U.S. patent application number 16/773620 was filed with the patent office on 2021-07-29 for throttling a point-in-time snapshot copy operation within a data consistency application.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to Theresa Mary Brown, Nedlaya Yazzie Francisco, Gail Spear, Matthew J. Ward.
Application Number | 20210232316 16/773620 |
Document ID | / |
Family ID | 1000005705631 |
Filed Date | 2021-07-29 |
United States Patent
Application |
20210232316 |
Kind Code |
A1 |
Ward; Matthew J. ; et
al. |
July 29, 2021 |
THROTTLING A POINT-IN-TIME SNAPSHOT COPY OPERATION WITHIN A DATA
CONSISTENCY APPLICATION
Abstract
A computer-implemented method according to one embodiment
includes determining that a consistency group has not been created
within a predetermined period of time; sending a request to create
the consistency group, where the request includes an indication
that a creation of the consistency group is mandatory; identifying
one or more logical storage volumes associated with the request to
create the consistency group; marking each of the identified one or
more logical storage volumes to indicate that a point-in-time
snapshot copy operation is not allowed for the one or more logical
storage volumes; creating the consistency group; sending the
consistency group from a source site to a destination site; and
removing the marking from each of the identified one or more
logical storage volumes to indicate that a point-in-time snapshot
copy operation is allowed for the one or more logical storage
volumes.
Inventors: |
Ward; Matthew J.; (Vail,
AZ) ; Brown; Theresa Mary; (Tucson, AZ) ;
Francisco; Nedlaya Yazzie; (Tucson, AZ) ; Spear;
Gail; (Tucson, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
1000005705631 |
Appl. No.: |
16/773620 |
Filed: |
January 27, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/0659 20130101;
G06F 3/065 20130101; G06F 3/0665 20130101; G06F 3/067 20130101;
G06F 11/1461 20130101; G06F 11/1451 20130101; G06F 11/1464
20130101; G06F 3/0653 20130101; G06F 2201/84 20130101; G06F 3/0619
20130101 |
International
Class: |
G06F 3/06 20060101
G06F003/06; G06F 11/14 20060101 G06F011/14 |
Claims
1. A computer-implemented method, comprising: determining, by a
master process, that a consistency group has not been created by a
data consistency application within a predetermined period of time;
sending, by the master process to a subordinate process, a request
to create the consistency group, where the request includes an
indication that a creation of the consistency group is mandatory;
identifying, by the subordinate process, one or more logical
storage volumes associated with the request to create the
consistency group; marking, by the subordinate process, each of the
identified one or more logical storage volumes to indicate that a
point-in-time snapshot copy operation is not allowed for the one or
more logical storage volumes; creating, by the subordinate process,
the consistency group; sending, by the subordinate process, the
consistency group from a source site to a destination site; and
removing, by the subordinate process, the marking from each of the
identified one or more logical storage volumes to indicate that a
point-in-time snapshot copy operation is allowed for the one or
more logical storage volumes.
2. The computer-implemented method of claim 1, wherein the data
consistency application maintains data consistency during
asynchronous data replication from the source site to a destination
site.
3. The computer-implemented method of claim 1, wherein the
consistency group includes a group of data to be sent during data
replication from a source site to a destination site.
4. The computer-implemented method of claim 1, wherein the master
process coordinates a creation of consistency groups within a first
site.
5. The computer-implemented method of claim 1, wherein the master
process: starts a timer after a consistency group has been created
and sent from a first site, and compares a current elapsed time
indicated by the timer to the predetermined period of time, and
determines that the consistency group has not been created by the
data consistency application within the predetermined period of
time in response to determining that the current elapsed time
exceeds the predetermined period of time.
6. The computer-implemented method of claim 1, wherein the request
to create the consistency group is sent by the master process in
response to determining that the consistency group has not been
created by the data consistency application within the
predetermined period of time.
7. The computer-implemented method of claim 1, wherein the
subordinate process controls one or more logical storage volumes
that contain data within the consistency group.
8. The computer-implemented method of claim 1, wherein the request
to create the consistency group is sent by the master process to a
plurality of subordinate processes running on a plurality of
servers within a first site.
9. The computer-implemented method of claim 1, wherein the
indication that the creation of the consistency group is mandatory
includes a flag that is set within the request.
10. The computer-implemented method of claim 1, wherein the request
includes a start increment command used to create the consistency
group within servers of a first site.
11. The computer-implemented method of claim 1, wherein each of the
identified one or more logical storage volumes are marked by the
subordinate process setting a flag for the logical storage volume,
where the flag indicates that the point-in-time snapshot copy
operation is not currently allowed for the logical storage
volume.
12. The computer-implemented method of claim 1, wherein the marking
is removed from the identified one or more logical storage volumes
in response to a completion of a transfer of the consistency group
from a source site to a destination site.
13. A computer program product for throttling a point-in-time
snapshot copy operation within a data consistency application, the
computer program product comprising a computer readable storage
medium having program instructions embodied therewith, wherein the
computer readable storage medium is not a transitory signal per se,
the program instructions executable by a processor to cause the
processor to perform a method comprising: determining, by a master
process utilizing the processor, that a consistency group has not
been created by a data consistency application within a
predetermined period of time; sending, by the master process to a
subordinate process utilizing the processor, a request to create
the consistency group, where the request includes an indication
that a creation of the consistency group is mandatory; identifying,
by the subordinate process utilizing the processor, one or more
logical storage volumes associated with the request to create the
consistency group; marking, by the subordinate process utilizing
the processor, each of the identified one or more logical storage
volumes to indicate that a point-in-time snapshot copy operation is
not allowed for the one or more logical storage volumes; creating,
by the subordinate process utilizing the processor, the consistency
group; sending, by the subordinate process utilizing the processor,
the consistency group from a source site to a destination site; and
removing, by the subordinate process utilizing the processor, the
marking from each of the identified one or more logical storage
volumes to indicate that a point-in-time snapshot copy operation is
allowed for the one or more logical storage volumes.
14. The computer program product of claim 13, wherein the data
consistency application maintains data consistency during
asynchronous data replication from a source site to a destination
site.
15. The computer program product of claim 13, wherein the
consistency group includes a group of data to be sent during data
replication from a source site to a destination site.
16. The computer program product of claim 13, wherein the master
process coordinates a creation of consistency groups within a first
site.
17. The computer program product of claim 13, wherein the master
process: starts a timer after a consistency group has been created
and sent from a first site, and compares a current elapsed time
indicated by the timer to the predetermined period of time, and
determines that the consistency group has not been created by the
data consistency application within the predetermined period of
time in response to determining that the current elapsed time
exceeds the predetermined period of time.
18. The computer program product of claim 13, wherein the request
to create the consistency group is sent by the master process in
response to determining that the consistency group has not been
created by the data consistency application within the
predetermined period of time.
19. The computer program product of claim 13, wherein the
subordinate process controls one or more logical storage volumes
that contain data within the consistency group.
20. A system, comprising: a processor; and logic integrated with
the processor, executable by the processor, or integrated with and
executable by the processor, the logic being configured to:
determine, by a master process, that a consistency group has not
been created by a data consistency application within a
predetermined period of time; send, by the master process to a
subordinate process, a request to create the consistency group,
where the request includes an indication that a creation of the
consistency group is mandatory; identify, by the subordinate
process, one or more logical storage volumes associated with the
request to create the consistency group; mark, by the subordinate
process, each of the identified one or more logical storage volumes
to indicate that a point-in-time snapshot copy operation is not
allowed for the one or more logical storage volumes; create, by the
subordinate process, the consistency group; send, by the
subordinate process, the consistency group from a source site to a
destination site; and remove, by the subordinate process, the
marking from each of the identified one or more logical storage
volumes to indicate that a point-in-time snapshot copy operation is
allowed for the one or more logical storage volumes.
Description
BACKGROUND
[0001] The present invention relates to data replication, and more
particularly, this invention relates to throttling a point-in-time
snapshot copy operation within a data replication environment.
[0002] Data replication is a popular way of securing important data
to provide protection against system outages. Performing a
point-in-time snapshot copy of data also preserves a current state
of data within a system. However, performing a point-in-time
snapshot copy of data within a data replication environment affects
a consistent asynchronous replication application. Further, too
many consecutive point-in-time snapshot copies may affect a
recovery point objective (RPO) of a system.
BRIEF SUMMARY
[0003] A computer-implemented method according to one embodiment
includes determining, by a master process, that a consistency group
has not been created by a data consistency application within a
predetermined period of time; sending, by the master process to a
subordinate process, a request to create the consistency group,
where the request includes an indication that a creation of the
consistency group is mandatory; identifying, by the subordinate
process, one or more logical storage volumes associated with the
request to create the consistency group; marking, by the
subordinate process, each of the identified one or more logical
storage volumes to indicate that a point-in-time snapshot copy
operation is not allowed for the one or more logical storage
volumes; creating, by the subordinate process, the consistency
group; sending, by the subordinate process, the consistency group
from a source site to a destination site; and removing, by the
subordinate process, the marking from each of the identified one or
more logical storage volumes to indicate that a point-in-time
snapshot copy operation is allowed for the one or more logical
storage volumes.
[0004] According to another embodiment, a computer program product
for throttling a point-in-time snapshot copy operation within a
data consistency application includes a computer readable storage
medium having program instructions embodied therewith, where the
computer readable storage medium is not a transitory signal per se,
and where the program instructions are executable by a processor to
cause the processor to perform a method including determining, by a
master process utilizing the processor, that a consistency group
has not been created by a data consistency application within a
predetermined period of time; sending, by the master process to a
subordinate process utilizing the processor, a request to create
the consistency group, where the request includes an indication
that a creation of the consistency group is mandatory; identifying,
by the subordinate process utilizing the processor, one or more
logical storage volumes associated with the request to create the
consistency group; marking, by the subordinate process utilizing
the processor, each of the identified one or more logical storage
volumes to indicate that a point-in-time snapshot copy operation is
not allowed for the one or more logical storage volumes; creating,
by the subordinate process utilizing the processor, the consistency
group; sending, by the subordinate process utilizing the processor,
the consistency group from a source site to a destination site; and
removing, by the subordinate process utilizing the processor, the
marking from each of the identified one or more logical storage
volumes to indicate that a point-in-time snapshot copy operation is
allowed for the one or more logical storage volumes.
[0005] According to another embodiment, a system includes a
processor; and logic integrated with the processor, executable by
the processor, or integrated with and executable by the processor,
where the logic is configured to determine, by a master process,
that a consistency group has not been created by a data consistency
application within a predetermined period of time; send, by the
master process to a subordinate process, a request to create the
consistency group, where the request includes an indication that a
creation of the consistency group is mandatory; identify, by the
subordinate process, one or more logical storage volumes associated
with the request to create the consistency group; mark, by the
subordinate process, each of the identified one or more logical
storage volumes to indicate that a point-in-time snapshot copy
operation is not allowed for the one or more logical storage
volumes; create, by the subordinate process, the consistency group;
send, by the subordinate process, the consistency group from a
source site to a destination site; and remove, by the subordinate
process, the marking from each of the identified one or more
logical storage volumes to indicate that a point-in-time snapshot
copy operation is allowed for the one or more logical storage
volumes.
[0006] Other aspects and embodiments of the present invention will
become apparent from the following detailed description, which,
when taken in conjunction with the drawings, illustrate by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 depicts a cloud computing environment in accordance
with one embodiment of the present invention.
[0008] FIG. 2 depicts abstraction model layers in accordance with
one embodiment of the present invention.
[0009] FIG. 3 depicts a cloud computing node in accordance with one
embodiment of the present invention.
[0010] FIG. 4 illustrates a tiered data storage system in
accordance with one embodiment of the present invention.
[0011] FIG. 5 illustrates a flowchart of a method for performing a
point-in-time snapshot copy operation within a data consistency
application, in accordance with one embodiment of the present
invention.
[0012] FIG. 6 illustrates a flowchart of a method for throttling a
point-in-time snapshot copy operation within a data consistency
application, in accordance with one embodiment of the present
invention.
[0013] FIG. 7 illustrates a flowchart of a method for attempting to
implement a point-in-time snapshot copy operation, in accordance
with one embodiment of the present invention.
[0014] FIG. 8 illustrates an exemplary environment for throttling a
point-in-time snapshot copy operation, in accordance with one
embodiment of the present invention.
DETAILED DESCRIPTION
[0015] The following description is made for the purpose of
illustrating the general principles of the present invention and is
not meant to limit the inventive concepts claimed herein. Further,
particular features described herein can be used in combination
with other described features in each of the various possible
combinations and permutations.
[0016] Unless otherwise specifically defined herein, all terms are
to be given their broadest possible interpretation including
meanings implied from the specification as well as meanings
understood by those skilled in the art and/or as defined in
dictionaries, treatises, etc.
[0017] It must also be noted that, as used in the specification and
the appended claims, the singular forms "a," "an" and "the" include
plural referents unless otherwise specified. It will be further
understood that the terms "comprises" and/or "comprising," when
used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, elements, components, and/or
groups thereof.
[0018] The following description discloses several embodiments of
throttling a point-in-time snapshot copy operation within a data
consistency application.
[0019] In one general embodiment, a computer-implemented method
includes determining, by a master process, that a consistency group
has not been created by a data consistency application within a
predetermined period of time; sending, by the master process to a
subordinate process, a request to create the consistency group,
where the request includes an indication that a creation of the
consistency group is mandatory; identifying, by the subordinate
process, one or more logical storage volumes associated with the
request to create the consistency group; marking, by the
subordinate process, each of the identified one or more logical
storage volumes to indicate that a point-in-time snapshot copy
operation is not allowed for the one or more logical storage
volumes; creating, by the subordinate process, the consistency
group; sending, by the subordinate process, the consistency group
from a source site to a destination site; and removing, by the
subordinate process, the marking from each of the identified one or
more logical storage volumes to indicate that a point-in-time
snapshot copy operation is allowed for the one or more logical
storage volumes.
[0020] In another general embodiment, a computer program product
for throttling a point-in-time snapshot copy operation within a
data consistency application includes a computer readable storage
medium having program instructions embodied therewith, where the
computer readable storage medium is not a transitory signal per se,
and where the program instructions are executable by a processor to
cause the processor to perform a method including determining, by a
master process utilizing the processor, that a consistency group
has not been created by a data consistency application within a
predetermined period of time; sending, by the master process to a
subordinate process utilizing the processor, a request to create
the consistency group, where the request includes an indication
that a creation of the consistency group is mandatory; identifying,
by the subordinate process utilizing the processor, one or more
logical storage volumes associated with the request to create the
consistency group; marking, by the subordinate process utilizing
the processor, each of the identified one or more logical storage
volumes to indicate that a point-in-time snapshot copy operation is
not allowed for the one or more logical storage volumes; creating,
by the subordinate process utilizing the processor, the consistency
group; sending, by the subordinate process utilizing the processor,
the consistency group from a source site to a destination site; and
removing, by the subordinate process utilizing the processor, the
marking from each of the identified one or more logical storage
volumes to indicate that a point-in-time snapshot copy operation is
allowed for the one or more logical storage volumes.
[0021] In another general embodiment, a system includes a
processor; and logic integrated with the processor, executable by
the processor, or integrated with and executable by the processor,
where the logic is configured to determine, by a master process,
that a consistency group has not been created by a data consistency
application within a predetermined period of time; send, by the
master process to a subordinate process, a request to create the
consistency group, where the request includes an indication that a
creation of the consistency group is mandatory; identify, by the
subordinate process, one or more logical storage volumes associated
with the request to create the consistency group; mark, by the
subordinate process, each of the identified one or more logical
storage volumes to indicate that a point-in-time snapshot copy
operation is not allowed for the one or more logical storage
volumes; create, by the subordinate process, the consistency group;
send, by the subordinate process, the consistency group from a
source site to a destination site; and remove, by the subordinate
process, the marking from each of the identified one or more
logical storage volumes to indicate that a point-in-time snapshot
copy operation is allowed for the one or more logical storage
volumes.
[0022] It is to be understood that although this disclosure
includes a detailed description on cloud computing, implementation
of the teachings recited herein are not limited to a cloud
computing environment. Rather, embodiments of the present invention
are capable of being implemented in conjunction with any other type
of computing environment now known or later developed.
[0023] Cloud computing is a model of service delivery for enabling
convenient, on-demand network access to a shared pool of
configurable computing resources (e.g., networks, network
bandwidth, servers, processing, memory, storage, applications,
virtual machines, and services) that can be rapidly provisioned and
released with minimal management effort or interaction with a
provider of the service. This cloud model may include at least five
characteristics, at least three service models, and at least four
deployment models.
[0024] Characteristics are as follows:
[0025] On-demand self-service: a cloud consumer can unilaterally
provision computing capabilities, such as server time and network
storage, as needed automatically without requiring human
interaction with the service's provider.
[0026] Broad network access: capabilities are available over a
network and accessed through standard mechanisms that promote use
by heterogeneous thin or thick client platforms (e.g., mobile
phones, laptops, and PDAs).
[0027] Resource pooling: the provider's computing resources are
pooled to serve multiple consumers using a multi-tenant model, with
different physical and virtual resources dynamically assigned and
reassigned according to demand. There is a sense of location
independence in that the consumer generally has no control or
knowledge over the exact location of the provided resources but may
be able to specify location at a higher level of abstraction (e.g.,
country, state, or datacenter).
[0028] Rapid elasticity: capabilities can be rapidly and
elastically provisioned, in some cases automatically, to quickly
scale out and rapidly released to quickly scale in. To the
consumer, the capabilities available for provisioning often appear
to be unlimited and can be purchased in any quantity at any
time.
[0029] Measured service: cloud systems automatically control and
optimize resource use by leveraging a metering capability at some
level of abstraction appropriate to the type of service (e.g.,
storage, processing, bandwidth, and active user accounts). Resource
usage can be monitored, controlled, and reported, providing
transparency for both the provider and consumer of the utilized
service.
[0030] Service Models are as follows:
[0031] Software as a Service (SaaS): the capability provided to the
consumer is to use the provider's applications running on a cloud
infrastructure. The applications are accessible from various client
devices through a thin client interface such as a web browser
(e.g., web-based e-mail). The consumer does not manage or control
the underlying cloud infrastructure including network, servers,
operating systems, storage, or even individual application
capabilities, with the possible exception of limited user-specific
application configuration settings.
[0032] Platform as a Service (PaaS): the capability provided to the
consumer is to deploy onto the cloud infrastructure
consumer-created or acquired applications created using programming
languages and tools supported by the provider. The consumer does
not manage or control the underlying cloud infrastructure including
networks, servers, operating systems, or storage, but has control
over the deployed applications and possibly application hosting
environment configurations.
[0033] Infrastructure as a Service (IaaS): the capability provided
to the consumer is to provision processing, storage, networks, and
other fundamental computing resources where the consumer is able to
deploy and run arbitrary software, which can include operating
systems and applications. The consumer does not manage or control
the underlying cloud infrastructure but has control over operating
systems, storage, deployed applications, and possibly limited
control of select networking components (e.g., host firewalls).
[0034] Deployment Models are as follows:
[0035] Private cloud: the cloud infrastructure is operated solely
for an organization. It may be managed by the organization or a
third party and may exist on-premises or off-premises.
[0036] Community cloud: the cloud infrastructure is shared by
several organizations and supports a specific community that has
shared concerns (e.g., mission, security requirements, policy, and
compliance considerations). It may be managed by the organizations
or a third party and may exist on-premises or off-premises.
[0037] Public cloud: the cloud infrastructure is made available to
the general public or a large industry group and is owned by an
organization selling cloud services.
[0038] Hybrid cloud: the cloud infrastructure is a composition of
two or more clouds (private, community, or public) that remain
unique entities but are bound together by standardized or
proprietary technology that enables data and application
portability (e.g., cloud bursting for load-balancing between
clouds).
[0039] A cloud computing environment is service oriented with a
focus on statelessness, low coupling, modularity, and semantic
interoperability. At the heart of cloud computing is an
infrastructure that includes a network of interconnected nodes.
[0040] Referring now to FIG. 1, illustrative cloud computing
environment 50 is depicted. As shown, cloud computing environment
50 includes one or more cloud computing nodes 10 with which local
computing devices used by cloud consumers, such as, for example,
personal digital assistant (PDA) or cellular telephone 54A, desktop
computer 54B, laptop computer 54C, and/or automobile computer
system 54N may communicate. Nodes 10 may communicate with one
another. They may be grouped (not shown) physically or virtually,
in one or more networks, such as Private, Community, Public, or
Hybrid clouds as described hereinabove, or a combination thereof.
This allows cloud computing environment 50 to offer infrastructure,
platforms and/or software as services for which a cloud consumer
does not need to maintain resources on a local computing device. It
is understood that the types of computing devices 54A-N shown in
FIG. 1 are intended to be illustrative only and that computing
nodes 10 and cloud computing environment 50 can communicate with
any type of computerized device over any type of network and/or
network addressable connection (e.g., using a web browser).
[0041] Referring now to FIG. 2, a set of functional abstraction
layers provided by cloud computing environment 50 (FIG. 1) is
shown. It should be understood in advance that the components,
layers, and functions shown in FIG. 2 are intended to be
illustrative only and embodiments of the invention are not limited
thereto. As depicted, the following layers and corresponding
functions are provided:
[0042] Hardware and software layer 60 includes hardware and
software components. Examples of hardware components include:
mainframes 61; RISC (Reduced Instruction Set Computer) architecture
based servers 62; servers 63; blade servers 64; storage devices 65;
and networks and networking components 66. In some embodiments,
software components include network application server software 67
and database software 68.
[0043] Virtualization layer 70 provides an abstraction layer from
which the following examples of virtual entities may be provided:
virtual servers 71; virtual storage 72; virtual networks 73,
including virtual private networks; virtual applications and
operating systems 74; and virtual clients 75.
[0044] In one example, management layer 80 may provide the
functions described below. Resource provisioning 81 provides
dynamic procurement of computing resources and other resources that
are utilized to perform tasks within the cloud computing
environment. Metering and Pricing 82 provide cost tracking as
resources are utilized within the cloud computing environment, and
billing or invoicing for consumption of these resources. In one
example, these resources may include application software licenses.
Security provides identity verification for cloud consumers and
tasks, as well as protection for data and other resources. User
portal 83 provides access to the cloud computing environment for
consumers and system administrators. Service level management 84
provides cloud computing resource allocation and management such
that required service levels are met. Service Level Agreement (SLA)
planning and fulfillment 85 provide pre-arrangement for, and
procurement of, cloud computing resources for which a future
requirement is anticipated in accordance with an SLA.
[0045] Workloads layer 90 provides examples of functionality for
which the cloud computing environment may be utilized. Examples of
workloads and functions which may be provided from this layer
include: mapping and navigation 91; software development and
lifecycle management 92; virtual classroom education delivery 93;
data analytics processing 94; transaction processing 95; and data
consistency implementation 96.
[0046] Referring now to FIG. 3, a schematic of an example of a
cloud computing node is shown. Cloud computing node 10 is only one
example of a suitable cloud computing node and is not intended to
suggest any limitation as to the scope of use or functionality of
embodiments of the invention described herein. Regardless, cloud
computing node 10 is capable of being implemented and/or performing
any of the functionality set forth hereinabove.
[0047] In cloud computing node 10 there is a computer system/server
12, which is operational with numerous other general purpose or
special purpose computing system environments or configurations.
Examples of well-known computing systems, environments, and/or
configurations that may be suitable for use with computer
system/server 12 include, but are not limited to, personal computer
systems, server computer systems, thin clients, thick clients,
hand-held or laptop devices, multiprocessor systems,
microprocessor-based systems, set top boxes, programmable consumer
electronics, network PCs, minicomputer systems, mainframe computer
systems, and distributed cloud computing environments that include
any of the above systems or devices, and the like.
[0048] Computer system/server 12 may be described in the general
context of computer system-executable instructions, such as program
modules, being executed by a computer system. Generally, program
modules may include routines, programs, objects, components, logic,
data structures, and so on that perform particular tasks or
implement particular abstract data types. Computer system/server 12
may be practiced in distributed cloud computing environments where
tasks are performed by remote processing devices that are linked
through a communications network. In a distributed cloud computing
environment, program modules may be located in both local and
remote computer system storage media including memory storage
devices.
[0049] As shown in FIG. 3, computer system/server 12 in cloud
computing node 10 is shown in the form of a general-purpose
computing device. The components of computer system/server 12 may
include, but are not limited to, one or more processors or
processing units 16, a system memory 28, and a bus 18 that couples
various system components including system memory 28 to processor
16.
[0050] Bus 18 represents one or more of any of several types of bus
structures, including a memory bus or memory controller, a
peripheral bus, an accelerated graphics port, and a processor or
local bus using any of a variety of bus architectures. By way of
example, and not limitation, such architectures include Industry
Standard Architecture (ISA) bus, Micro Channel Architecture (MCA)
bus, Enhanced ISA (EISA) bus, Video Electronics Standards
Association (VESA) local bus, and Peripheral Component
Interconnects (PCI) bus.
[0051] Computer system/server 12 typically includes a variety of
computer system readable media. Such media may be any available
media that is accessible by computer system/server 12, and it
includes both volatile and non-volatile media, removable and
non-removable media.
[0052] System memory 28 can include computer system readable media
in the form of volatile memory, such as random access memory (RAM)
30 and/or cache memory 32. Computer system/server 12 may further
include other removable/non-removable, volatile/non-volatile
computer system storage media. By way of example only, storage
system 34 can be provided for reading from and writing to a
non-removable, non-volatile magnetic media (not shown and typically
called a "hard drive"). Although not shown, a magnetic disk drive
for reading from and writing to a removable, non-volatile magnetic
disk (e.g., a "floppy disk"), and an optical disk drive for reading
from or writing to a removable, non-volatile optical disk such as a
CD-ROM, DVD-ROM or other optical media can be provided. In such
instances, each can be connected to bus 18 by one or more data
media interfaces. As will be further depicted and described below,
memory 28 may include at least one program product having a set
(e.g., at least one) of program modules that are configured to
carry out the functions of embodiments of the invention.
[0053] Program/utility 40, having a set (at least one) of program
modules 42, may be stored in memory 28 by way of example, and not
limitation, as well as an operating system, one or more application
programs, other program modules, and program data. Each of the
operating system, one or more application programs, other program
modules, and program data or some combination thereof, may include
an implementation of a networking environment. Program modules 42
generally carry out the functions and/or methodologies of
embodiments of the invention as described herein.
[0054] Computer system/server 12 may also communicate with one or
more external devices 14 such as a keyboard, a pointing device, a
display 24, etc.; one or more devices that enable a user to
interact with computer system/server 12; and/or any devices (e.g.,
network card, modem, etc.) that enable computer system/server 12 to
communicate with one or more other computing devices. Such
communication can occur via Input/Output (I/O) interfaces 22. Still
yet, computer system/server 12 can communicate with one or more
networks such as a local area network (LAN), a general wide area
network (WAN), and/or a public network (e.g., the Internet) via
network adapter 20. As depicted, network adapter 20 communicates
with the other components of computer system/server 12 via bus 18.
It should be understood that although not shown, other hardware
and/or software components could be used in conjunction with
computer system/server 12. Examples, include, but are not limited
to: microcode, device drivers, redundant processing units, external
disk drive arrays, RAID systems, tape drives, and data archival
storage systems, etc.
[0055] Now referring to FIG. 4, a storage system 400 is shown
according to one embodiment. Note that some of the elements shown
in FIG. 4 may be implemented as hardware and/or software, according
to various embodiments. The storage system 400 may include a
storage system manager 412 for communicating with a plurality of
media on at least one higher storage tier 402 and at least one
lower storage tier 406. The higher storage tier(s) 402 preferably
may include one or more random access and/or direct access media
404, such as hard disks in hard disk drives (HDDs), nonvolatile
memory (NVM), solid state memory in solid state drives (SSDs),
flash memory, SSD arrays, flash memory arrays, etc., and/or others
noted herein or known in the art. The lower storage tier(s) 406 may
preferably include one or more lower performing storage media 408,
including sequential access media such as magnetic tape in tape
drives and/or optical media, slower accessing HDDs, slower
accessing SSDs, etc., and/or others noted herein or known in the
art. One or more additional storage tiers 416 may include any
combination of storage memory media as desired by a designer of the
system 400. Also, any of the higher storage tiers 402 and/or the
lower storage tiers 406 may include some combination of storage
devices and/or storage media.
[0056] The storage system manager 412 may communicate with the
storage media 404, 408 on the higher storage tier(s) 402 and lower
storage tier(s) 406 through a network 410, such as a storage area
network (SAN), as shown in FIG. 4, or some other suitable network
type. The storage system manager 412 may also communicate with one
or more host systems (not shown) through a host interface 414,
which may or may not be a part of the storage system manager 412.
The storage system manager 412 and/or any other component of the
storage system 400 may be implemented in hardware and/or software,
and may make use of a processor (not shown) for executing commands
of a type known in the art, such as a central processing unit
(CPU), a field programmable gate array (FPGA), an application
specific integrated circuit (ASIC), etc. Of course, any arrangement
of a storage system may be used, as will be apparent to those of
skill in the art upon reading the present description.
[0057] In more embodiments, the storage system 400 may include any
number of data storage tiers, and may include the same or different
storage memory media within each storage tier. For example, each
data storage tier may include the same type of storage memory
media, such as HDDs, SSDs, sequential access media (tape in tape
drives, optical disk in optical disk drives, etc.), direct access
media (CD-ROM, DVD-ROM, etc.), or any combination of media storage
types. In one such configuration, a higher storage tier 402, may
include a majority of SSD storage media for storing data in a
higher performing storage environment, and remaining storage tiers,
including lower storage tier 406 and additional storage tiers 416
may include any combination of SSDs, HDDs, tape drives, etc., for
storing data in a lower performing storage environment. In this
way, more frequently accessed data, data having a higher priority,
data needing to be accessed more quickly, etc., may be stored to
the higher storage tier 402, while data not having one of these
attributes may be stored to the additional storage tiers 416,
including lower storage tier 406. Of course, one of skill in the
art, upon reading the present descriptions, may devise many other
combinations of storage media types to implement into different
storage schemes, according to the embodiments presented herein.
[0058] According to some embodiments, the storage system (such as
400) may include logic configured to receive a request to open a
data set, logic configured to determine if the requested data set
is stored to a lower storage tier 406 of a tiered data storage
system 400 in multiple associated portions, logic configured to
move each associated portion of the requested data set to a higher
storage tier 402 of the tiered data storage system 400, and logic
configured to assemble the requested data set on the higher storage
tier 402 of the tiered data storage system 400 from the associated
portions.
[0059] Of course, this logic may be implemented as a method on any
device and/or system or as a computer program product, according to
various embodiments.
[0060] Now referring to FIG. 5, a flowchart of a method 500 for
performing a point-in-time snapshot copy operation within a data
consistency application is shown according to one embodiment. The
method 500 may be performed in accordance with the present
invention in any of the environments depicted in FIGS. 1-4 and 8,
among others, in various embodiments. Of course, more or less
operations than those specifically described in FIG. 5 may be
included in method 500, as would be understood by one of skill in
the art upon reading the present descriptions.
[0061] Each of the steps of the method 500 may be performed by any
suitable component of the operating environment. For example, in
various embodiments, the method 500 may be partially or entirely
performed by one or more servers, computers, or some other device
having one or more processors therein. The processor, e.g.,
processing circuit(s), chip(s), and/or module(s) implemented in
hardware and/or software, and preferably having at least one
hardware component may be utilized in any device to perform one or
more steps of the method 500. Illustrative processors include, but
are not limited to, a central processing unit (CPU), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA), etc., combinations thereof, or any other suitable computing
device known in the art.
[0062] As shown in FIG. 5, method 500 may initiate with operation
502, where data to be transferred as part of a point-in-time
snapshot copy operation is identified. In one embodiment, the
point-in-time snapshot copy operation may include the transfer of a
point-in-time copy of the data from a first logical storage volume
(e.g., a source volume) to a second logical storage volume (e.g., a
target volume). For example, in response to one or more changes
made to data within a source volume, specific portions of the data
affected by the changes may be identified. In another example, the
specific portions of the data may be included within the data to be
transferred as part of the point-in-time snapshot copy
operation.
[0063] Additionally, in one embodiment, the point-in-time snapshot
copy operation may include an IBM.RTM. FlashCopy operation. In
another embodiment, a logical storage volume may include
virtualized representation of physical storage from one or more
physical storage volumes. For example, the first logical storage
volume may represent first physical storage located at a first site
(e.g., physical storage environment location).
[0064] Further, in one embodiment, the first site may include a
plurality of logical partitions (LPARs). For example, each LPAR may
include computing hardware (e.g., one or more processors, etc.). In
another example, each LPAR may include storage hardware (e.g.,
physical storage drives such as hard disk drives, flash drives,
tape drives, etc.). In yet another example, the storage hardware
may provide the physical storage resources for the logical storage
volume. In still another example, an exemplary LPAR may include an
IBM.RTM. DS8000.RTM. series server.
[0065] Further still, in one embodiment, the second logical storage
volume may represent second physical storage located at a second
site separate from the first site. In another embodiment, the data
may include one or more tracks of a logical storage volume, an
entire logical storage volume, a predetermined data set, etc.
[0066] Also, method 500 may proceed with operation 504, where a
data consistency application is set in an idle state. In one
embodiment, a global copy application may perform asynchronous data
replication between a first logical storage volume (e.g., a source
volume) located at a first site and a second logical storage volume
(e.g., a target volume) located at a second site. In another
embodiment, the asynchronous data replication may include
identifying changes made to data at a first site, and implementing
those changes to data at a second site.
[0067] In addition, in one embodiment, the asynchronous data
replication may be performed to create a backup volume to protect
against hardware failure, malware, etc. In another embodiment, the
data consistency application may maintain data consistency during
asynchronous data replication by ensuring a predetermined order of
data being replicated. For example, the global copy application may
not guarantee consistency (e.g., an order in which the data is
being sent during asynchronous data replication).
[0068] Furthermore, in one embodiment, the data consistency
application may include an instance of IBM.RTM. Global Mirror. In
another embodiment, the data consistency application may have two
states. For example, a first state of the data consistency
application may include an active state in which the data
consistency application is currently forming a consistency group
(e.g., a group of data to be sent during data replication). In
another example, a second state of the data consistency application
may include an idle state in which the data consistency application
does not form a consistency group.
[0069] Further still, in one embodiment, the data consistency
application may be set in an idle state by sending one or more
commands to the data consistency application (e.g., an idle state
initiation command, etc.). In another embodiment, by setting the
data consistency application in the idle state, the data
consistency application may be temporarily prevented from creating
a consistency group.
[0070] Also, method 500 may proceed with operation 506, where the
data is marked while the data consistency application is in the
idle state. In one embodiment, the data may be marked as data to be
replicated during asynchronous data replication. In another
embodiment, the data may be marked by setting an out of sync bit
map for a global copy relationship for the data. In yet another
embodiment, the data consistency application may be maintained in
the idle state while the data is marked (e.g., by periodically
sending one or more idle commands, etc.).
[0071] Additionally, method 500 may proceed with operation 508,
where the data consistency application is restarted. In one
embodiment, the data consistency application may be restarted by
changing the state of the data consistency application. In another
embodiment, the data consistency application may be set in an
active state by sending one or more commands to the data
consistency application (e.g., an active state initiation command,
etc.).
[0072] Further, method 500 may proceed with operation 510, where
the marked data is identified by the data consistency application.
In one embodiment, while in the active state, the data consistency
application may identify the out of sync bit map for a global copy
relationship set for the data. In another embodiment, in response
to the identification, the data consistency application may
identify the marked data as data located at a first site that is
not synchronized with a second site.
[0073] Further still, method 500 may proceed with operation 512,
where a consistency group including the marked data is created by
the data consistency application. In one embodiment, in response to
the identification of the marked data, the data consistency
application may create a data consistency group that includes the
marked data. In another embodiment, the data consistency
application may create a data consistency group in response to a
request received from a master process at a subordinate
process.
[0074] Also, in one embodiment, the data consistency group may
include data in addition to the data to be transferred as part of a
point-in-time snapshot copy operation. In another embodiment,
creating the consistency group may include tagging the marked data
(e.g., using one or more flags) as data to be synchronized with a
second site. In yet another embodiment, the consistency group may
be created by a subordinate process within one or more servers of
the first site.
[0075] In addition, method 500 may proceed with operation 514,
where replication of the consistency group is performed. In one
embodiment, performing replication of the consistency group may
include sending data within the consistency group from a first site
to a second site for integration at the second site. For example,
the marked data within the consistency group may be sent from a
first site (where changes were made to data within a source volume
of the first site) to replace corresponding data at a second site
(where a target volume of the second site stores a mirrored copy of
all data within the source volume of the first site).
[0076] In this way, a point-in-time snapshot copy operation may be
performed while maintaining data consistency between the first site
and the second site during data replication. As a result, data at
the second site may be used to restore data at the first site in
response to one or more events (e.g., hardware or software failure
at the first site, malware at the first site, etc.). This may
protect data stored within the first site, and may improve a
performance of hardware at the first site in response to one or
more failures.
[0077] Now referring to FIG. 6, a flowchart of a method 600 is
shown according to one embodiment. The method 600 may be performed
in accordance with the present invention in any of the environments
depicted in FIGS. 1-4 and 8, among others, in various embodiments.
Of course, more or less operations than those specifically
described in FIG. 6 may be included in method 600, as would be
understood by one of skill in the art upon reading the present
descriptions.
[0078] Each of the steps of the method 600 may be performed by any
suitable component of the operating environment. For example, in
various embodiments, the method 600 may be partially or entirely
performed by one or more servers, computers, or some other device
having one or more processors therein. The processor, e.g.,
processing circuit(s), chip(s), and/or module(s) implemented in
hardware and/or software, and preferably having at least one
hardware component may be utilized in any device to perform one or
more steps of the method 600. Illustrative processors include, but
are not limited to, a central processing unit (CPU), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA), etc., combinations thereof, or any other suitable computing
device known in the art.
[0079] As shown in FIG. 6, method 600 may initiate with operation
602, where a master process determines that a consistency group has
not been created by a data consistency application within a
predetermined period of time. In one embodiment, the master process
may include an application running on a server (e.g., a logical
partition (LPAR), etc.). In another embodiment, the server may be
one of a plurality of servers located at a first site (e.g., a
source site, etc.).
[0080] Additionally, in one embodiment, the data consistency
application may maintain data consistency during asynchronous data
replication from the first site to a second site (e.g., from a
source site to a destination site). In another embodiment, the data
consistency application may maintain data consistency by ensuring a
predetermined order of data being replicated during the
asynchronous data replication. In yet another embodiment, the
consistency group may include a group of data to be sent during
data replication from the first site to the second site.
[0081] Further, in one embodiment, the data consistency application
may include an instance of IBM.RTM. Global Mirror. In another
embodiment, the master process may be implemented within the data
consistency application. In yet another embodiment, the master
process may include a Global Mirror master.
[0082] Further still, in one embodiment, the master process may
coordinate the creation of consistency groups within the first
site. For example, the master process may reside on one of a
plurality of servers within the first site, and may instruct each
of the plurality of servers to create and send consistency groups
as part of the data consistency application. In another embodiment,
the master process may start a timer after a consistency group has
been created and sent from the first site.
[0083] Also, in one embodiment, the master process may compare a
current elapsed time indicated by the timer to the predetermined
period of time. For example, the predetermined period of time may
be set by one or more users, may be dynamically determined based on
historical pattern analysis, etc. In another embodiment, it may be
determined that the consistency group has not been created by the
data consistency application within the predetermined period of
time in response to determining that the current elapsed time
exceeds the predetermined period of time.
[0084] In addition, method 600 may proceed with operation 604,
where the master process sends a request to create the consistency
group to a subordinate process, where the request includes an
indication that a creation of the consistency group is mandatory.
In one embodiment, the request to create the consistency group may
be sent by the master process in response to determining that the
consistency group has not been created by the data consistency
application within the predetermined period of time.
[0085] Furthermore, in one embodiment, the request to create the
consistency group may be sent by the master process in response to
a predetermined schedule. In another embodiment, the subordinate
process may include an application running on the same server as
the master process. In yet another embodiment, the subordinate
process may include an application running on a different server
from the master process.
[0086] Further still, in one embodiment, the subordinate process
may control one or more logical storage volumes that contain data
within the consistency group. In another embodiment, the request to
create the consistency group may be sent by the master process to a
plurality of subordinate processes running on a plurality of
servers within the first site. For example, each of the plurality
of servers within the first site may have a subordinate process
running on the server.
[0087] Also, in one embodiment, the indication that the creation of
the consistency group is mandatory may include a flag that is set
within the request. For example, the flag may indicate a request
for a forced creation of the consistency group. In another
embodiment, the request may include a start increment command used
to create the consistency group within the servers of the first
site.
[0088] Additionally, method 600 may proceed with operation 606,
where the subordinate process identifies one or more logical
storage volumes associated with the request to create the
consistency group. In one embodiment, the subordinate process may
receive the request to create the consistency group from the master
process. In another embodiment, the subordinate process may
identify the indication that the creation of the consistency group
is mandatory from within the request. For example, when creation of
a consistency group is mandatory, the consistency group is not
constrained to complete within a designated time, and interruption
from point-in-time copies are prevented. In another example, the
subordinate process may identify the flag indicating that the
request is a request for a forced creation of the consistency
group.
[0089] Further, in one embodiment, the data consistency application
may identify all data located at its associated server that is not
synchronized with a second site. For example, all data consistency
applications may identify all data located at the source site that
is not synchronized with the second site. In another embodiment,
data located at an associated server that is not synchronized with
a second site may include data that has been altered since a last
synchronization even has occurred between the first site and the
second site.
[0090] Further still, in one embodiment, the data consistency
application may identify all out of sync bits in an out of sync bit
map for a global copy relationship set for the data within the
associated server. In another embodiment, the data consistency
application may identify the one or more logical storage volumes
that contain the data that is not synchronized with the second
site. For example, these identified logical storage volumes may
comprise the one or more logical storage volumes associated with
the request to create the consistency group.
[0091] Also, method 600 may proceed with operation 608, where the
subordinate process marks each of the identified one or more
logical storage volumes to indicate that a point-in-time snapshot
copy operation is not allowed for the one or more logical storage
volumes. In one embodiment, each of the identified logical storage
volumes may be marked before a start of a creation of the
consistency group by the subordinate process. In another
embodiment, each of the identified logical storage volumes may be
marked by the subordinate process setting a flag for the logical
storage volume, where the flag indicates that a point-in-time
snapshot copy operation is not currently allowed for the logical
storage volume.
[0092] In addition, method 600 may proceed with operation 610,
where the subordinate process creates the consistency group. In one
embodiment, creating the consistency group may include identifying
marked data within the server as data located at the first site
that is not synchronized with the second site. In another
embodiment, creating the consistency group may include tagging the
marked data (e.g., using one or more flags) as data to be
synchronized with the second site.
[0093] Furthermore, method 600 may proceed with operation 612,
where the subordinate process sends the consistency group from a
source site to a destination site. In one embodiment, the
consistency group may include all data located at the server that
is not synchronized with the second site. In another embodiment,
the data within the consistency group may be sent from the first
site (e.g., the source site) to a second site (e.g., the
destination site) for integration at the second site, as part of a
replication operation.
[0094] Further still, method 600 may proceed with operation 614,
where the subordinate process removes the marking from each of the
identified one or more logical storage volumes to indicate that a
point-in-time snapshot copy operation is allowed for the one or
more logical storage volumes. In one embodiment, the marking may be
removed from the identified one or more logical storage volumes in
response to a completion of a transfer of the consistency group
from the source site to the destination site. In another
embodiment, removing the marking may include resetting the flag for
each of the one or more logical storage volumes.
[0095] In this way, point-in-time snapshot copy operations may be
prevented from interrupting the creation and transfer of the
consistency group. This may ensure that consistency groups are
created and sent on a regular basis (e.g., at least once during a
predetermined period of time). This in turn may keep a recovery
point objective (RPO) from exceeding a predetermined point, which
may minimize an amount of data that is lost in response to one or
more events at the first site (e.g., hardware or software failure
at the first site, malware at the first site, etc.). For example,
data at the second site may be used to restore data at the first
site in response to the one or more events at the first site. This
may protect data stored within the first site, and may improve a
performance of hardware at the first site in response to one or
more failures.
[0096] Now referring to FIG. 7, a flowchart of a method 700 for
attempting to implement a point-in-time snapshot copy operation is
shown according to one embodiment. The method 700 may be performed
in accordance with the present invention in any of the environments
depicted in FIGS. 1-4 and 8, among others, in various embodiments.
Of course, more or less operations than those specifically
described in FIG. 7 may be included in method 700, as would be
understood by one of skill in the art upon reading the present
descriptions.
[0097] Each of the steps of the method 700 may be performed by any
suitable component of the operating environment. For example, in
various embodiments, the method 700 may be partially or entirely
performed by one or more servers, computers, or some other device
having one or more processors therein. The processor, e.g.,
processing circuit(s), chip(s), and/or module(s) implemented in
hardware and/or software, and preferably having at least one
hardware component may be utilized in any device to perform one or
more steps of the method 700. Illustrative processors include, but
are not limited to, a central processing unit (CPU), an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA), etc., combinations thereof, or any other suitable computing
device known in the art.
[0098] As shown in FIG. 7, method 700 may initiate with operation
702, where data to be transferred as part of a point-in-time
snapshot copy operation is identified. Additionally, method 700 may
proceed with operation 704, where a logical storage volume storing
the data to be transferred is identified. Further, method 700 may
proceed with operation 706, where it is determined that the logical
storage volume is marked with an indication that the point-in-time
snapshot copy operation is not allowed for the logical storage
volume. For example, the indication may include a flag.
[0099] Additionally, method 700 may proceed with operation 708,
where the point-in-time snapshot copy operation is deferred or
failed. In one embodiment, deferring the point-in-time snapshot
copy operation may include rescheduling the point-in-time snapshot
copy operation. In another embodiment, failing the point-in-time
snapshot copy operation may include preventing the setting of a
data consistency application in an idle state.
[0100] FIG. 8 illustrates an exemplary environment 800 for
throttling a point-in-time snapshot copy operation, according to
one embodiment. As shown, a source site 802 includes a plurality of
servers 804A-N. Each of the plurality of plurality of servers
804A-N may be a logical partition (LPAR). Each of the plurality of
servers 804A-N includes one or more logical storage volumes
806A-N.
[0101] Additionally, in one embodiment, a master process 808 of a
first server 804A determines that a consistency group has not been
created by a data consistency application within a predetermined
period of time. In response, the master process 808 sends a request
to create a consistency group to a subordinate process 810A-N
within each of the plurality of servers 804A-N. The request
includes an indication that the creation of the consistency group
is mandatory.
[0102] Additionally, in one embodiment, in response to receiving
the request, each subordinate process 810A-N identifies one or more
of its corresponding storage volumes 806A-N that are associated
with the request to create the consistency group, and marks these
identified storage volumes 806A-N with a flag to indicate that a
point-in-time snapshot copy operation is not allowed for the one or
more logical storage volumes.
[0103] Further, in one embodiment, each subordinate process 810A-N
creates an associated consistency group 812A-N and sends the
associated consistency group 812A-N from the source site 802 to a
destination site 814. For example, the destination site 814 may
include one or more target storage volumes that receive and store
the data within each of the consistency groups 812A-N as part of a
replication operation.
[0104] Flash Copy Throttling within Global Mirror
[0105] Flash copy is used by processes to quickly move data within
a system using internal resources. Once flash copy is allowed onto
a global mirror (with no software changes) in a system where
consistency groups are failed during the establish process it would
be advantageous to have a system that protects the global mirror
recovery point objective (RPO) times. In particular, a steady
stream of small data set level flash copies may affect RPO even
though there is not much data to send in the consistency
groups.
[0106] In one embodiment, a master-controlled throttling mechanism
may be used, where there are periods during consistency group (CG)
formation where flash copy establishes are not allowed and instead
host writes must occur.
[0107] In another embodiment, if the global mirror hasn't formed a
consistency group within a tunable parameter (e.g., a max CG time,
etc.), on the next start increment, a new flag may be set
indicating that a consistency group is to be forced. Each
subordinate may detect the force flag being set during a start
Increment.
[0108] If the force flag is set, a session level flag may be set on
each LPAR in the session. If one or more volumes are suspended, the
consistency group may be failed; otherwise it may be allowed to
form.
[0109] Additionally, a flash copy establish may be implemented. For
example, before issuing a flash copy establish command onto the
global mirror, software may perform a "capability query." If the
flash copy is not allowed due to the forced consistency group flag
being set, then software will perform a host write for data set. If
the flash copy is issued, it will be rejected with an indication to
try again later.
[0110] Further, in one embodiment, a global mirror master may
ignore a drain timer during the creation of the "forced"
consistency group, and may allow the consistency group to form.
Upon successfully creating the consistency group, the master may
send a reset "force consistency group" flag (e.g., on an increment
complete command, on a global mirror fatal command, on a global
mirror terminate command, etc.). If the consistency group is not
successfully created, the master may not issue a command to reset
the force flag, though certain failures or time limits could be
implemented to allow resets.
[0111] Upon determining that an increment is complete, the
subordinate may detect the "reset force consistency group" flag and
may reset the session level flag on each LPAR in the session (which
may indicate that a flash copy operation is again allowed). A
tunable parameter may also exist to indicate when flash copy is
allowed based on how far along the global mirror is with the
creation of the current consistency group. For example, if the data
is drained and the global mirror is in the flash copy state, then
an indication to attempt a command at a later time (e.g., a
predetermined number of seconds, etc.) may be returned.
[0112] In another embodiment, if the global mirror has drained a
predetermined percentage of the current consistency group, then
flash copy may not be allowed. One default may be for flash copy to
always be allowed unless a force flag is set, but users may adjust
this parameter to allow the global mirror to have better RPO.
[0113] In one embodiment, a method for providing a point-in-time
copy process in a remote copy process having consistency groups is
provided, where the processes originate at a Master and having at
least one Subordinate. The method includes detecting formation and
completion of consistency groups, and detecting lack of formation
of a consistency group within a predetermined "Max CG" time,
determining by the Master, subsequent to the detected "Max CG" time
having been exceeded, whether to throttle point-in-time copy
processing, and sending the decision to all Subordinates.
[0114] In one embodiment, the Master, having determined to throttle
point-in-time processing, rejects point-in-time copy processing,
sets a "Force CG" flag detectable by each Subordinate, and allows a
consistency group to form. In another embodiment, each Subordinate,
in response to the "Force CG" flag, sets session level flag for the
current session which indicates that point-in time processing is
not allowed. In yet another embodiment, the Master determines the
status of allowed consistency groups, and determines whether to
allow point-in-time processing.
[0115] The present invention may be a system, a method, and/or a
computer program product at any possible technical detail level of
integration. The computer program product may include a computer
readable storage medium (or media) having computer readable program
instructions thereon for causing a processor to carry out
embodiments of the present invention.
[0116] The computer readable storage medium can be a tangible
device that can retain and store instructions for use by an
instruction execution device. The computer readable storage medium
may be, for example, but is not limited to, an electronic storage
device, a magnetic storage device, an optical storage device, an
electromagnetic storage device, a semiconductor storage device, or
any suitable combination of the foregoing. A non-exhaustive list of
more specific examples of the computer readable storage medium
includes the following: a portable computer diskette, a hard disk,
a random access memory (RAM), a read-only memory (ROM), an erasable
programmable read-only memory (EPROM or Flash memory), a static
random access memory (SRAM), a portable compact disc read-only
memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a
floppy disk, a mechanically encoded device such as punch-cards or
raised structures in a groove having instructions recorded thereon,
and any suitable combination of the foregoing. A computer readable
storage medium, as used herein, is not to be construed as being
transitory signals per se, such as radio waves or other freely
propagating electromagnetic waves, electromagnetic waves
propagating through a waveguide or other transmission media (e.g.,
light pulses passing through a fiber-optic cable), or electrical
signals transmitted through a wire.
[0117] Computer readable program instructions described herein can
be downloaded to respective computing/processing devices from a
computer readable storage medium or to an external computer or
external storage device via a network, for example, the Internet, a
local area network, a wide area network and/or a wireless network.
The network may comprise copper transmission cables, optical
transmission fibers, wireless transmission, routers, firewalls,
switches, gateway computers and/or edge servers. A network adapter
card or network interface in each computing/processing device
receives computer readable program instructions from the network
and forwards the computer readable program instructions for storage
in a computer readable storage medium within the respective
computing/processing device.
[0118] Computer readable program instructions for carrying out
operations of the present invention may be assembler instructions,
instruction-set-architecture (ISA) instructions, machine
instructions, machine dependent instructions, microcode, firmware
instructions, state-setting data, configuration data for integrated
circuitry, or either source code or object code written in any
combination of one or more programming languages, including an
object oriented programming language such as Smalltalk, C++, or the
like, and procedural programming languages, such as the "C"
programming language or similar programming languages. The computer
readable program instructions may execute entirely on the user's
computer, partly on the user's computer, as a stand-alone software
package, partly on the user's computer and partly on a remote
computer or entirely on the remote computer or server. In the
latter scenario, the remote computer may be connected to the user's
computer through any type of network, including a local area
network (LAN) or a wide area network (WAN), or the connection may
be made to an external computer (for example, through the Internet
using an Internet Service Provider). In some embodiments,
electronic circuitry including, for example, programmable logic
circuitry, field-programmable gate arrays (FPGA), or programmable
logic arrays (PLA) may execute the computer readable program
instructions by utilizing state information of the computer
readable program instructions to personalize the electronic
circuitry, in order to perform embodiments of the present
invention.
[0119] Embodiments of the present invention are described herein
with reference to flowchart illustrations and/or block diagrams of
methods, apparatus (systems), and computer program products
according to embodiments of the invention. It will be understood
that each block of the flowchart illustrations and/or block
diagrams, and combinations of blocks in the flowchart illustrations
and/or block diagrams, can be implemented by computer readable
program instructions.
[0120] These computer readable program instructions may be provided
to a processor of a computer, or other programmable data processing
apparatus to produce a machine, such that the instructions, which
execute via the processor of the computer or other programmable
data processing apparatus, create means for implementing the
functions/acts specified in the flowchart and/or block diagram
block or blocks. These computer readable program instructions may
also be stored in a computer readable storage medium that can
direct a computer, a programmable data processing apparatus, and/or
other devices to function in a particular manner, such that the
computer readable storage medium having instructions stored therein
comprises an article of manufacture including instructions which
implement embodiments of the function/act specified in the
flowchart and/or block diagram block or blocks.
[0121] The computer readable program instructions may also be
loaded onto a computer, other programmable data processing
apparatus, or other device to cause a series of operational steps
to be performed on the computer, other programmable apparatus or
other device to produce a computer implemented process, such that
the instructions which execute on the computer, other programmable
apparatus, or other device implement the functions/acts specified
in the flowchart and/or block diagram block or blocks.
[0122] The flowchart and block diagrams in the Figures illustrate
the architecture, functionality, and operation of possible
implementations of systems, methods, and computer program products
according to various embodiments of the present invention. In this
regard, each block in the flowchart or block diagrams may represent
a module, segment, or portion of instructions, which comprises one
or more executable instructions for implementing the specified
logical function(s). In some alternative implementations, the
functions noted in the blocks may occur out of the order noted in
the Figures. For example, two blocks shown in succession may, in
fact, be accomplished as one step, executed concurrently,
substantially concurrently, in a partially or wholly temporally
overlapping manner, or the blocks may sometimes be executed in the
reverse order, depending upon the functionality involved. It will
also be noted that each block of the block diagrams and/or
flowchart illustration, and combinations of blocks in the block
diagrams and/or flowchart illustration, can be implemented by
special purpose hardware-based systems that perform the specified
functions or acts or carry out combinations of special purpose
hardware and computer instructions.
[0123] Moreover, a system according to various embodiments may
include a processor and logic integrated with and/or executable by
the processor, the logic being configured to perform one or more of
the process steps recited herein. By integrated with, what is meant
is that the processor has logic embedded therewith as hardware
logic, such as an application specific integrated circuit (ASIC), a
FPGA, etc. By executable by the processor, what is meant is that
the logic is hardware logic; software logic such as firmware, part
of an operating system, part of an application program; etc., or
some combination of hardware and software logic that is accessible
by the processor and configured to cause the processor to perform
some functionality upon execution by the processor. Software logic
may be stored on local and/or remote memory of any memory type, as
known in the art. Any processor known in the art may be used, such
as a software processor module and/or a hardware processor such as
an ASIC, a FPGA, a central processing unit (CPU), an integrated
circuit (IC), a graphics processing unit (GPU), etc.
[0124] It will be clear that the various features of the foregoing
systems and/or methodologies may be combined in any way, creating a
plurality of combinations from the descriptions presented
above.
[0125] It will be further appreciated that embodiments of the
present invention may be provided in the form of a service deployed
on behalf of a customer to offer service on demand.
[0126] The descriptions of the various embodiments of the present
invention have been presented for purposes of illustration, but are
not intended to be exhaustive or limited to the embodiments
disclosed. Many modifications and variations will be apparent to
those of ordinary skill in the art without departing from the scope
and spirit of the described embodiments. The terminology used
herein was chosen to best explain the principles of the
embodiments, the practical application or technical improvement
over technologies found in the marketplace, or to enable others of
ordinary skill in the art to understand the embodiments disclosed
herein.
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