U.S. patent application number 16/796983 was filed with the patent office on 2021-08-26 for queue management in multi-site storage systems.
The applicant listed for this patent is International Business Machines Corporation. Invention is credited to Kushal Patel, Sarvesh S. Patel, Subhojit Roy.
Application Number | 20210263676 16/796983 |
Document ID | / |
Family ID | 1000005764809 |
Filed Date | 2021-08-26 |
United States Patent
Application |
20210263676 |
Kind Code |
A1 |
Patel; Kushal ; et
al. |
August 26, 2021 |
QUEUE MANAGEMENT IN MULTI-SITE STORAGE SYSTEMS
Abstract
A computer-implemented method to identify redundant Input/Output
(I/O) queues in a multi-site storage system. The method includes
receiving, from a host, by a backup storage system, a request to
process a first set of Input/Output (I/O) queues, wherein the
backup storage system is a second subsystem in a multi-site storage
system. The method includes, allocating memory on the backup
storage system. The method includes, identifying a second set of
I/O queues established at a primary storage system, a first
subsystem in the multi-site storage system. The method includes,
determining the first set of I/O queues and the second set of I/O
queues are redundant. The method includes, responsive to
determining queues are redundant: notifying via the host, that the
first set of the redundancy, terminating a connection between the
host and the backup storage system, and de-allocating the memory to
process the first set of I/O queues.
Inventors: |
Patel; Kushal; (Pune,
IN) ; Roy; Subhojit; (Pune, IN) ; Patel;
Sarvesh S.; (Pune, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
International Business Machines Corporation |
Armonk |
NY |
US |
|
|
Family ID: |
1000005764809 |
Appl. No.: |
16/796983 |
Filed: |
February 21, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06F 3/065 20130101;
G06F 3/0659 20130101; G06F 3/0653 20130101; G06F 3/0604 20130101;
G06F 3/067 20130101 |
International
Class: |
G06F 3/06 20060101
G06F003/06 |
Claims
1. A computer-implemented method comprising: receiving, from a
host, by a backup storage system, a request to process a first set
of Input/Output (I/O) queues on the backup storage system, wherein
the backup storage system is a second subsystem in a multi-site
storage system; allocating memory on the backup storage system for
processing the first set of I/O queues; identifying a second set of
I/O queues established at a primary storage system, wherein the
primary storage system is a first subsystem in the multi-site
storage system. and the backup storage system includes a backup
copy of data stored on the primary storage system; determining the
first set of I/O queues are redundant; determining the second set
of I/O queues are redundant; responsive to determining that the
first set of I/O queues are redundant and the second set of queues
are redundant: notifying via the host, that the first set of I/O
queues are redundant; terminating a connection between the host and
the backup storage system; and de-allocating the memory to process
the first set of I/O queues.
2. The method of claim 1 further comprising: monitoring processing
of the second set of queues; determining a failure of the primary
storage system; notifying the host of the failure of the primary
storage system; in response to determining the failure of the
primary storage system, re-establishing the connection between the
host and the backup storage system and re-allocating the memory to
the second set of I/O queues on the backup storage system; and
processing the second set of I/O queues on the backup storage
system.
3. The method of claim 1, wherein the first set of I/O queues are
redundant when the first set of I/O queues and the second set of
I/O queues process an equivalent set of commands, as included in
the request.
4. The method of claim 1, wherein the host, the primary storage
system, and the backup storage system use a non-volatile memory
express (NVMe) protocol.
5. The method of claim 4, wherein the notifying occurs via an
asynchronous event request through an NVMe qualified name (NQN)
connection.
6. The method of claim 1, further comprising: receiving, from the
host, a second request to process the first set of I/O queues;
determining the request includes an override flag; processing, in
response to the determining that the request includes the override
flag, the first set of I/O queues on the backup storage system.
7. The method of claim 1, wherein the notifying occurs via an
out-of-band communications.
8. The method of claim 7, wherein the out of band communication
includes an application programming interface call.
9. The method of claim 1, wherein the primary storage system and
the backup storage system are included in a disaster recovery
system.
10. The method of claim 9, wherein the disaster recovery system
syncs data between the primary storage system and the backup
storage system.
11. A system comprising: a processor; and a computer-readable
storage medium communicatively coupled to the processor and storing
program instructions which, when executed by the processor, are
configured to cause the processor to: receive, from a host, by a
backup storage system, a request to process a first set of
Input/Output (I/O) queues on the backup storage system, wherein the
backup storage system is a second subsystem in a multi-site storage
system; allocate memory on the backup storage system for processing
the first set of I/O queues; identify a second set of I/O queues
established at a primary storage system, wherein the primary
storage system is a first subsystem in the multi-site storage
system. and the backup storage system includes a backup copy of
data stored on the primary storage system; determine the first set
of I/O queues are redundant; determine the second set of queues are
redundant; responsive to determining that the first set of I/O
queues are redundant and the second set of queues are redundant:
notify via the host, that the first set of I/O queues are
redundant; terminate a connection between the host and the backup
storage system; and de-allocate the memory to process the first set
of I/O queues.
12. The system of claim 11, wherein the program instructions are
further configured to cause the processor to: monitor processing of
the second set of queues; determine, a failure of the primary
storage system; notify the host of the failure of the primary
storage system; re-establish, in response to determining the
failure of the primary storage system, the connection between the
host and the backup storage system and re-allocate the memory to
the second set of I/O queues on the backup storage system; and
process the second set of I/O queues on the backup storage
system.
13. The system of claim 11, wherein the first set of I/O queues are
redundant when the first set of I/O queues and the second set of
I/O queues process an equivalent set of commands, as included in
the request.
14. The system of claim 11, wherein the host, the primary storage
system, and the backup storage system use a non-volatile memory
express (NVMe) protocol.
15. The system of claim 11, wherein the program instructions are
further configured to cause the processor to: receive, from the
host, a second request to process the first set of I/O queues;
determine, the request includes an override flag; process, in
response to determining the request includes the override flag, the
first set of I/O queues on the backup storage system.
16. A computer program product, the computer program product
comprising a computer readable storage medium having program
instructions embodied therewith, the program instructions
executable by a processing unit to cause the processing unit to:
receive, from a host, by a backup storage system, a request to
process a first set of Input/Output (I/O) queues on the backup
storage system, wherein the backup storage system is a second
subsystem in a multi-site storage system; allocate memory on the
backup storage system for processing the first set of I/O queues;
identify a second set of I/O queues established at a primary
storage system, wherein the primary storage system is a first
subsystem in the multi-site storage system. and the backup storage
system includes a backup copy of data stored on the primary storage
system; determine the first set of I/O queues are redundant;
determine the second set of queues are redundant; responsive to
determining that the first set of I/O queues are redundant and the
second set of queues are redundant: notify via the host, that the
first set of I/O queues are redundant; terminate a connection
between the host and the backup storage system; and de-allocate the
memory to process the first set of I/O queues.
17. The computer program product of claim 16, wherein the program
instructions are further configured to cause the processing unit
to: monitor processing of the second set of queues; determine, a
failure of the primary storage system; notify the host of the
failure of the primary storage system; re-establish, in response to
determining the failure of the primary storage system, the
connection between the host and the backup storage system and
re-allocate the memory to the second set of I/O queues on the
backup storage system; and process the second set of I/O queues on
the backup storage system.
18. The computer program product of claim 16, wherein the first set
of I/O queues are redundant when the first set of I/O queues and
the second set of I/O queues process an equivalent set of commands,
as included in the request.
19. The computer program product of claim 16, wherein the host, the
primary storage system, and the backup storage system use a
non-volatile memory express (NVMe) protocol.
20. The computer program product of claim 16, wherein the program
instructions are further configured to cause the processing unit
to: receive, from the host, a second request to process the first
set of I/O queues; determine, the request includes an override
flag; process, in response to determining the request includes the
override flag, the first set of I/O queues on the backup storage
system.
Description
BACKGROUND
[0001] The present disclosure relates to storage systems, and, more
specifically, to improving queue management in multi-site storage
systems.
[0002] Solid state memory systems (e.g., flash, solid-state disks
(SSD), etc.) have many benefits over traditional hard disk drives
(HDD). Solid state is faster and has no moving parts that can fail.
However, many interface standards were developed to operate with
the moving parts of a traditional HDD (e.g., Serial Advanced
Technology Attachment (SATA), Serial Attached Small Computer System
Interface (SAS), etc.). There are new protocols that are designed
for faster data transfer between servers, storage devices, flash
controllers, and other similar components. These new systems can
provide a register interface and command set that enables high
performance storing and retrieving of data in a storage medium.
SUMMARY
[0003] Disclosed is a computer-implemented method to identify
redundant Input/Output (I/O) queues in a multi-site storage system.
The method includes receiving, from a host, by a backup storage
system, a request to process a first set of Input/Output (I/O)
queues on the backup storage system, wherein the backup storage
system is a second subsystem in a multi-site storage system. The
method also includes, allocating memory on the backup storage
system for processing the first set of I/O queues. The method
further includes, identifying a second set of I/O queues
established at a primary storage system, wherein the primary
storage system is a first subsystem in the multi-site storage
system the secondary storage system includes a backup copy of data
stored on the primary storage system. The method includes,
determining the first set of I/O queues are redundant and
determining the second set of I/O queues are redundant. The method
also includes, responsive to determining that the first set of I/O
queues are redundant and the second set of queues are redundant:
notifying via the host, that the first set of I/O queues are
redundant, terminating a connection between the host and the backup
storage system, and de-allocating the memory to process the first
set of I/O queues. Further aspects of the present disclosure are
directed to systems and computer program products containing
functionality consistent with the method described above.
[0004] The present Summary is not intended to illustrate each
aspect of, every implementation of, and/or every embodiment of the
present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Various embodiments are described herein with reference to
different subject-matter. In particular, some embodiments may be
described with reference to methods, whereas other embodiments may
be described with reference to apparatuses and systems. However, a
person skilled in the art will gather from the above and the
following description that, unless otherwise notified, in addition
to any combination of features belonging to one type of
subject-matter, also any combination between features relating to
different subject-matter, in particular, between features of the
methods, and features of the apparatuses and systems, are
considered as to be disclosed within this document.
[0006] The aspects defined above, and further aspects disclosed
herein, are apparent from the examples of one or more embodiments
to be described hereinafter and are explained with reference to the
examples of the one or more embodiments, but to which the invention
is not limited. Various embodiments are described, by way of
example only, and with reference to the following drawings:
[0007] FIG. 1 depicts a cloud computing environment according to an
embodiment of the present invention.
[0008] FIG. 2 depicts abstraction model layers according to an
embodiment of the present invention.
[0009] FIG. 3 is a block diagram of a DPS according to one or more
embodiments disclosed herein.
[0010] FIG. 4 illustrates a functional diagram of a computing
environment suitable for operation of a queue manager, in
accordance with some embodiments of the present disclosure.
[0011] FIG. 5 illustrates a function diagram of a clustering layer,
in accordance with some embodiments of the present disclosure.
[0012] FIG. 6 illustrates a flow chart of an example method to
identify redundant I/O queues in a multi-site storage system, in
accordance with some embodiments of the present disclosure.
DETAILED DESCRIPTION
[0013] Many storage systems provide a mechanism for disaster
recovery via multi-site solutions that can replicate and store
multiple copies of data across multiple storage sites. In disaster
recovery systems, a back-up copy of the customer data is kept at a
site remote from the primary storage location. This copy is in sync
with the primary copy which is used by a host for I/O operations.
If a disaster strikes the primary storage location, the customer
data can be recovered from the back-up copies located at the remote
site.
[0014] In order to better utilize computing resources in multi-site
storage systems, embodiments of the present disclosure may identify
when the host establishes redundant I/O queues for multiple remote
storage systems. Further, embodiments of the present disclosure may
close/delete the redundant queues, thereby increasing the overall
storage system efficiency.
[0015] The following acronyms may be used below:
TABLE-US-00001 API application program interface ARM advanced RISC
machine CD-ROM compact disc ROM CMS content management system CoD
capacity on demand CPU central processing unit CUoD capacity
upgrade on demand DPS data processing system DVD digital versatile
disk EPROM erasable programmable read-only memory FPGA
field-programmable gate arrays HA high availability IaaS
infrastructure as a service I/O input/output IPL initial program
load ISP Internet service provider ISA instruction-set-architecture
LAN local-area network LPAR logical partition PaaS platform as a
service PDA personal digital assistant PLA programmable logic
arrays RAM random access memory RISC reduced instruction set
computer ROM read-only memory SaaS software as a service SLA
service level agreement SRAM static random-access memory WAN
wide-area network
Cloud Computing in General
[0016] 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.
[0017] 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.
Characteristics Are As Follows
[0018] 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.
[0019] 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).
[0020] 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).
[0021] 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.
[0022] 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.
Service Models Are As Follows
[0023] 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.
[0024] 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.
[0025] 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).
Deployment Models Are As Follows
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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).
[0030] 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.
[0031] 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).
[0032] 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:
[0033] 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.
[0034] 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.
[0035] 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.
[0036] 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 mobile
desktop 96.
Data Processing System in General
[0037] FIG. 3 is a block diagram of an example DPS according to one
or more embodiments. The DPS may be used as a cloud computing node
10. In this illustrative example, the DPS 100 may include
communications bus 102, which may provide communications between a
processor unit 104, a memory 106, persistent storage 108, a
communications unit 110, an I/O unit 112, and a display 114.
[0038] The processor unit 104 serves to execute instructions for
software that may be loaded into the memory 106. The processor unit
104 may be a number of processors, a multi-core processor, or some
other type of processor, depending on the particular
implementation. A number, as used herein with reference to an item,
means one or more items. Further, the processor unit 104 may be
implemented using a number of heterogeneous processor systems in
which a main processor is present with secondary processors on a
single chip. As another illustrative example, the processor unit
104 may be a symmetric multi-processor system containing multiple
processors of the same type.
[0039] The memory 106 and persistent storage 108 are examples of
storage devices 116. A storage device may be any piece of hardware
that is capable of storing information, such as, for example
without limitation, data, program code in functional form, and/or
other suitable information either on a temporary basis and/or a
permanent basis. The memory 106, in these examples, may be, for
example, a random access memory or any other suitable volatile or
non-volatile storage device. The persistent storage 108 may take
various forms depending on the particular implementation.
[0040] For example, the persistent storage 108 may contain one or
more components or devices. For example, the persistent storage 108
may be a hard drive, a flash memory, a rewritable optical disk, a
rewritable magnetic tape, or some combination of the above. The
media used by the persistent storage 108 also may be removable. For
example, a removable hard drive may be used for the persistent
storage 108.
[0041] The communications unit 110 in these examples may provide
for communications with other DPSs or devices. In these examples,
the communications unit 110 is a network interface card. The
communications unit 110 may provide communications through the use
of either or both physical and wireless communications links.
[0042] The input/output unit 112 may allow for input and output of
data with other devices that may be connected to the DPS 100. For
example, the input/output unit 112 may provide a connection for
user input through a keyboard, a mouse, and/or some other suitable
input device. Further, the input/output unit 112 may send output to
a printer. The display 114 may provide a mechanism to display
information to a user.
[0043] Instructions for the operating system, applications and/or
programs may be located in the storage devices 116, which are in
communication with the processor unit 104 through the
communications bus 102. In these illustrative examples, the
instructions are in a functional form on the persistent storage
108. These instructions may be loaded into the memory 106 for
execution by the processor unit 104. The processes of the different
embodiments may be performed by the processor unit 104 using
computer implemented instructions, which may be located in a
memory, such as the memory 106.
[0044] These instructions are referred to as program code, computer
usable program code, or computer readable program code that may be
read and executed by a processor in the processor unit 104. The
program code in the different embodiments may be embodied on
different physical or tangible computer readable media, such as the
memory 106 or the persistent storage 108.
[0045] The program code 118 may be located in a functional form on
the computer readable media 120 that is selectively removable and
may be loaded onto or transferred to the DPS 100 for execution by
the processor unit 104. The program code 118 and computer readable
media 120 may form a computer program product 122 in these
examples. In one example, the computer readable media 120 may be
computer readable storage media 124 or computer readable signal
media 126. Computer readable storage media 124 may include, for
example, an optical or magnetic disk that is inserted or placed
into a drive or other device that is part of the persistent storage
108 for transfer onto a storage device, such as a hard drive, that
is part of the persistent storage 108. The computer readable
storage media 124 also may take the form of a persistent storage,
such as a hard drive, a thumb drive, or a flash memory, that is
connected to the DPS 100. In some instances, the computer readable
storage media 124 may not be removable from the DPS 100.
[0046] Alternatively, the program code 118 may be transferred to
the DPS 100 using the computer readable signal media 126. The
computer readable signal media 126 may be, for example, a
propagated data signal containing the program code 118. For
example, the computer readable signal media 126 may be an
electromagnetic signal, an optical signal, and/or any other
suitable type of signal. These signals may be transmitted over
communications links, such as wireless communications links,
optical fiber cable, coaxial cable, a wire, and/or any other
suitable type of communications link. In other words, the
communications link and/or the connection may be physical or
wireless in the illustrative examples.
[0047] In some illustrative embodiments, the program code 118 may
be downloaded over a network to the persistent storage 108 from
another device or DPS through the computer readable signal media
126 for use within the DPS 100. For instance, program code stored
in a computer readable storage medium in a server DPS may be
downloaded over a network from the server to the DPS 100. The DPS
providing the program code 118 may be a server computer, a client
computer, or some other device capable of storing and transmitting
the program code 118.
[0048] The different components illustrated for the DPS 100 are not
meant to provide architectural limitations to the manner in which
different embodiments may be implemented. The different
illustrative embodiments may be implemented in a DPS including
components in addition to or in place of those illustrated for the
DPS 100. Other components shown in FIG. 1
[0049] 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 aspects
of the present invention.
[0050] 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.
[0051] 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.
[0052] 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 aspects of the present
invention.
[0053] Aspects 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.
[0054] These computer readable program instructions may be provided
to a processor of a general purpose computer, special purpose
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
aspects of the function/act specified in the flowchart and/or block
diagram block or blocks.
[0055] 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.
[0056] 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 executed substantially concurrently, 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.
NVMe Queue Manager in Multi-Site Storage Systems
[0057] Non-volatile Memory Express (NVMe) is a storage protocol
that is designed for fast data transfer between servers, storage
devices, and Flash Controllers that typically uses a peripheral
component interconnect express (PCIe) bus. The specification of
NVMe provides a register interface and a command set that enables
high performance Input/Output (I/O). This is an alternative to the
traditional Small Computer System Interface (SCSI) standards (and
other standards like SAS, SATA, etc.) for data transmission across
the hosts and storage systems. One of the major advantages of
NVMe-based Peripheral Components Interconnect Express (PCIe) Flash
over SAS and SATA-based SSDs is reduced latency of access in the
host software stack, leading to higher inputs outputs per second
(IOPS) and lower computing resource utilization.
[0058] NVMe supports parallel I/O processing with multicore servers
that results in faster I/O dispensation that leads to reduction in
I/O latency. Since there are multiple cores that are processing I/O
requests simultaneously, system performance increases due to
optimal utilization of CPU resources. Additionally, NVMe is
designed in a way that it expects to use a lesser number of CPU
instructions per I/O. NVMe also supports 64,000 commands in a
single message queue and a maximum of 65,535 I/O queues.
[0059] NVMe over Fabrics (NVMe-oF) is an extension to local PCIe
NVMe that allows the benefits of NVMe like high-performance and
low-latency across network fabrics. Servers and storage devices can
be connected over an Ethernet network or a fiber channel, and both
of these interconnects support NVMe commands over the fabric that
extends the advantages of NVMe protocol to interconnected system
components.
[0060] NVMe-oF supports multiple I/O queues for regular I/O
operation from host to storage systems. A maximum of .about.65000
queues are supported by NVMe with .about.64000 entries in each
queue. The host driver generally creates the queues once a
connection is established. Once the host is connected to the target
system, a special purpose queue is created upon association (e.g.,
an Admin Queue). As the name suggests, the Admin Queue is used to
transfers control commands from an initiator to the target device.
Once the Admin Queue is created, it is used by the host to create
I/O queues based on system requirements. The host may establish
multiple I/O queues to a single controller with the same NVMe
qualified name (NQN) and have multiple namespaces (or Volumes)
mapped to it. A volume can be a set of data (e.g., one or more
extents, etc.) An NQN is a naming convention used to identify a
connection between a host and a remote storage system. Once I/O
queues are established, I/O commands are submitted to the I/O
Submission queue (SQ) and I/O responses are collected from the
completion queue (CQ). These I/O queues can be added or removed
using control instructions sent via the Admin Queue for that
session.
[0061] When a command is received on the target device for I/O
queue creation, it performs initial system checks for max supported
queues and other relevant fields, creates an I/O queue, and assigns
this I/O queue to a CPU core on the storage controller. Once done,
a response to the queue creation request is returned via the admin
completion queue. Each I/O queue is assigned to a specific CPU core
by the storage controller. This allows parallelism and boosts
throughput of the system. Core assignment logic is implemented at
the target storage controller and I/O queues to core mapping is
performed based on a predefined policy at the storage
controller.
[0062] Many storage systems provide a mechanism for disaster
recovery. A disaster can be any natural or human caused event that
permanently or temporarily renders a storage system inoperable.
Disaster recovery systems may include multi-site solutions that can
replicated data across the various sites. In disaster recovery
systems, a back-up copy of the customer data may be kept at a site
remote from the primary storage location. In some instances, the
remote site may be at the same physical location, but have a
separate power source. If a disaster strikes the primary storage
location, the data can be recovered from the back-up copies located
at one or more remote sites. Synchronous copying involves sending
primary data to the secondary location and confirming the reception
of such data before completing the current I/O operation. That is,
a subsequent I/O operation at the primary site cannot start until
the primary data has been successfully copied to the secondary
storage system. Data transfer and synchronization between the two
sites is managed by a controller (e.g., storage area network (SAN)
Volume Controller). The controllers may be configured to act as a
clustered system.
[0063] In some embodiments of disaster recovery systems, the host
is connected to both the primary and the backup storage site. An
application can send an instruction to store a set of data on the
disaster recovery system. In response to the request/command, I/O
queues are established at both the primary and secondary storage
systems. Establishing the I/O queues includes allocating memory
space to process the I/O queue (e.g., mapping host volumes to
memory). However, the host will generally process the queues at the
primary site. In the disaster recovery system, the primary site may
have functionality to automatically sync/backup the data on the
backup site. Thus, establishing I/O queues while the primary site
is processing the same queues unnecessarily utilizes valuable
memory at the secondary site, preventing other applications from
using the previously allocated space.
[0064] Embodiments of the present disclosure can reduce the
inefficiencies described above. Embodiments of the present
disclosure monitor for redundant I/O queues established on multiple
locations in a multi-site storage system. In response to
identifying/determining there are redundant queues, the storage
system may notify the host to deallocate the allocated memory.
Thus, other applications/processes may utilize the de-allocated
memory and other computing resources, thereby increasing the
overall efficiency of the system.
[0065] Embodiments of the present disclosure increase system
efficiency at the host. Once the host receives a notification of
the redundant queues, it may also deallocate the memory reserved
from the processing the I/O queues on the secondary system. The
host may then track which queues are completed with the primary
system, and store completion information. This may reduce a queue
bottleneck in the host, allowing for more efficient processing of
the I/O queues associated with the primary storage system and/or
the host allocating additional queues for the primary system.
[0066] Embodiments of the present disclosure may be implemented
within existing and deployed multi-site and/or disaster recovery
storage systems. No significant hardware and/or software changes
are needed to gain some benefits of the current disclosure.
[0067] In some embodiments, a storage manager identifies queues (or
a request to establish queues) that have been received from a host.
The storage manager may then determine similar queues are being
processed on a different storage system. The two storage systems
may be part of a disaster recovery system. The storage manager may
notify the host of the redundant queues. In some embodiments, the
notification is through the same channel the queues are established
(e.g., NVMe Qualified Name (NQN) connections). In some embodiments,
the notification is out-of-band (e.g., using a separate
communication protocol). The host may terminate the connection in
response the notification, and the de-allocated memory in the host
and the storage system may be allocated to a different process.
[0068] In some embodiments, the host monitors and/or tracks the
completion of queues from processes on the primary storage system.
In the event of a disaster (e.g., loss of connection to the primary
storage system), the host may re-establish the connection to the
secondary storage system. The queues may not be established with
the secondary storage system.
[0069] The aforementioned advantages are example advantages, and
embodiments exist that can contain all, some, or none of the
aforementioned advantages while remaining within the spirit and
scope of the present disclosure.
[0070] Referring now to various embodiments of the disclosure in
more detail, FIG. 4 is a representation of a computing environment
400 that is capable of running a storage manager, in accordance
with one or more embodiments of the present disclosure. Many
modifications to the depicted environment may be made by those
skilled in the art without departing from the scope of the
disclosure.
[0071] Computing environment 400 includes host 410, primary storage
420, backup storage 430, clustering layer 440, and network 450.
Network 450 can be, for example, a telecommunications network, a
local area network (LAN), a wide area network (WAN), such as the
Internet, or a combination of the three, and can include wired,
wireless, or fiber optic connections. Network 450 may include one
or more wired and/or wireless networks that are capable of
receiving and transmitting data, voice, and/or video signals,
including multimedia signals that include voice, data, and video
information. In general, network 450 may be any combination of
connections and protocols that will support communications between
host 410, primary storage 420, backup storage 430, clustering layer
440, and other computing devices (not shown) within computing
environment 400. In some embodiments, host 410, primary storage
420, and backup storage 430, may include a computer system, such as
the data processing system 100.
[0072] Host 410 can be a standalone computing device, a management
server, a web server, a mobile computing device, or any other
electronic device or computing system capable of receiving,
sending, and processing data. In some embodiments, host 410 can
represent a server computing system utilizing multiple computers as
a server system, such as in a cloud computing environment shown in
FIG. 1. In some embodiments, host 410 represents a computing system
utilizing clustered computers and components (e.g., database server
computers, application server computers, etc.) that act as a single
pool of seamless resources when accessed within computing
environment 400. In some embodiments host 410 includes, storage
manager 412, application 414, host controller 416, and queue
manager 418.
[0073] Storage manager 412 can be any combination of hardware and
software configured to monitor for and remedy inessential I/O
queues in a multi-site storage system. Storage manager 412 may be
included in one or more of host 410, primary storage 420, backup
storage 430, and clustering layer 440. However, it is shown in host
410 for illustration and by way of example.
[0074] In some embodiments, storage manager 412 can track the
generation and completion of I/O queues being processed at remote
storage sites (e.g., primary storage 420). In some embodiments, the
tracking is in response to a notification and/or signal of
redundant I/O queues. The tracked data may be stored within host
410 existing storage structure. The signal may be received from
notifier engine 444 and/or out of band API 445. In some
embodiments, the connection to backup storage 430 is terminated in
response to receiving the signal. In some embodiments, storage
manager 412 re-initiates a connection to backup storage 430 in
response to storage 420 failing. The connection may include
establishing I/O queues based on tracking data stored in host
410.
[0075] In some embodiments, storage manager 412 overrides the
termination signal. A flag may be included in the initial request
or sent in response to the signal.
[0076] Application 414 can be any combination of hardware and/or
software configured to perform a function (e.g., messaging
application, etc.) on host 410. In some embodiments, application
414 includes two or more separate applications. Application 414 may
be configured to retrieve data from and/or store data in primary
storage 420 and/or backup storage 430. In some embodiments,
application 414 is configured to backup data on a disaster recovery
system.
[0077] Host controller 416 can be any combination of hardware
and/or software configured to facilitate the I/O queue transfer
from an initiating device (e.g., host 410) and a storage system
(e.g., primary storage 420). In various embodiments, host
controller 416 may include one or more of storage manager 412,
and/or queue manager 418. However, FIG. 4 shows them as separate
components within host 410.
[0078] In some embodiments, host controller 416 generates and
assigns I/O queues to various cores. The queues may be generated
and assigned based on the requirements of the capabilities and need
of host 410 and/or the capabilities and need of the target storage
system(s). In some embodiments, host controller allocates memory
for the processing of the queues on the initiator (e.g., host)
and/or target devices.
[0079] Primary storage 420 can be a standalone computing device, a
management server, a web server, a mobile computing device, or any
other electronic device or computing system capable of receiving,
sending, and processing data. In other embodiments, primary storage
420 can represent a server computing system utilizing multiple
computers as a server system, such as in a cloud computing
environment. In some embodiments, primary storage 420 represents a
computing system utilizing clustered computers and components
(e.g., database server computers, application server computers,
etc.) that act as a single pool of seamless resources when accessed
within computing environment 400. In some embodiments, primary
storage 420 is an NVMe storage system. In some embodiments, primary
storage 420 uses peripheral component interconnect express (PCLe)
as a physical component to transfer data to and from the storage
medium. PCLe is a high-speed connection and bus. PCLe can have a
higher throughput with a lower pin count than some other standard
connection types (e.g., PCI, accelerated graphics port (AGP),
etc.). In some embodiments, primary storage 420 includes primary
controller 421, primary cores 422, and primary storage devices
423.
[0080] Primary controller 421 can be any combination of hardware
and/or software configured to facilitate the I/O queue transfer
from an initiating device (e.g., host 410) and primary storage 420.
In some embodiments, primary controller 421 is consistent with host
controller 416. In various embodiments, Primary controller 421 can
include one or more of storage manager 412, and/or queue manager
418.
[0081] Primary cores 422 can be any combination of hardware and/or
software configured to process data. In some embodiments, primary
cores 422 includes primary cores 422-1, 422-2, through 422-n.
Primary cores 422 may refer to 422-1 through 422-n collectively or
representatively. In various embodiments, primary cores 422 may
include any number of cores. In some embodiments, each core of
primary core 422 may be assigned to process one or more I/O queues.
Primary cores 422 may perform read/write operations for primary
storage devices 423.
[0082] Primary storage devices 423 can be any combination of
hardware and/or software configured for the long-term storage of
data. In some embodiments, primary storage devices 423 includes
primary storage devices 423-1, 423-2, through 423-n. Primary
storage devices 423 may refer to 423-1 through 423-n collectively
or representatively. In various embodiments, primary storage
devices 423 may include any number of devices (e.g., n can be any
number). Each device of storage device 423 may be the same type of
device, may be different types, or may be any combination of
devices. The storage devices may include any type of storage medium
(e.g., tape drives, hard disk drives (HDD), solid state drives
(SSD), flash, etc.)
[0083] Backup storage 430 (secondary storage) can be a standalone
computing device, a management server, a web server, a mobile
computing device, or any other electronic device or computing
system capable of receiving, sending, and processing data. In other
embodiments, primary storage 420 can represent a server computing
system utilizing multiple computers as a server system, such as in
a cloud computing environment, as shown in FIG. 1. In some
embodiments, primary storage 420 represents a computing system
utilizing clustered computers and components (e.g., database server
computers, application server computers, etc.) that act as a single
pool of seamless resources when accessed within computing
environment 400. In some embodiments, backup storage 430 is an NVMe
storage system. In some embodiments, primary storage 420 uses
peripheral component interconnect express (PCLe) as a physical
component to transfer data to and from the storage medium. PCLe is
a high-speed connection and bus. PCLe can have a higher throughput
with a lower pin count than some other standard connection types
(e.g., PCI, AGP, etc.). In some embodiments, backup storage 430
includes backup controller 431, backup cores 432, and backup
storage devices 433. In some embodiments, backup storage 430 is
consistent with primary storage 420.
[0084] Backup controller 431 can be any combination of hardware
and/or software configured to facilitate the I/O queue transfer
from an initiating device (e.g., host 410) and backup storage 430.
In some embodiments, backup controller 431 is consistent with
primary controller 421.
[0085] Backup cores 432 can be any combination of hardware and/or
software configured to process data. In some embodiments, backup
cores 432 includes secondary cores 432-1, 432-2, through 432-n.
backup cores 432 may refer to 432-1 through 432-n collectively or
representatively. In various embodiments, backup cores 432 may
include any number of cores. In some embodiments, backup cores 432
may be consistent with primary cores 422.
[0086] Backup storage devices 433 can be any combination of
hardware and/or software configured for the long-term storage of
data. In some embodiments, backup storage devices 433 includes
backup storage devices 433-1, 433-2, through 433-n. Backup storage
devices 433 may refer to 433-1 through 433-n collectively or
representatively. However, in various embodiments, backup storage
devices 433 may include any number of devices. In some embodiments,
backup storage devices may be consistent with primary storage
devices 423.
[0087] Clustering layer 440 can be any combination of hardware
and/or software configured to sync data between primary storage 420
and backup storage 430. In some embodiments, clustering layer 440
includes primary controller 421 and backup controller 431. In some
embodiments, clustering layer monitors data
transfers/requests/connections between host 410 and the associated
storage systems. This may include identical/equivalent/redundant
queues established by the host between multiple storage systems.
Redundant doesn't necessarily mean exactly the same, such as the
same I/O commands in the queue, rather the commands in the I/O
queues stem from a common source. The common source may be a common
application, a common command. Said differently, redundant queues
may include queues, where the automatic backup processes of the
disaster recovery system provide the same results (e.g., backup
copy of the data after the I/O commands are complete on a different
storage subsystem) as being processed via the host to primary
storage and host to backup storage I/O commands.
[0088] In some embodiments, clustering layer 440 can transfer data
and/or messages between host 410, primary storage 420, and backup
storage 430. The messages may be sent via pre-established
connections (e.g., NQN's), or out of band communications.
Clustering layer 440 is discussed in further detail in relation to
FIG. 5.
[0089] FIG. 5 is an expanded view of clustering layer 440. In some
embodiments, clustering layer 440 includes queue manager 441, site
mapper 442, queue identifier 443, notifier engine 444, and
out-of-band API 445.
[0090] Queue manager 441 can be any combination of hardware and or
software configured to set up and maintain an admin queue for each
host connected to the storage system. Each time an I/O queue is
sent from a host to the target, it passes through the admin queue.
The admin queue then assigns the queue to a core, based on
instruction and logic in an NVMe storage controller (e.g., primary
controller 421). After a core completes the processing of the
command I/O queue, the result is placed in the admin queue and is
subsequently forwarded to the host.
[0091] In some embodiments, queue manager 441 keeps a record of how
many queues have been sent to and returned from each core.
Therefore, at any time, queue manager 441 can determine the number
of queues distributed to any particular core.
[0092] Site to queue mapper 442 can be any combination of hardware
and/or software configured to map I/O queue creation requests to
one or more storage devices in a multi-site storage system. In some
embodiments, site to queue mapper 442 monitors and/or tracks which
I/O queues are established at each storage site. The monitoring may
include tracking which queues are processed. This may include
relating to the source of the I/O queue request. For example, site
to queue mapper 442 may include which queues are the result of
which request by host 110/application 114. In some embodiments,
site to queue mapper can map I/O queues to more than one storage
site simultaneously. The processing of each the I/O queue at each
site may be tracked.
[0093] Queue identifier 443 can be any combination of hardware
and/or software configured to identify I/O queues established
across multiple sites in a multi-site storage system. In some
embodiments, queue identifier 443 can identify redundant queues. A
redundant I/O queue may be one or more queues that are created by a
request from host 410 and/or application 414 on multiple storage
systems in a multi-site storage system.
[0094] Notifier engine 444 can be any combination of hardware
and/or software configured to communicate data with host 410. In
some embodiments, notifier engine 444 sends a signal in response
redundant queues being identified. The signal may instruct host 410
to terminate the connection, thereby freeing up resources used to
maintain the redundant queues. In some embodiments, the signal may
include an instruction for the host to track and record completion
of the I/O queues in the related request. Thus, in the event of a
site failure, the connection may be re-established, and the backup
storage system may provide I/O support for host 410.
[0095] In some embodiments, the notifications are sent as an
asynchronous event request (AER). An AER is a request that is
returned after a condition is met. For example, an AER may be
sent/returned to notify the host of redundant queues.
[0096] Out of band API 445 can be any combination of hardware
and/or software configured to notify host outside of the NQN
connection, of redundant I/O queue creation. The out-of-band API
445 allows for a separate communication method. This may provide
notification in the event of issues (e.g., bandwidths, bottleneck,
etc.) within the NQN. This may be sent to storage manager 412,
application 414 and/or host 410.
[0097] FIG. 6 depicts a flowchart of an example method, method 600,
for managing I/O queues in a multi-site storage system, that can be
performed in a computing environment (e.g., computing environment
400 and/or host 410). One or more of the advantages and
improvements described above for identifying and correcting
duplicate queues may be realized by method 600, consistent with
various embodiments of the present disclosure.
[0098] Method 600 can be implemented by one or more processors,
host 410, storage manager 412, primary storage 420, backup storage
430, clustering layer 440, their subcomponents, and/or a different
combination of hardware and/or software. In various embodiments,
the various operations of method 600 are performed by one or more
of host 410, storage manager 412, primary storage 420, backup
storage 430, clustering layer 440, and the subcomponents of each of
the foregoing. For illustrative purposes, the method 600 will be
described as being performed by queue manager 441.
[0099] At operation 602, queue manager 441 receives an I/O queue
creation request. In some embodiments, the request is generated by
host 410. Host 410 may send the request to primary storage 420
and/or backup storage 430. In some embodiments, the request is
generated by application 414. In some embodiments, receiving the
request includes assigning the queues to one or more of backup
cores 432. In some embodiments, the request is sent to a disaster
recovery system.
[0100] In some embodiments, operation 602 includes
obtaining/checking for the volume details mapped to host 410. This
may be obtained from a volume mapping table. The volume mapping
table shows what volumes of memory are currently being
accessed/used by one or more systems. It may include details about
which and/or how many I/O queues have been established.
[0101] At operation 604, queue manager 441 identifies I/O queues
established on a separate storage system. For example, if the
request was received by backup storage 430, then queue manager 441
may check primary storage 420 for established I/O queues. In some
embodiments, operation 604 includes fetching NQN data for the
connections. This may be stored as metadata on primary storage
420.
[0102] In some embodiments, the previously established queues are
obtained by clustering layer 440, and/or backup controller 431.
These can be obtained from host 410, and/or storage manager 412
[0103] At operation 608, queue manager 441 determines if the
request includes redundant queues. In some embodiments, a queue is
redundant/unnecessary/inessential if the queues that would be
established in response to the request are the same as the queues
established between host 410 and primary storage 420. In some
embodiments, determining the queues are inessential is based on
comparing volume mapping data with host 410 against the NQN's (or
established I/O queues) on primary storage 420.
[0104] In some embodiments, operation 608 includes checking for
additional data with the request. The additional data may include a
signal to process the I/O queues even if the queues are redundant.
The additional data may be a flag or other similar data. This may
be an override flag. If the additional flag is present, then queue
manager 441 may proceed as through there are no inessential queues.
For example, an override flag may cause queue manager 441 to skip
operation 606 and/or define the outcome of operation 608.
[0105] If it is determined there are inessential queues (608:YES)
then queue manager 441 proceeds to operation 610. If it is
determined there are no inessential queues (608:NO) then queue
manager 441 proceeds to operation 620.
[0106] At operation 610, queue manager 441 notifies the host of the
inessential queues from the request. In some embodiments, the
notification is sent from the target (e.g., backup storage 430), to
host 410. The signal may be sent via the same method the request
was received, such as through the NQN connection. In some
embodiments, the notification of inessential queues is sent out of
band. The out of band may be an API and/or other similar
communication protocol. In some embodiments, the notification is
sent as an AER.
[0107] In some embodiments, operation 610 includes notifying backup
controller 431 of the essential queues. This may allow the backup
controller 431 to release/deallocate any resources related to the
request.
[0108] At operation 612, queue manager 441 monitors the progress of
I/O queue completion at primary storage 420. In some embodiments,
monitoring includes tracking and recording the completion of each
queue, request, extent, and/or volume. In some embodiments, the one
or more of host 410, host controller 416, and application 414
monitor I/O queue processing. In some embodiments, one or more of
clustering layer 440 backup storage 430, and backup controller 431
monitor I/O queue processing. In some embodiments, the monitoring
is commenced in response to the inessential queue notification
being generated and/or sent. While it will use some computing
resources to monitor queue processing, it will be less than is
needed to maintain the redundant queues on both host 410 and backup
storage 430. The now freed resources can be utilized by different
applications and/or processes.
[0109] At operation 614, queue manager 441 determines if primary
storage 420 failed (e.g., is no longer operating). The failure may
be in response to a natural or human caused event. In some
embodiments, failure is when the system can no longer
send/receive/process data. In some embodiments, primary storage 420
failed when NQN and/or other connections are terminated before the
queues are completed. In some embodiments, host 410 determines
primary storage 420 failed. In some embodiments, clustering layer
440 determines primary storage 420 failed. For example, if backup
controller 431 loses communication with primary controller 421,
that may indicate a loss of power, and thereby a failure.
[0110] If it is determined primary storage 420 failed (614:YES)
then queue manager 441 proceeds to operation 618. If it is
determined primary storage 420 has not failed (614:NO) then queue
manager 441 proceeds to operation 616.
[0111] At operation 616, queue manager 441 completes processing of
all I/O queues at primary storage 420 per received request. In some
embodiments, queue manager 441 returns to operation 602 in response
to processing/completing all I/O queues.
[0112] At operation 618, queue manager 441 reestablishes I/O queues
to backup storage 430. In some embodiments, this includes a new
request for an NQN connection between host 410 and backup storage
430. In some embodiments, the I/O queues established on the
reestablished connection are based on the monitoring of operation
612.
[0113] At operation 620, queue manager 441 processes the queues at
backup storage 430 per received request. In some embodiments, queue
manager 441 returns to operation 602 in response to
processing/completing all I/O queues.
Computer Technology and Computer Readable Media
[0114] The one or more embodiments disclosed herein accordingly
provide an improvement to computer technology. For example, an
improvement to a search engine allows for a more efficient and
effective search for information by the user. The ability to access
stored information with which the user has interacted with in some
manner, and allowing the weighting of the importance of this
information to decay over time beneficially improves the operation
of the search and benefits the user in that more pertinent results
may be presented to the user.
[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 aspects
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 aspects of the present
invention.
[0119] Aspects 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 general purpose computer, special purpose
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
aspects 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 executed substantially concurrently, 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.
* * * * *