Media distribution to a plurality of devices utilizing buffered dispersed storage

• US 9,215,476 B2
• Filed: 06/17/2013
• Issued: 12/15/2015
• Est. Priority Date: 10/29/2009
• Status: Expired due to Fees

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Cleversafe Incorporated (International Business Machines Corporation)
• Inventors: Gladwin, S. Christopher, Holmes, Alan E., Leggette, Wesley, Resch, Jason K.
• Primary Examiner(s): RABOVIANSKI, JIVKA A
• Application Number:
  US13/919,746
• Publication Number:
  US 20130283326A1
• Time in Patent Office: 911 Days
• Field of Search: 725/28
• 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 a processing module receiving a plurality of playback requests for a stored program, wherein the stored program is stored in a dispersed storage network (DSN) memory as sets of encoded data slices. In response to the playback requests, the method continues with the processing module entering a loop that begins with retrieving a group of sets of encoded data slices, generating copies therefrom, and storing the copies. The loop continues with the processing module sending a unique copy of the copies to a requesting device. The method continues with the processing module existing the loop when the last group of the request has been retrieved and repeating the loop when it has not.

Claims

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

receiving, from a plurality of requesting devices, a plurality of playback requests for a stored program, wherein the stored program is stored in a dispersed storage network (DSN) memory as a plurality of groups of sets of encoded data slices, wherein a group of sets of the plurality of groups of sets of encoded data slices corresponds to a time window of the stored program and a set of encoded data slices of the group of sets of the plurality of groups of sets of encoded data slices corresponds to a data segment of the time window; and

in response to the plurality of playback requests, entering a loop that includes;

retrieving a group of the plurality of groups of sets of encoded data slices from the DSN memory;

generating copies of the group of the plurality of groups of sets of encoded data slices;

storing the copies of the group of the plurality of groups of sets of encoded data slices in a playback DSN memory;

for each of at least some of the plurality of playback requests, sending a unique copy of the copies of the group of the plurality of groups of sets of encoded data slices to one of the plurality of requesting devices;

existing the loop when the group of the plurality of groups of sets of encoded data slices is identified as a last group to be retrieved; and

repeating the loop with another group of the plurality of groups of sets of encoded data slices as the group of the plurality of groups of sets of encoded data slices when the group of the plurality of groups of sets of encoded data slices is not identified as the last group to be retrieved.

2. The method of claim 1, wherein the storing the group of the plurality of groups of sets of encoded data slices further comprises at least one of:

overwriting, in the playback DSN memory, previous copies of a previous group of the plurality of groups of sets of encoded data slices with the copies of the group of the plurality of groups of sets of encoded data slices; and

deleting the previous copies of the previous group of the plurality of groups of sets of encoded data slices from the playback DSN memory.

3. The method of claim 1, wherein the storing the group further comprises:

decoding the group of the plurality of groups of sets of encoded data slices in accordance with an error coding dispersal storage function to produce a recaptured time window of the stored program;

encoding the recaptured time window in accordance with a second error coding dispersal storage function to produce a re-encoded first group; and

storing copies of the re-encoded first group in the playback DSN memory as the copies of the group of the plurality of groups of sets of encoded data slices.

4. The method of claim 1, wherein the sending a unique copy of the copies of the group of the plurality of groups of sets of encoded data slices to one of the plurality of requesting devices comprises:

for the one of the plurality of requesting devices, selecting the unique copy of the copies of the group of the plurality of groups of sets of encoded data slices;

decoding the unique copy of the group of the plurality of groups of sets of encoded data slices in accordance with an error coding dispersal storage function to produce a time window of the stored program; and

outputting the time window of the stored program to the one of the plurality of requesting devices.

5. The method of claim 1 further comprises at least one of:

receiving a pause command from a particular requesting device of the plurality of requesting devices;

pausing processing of the loop for the particular requesting device; and

flagging the group of the plurality of groups of sets of encoded data slices for the particular requesting device to produce a most recent group indicator; and

receiving a play command from the particular requesting device;

resuming the processing of the loop from the most recent group indicator; and

receiving a rewind command from the particular requesting device;

repeating the loop with the other group of the plurality of groups of sets of encoded data slices as the group of the plurality of groups of sets of encoded data slices, wherein the other group of the plurality of groups of sets of encoded data slices is the previous group of the plurality of groups of sets of encoded data slices; and

receiving a fast forward command from the particular requesting device;

repeating the loop with the other group of the plurality of groups of sets of encoded data slices as the group of the plurality of groups of sets of encoded data slices, wherein the other group of the plurality of groups of sets of encoded data slices is a subsequent and not a next sequential time window of the stored program.

6. The method of claim 1 further comprises:

generating a number of copies of the group of the plurality of groups of sets of encoded data slices to correspond to a number of the plurality of playback requests; and

sending one of the number of copies as the unique copy to the one of the plurality of requesting devices.

7. The method of claim 1 further comprises:

generating a limited number of copies of the group of the plurality of groups of sets of encoded data slices that is less than a number of the plurality of playback requests;

selecting a subset of encoded data slices for each of the sets of encoded data slices of one of the limited number of copies of the group of the plurality of groups of sets of encoded data slices as the unique copy; and

sending the unique copy to the one of the plurality of requesting devices.

8. A computer comprises:

an interface; and

a processing module operable to;

receive, via the interface from a plurality of requesting devices, a plurality of playback requests for a stored program, wherein the stored program is stored in a dispersed storage network (DSN) memory as a plurality of groups of sets of encoded data slices, wherein a group of sets of the plurality of groups of sets of encoded data slices corresponds to a time window of the stored program and a set of encoded data slices of the group of sets of the plurality of groups of sets of encoded data slices corresponds to a data segment of the time window; and

in response to the plurality of playback requests, perform a loop that includes;

retrieving, via the interface, a group of the plurality of groups of sets of encoded data slices from the DSN memory;

generating copies of the group of the plurality of groups of sets of encoded data slices;

storing the copies of the group of the plurality of groups of sets of encoded data slices in a playback DSN memory;

for each of at least some of the plurality of playback requests, sending, via the interface, a unique copy of the copies of the group of the plurality of groups of sets of encoded data slices to one of the plurality of requesting devices;

existing the loop when the group of the plurality of groups of sets of encoded data slices is identified as a last group to be retrieved; and

repeating the loop with another group of the plurality of groups of sets of encoded data slices as the group of the plurality of groups of sets of encoded data slices when the group of the plurality of groups of sets of encoded data slices is not identified as the last group to be retrieved.

9. The computer of claim 8, wherein the processing module further functions to store the group of the plurality of groups of sets of encoded data slices by at least one of:

overwriting, in the playback DSN memory, previous copies of a previous group of the plurality of groups of sets of encoded data slices with the copies of the group of the plurality of groups of sets of encoded data slices; and

deleting the previous copies of the previous group of the plurality of groups of sets of encoded data slices from the playback DSN memory.

10. The computer of claim 8, wherein the processing module further functions to store the group by:

decoding the group of the plurality of groups of sets of encoded data slices in accordance with an error coding dispersal storage function to produce a recaptured time window of the stored program;

encoding the recaptured time window in accordance with a second error coding dispersal storage function to produce a re-encoded first group; and

storing, via the interface, copies of the re-encoded first group in the playback DSN memory as the copies of the group of the plurality of groups of sets of encoded data slices.

11. The computer of claim 8, wherein the processing module further functions to send the unique copy of the copies of the group of the plurality of groups of sets of encoded data slices to one of the plurality of requesting devices by:

for the one of the plurality of requesting devices, selecting the unique copy of the copies of the group of the plurality of groups of sets of encoded data slices;

decoding the unique copy of the group of the plurality of groups of sets of encoded data slices in accordance with an error coding dispersal storage function to produce a time window of the stored program; and

outputting the time window of the stored program to the one of the plurality of requesting devices.

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

receive, via the interface, a pause command from a particular requesting device of the plurality of requesting devices;

pausing processing of the loop for the particular requesting device; and

flagging the group of the plurality of groups of sets of encoded data slices for the particular requesting device to produce a most recent group indicator; and

receive, via the interface, a play command from the particular requesting device;

resuming the processing of the loop from the most recent group indicator; and

receive, via the interface, a rewind command from the particular requesting device;

repeating the loop with the other group of the plurality of groups of sets of encoded data slices as the group of the plurality of groups of sets of encoded data slices, wherein the other group of the plurality of groups of sets of encoded data slices is the previous group of the plurality of groups of sets of encoded data slices; and

receive, via the interface, a fast forward command from the particular requesting device;

repeating the loop with the other group of the plurality of groups of sets of encoded data slices as the group of the plurality of groups of sets of encoded data slices, wherein the other group of the plurality of groups of sets of encoded data slices is a subsequent and not a next sequential time window of the stored program.

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

generate a number of copies of the group of the plurality of groups of sets of encoded data slices to correspond to a number of the plurality of playback requests; and

send one of the number of copies as the unique copy to the one of the plurality of requesting devices.

14. The computer of claim 8, wherein the processing module further functions to:

generate a limited number of copies of the group of the plurality of groups of sets of encoded data slices that is less than a number of the plurality of playback requests;

select a subset of encoded data slices for each of the sets of encoded data slices of one of the limited number of copies of the group of the plurality of groups of sets of encoded data slices as the unique copy; and

send the unique copy to the one of the plurality of requesting devices.