U.S. patent application number 16/108905 was filed with the patent office on 2018-12-20 for establishing an operation execution schedule in a dispersed storage network.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to Bruno H. Cabral, Thomas D. Cocagne, Greg R. Dhuse, Gary W. Grube, Ravi V. Khadiwala, Wesley B. Leggette, Timothy W. Markison, Manish Motwani, Jason K. Resch, Michael C. Storm, Yogesh R. Vedpathak, Ilya Volvovski.
Application Number | 20180365105 16/108905 |
Document ID | / |
Family ID | 64656276 |
Filed Date | 2018-12-20 |
United States Patent
Application |
20180365105 |
Kind Code |
A1 |
Volvovski; Ilya ; et
al. |
December 20, 2018 |
ESTABLISHING AN OPERATION EXECUTION SCHEDULE IN A DISPERSED STORAGE
NETWORK
Abstract
A method for execution by a dispersed storage and task (DST)
execution unit includes identifying a plurality of pending
operations. A resource availability level to support execution of
at least one of the plurality of pending operations is determined,
and a required resource level to execute the at least one of the
plurality of pending operations is determined. A balance factor
between at least two types of the plurality of pending operations
is determined based on the resource availability level and the
required resource level. Determination of required timing of the
execution of the at least one of the plurality of pending
operations is coordinated with at least one other DST execution
unit. An operation execution schedule is updated based on the
required resource levels, the resource availability level, the
balance factor, and the required timing of the execution.
Inventors: |
Volvovski; Ilya; (Chicago,
IL) ; Cabral; Bruno H.; (Chicago, IL) ;
Motwani; Manish; (Chicago, IL) ; Cocagne; Thomas
D.; (Elk Grove Village, IL) ; Markison; Timothy
W.; (Mesa, AZ) ; Grube; Gary W.; (Barrington
Hills, IL) ; Leggette; Wesley B.; (Chicago, IL)
; Resch; Jason K.; (Chicago, IL) ; Storm; Michael
C.; (Palo Alto, CA) ; Dhuse; Greg R.;
(Chicago, IL) ; Vedpathak; Yogesh R.; (Chicago,
IL) ; Khadiwala; Ravi V.; (Bartlett, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
64656276 |
Appl. No.: |
16/108905 |
Filed: |
August 22, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15400767 |
Jan 6, 2017 |
10102069 |
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16108905 |
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14680459 |
Apr 7, 2015 |
9606867 |
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15400767 |
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62008207 |
Jun 5, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 11/0709 20130101;
G06F 11/0727 20130101; G06F 2211/1028 20130101; G06F 3/0635
20130101; H04L 67/325 20130101; G06F 11/1076 20130101; G06F 16/00
20190101; G06F 3/0659 20130101; H04L 67/1097 20130101; G06F 3/067
20130101; G06F 3/061 20130101; G06F 11/0775 20130101; G06F
2211/1004 20130101 |
International
Class: |
G06F 11/10 20060101
G06F011/10; G06F 17/30 20060101 G06F017/30; G06F 11/07 20060101
G06F011/07; H04L 29/08 20060101 H04L029/08 |
Claims
1. A method for execution by a dispersed storage and task (DST)
execution unit that includes a processor, the method comprises:
identifying a plurality of pending operations; determining a
resource availability level to support execution of at least one of
the plurality of pending operations; determining a required
resource level to execute the at least one of the plurality of
pending operations; determining a balance factor between at least
two types of the plurality of pending operations based on the
resource availability level and the required resource level;
coordinating determination of required timing of the execution of
the at least one of the plurality of pending operations with at
least one other DST execution unit; and updating an operation
execution schedule based on the required resource levels, the
resource availability level, the balance factor, and the required
timing of the execution.
2. The method of claim 1, wherein a data segment was dispersed
storage error encoded to produce a set of encoded data slices
stored in a set of DST execution units that includes the DST
execution unit, and wherein the at least one of the plurality of
pending operations includes at least one of: rebuilding at least
one of the set of encoded data slices or migrating at least one of
the set of encoded data slices.
3. The method of claim 1, wherein the at least two types of the
plurality of pending operations includes a maintenance type and a
non-maintenance type, and wherein the at least one of the plurality
of pending operations correspond to the maintenance type.
4. The method of claim 3, wherein the plurality of pending
operations includes a set of non-maintenance operations
corresponding to the non-maintenance type, further comprising:
estimating a second required resource level to execute the set of
non-maintenance operations; wherein the balance factor is further
determined based on second required resource level.
5. The method of claim 4, wherein the balance factor is further
determined based on a number a set of the plurality of pending
operations corresponding to the maintenance type, wherein the
balance factor indicates a first proportion of available resources
be allocated to pending operations corresponding to the maintenance
type when the number corresponds to a first value, wherein the
balance factor indicates a second proportion of available resources
be allocated to pending operations corresponding to the maintenance
type when the number corresponds to a second value, and wherein the
first proportion is larger than the second proportion as a result
of the first value being greater than the second value.
6. The method of claim 4, wherein the balance factor is further
determined based on a set of priority levels corresponding to the
set of non-maintenance operations, and is further determined based
at least one priority level corresponding to the at least one of
the plurality of pending operations corresponding to the
maintenance type.
7. The method of claim 6, wherein the balance factor indicates a
first proportion of available resources be allocated to pending
operations of the non-maintenance type when a first average
priority level of the set of priority levels is determined, wherein
the balance factor indicates a second proportion of available
resources be allocated to pending operations of the non-maintenance
type when a second overall priority level of the set of priority
levels is determined, and wherein the first proportion is larger
than the second proportion as a result of the first average
priority level indicating a higher priority than the second overall
priority level.
8. The method of claim 1, wherein the resource availability level
is determined for a future timeframe.
9. The method of claim 1, further comprising receiving resource
allocation information from the at least one other DST execution
unit, wherein the resource allocation information corresponds to
resources of the at least one other DST execution unit, and wherein
the resource availability level is determined based on the resource
allocation information.
10. The method of claim 9, wherein the resource allocation
information includes a current operation execution schedule of the
at least one other DST execution unit, a list of pending operations
of the at least one other DST execution unit, and an estimate of
required resources associated with execution of the plurality of
pending operations of the at least one other DST execution
unit.
11. The method of claim 1, wherein coordinating determination of
required timing of the execution of the at least one of the
plurality of pending operations with at least one other DST
execution unit includes: determining proposed required timing for
the at least one of the plurality of pending operations based on
the resource availability level, the required resource level, and
the balance factor; transmitting the proposed required timing to
the at least one other DST execution unit; and receiving an updated
proposed required timing from the at least one other DST execution
unit that is different from the proposed required timing, wherein
the required timing of the execution is determined to reflect the
updated proposed required timing.
12. The method of claim 1, wherein the at least one of the
plurality of pending operations includes execution of a partial
task of a common task, wherein the common task includes additional
partial tasks for execution by the at least one other DST execution
unit, and wherein coordinating determination of required timing of
the execution includes coordinating execution of the partial task
by the DST execution unit and execution of the additional partial
tasks by the at least one other DST execution unit within a fixed
timeframe.
13. The method of claim 1, further comprising: receiving a request
for second resource allocation information from the at least one
other DST execution unit, wherein the request indicates a future
timeframe; generating second resource allocation information based
on the operation execution schedule and the future timeframe;
transmitting second resource allocation information to the at least
one other DST execution unit, wherein the at least one other DST
execution unit updates their own operation execution schedule based
on the second resource allocation information.
14. A processing system of a dispersed storage and task (DST)
execution unit comprises: at least one processor; a memory that
stores operational instructions, that when executed by the at least
one processor cause the processing system to: identify a plurality
of pending operations; determine a resource availability level to
support execution of at least one of the plurality of pending
operations; determine a required resource level to execute the at
least one of the plurality of pending operations; determine a
balance factor between at least two types of the plurality of
pending operations based on the resource availability level and the
required resource level; coordinate determination of required
timing of the execution of the at least one of the plurality of
pending operations with at least one other DST execution unit; and
update an operation execution schedule based on the required
resource levels, the resource availability level, the balance
factor, and the required timing of the execution.
15. The processing system of claim 14, wherein a data segment was
dispersed storage error encoded to produce a set of encoded data
slices stored in a set of DST execution units that includes the DST
execution unit, and wherein the at least one of the plurality of
pending operations includes at least one of: rebuilding at least
one of the set of encoded data slices or migrating at least one of
the set of encoded data slices.
16. The processing system of claim 14, wherein the at least two
types of pending operations includes a maintenance type and a
non-maintenance type, and wherein the at least one of the plurality
of pending operations correspond to the maintenance type.
17. The processing system of claim 14, further comprising receiving
resource allocation information from the at least one other DST
execution unit, wherein the resource allocation information
corresponds to resources of the at least one other DST execution
unit, and wherein the resource availability level is determined
based on the resource allocation information.
18. The processing system of claim 14, wherein coordinating
determination of required timing of the execution of the at least
one of the plurality of pending operations with at least one other
DST execution unit includes: determining proposed required timing
for the at least one of the plurality of pending operations based
on the resource availability level, the required resource level,
and the balance factor; transmitting the proposed required timing
to the at least one other DST execution unit; and receiving an
updated proposed required timing from the at least one other DST
execution unit that is different from the proposed required timing,
wherein the required timing of the execution is determined to
reflect the updated proposed required timing.
19. The processing system of claim 14, wherein the at least one of
the plurality of pending operations includes execution of a partial
task of a common task, wherein the common task includes additional
partial tasks for execution by the at least one other DST execution
unit, and wherein coordinating determination of required timing of
the execution includes coordinating execution of the partial task
by the DST execution unit and execution of the additional partial
tasks by the at least one other DST execution unit within a fixed
timeframe.
20. A computer readable storage medium comprises: at least one
memory section that stores operational instructions that, when
executed by a processing system of a dispersed storage network
(DSN) that includes a processor and a memory, causes the processing
system to: identify a plurality of pending operations; determine a
resource availability level to support execution of at least one of
the plurality of pending operations; determine a required resource
level to execute the at least one of the plurality of pending
operations; determine a balance factor between at least two types
of the plurality of pending operations based on the resource
availability level and the required resource level; coordinate
determination of required timing of the execution of the at least
one of the plurality of pending operations with at least one other
DST execution unit; and update an operation execution schedule
based on the required resource levels, the resource availability
level, the balance factor, and the required timing of the
execution.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present U.S. Utility patent application claims priority
pursuant to 35 U.S.C. .sctn. 120 as a continuation-in-part of U.S.
Utility application Ser. No. 15/400,767, entitled "MAINTAINING DATA
STORAGE IN ACCORDANCE WITH AN ACCESS METRIC", filed Jan. 6, 2017,
which is a continuation of U.S. Utility application Ser. No.
14/680,459, entitled "MAINTAINING DATA STORAGE IN ACCORDANCE WITH
AN ACCESS METRIC", filed Apr. 7, 2015, issued as U.S. Pat. No.
9,606,867 on Mar. 28, 2017, which claims priority pursuant to 35
U.S.C. .sctn. 119(e) to U.S. Provisional Application No.
62/008,207, entitled "PRIORITIZING TASKS IN A STORAGE UNIT", filed
Jun. 5, 2014, all of which are hereby incorporated herein by
reference in their entirety and made part of the present U.S.
Utility patent application for all purposes.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0003] Not applicable.
BACKGROUND OF THE INVENTION
Technical Field of the Invention
[0004] This invention relates generally to computer networks and
more particularly to dispersing error encoded data.
Description of Related Art
[0005] Computing devices are known to communicate data, process
data, and/or store data. Such computing devices range from wireless
smart phones, laptops, tablets, personal computers (PC), work
stations, and video game devices, to data centers that support
millions of web searches, stock trades, or on-line purchases every
day. In general, a computing device includes a central processing
unit (CPU), a memory system, user input/output interfaces,
peripheral device interfaces, and an interconnecting bus
structure.
[0006] As is further known, a computer may effectively extend its
CPU by using "cloud computing" to perform one or more computing
functions (e.g., a service, an application, an algorithm, an
arithmetic logic function, etc.) on behalf of the computer.
Further, for large services, applications, and/or functions, cloud
computing may be performed by multiple cloud computing resources in
a distributed manner to improve the response time for completion of
the service, application, and/or function. For example, Hadoop is
an open source software framework that supports distributed
applications enabling application execution by thousands of
computers.
[0007] In addition to cloud computing, a computer may use "cloud
storage" as part of its memory system. As is known, cloud storage
enables a user, via its computer, to store files, applications,
etc. on an Internet storage system. The Internet storage system may
include a RAID (redundant array of independent disks) system and/or
a dispersed storage system that uses an error correction scheme to
encode data for storage.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0008] FIG. 1 is a schematic block diagram of an embodiment of a
dispersed or distributed storage network (DSN) in accordance with
the present invention;
[0009] FIG. 2 is a schematic block diagram of an embodiment of a
computing core in accordance with the present invention;
[0010] FIG. 3 is a schematic block diagram of an example of
dispersed storage error encoding of data in accordance with the
present invention;
[0011] FIG. 4 is a schematic block diagram of a generic example of
an error encoding function in accordance with the present
invention;
[0012] FIG. 5 is a schematic block diagram of a specific example of
an error encoding function in accordance with the present
invention;
[0013] FIG. 6 is a schematic block diagram of an example of a slice
name of an encoded data slice (EDS) in accordance with the present
invention;
[0014] FIG. 7 is a schematic block diagram of an example of
dispersed storage error decoding of data in accordance with the
present invention;
[0015] FIG. 8 is a schematic block diagram of a generic example of
an error decoding function in accordance with the present
invention;
[0016] FIG. 9 is a schematic block diagram of an embodiment of a
dispersed or distributed storage network (DSN) in accordance with
the present invention; and
[0017] FIG. 10 is a logic diagram of an example of a method of
establishing an operation execution schedule in accordance with the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] FIG. 1 is a schematic block diagram of an embodiment of a
dispersed, or distributed, storage network (DSN) 10 that includes a
plurality of computing devices 12-16, a managing unit 18, an
integrity processing unit 20, and a DSN memory 22. The components
of the DSN 10 are coupled to a network 24, which may include one or
more wireless and/or wire lined communication systems; one or more
non-public intranet systems and/or public internet systems; and/or
one or more local area networks (LAN) and/or wide area networks
(WAN).
[0019] The DSN memory 22 includes a plurality of storage units 36
that may be located at geographically different sites (e.g., one in
Chicago, one in Milwaukee, etc.), at a common site, or a
combination thereof. For example, if the DSN memory 22 includes
eight storage units 36, each storage unit is located at a different
site. As another example, if the DSN memory 22 includes eight
storage units 36, all eight storage units are located at the same
site. As yet another example, if the DSN memory 22 includes eight
storage units 36, a first pair of storage units are at a first
common site, a second pair of storage units are at a second common
site, a third pair of storage units are at a third common site, and
a fourth pair of storage units are at a fourth common site. Note
that a DSN memory 22 may include more or less than eight storage
units 36. Further note that each storage unit 36 includes a
computing core (as shown in FIG. 2, or components thereof) and a
plurality of memory devices for storing dispersed error encoded
data.
[0020] In various embodiments, each of the storage units operates
as a distributed storage and task (DST) execution unit, and is
operable to store dispersed error encoded data and/or to execute,
in a distributed manner, one or more tasks on data. The tasks may
be a simple function (e.g., a mathematical function, a logic
function, an identify function, a find function, a search engine
function, a replace function, etc.), a complex function (e.g.,
compression, human and/or computer language translation,
text-to-voice conversion, voice-to-text conversion, etc.), multiple
simple and/or complex functions, one or more algorithms, one or
more applications, etc. Hereafter, a storage unit may be
interchangeably referred to as a dispersed storage and task (DST)
execution unit and a set of storage units may be interchangeably
referred to as a set of DST execution units.
[0021] Each of the computing devices 12-16, the managing unit 18,
and the integrity processing unit 20 include a computing core 26,
which includes network interfaces 30-33. Computing devices 12-16
may each be a portable computing device and/or a fixed computing
device. A portable computing device may be a social networking
device, a gaming device, a cell phone, a smart phone, a digital
assistant, a digital music player, a digital video player, a laptop
computer, a handheld computer, a tablet, a video game controller,
and/or any other portable device that includes a computing core. A
fixed computing device may be a computer (PC), a computer server, a
cable set-top box, a satellite receiver, a television set, a
printer, a fax machine, home entertainment equipment, a video game
console, and/or any type of home or office computing equipment.
Note that each managing unit 18 and the integrity processing unit
20 may be separate computing devices, may be a common computing
device, and/or may be integrated into one or more of the computing
devices 12-16 and/or into one or more of the storage units 36. In
various embodiments, computing devices 12-16 can include user
devices and/or can be utilized by a requesting entity generating
access requests, which can include requests to read or write data
to storage units in the DSN.
[0022] Each interface 30, 32, and 33 includes software and hardware
to support one or more communication links via the network 24
indirectly and/or directly. For example, interface 30 supports a
communication link (e.g., wired, wireless, direct, via a LAN, via
the network 24, etc.) between computing devices 14 and 16. As
another example, interface 32 supports communication links (e.g., a
wired connection, a wireless connection, a LAN connection, and/or
any other type of connection to/from the network 24) between
computing devices 12 & 16 and the DSN memory 22. As yet another
example, interface 33 supports a communication link for each of the
managing unit 18 and the integrity processing unit 20 to the
network 24.
[0023] Computing devices 12 and 16 include a dispersed storage (DS)
client module 34, which enables the computing device to dispersed
storage error encode and decode data as subsequently described with
reference to one or more of FIGS. 3-8. In this example embodiment,
computing device 16 functions as a dispersed storage processing
agent for computing device 14. In this role, computing device 16
dispersed storage error encodes and decodes data on behalf of
computing device 14. With the use of dispersed storage error
encoding and decoding, the DSN 10 is tolerant of a significant
number of storage unit failures (the number of failures is based on
parameters of the dispersed storage error encoding function)
without loss of data and without the need for a redundant or backup
copies of the data. Further, the DSN 10 stores data for an
indefinite period of time without data loss and in a secure manner
(e.g., the system is very resistant to unauthorized attempts at
accessing the data).
[0024] In operation, the managing unit 18 performs DS management
services. For example, the managing unit 18 establishes distributed
data storage parameters (e.g., vault creation, distributed storage
parameters, security parameters, billing information, user profile
information, etc.) for computing devices 12-14 individually or as
part of a group of user devices. As a specific example, the
managing unit 18 coordinates creation of a vault (e.g., a virtual
memory block associated with a portion of an overall namespace of
the DSN) within the DSN memory 22 for a user device, a group of
devices, or for public access and establishes per vault dispersed
storage (DS) error encoding parameters for a vault. The managing
unit 18 facilitates storage of DS error encoding parameters for
each vault by updating registry information of the DSN 10, where
the registry information may be stored in the DSN memory 22, a
computing device 12-16, the managing unit 18, and/or the integrity
processing unit 20.
[0025] The DSN managing unit 18 creates and stores user profile
information (e.g., an access control list (ACL)) in local memory
and/or within memory of the DSN memory 22. The user profile
information includes authentication information, permissions,
and/or the security parameters. The security parameters may include
encryption/decryption scheme, one or more encryption keys, key
generation scheme, and/or data encoding/decoding scheme.
[0026] The DSN managing unit 18 creates billing information for a
particular user, a user group, a vault access, public vault access,
etc. For instance, the DSN managing unit 18 tracks the number of
times a user accesses a non-public vault and/or public vaults,
which can be used to generate a per-access billing information. In
another instance, the DSN managing unit 18 tracks the amount of
data stored and/or retrieved by a user device and/or a user group,
which can be used to generate a per-data-amount billing
information.
[0027] As another example, the managing unit 18 performs network
operations, network administration, and/or network maintenance.
Network operations includes authenticating user data allocation
requests (e.g., read and/or write requests), managing creation of
vaults, establishing authentication credentials for user devices,
adding/deleting components (e.g., user devices, storage units,
and/or computing devices with a DS client module 34) to/from the
DSN 10, and/or establishing authentication credentials for the
storage units 36. Network administration includes monitoring
devices and/or units for failures, maintaining vault information,
determining device and/or unit activation status, determining
device and/or unit loading, and/or determining any other system
level operation that affects the performance level of the DSN 10.
Network maintenance includes facilitating replacing, upgrading,
repairing, and/or expanding a device and/or unit of the DSN 10.
[0028] The integrity processing unit 20 performs rebuilding of
`bad` or missing encoded data slices. At a high level, the
integrity processing unit 20 performs rebuilding by periodically
attempting to retrieve/list encoded data slices, and/or slice names
of the encoded data slices, from the DSN memory 22. For retrieved
encoded slices, they are checked for errors due to data corruption,
outdated version, etc. If a slice includes an error, it is flagged
as a `bad` slice. For encoded data slices that were not received
and/or not listed, they are flagged as missing slices. Bad and/or
missing slices are subsequently rebuilt using other retrieved
encoded data slices that are deemed to be good slices to produce
rebuilt slices. The rebuilt slices are stored in the DSN memory
22.
[0029] FIG. 2 is a schematic block diagram of an embodiment of a
computing core 26 that includes a processing module 50, a memory
controller 52, main memory 54, a video graphics processing unit 55,
an input/output (TO) controller 56, a peripheral component
interconnect (PCI) interface 58, an IO interface module 60, at
least one IO device interface module 62, a read only memory (ROM)
basic input output system (BIOS) 64, and one or more memory
interface modules. The one or more memory interface module(s)
includes one or more of a universal serial bus (USB) interface
module 66, a host bus adapter (HBA) interface module 68, a network
interface module 70, a flash interface module 72, a hard drive
interface module 74, and a DSN interface module 76.
[0030] The DSN interface module 76 functions to mimic a
conventional operating system (OS) file system interface (e.g.,
network file system (NFS), flash file system (FFS), disk file
system (DFS), file transfer protocol (FTP), web-based distributed
authoring and versioning (WebDAV), etc.) and/or a block memory
interface (e.g., small computer system interface (SCSI), internet
small computer system interface (iSCSI), etc.). The DSN interface
module 76 and/or the network interface module 70 may function as
one or more of the interface 30-33 of FIG. 1. Note that the IO
device interface module 62 and/or the memory interface modules
66-76 may be collectively or individually referred to as IO
ports.
[0031] FIG. 3 is a schematic block diagram of an example of
dispersed storage error encoding of data. When a computing device
12 or 16 has data to store it disperse storage error encodes the
data in accordance with a dispersed storage error encoding process
based on dispersed storage error encoding parameters. Here, the
computing device stores data object 40, which can include a file
(e.g., text, video, audio, etc.), or other data arrangement. The
dispersed storage error encoding parameters include an encoding
function (e.g., information dispersal algorithm (IDA),
Reed-Solomon, Cauchy Reed-Solomon, systematic encoding,
non-systematic encoding, on-line codes, etc.), a data segmenting
protocol (e.g., data segment size, fixed, variable, etc.), and per
data segment encoding values. The per data segment encoding values
include a total, or pillar width, number (T) of encoded data slices
per encoding of a data segment i.e., in a set of encoded data
slices); a decode threshold number (D) of encoded data slices of a
set of encoded data slices that are needed to recover the data
segment; a read threshold number (R) of encoded data slices to
indicate a number of encoded data slices per set to be read from
storage for decoding of the data segment; and/or a write threshold
number (W) to indicate a number of encoded data slices per set that
must be accurately stored before the encoded data segment is deemed
to have been properly stored. The dispersed storage error encoding
parameters may further include slicing information (e.g., the
number of encoded data slices that will be created for each data
segment) and/or slice security information (e.g., per encoded data
slice encryption, compression, integrity checksum, etc.).
[0032] In the present example, Cauchy Reed-Solomon has been
selected as the encoding function (a generic example is shown in
FIG. 4 and a specific example is shown in FIG. 5); the data
segmenting protocol is to divide the data object into fixed sized
data segments; and the per data segment encoding values include: a
pillar width of 5, a decode threshold of 3, a read threshold of 4,
and a write threshold of 4. In accordance with the data segmenting
protocol, the computing device 12 or 16 divides data object 40 into
a plurality of fixed sized data segments (e.g., 1 through Y of a
fixed size in range of Kilo-bytes to Tera-bytes or more). The
number of data segments created is dependent of the size of the
data and the data segmenting protocol.
[0033] The computing device 12 or 16 then disperse storage error
encodes a data segment using the selected encoding function (e.g.,
Cauchy Reed-Solomon) to produce a set of encoded data slices. FIG.
4 illustrates a generic Cauchy Reed-Solomon encoding function,
which includes an encoding matrix (EM), a data matrix (DM), and a
coded matrix (CM). The size of the encoding matrix (EM) is
dependent on the pillar width number (T) and the decode threshold
number (D) of selected per data segment encoding values. To produce
the data matrix (DM), the data segment is divided into a plurality
of data blocks and the data blocks are arranged into D number of
rows with Z data blocks per row. Note that Z is a function of the
number of data blocks created from the data segment and the decode
threshold number (D). The coded matrix is produced by matrix
multiplying the data matrix by the encoding matrix.
[0034] FIG. 5 illustrates a specific example of Cauchy Reed-Solomon
encoding with a pillar number (T) of five and decode threshold
number of three. In this example, a first data segment is divided
into twelve data blocks (D1-D12). The coded matrix includes five
rows of coded data blocks, where the first row of X11-X14
corresponds to a first encoded data slice (EDS 1_1), the second row
of X21-X24 corresponds to a second encoded data slice (EDS 2_1),
the third row of X31-X34 corresponds to a third encoded data slice
(EDS 3_1), the fourth row of X41-X44 corresponds to a fourth
encoded data slice (EDS 4_1), and the fifth row of X51-X54
corresponds to a fifth encoded data slice (EDS 5_1). Note that the
second number of the EDS designation corresponds to the data
segment number.
[0035] Returning to the discussion of FIG. 3, the computing device
also creates a slice name (SN) for each encoded data slice (EDS) in
the set of encoded data slices. A typical format for a slice name
80 is shown in FIG. 6. As shown, the slice name (SN) 80 includes a
pillar number of the encoded data slice (e.g., one of 1-T), a data
segment number (e.g., one of 1-Y), a vault identifier (ID), a data
object identifier (ID), and may further include revision level
information of the encoded data slices. The slice name functions
as, at least part of, a DSN address for the encoded data slice for
storage and retrieval from the DSN memory 22.
[0036] As a result of encoding, the computing device 12 or 16
produces a plurality of sets of encoded data slices, which are
provided with their respective slice names to the storage units for
storage. As shown, the first set of encoded data slices includes
EDS 1_1 through EDS 5_1 and the first set of slice names includes
SN 1_1 through SN 5_1 and the last set of encoded data slices
includes EDS 1_Y through EDS 5_Y and the last set of slice names
includes SN 1_Y through SN 5_Y.
[0037] FIG. 7 is a schematic block diagram of an example of
dispersed storage error decoding of a data object that was
dispersed storage error encoded and stored in the example of FIG.
4. In this example, the computing device 12 or 16 retrieves from
the storage units at least the decode threshold number of encoded
data slices per data segment. As a specific example, the computing
device retrieves a read threshold number of encoded data
slices.
[0038] To recover a data segment from a decode threshold number of
encoded data slices, the computing device uses a decoding function
as shown in FIG. 8. As shown, the decoding function is essentially
an inverse of the encoding function of FIG. 4. The coded matrix
includes a decode threshold number of rows (e.g., three in this
example) and the decoding matrix in an inversion of the encoding
matrix that includes the corresponding rows of the coded matrix.
For example, if the coded matrix includes rows 1, 2, and 4, the
encoding matrix is reduced to rows 1, 2, and 4, and then inverted
to produce the decoding matrix.
[0039] FIG. 9 is a schematic block diagram of an embodiment of a
dispersed storage network (DSN) that includes a set of distributed
storage and task (DST) execution units 1-n and the network 24 of
FIG. 1. Alternatively, the DSN may include any number of DST
execution units. Each DST execution unit may be implemented
utilizing the storage unit 36 of FIG. 1. Each DST execution unit
includes a processing module 84, memory 88, a DST client module 34
of FIG. 1, and/or a distributed task (DT) execution module 90. The
processing module 84, the memory 88, and/or the DT execution module
90 can be implemented, for example, by utilizing the computing core
26 of FIG. 2. One or more portions of the memory 88 can be utilized
for storage of a maintenance queue 350, a non-maintenance queue
352, and encoded data slices 354. For example, one or more of the
encoded data slices 354 can be generated by performing a dispersed
storage error encoding function on a data segment of a data object
as discussed in conjunction with FIGS. 3-6. The DSN functions to
establish an operation execution schedule for instructions for
execution by the set of DST execution units. In particular, DST
execution units can achieve this by pre-allocating resources in
advance of an expensive operation.
[0040] There are many examples of operations in a DSN memory that
are resource intensive. Such resource intensive operations include,
for example, rebuilding, migration, transferring foster slices, and
placing local redundancy. In each of these examples, at least two
parties, such as two storage units, are involved. Often, such
operations can be deferred to times of otherwise lessened activity,
but since these examples involve multiple parties some negotiation
is required to determine a time that is adequate for all of the
involved parties. For this purpose, storage units may schedule and
make appointments for these "maintenance type" operations, well
into advance of the time they are first requested. For example, if
a storage unit budgets 5% of its resources for such maintenance
tasks, then any other entity which wishes to use some of its
resources for maintenance tasks must indicate the number of
expected resources required. The responding storage unit can then
compute how long it will take given its resource budget, and can
choose at least one time to schedule the operation. In the
meantime, other scheduled operations can be completed. If a storage
unit finds that its schedule ends up extending too far into the
future, it can decide to allocate a larger fraction of its
resources for servicing maintenance tasks, e.g. 10% instead of 5%.
Storage units may report their schedules and allocations of
resources as a general measure of health and how on top of tasks
they are.
[0041] In an example of operation, the processing module 84 of each
DST execution unit can identify at least one pending maintenance
operation. Such maintenance operations can include rebuilding
encoded data slices associated with storage errors, migrating
encoded data slices, transferring encoded data slices, copying
encoded data slices, and/or the DST client module 34 encoding
encoded data slices to produce local redundancy slices. The
identifying can include accessing the maintenance queue 350 of the
memory 88, where the maintenance queue 350 includes instructions
for execution associated with the maintenance operations.
[0042] Having identified the pending maintenance operations, the
processing module 84 can identify pending non-maintenance
operations. Such non-maintenance operations includes one or more of
storing encoded data slices, retrieving encoded data slices, and
the DT execution module 90 executing the partial tasks to produce
partial results. The identifying can include accessing the
non-maintenance queue 352 of the memory 88, where the
non-maintenance queue 352 includes instructions for execution
associated with the non-maintenance operations.
[0043] Having identified the pending non-maintenance operations,
for a future timeframe, the processing module 84 can determine a
resource availability level to support execution of at least some
of the pending maintenance and non-maintenance operations. For
example, the processing module obtains, via the network 24,
resource allocation information 356 from two or more of the DST
execution units of the set of DST execution units. The resource
allocation information 356 can include one or more of available
resources, a current operation execution schedule, a list of
pending operations, and/or an estimate of required resources
associated with execution of the pending operations.
[0044] Having determined the resource availability level, the
processing module 84 can estimate a required resource level to
execute at least some of the pending maintenance operations. For
example, the processing module can estimate the required resource
level for each type of pending operation based on one or more of
historical execution records, an operation type, a
predetermination, performing a test, and interpreting test results.
Having estimated the required resource level to execute the at
least some of the pending maintenance operations, the processing
module 84 estimates a required resource level to execute at least
some of the pending non-maintenance operations.
[0045] Having estimated the required resource levels, the
processing module 84 can determine a balance factor to balance
utilization of resources between the execution of pending
maintenance operations and pending non-maintenance operations. The
determining can be based on one or more of historical operation
execution records, a priority level for the pending non-maintenance
operations, and a number of pending maintenance operations. For
example, the processing module 84 allocates a portion of an overall
resource (e.g., time, number of modules) budget to execution of
instructions associated with the maintenance queue in the
non-maintenance queue. For instance, the processing module 84
allocates 15% of available resources for maintenance operations and
a remaining 85% of available resources for non-maintenance
operations.
[0046] Having determined the balance factor, the processing module
84 can coordinate determination of required timing of pending
operation execution with one or more other DST execution units of
the set of DST execution units. For example, the processing module
84 coordinates producing of partial results for a common partial
task substantially the same time. As another example, the
processing module 84 coordinates retrieval of the set of encoded
data slices 354 at substantially the same time. As another example,
the processing module 84 coordinates scheduling of the time frames
with other DST execution units of a set of DST execution units that
includes the DST execution unit to provide favorable coordinated
execution of associated operations across the set of DST execution
units. As yet another example, the processing module 84 coordinates
scanning of the common DSN address range for storage errors by
certain timeframe. Having coordinated the required timing, the
processing module 84 updates an operation execution schedule based
on one or more of the resource availability level, the required
resource levels, the balance factor, and the required timing. For
example, the processing module 84 coordinates with the at least one
other DST execution unit to arrive at substantially similar time
frames for initiation of execution of pending operations.
[0047] FIG. 10 is a flowchart illustrating an example of
establishing an operation execution schedule in accordance the
present invention. In particular, a method is presented for use in
association with one or more functions and features described in
conjunction with FIGS. 1-9, for execution by a dispersed storage
and task (DST) execution unit that includes a processor or via
processing module 84 or another processing system of a dispersed
storage network that includes at least one processor and memory
that stores instruction that configure the processor or processors
to perform the steps described below.
[0048] The method begins or continues at step 358 where a
processing module (e.g., of a distributed storage and task (DST)
execution unit) identifies a plurality of pending operations. The
identifying includes at least one of receiving an operation
request, interpreting a list of pending operations, and searching
for pending operations. The identifying may further include
identifying a type of pending operation, e.g., maintenance, and
non-maintenance.
[0049] The method continues at step 360, which includes determining
a resource availability level, or a plurality of resource
availability levels, to support execution of at least one of the
plurality of pending operations. This can include, for example,
identifying resources, interpreting an operation execution schedule
associated with the identified resources, determining an execution
capacity level for an identified resource, and/or measuring a
loading level of an identified resource. The resource availability
level can be determined for a future timeframe, for example,
determined by the processing module. The step continues at 362,
which includes determining a required resource level, or a
plurality of required resource levels, to execute at least one of
the plurality of pending operations. This can include, for example,
determining an estimate for each type of pending operation and/or
determining an estimate based on one or more of historical
execution records, an operation type, a predetermination, and/or
performing a test. In some embodiments, the method continues from
step 362 to step 364. In other embodiments, step 362 can follow
step 358 and precede step 360, and step 360 can continue to step
364.
[0050] In step 364, the processing module determines a balance
factor between two or more types of the pending operations. The at
least two types of pending operations can include a maintenance
type and a non-maintenance type, and the at least one of the
plurality of pending operations, corresponding to the resource
availability level and/or the required resource level, can
correspond to the maintenance type. The determining can be based on
the resource availability level and/or the required resource level.
The determining includes at least one of interpreting a goal,
interpreting historical operation execution records, interpreting a
priority level for an operation, identifying a number of pending
maintenance operations, and identifying a current balance
factor.
[0051] The method continues at step 366 where the processing module
coordinates determining of required timing of the execution of the
at least some of the pending operations with one or more other
operation execution entities, such as at least one other DST
execution unit. The coordinating includes one or more of
identifying candidate operations requiring coordination, sending
identifiers of the candidate operations to the one or more other
operation execution entities (e.g., other storage units),
estimating the required timing of the execution, and modifying the
estimate of the required timing of execution based on received
resource allocation information.
[0052] The method continues at step 368 where the processing module
updates an operation execution schedule based on one or more of the
required resource levels, the resource availability level, the
balance factor, and/or the required timing of the execution. For
example, the processing module modifies a previous operation
scheduled to achieve execution of pending operations within a
desired time frame utilizing available resources.
[0053] In various embodiments, a data segment was dispersed storage
error encoded to produce a set of encoded data slices stored in a
set of DST execution units that includes the DST execution unit,
and where the at least one of the plurality of pending operations
includes at least one of: rebuilding at least one of the set of
encoded data slices or migrating at least one of the set of encoded
data slices.
[0054] In various embodiments, the plurality of pending operations
can include a set of non-maintenance operations corresponding to
the non-maintenance type. The processing module can estimate a
second required resource level to execute the set of
non-maintenance operations, where the balance factor is further
determined based on second required resource level.
[0055] In various embodiments, the balance factor is further
determined based on a number a set of the plurality of pending
operations corresponding to the maintenance type. The balance
factor indicates a first proportion of available resources be
allocated to pending operations corresponding to the maintenance
type when the number corresponds to a first value, and the balance
factor indicates a second proportion of available resources be
allocated to pending operations corresponding to the maintenance
type when the number corresponds to a second value. The first
proportion can be larger than the second proportion as a result of
the first value being greater than the second value.
[0056] In various embodiments, the balance factor is further
determined based on a set of priority levels corresponding to the
set of non-maintenance operations, and is further determined based
at least one priority level corresponding to the at least one of
the plurality of pending operations corresponding to the
maintenance type. The balance factor can indicate a first
proportion of available resources be allocated to pending
operations of the non-maintenance type when a first average
priority level of the set of priority levels is determined, and the
balance factor indicates a second proportion of available resources
be allocated to pending operations of the non-maintenance type when
a second overall priority level of the set of priority levels is
determined. The first proportion can is larger than the second
proportion as a result of the first average priority level
indicating a higher priority than the second overall priority
level.
[0057] In various embodiments, resource allocation information is
received from the at least one other DST execution unit, where the
resource allocation information corresponds to resources of the at
least one other DST execution unit. The resource availability level
is determined based on the resource allocation information. The
resource allocation information can include current operation
execution schedule of the at least one other DST execution unit, a
list of pending operations of the at least one other DST execution
unit, and/or an estimate of required resources associated with
execution of the plurality of pending operations of the at least
one other DST execution unit.
[0058] In various embodiments, coordinating determination of
required timing of the execution of the at least one of the
plurality of pending operations with at least one other DST
execution unit includes determining proposed required timing for
the at least one of the plurality of pending operations based on
the resource availability level, the required resource level, and
the balance factor. the proposed required timing is transmitted to
the at least one other DST execution unit. An updated proposed
required timing is received from the at least one other DST
execution unit that is different from the proposed required timing,
where the required timing of the execution is determined to reflect
the updated proposed required timing.
[0059] In various embodiments, the at least one of the plurality of
pending operations includes execution of a partial task of a common
task, where the common task includes additional partial tasks for
execution by the at least one other DST execution unit.
Coordinating determination of required timing of the execution can
include coordinating execution of the partial task by the DST
execution unit and execution of the additional partial tasks by the
at least one other DST execution unit within a fixed timeframe.
[0060] In various embodiments, a request for resource allocation
information is received by the processing module from at least one
other DST execution unit or other execution entity, where the
request indicates a future timeframe. The processing module can
generate its own resource allocation information based on the
operation execution schedule and the future timeframe, and can
transmit the resource allocation information to the at least one
other DST execution unit from which the request was received. The
at least one other DST execution unit can update their own
operation execution schedule, their own balance factor, and/or can
coordinate their own required timing based on the resource
allocation information received from the processing module.
[0061] In various embodiments, a non-transitory computer readable
storage medium includes at least one memory section that stores
operational instructions that, when executed by a processing system
of a dispersed storage network (DSN) that includes a processor and
a memory, causes the processing system to identify a plurality of
pending operations. A resource availability level to support
execution of at least one of the plurality of pending operations is
determined, and a required resource level to execute the at least
one of the plurality of pending operations is determined. A balance
factor between at least two types of the plurality of pending
operations is determined based on the resource availability level
and the required resource level. Determination of required timing
of the execution of the at least one of the plurality of pending
operations is coordinated with at least one other DST execution
unit. An operation execution schedule is updated based on the
required resource levels, the resource availability level, the
balance factor, and the required timing of the execution.
[0062] It is noted that terminologies as may be used herein such as
bit stream, stream, signal sequence, etc. (or their equivalents)
have been used interchangeably to describe digital information
whose content corresponds to any of a number of desired types
(e.g., data, video, speech, text, graphics, audio, etc. any of
which may generally be referred to as `data`).
[0063] As may be used herein, the terms "substantially" and
"approximately" provides an industry-accepted tolerance for its
corresponding term and/or relativity between items. For some
industries, an industry-accepted tolerance is less than one percent
and, for other industries, the industry-accepted tolerance is 10
percent or more. Industry-accepted tolerances correspond to, but
are not limited to, component values, integrated circuit process
variations, temperature variations, rise and fall times, thermal
noise, dimensions, signaling errors, dropped packets, temperatures,
pressures, material compositions, and/or performance metrics.
Within an industry, tolerance variances of accepted tolerances may
be more or less than a percentage level (e.g., dimension tolerance
of less than +/-1%).
[0064] As may also be used herein, the term(s) "configured to",
"operably coupled to", "coupled to", and/or "coupling" includes
direct coupling between items and/or indirect coupling between
items via an intervening item (e.g., an item includes, but is not
limited to, a component, an element, a circuit, and/or a module)
where, for an example of indirect coupling, the intervening item
does not modify the information of a signal but may adjust its
current level, voltage level, and/or power level. As may further be
used herein, inferred coupling (i.e., where one element is coupled
to another element by inference) includes direct and indirect
coupling between two items in the same manner as "coupled to".
[0065] As may even further be used herein, the term "configured
to", "operable to", "coupled to", or "operably coupled to"
indicates that an item includes one or more of power connections,
input(s), output(s), etc., to perform, when activated, one or more
its corresponding functions and may further include inferred
coupling to one or more other items. As may still further be used
herein, the term "associated with", includes direct and/or indirect
coupling of separate items and/or one item being embedded within
another item.
[0066] As may be used herein, the term "compares favorably",
indicates that a comparison between two or more items, signals,
etc., provides a desired relationship. For example, when the
desired relationship is that signal 1 has a greater magnitude than
signal 2, a favorable comparison may be achieved when the magnitude
of signal 1 is greater than that of signal 2 or when the magnitude
of signal 2 is less than that of signal 1. As may be used herein,
the term "compares unfavorably", indicates that a comparison
between two or more items, signals, etc., fails to provide the
desired relationship.
[0067] As may be used herein, one or more claims may include, in a
specific form of this generic form, the phrase "at least one of a,
b, and c" or of this generic form "at least one of a, b, or c",
with more or less elements than "a", "b", and "c". In either
phrasing, the phrases are to be interpreted identically. In
particular, "at least one of a, b, and c" is equivalent to "at
least one of a, b, or c" and shall mean a, b, and/or c. As an
example, it means: "a" only, "b" only, "c" only, "a" and "b", "a"
and "c", "b" and "c", and/or "a", "b", and "c".
[0068] As may also be used herein, the terms "processing system",
"processing module", "processing circuit", "processor", and/or
"processing unit" may be a single processing device or a plurality
of processing devices. Such a processing device may be a
microprocessor, micro-controller, digital signal processor,
microcomputer, central processing unit, field programmable gate
array, programmable logic device, state machine, logic circuitry,
analog circuitry, digital circuitry, and/or any device that
manipulates signals (analog and/or digital) based on hard coding of
the circuitry and/or operational instructions. The processing
module, module, processing circuit, and/or processing unit may be,
or further include, memory and/or an integrated memory element,
which may be a single memory device, a plurality of memory devices,
and/or embedded circuitry of another processing module, module,
processing circuit, and/or processing unit. Such a memory device
may be a read-only memory, random access memory, volatile memory,
non-volatile memory, static memory, dynamic memory, flash memory,
cache memory, and/or any device that stores digital information.
Note that if the processing module, module, processing circuit,
and/or processing unit includes more than one processing device,
the processing devices may be centrally located (e.g., directly
coupled together via a wired and/or wireless bus structure) or may
be distributedly located (e.g., cloud computing via indirect
coupling via a local area network and/or a wide area network).
Further note that if the processing module, module, processing
circuit, and/or processing unit implements one or more of its
functions via a state machine, analog circuitry, digital circuitry,
and/or logic circuitry, the memory and/or memory element storing
the corresponding operational instructions may be embedded within,
or external to, the circuitry comprising the state machine, analog
circuitry, digital circuitry, and/or logic circuitry. Still further
note that, the memory element may store, and the processing module,
module, processing circuit, and/or processing unit executes, hard
coded and/or operational instructions corresponding to at least
some of the steps and/or functions illustrated in one or more of
the Figures. Such a memory device or memory element can be included
in an article of manufacture.
[0069] One or more embodiments have been described above with the
aid of method steps illustrating the performance of specified
functions and relationships thereof. The boundaries and sequence of
these functional building blocks and method steps have been
arbitrarily defined herein for convenience of description.
Alternate boundaries and sequences can be defined so long as the
specified functions and relationships are appropriately performed.
Any such alternate boundaries or sequences are thus within the
scope and spirit of the claims. Further, the boundaries of these
functional building blocks have been arbitrarily defined for
convenience of description. Alternate boundaries could be defined
as long as the certain significant functions are appropriately
performed. Similarly, flow diagram blocks may also have been
arbitrarily defined herein to illustrate certain significant
functionality.
[0070] To the extent used, the flow diagram block boundaries and
sequence could have been defined otherwise and still perform the
certain significant functionality. Such alternate definitions of
both functional building blocks and flow diagram blocks and
sequences are thus within the scope and spirit of the claims. One
of average skill in the art will also recognize that the functional
building blocks, and other illustrative blocks, modules and
components herein, can be implemented as illustrated or by discrete
components, application specific integrated circuits, processors
executing appropriate software and the like or any combination
thereof.
[0071] In addition, a flow diagram may include a "start" and/or
"continue" indication. The "start" and "continue" indications
reflect that the steps presented can optionally be incorporated in
or otherwise used in conjunction with other routines. In this
context, "start" indicates the beginning of the first step
presented and may be preceded by other activities not specifically
shown. Further, the "continue" indication reflects that the steps
presented may be performed multiple times and/or may be succeeded
by other activities not specifically shown. Further, while a flow
diagram indicates a particular ordering of steps, other orderings
are likewise possible provided that the principles of causality are
maintained.
[0072] The one or more embodiments are used herein to illustrate
one or more aspects, one or more features, one or more concepts,
and/or one or more examples. A physical embodiment of an apparatus,
an article of manufacture, a machine, and/or of a process may
include one or more of the aspects, features, concepts, examples,
etc. described with reference to one or more of the embodiments
discussed herein. Further, from figure to figure, the embodiments
may incorporate the same or similarly named functions, steps,
modules, etc. that may use the same or different reference numbers
and, as such, the functions, steps, modules, etc. may be the same
or similar functions, steps, modules, etc. or different ones.
[0073] While the transistors in the above described figure(s)
is/are shown as field effect transistors (FETs), as one of ordinary
skill in the art will appreciate, the transistors may be
implemented using any type of transistor structure including, but
not limited to, bipolar, metal oxide semiconductor field effect
transistors (MOSFET), N-well transistors, P-well transistors,
enhancement mode, depletion mode, and zero voltage threshold (VT)
transistors.
[0074] Unless specifically stated to the contra, signals to, from,
and/or between elements in a figure of any of the figures presented
herein may be analog or digital, continuous time or discrete time,
and single-ended or differential. For instance, if a signal path is
shown as a single-ended path, it also represents a differential
signal path. Similarly, if a signal path is shown as a differential
path, it also represents a single-ended signal path. While one or
more particular architectures are described herein, other
architectures can likewise be implemented that use one or more data
buses not expressly shown, direct connectivity between elements,
and/or indirect coupling between other elements as recognized by
one of average skill in the art.
[0075] The term "module" is used in the description of one or more
of the embodiments. A module implements one or more functions via a
device such as a processor or other processing device or other
hardware that may include or operate in association with a memory
that stores operational instructions. A module may operate
independently and/or in conjunction with software and/or firmware.
As also used herein, a module may contain one or more sub-modules,
each of which may be one or more modules.
[0076] As may further be used herein, a computer readable memory
includes one or more memory elements. A memory element may be a
separate memory device, multiple memory devices, or a set of memory
locations within a memory device. Such a memory device may be a
read-only memory, random access memory, volatile memory,
non-volatile memory, static memory, dynamic memory, flash memory,
cache memory, and/or any device that stores digital information.
The memory device may be in a form a solid-state memory, a hard
drive memory, cloud memory, thumb drive, server memory, computing
device memory, and/or other physical medium for storing digital
information.
[0077] While particular combinations of various functions and
features of the one or more embodiments have been expressly
described herein, other combinations of these features and
functions are likewise possible. The present disclosure is not
limited by the particular examples disclosed herein and expressly
incorporates these other combinations.
* * * * *