DATA DISTRIBUTION UTILIZING UNIQUE WRITE PARAMETERS IN A DISPERSED STORAGE SYSTEM

• US 20110107181A1
• Filed: 07/23/2010
• Published: 05/05/2011
• Est. Priority Date: 10/29/2009
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Markison, Timothy W., Grube, Gary W.
• Granted Patent: US 8,291,277 B2
• Time in Patent Office: Days
• US Class Current: 714/763
• 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 a processing module receiving a plurality of record requests to record a broadcast of data. The method continues with the processing module encoding the data using an error coding dispersal storage function to produce a plurality of sets of encoded data slices. The method continues with the processing module generating a list of requesting device identities corresponding to the plurality of requests and storing the plurality of sets of encoded data slices and the list of requesting device identities in a dispersed storage network memory. The method continues with the processing module receiving a playback request from a device identified in the list of requesting device identities, generating a unique retrieval matrix for the device, and outputting a unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the unique retrieval matrix.

Claims

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

receiving a plurality of record requests to record a broadcast of data;

encoding the data using an error coding dispersal storage function to produce a plurality of sets of encoded data slices when the data is broadcast and in response to a record request of the plurality of record requests;

generating a list of requesting device identities corresponding to the plurality of requests;

storing the plurality of sets of encoded data slices and the list of requesting device identities in a dispersed storage network (DSN) memory;

receiving a playback request from a device identified in the list of requesting device identities;

generating a unique retrieval matrix for the device based on the error coding dispersed storage function; and

outputting a unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the unique retrieval matrix.

2. The method of claim 1, wherein the unique retrieval matrix comprises:

a collective of pillar identifiers, wherein the collective includes pillar identifiers corresponding to at least one of the plurality of sets of encoded data slices for retrieving corresponding encoded data slices.

3. The method of claim 1, wherein the generating the unique retrieval matrix is further based on at least one of:

a data identifier;

a unique retrieval matrix associated with at least one other requesting device identified in the list of requesting device identities;

a unique retrieval matrix not associated with any other requesting device identified in the list of requesting device identities; and

a unique retrieval matrix functionality indicator.

4. The method of claim 1, wherein the unique retrieval matrix comprises one or more of:

a pillars list;

a segmenting protocol;

a pre-slice data manipulation function;

a forward error correction encoding function;

a slicing pillar width;

a post-slice data manipulation function;

a write threshold; and

a read threshold.

5. The method of claim 4, wherein the pillars list comprises one of:

at least one collective of pillar identifiers associated with less than a slicing pillar width number and at least the read threshold number of a plurality of dispersed storage (DS) units associated with the DSN memory; and

at least one collective of pillar identifiers associated with less than the slicing pillar width number and at least the read threshold number of the plurality of DS units, wherein the at least one collective of pillar identifiers is unique as compared to every other collective of pillar identifiers associated with previously determined unique retrieval matrixes for the same set of the plurality of sets of encoded data slices.

6. The method of claim 1 further comprises:

receiving a second playback request from the device;

generating a second unique retrieval matrix for the device based on the error coding dispersed storage function; and

outputting a second unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the second unique retrieval matrix.

7. The method of claim 1 further comprises:

storing the unique retrieval matrix for the device in the DSN memory;

receiving a subsequent playback request from the device;

retrieving the unique retrieval matrix for the device from the DSN memory; and

outputting the unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the unique retrieval matrix.

8. The method of claim 1 further comprises:

outputting the unique retrieval matrix for the device to the device;

receiving a subsequent playback request from the device, wherein the request includes the unique retrieval matrix for the device; and

outputting the unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the unique retrieval matrix.

9. The method of claim 1 further comprises:

decoding the unique plurality of sets of encoded data slices in accordance with the error coding dispersal storage function to produce a unique copy of the data; and

outputting the unique copy of the data to the device.

10. A computer comprises:

an interface; and

a processing module operable to;

receive, via the interface, a plurality of record requests to record a broadcast of data;

encode the data using an error coding dispersal storage function to produce a plurality of sets of encoded data slices when the data is broadcast and in response to a record request of the plurality of record requests;

generate a list of requesting device identities corresponding to the plurality of requests;

store, via the interface, the plurality of sets of encoded data slices and the list of requesting device identities in a dispersed storage network (DSN) memory;

receive, via the interface, a playback request from a device identified in the list of requesting device identities;

generate a unique retrieval matrix for the device based on the error coding dispersed storage function; and

output, via the interface, a unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the unique retrieval matrix.

11. The computer of claim 10, wherein the unique retrieval matrix comprises:

a collective of pillar identifiers, wherein the collective includes pillar identifiers corresponding to at least one of the plurality of sets of encoded data slices for retrieving corresponding encoded data slices.

12. The computer of claim 10, wherein the processing module further functions to generate the unique retrieval matrix based on at least one of:

a data identifier;

a unique retrieval matrix associated with at least one other requesting device identified in the list of requesting device identities;

a unique retrieval matrix not associated with any other requesting device identified in the list of requesting device identities; and

a unique retrieval matrix functionality indicator.

13. The computer of claim 10, wherein the unique retrieval matrix comprises one or more of:

a pillars list;

a segmenting protocol;

a pre-slice data manipulation function;

a forward error correction encoding function;

a slicing pillar width;

a post-slice data manipulation function;

a write threshold; and

a read threshold.

14. The computer of claim 13, wherein the pillars list comprises one of:

at least one collective of pillar identifiers associated with less than a slicing pillar width number and at least the read threshold number of a plurality of dispersed storage (DS) units associated with the DSN memory; and

at least one collective of pillar identifiers associated with less than the slicing pillar width number and at least the read threshold number of the plurality of DS units, wherein the at least one collective of pillar identifiers is unique as compared to every other collective of pillar identifiers associated with previously determined unique retrieval matrixes for the same set of the plurality of sets of encoded data slices.

15. The computer of claim 10, wherein the processing module further functions to:

receive, via the interface, a second playback request from the device;

generate a second unique retrieval matrix for the device based on the error coding dispersed storage function; and

output, via the interface, a second unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the second unique retrieval matrix.

16. The computer of claim 10, wherein the processing module further functions to:

store, via the interface, the unique retrieval matrix for the device in the DSN memory;

receive, via the interface, a subsequent playback request from the device;

retrieve, via the interface, the unique retrieval matrix for the device from the DSN memory; and

output, via the interface, the unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the unique retrieval matrix.

17. The computer of claim 10, wherein the processing module further functions to:

output, via the interface, the unique retrieval matrix for the device to the device;

receive, via the interface, a subsequent playback request from the device, wherein the request includes the unique retrieval matrix for the device; and

output, via the interface, the unique plurality of sets of encoded data slices from the plurality of sets of encoded data slices in accordance with the unique retrieval matrix.

18. The computer of claim 10, wherein the processing module further functions to:

decode the unique plurality of sets of encoded data slices in accordance with the error coding dispersal storage function to produce a unique copy of the data; and

output, via the interface, the unique copy of the data to the device.