, for each of the plurality of sets of encoded data slices, a first combination of a threshold number of encoded data slices; and

determine the second unique combination by identifying a second set of storage nodes of a plurality of storage nodes, wherein the set of storage nodes stores, for each of the plurality of sets of encoded data slices, a second combination of the threshold number of encoded data slices.

6. The memory of claim 1, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to:

determine the first unique combination by determining a first random pattern of a threshold number or more of encoded data slices to retrieve per set of the plurality of sets of encoded data slices; and

determine the second unique combination by determining a second random pattern of the threshold number or more of encoded data slices to retrieve per set of the plurality of sets of encoded data slices.

7. A method for execution by a dispersed storage processing module, the method comprises:

storing, in response to a plurality of storage requests, a single encoded copy of broadcast data as a plurality of sets of encoded data slices, wherein the broadcast data is encoded in accordance with an error coding dispersal storage function to produce the plurality of sets of encoded data slices;

receiving a plurality of playback requests for the broadcast data; and

for each of the plurality of playback requests;

retrieving, based on the error coding dispersal storage function, a unique combination of encoded data slices of the plurality of encoded data slices to produce a unique copy of the broadcast data; and

sending the unique combination of encoded data slices to a requesting entity corresponding to a playback request of the plurality of playback requests.

8. The method of claim 7, wherein the retrieving the unique combination of encoded data slices comprises:

for a first set of encoded data slices of the plurality of sets of encoded data slices, selecting a decode threshold number of first encoded data slices; and

for a second set of encoded data slices of the plurality of sets of encoded data slices, selecting the decode threshold number of second encoded data slices, wherein the first encoded data slices includes at least one encoded data slice that has a different pillar number or is stored by a different storage unit than encoded data slices of the second encoded data slices.

9. The method of claim 7, wherein the retrieving the unique combination of encoded data slices comprises:

for a first set of encoded data slices of the plurality of sets of encoded data slices, selecting a first number of first encoded data slices, wherein the first number is equal to or greater than a decode threshold number; and

for a second set of encoded data slices of the plurality of sets of encoded data slices, selecting a second number of second encoded data slices, wherein the second number is equal to or greater than the decode threshold number and wherein the first number of encoded data slices includes at least one encoded data slice that has a different pillar number or is stored by a different storage unit than encoded data slices of the second number of encoded data slices.

10. The method of claim 7 further comprises:

generating unique combinations when the plurality of storage requests are received by a plurality of devices sending the plurality of playback requests; and

storing one of the unique combinations as part of the unique copy for one of the plurality of devices.

11. A memory comprises:

a first memory section that stores operational instructions that, when executed by a computing device, causes the computing device to store, in response to a plurality of storage requests, a single encoded copy of broadcast data as a plurality of sets of encoded data slices, wherein the broadcast data is encoded in accordance with an error coding dispersal storage function to produce the plurality of sets of encoded data slices;

a second memory section that stores operational instructions that, when executed by the computing device, causes the computing device to receive a plurality of playback requests for the broadcast of data; and

for each of the plurality of playback requests, a third memory section that stores operational instructions that, when executed by the computing device, causes the computing device to;

retrieve, based on the error coding dispersal storage function, a unique combination of encoded data slices of the plurality of encoded data slices to produce a unique copy of the broadcast data; and

send the unique combination of encoded data slices to a requesting entity corresponding to a playback request of the plurality of playback requests.

12. The memory of claim 11, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to retrieve the unique combination of encoded data slices by:

for a first set of encoded data slices of the plurality of sets of encoded data slices, selecting a decode threshold number of first encoded data slices; and

for a second set of encoded data slices of the plurality of sets of encoded data slices, selecting the decode threshold number of second encoded data slices, wherein the first encoded data slices includes at least one encoded data slice that has a different pillar number or is stored by a different storage unit than encoded data slices of the second encoded data slices.

13. The memory of claim 11, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to retrieve the unique combination of encoded data slices by:

for a first set of encoded data slices of the plurality of sets of encoded data slices, selecting a first number of first encoded data slices, wherein the first number is equal to or greater than a decode threshold number; and

for a second set of encoded data slices of the plurality of sets of encoded data slices, selecting a second number of second encoded data slices, wherein the second number is equal to or greater than the decode threshold number and wherein the first number of encoded data slices includes at least one encoded data slice that has a different pillar number or is stored by a different storage unit than encoded data slices of the second number of encoded data slices.

14. The memory of claim 11, wherein the third memory section further stores operational instructions that, when executed by the computing device, causes the computing device to:

generate unique combinations when the plurality of storage requests are received by a plurality of devices sending the plurality of playback requests; and

store one of the unique combinations as part of the unique copy for one of the plurality of devices.