Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS AND METHOD FOR ASSURING RECOVERY OF TEMPORARY RESOURCES IN A
LOGICALLY PARTITIONED COMPUTER SYSTEM
BACKGROUND OF THE INVENTION
Technical Field
This invention generally relates to data processing, and more
specifically relates to resource management in a logically partitioned
computer system.
Backaround Art
Since the dawn of the computer age, computer systems have evolved
into extremely sophisticated devices that may be found in many different
settings. Computer systems typically include a combination of hardware
(e. g., semiconductors, circuit boards, etc.) and software (e. g., computer
programs). As advances in semiconductor processing and computer
architecture push the performance of the computer'hardware higher, more
sophisticated computer software has evolved to take advantage of the
higher performance of the hardware, resulting in computer systems today
that are much more powerful than just a few years ago.
The combination of hardware and software on a particular computer
system defines a computing environment. Different hardware platforms and
different operating systems thus provide different computing environments.
In recent years, engineers have recognized that it is possible to provide
different computing environments on the same physical computer system by
logically partitioning the computer system resources to different
computing environments. The eServer iSeries computer system developed lay
IBM is an example of a computer system that supports logical partitioning.
If logical partitioning on an iSeries computer system is desired,
partition manager code (referred to as a °°hypervisor" in
iSeries
terminology) is installed that allows defining different computing
environments on the same platform. ~nce the partition manager is
installed, logical partitions may be created that define different
computing environments. The partition manager manages the logical
partitions to assure they can share needed resources in the computer
system while maintaining the separate computing environments defined by
the logical partitions.
A computer system that includes multiple logical partitions
typically shares resources between the logical partitions. For example, a
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computer system with two logical partitions and a single CPU could be
defined that allocates 50~ of the CPU to each partition, that allocates
33~ of the memory to the first partition and 67~ of the memory to the
second partition, and that allocates two different I/0 slots to the two
logical partitions, one per partition. Once logical partitions are
defined and shared resources are allocated to the logical partitions, each
logical partition acts as a separate computer system. Thus, in the
example above that has a single computer system with two logical
partitions, the two logical partitions will appear for all practical
purposes to be two separate and distinct computer systems.
Recent developments in the computer industry allow a customer to
purchase additional resources on demand. In this scenario, a customer
purchases a computer system that may include one or more resources that
are initially disabled. There are several different ways a manufacturer
may then allow a customer to use these additional resources. If the
customer desires to permanently upgrade their system to include additional
resources, the customer can purchase a software key from the system
manufacturer. Entering the software key results in the resources)
specified in the software key being permanently enabled, as if the system
were purchased with these resources enabled. This is known in the art as
°'permanent capacity upgrade on demand.°° If the customer
does not need
permanent use of additional resources, the customer may request an
enablement code from the manufacturer to enable these resources for a
specified resource-time. This is known in the art as ~°temporary
capacity
on demand.°' The related application "METHOD TO PROVIDE ON-DEMAND
RESOURCE
ACCESS°', serial no. 10/406,652 filed on 04/03/03, discloses a
system and
method for providing temporary capacity on demand. One way to provide
temporary capacity on demand is to enable resources for a specified
resource-time, and to disable the resources once the specified
resource-time has expired.
Another way to provide temporary access to resources is known as
"metered capacity on demand", and is the subject of the related
application "APPARATUS AND METHOD FOR PROVIDING METERED CAPACITY OF
COMPUTER RESOURCES", serial no.l0/616/676 filed on 10 July 2003. V~h.en
metered capacity on demand is used, a temporary resource is enabled, and
only actual use of the resource is billed to the customer.
When either temporary capacity on demand or metered capacity on
demand are used, the customer typically enters into a contractual
agreement with the manufacturer, who monitors the system to assure the
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customer is properly billed for the temporary or metered capacity on
demand. Another way to provide temporary access to computer system
resources is known as "activate immediate", where a customer purchases (or
is given on a "trial" basis) an enablement code that includes a specified
resource-time, but the customer does not sign a contract and the
manufacturer does not monitor the system. Because the manufacturer does
not monitor the system, the system is vulnerable to potential tampering by
the customer. In an activate immediate scenario, the customer purchases'
an enablement code for a specified resource-time. The resources are then
enabled for the specified resource-time. When the specified resource-time
expires, the resources should be recovered (i.e., disabled).
However, there are limitations to what the system can do to recover
temporary resources due to system integrity and legal considerations. In
other words, it would be unacceptable to force recovery of temporary
resources because doing so may prevent the computer system from running
the customer's workload. This means that certain actions by the customer
could prevent the recovery of resources when the specified resource-time
expires. For example, if the customer changes the minimum resource
specification to a level that includes one or more of the temporary
resources, the system may be unsuccessful at recovering all of the
temporary resources. In this case, the customer could enjoy permanent
enablement of temporary resources without paying the manufacturer for
those resources.
The present invention seeks to address these problems.
STATEMENT OF INVENTION
A capacity manager provides temporary resources on demand in a
manner that assures the temporary resources may be recovered when the
specified resource-time expires. Access to minimum resource
specifications corresponding to the logical partitions is controlled to
prevent the sum of all minimum resource specifications from exceeding the
base resources on the system. By assuring the sum of minimum resource
specifications for all logical partitions is satisfied by the base
resources on the system, the temporary resources may always be recovered
when required without impacting the minimum level of service defined by
the customer.
The foregoing and other features and advantages of the invention
will be apparent from the following more particular description of
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preferred embodiments of the invention, as illustrated in the accompanying
drawings.
BRIEF DESCRIPTION OF DRAV~7INGS
The preferred embodiments of the present invention will hereinafter
be described in conjunction with the appended drawings, where like
designations denote like elements, and:
FIG. 1 is a block diagram of a computer apparatus in accordance with
the preferred embodiments;
FTG. 2 is a block diagram of the partition manager of FIG. 1;
FIG. 3 is a block diagram showing logical components in a logically
partitioned computer system;
FIG. 4 is a flow diagram of a method for providing temporary
resources on demand;
FIG. 5 is a flow diagram of a method in accordance with the
preferred embodiments for providing temporary resources on demand in a
manner that assures the temporary resources may be recovered; and
FIGS. G-10 each represent the allocation of processors between three
logical partitions to illustrate the principles of the preferred
embodiments.
DETAILED DESCRIPTION OF PREFERRED EMS~DI1'~NT
The preferred embodiments provide a significant advance over the
prior art by assuring that temporary resources may always be recovered
once the time period for enabling the temporary resources expires without
impacting the minimum level of service defined by the customer. Access to
the minimum resource specification in each logical partition is controlled
so the sum of minimum resource specifications for all logical partitions
cannot exceed the base resources in the system. Because the sum of
minimum resource specifications cannot exceed the available base
resources, recovery of all temporary resources is assured.
Referring to FIG. 1, a computer system 100 is an enhanced IBM
eServer iSeries computer system, and represents one suitable type of
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computer system that supports logical partitioning in accordance with the
preferred embodiments. Those skilled in the art will appreciate that the
mechanisms and apparatus of the present invention apply equally to any
computer system that supports logical partitions. As shown in FIG. 1,
computer system 100 comprises one or more processors 110 connected to a
main memory 120, a mass storage interface 130, a display interface 140, a
network interface 150, and a plurality of I/0 slots 180. These system
components are interconnected through the use of a system bus 160. Mass
storage interface 130 is used to connect mass storage devices (such as a
direct access storage device 155) to computer system 100. One specific
type of direct access storage device is a CD RW drive, which may read data
from a CD RW 195. Note that mass storage interface 130, display interface
140, and network interface 150 may actually be implemented in adapters
coupled to I/0 slots 180.
Main memory 120 contains a partition manager 121 and N logical
partitions 125, shown in FIG. 1 as logical partitions 125A through 125N.
Partition manager 121 preferably creates these N logical partitions 125.
Each logical partition preferably includes a corresponding operating
system 126, shown in FIG. 1 as operating systems 126A through 126N.
Operating system 126 is a multitasking operating system, such as
0S/400, AIX, or Linux; however, those skilled in the art will appreciate
that the spirit and scope of the present invention is not limited to any
one operating system. 1'W y suitable operating system can be used.
Operating system 126 is a sophisticated program that contains low- level
code to manage the resources of computer system 100. Some of these
resources are processor 110, main memory 120, mass storage interface 130,
display interface 140, network interface 150, system bus 1G0, and I/0
slots 180. The operating system 126 in each partition may be the same as
the operating system in other partitions, or may be a completely different
operating system. Thus, one partition can run the 0S/400 operating
system, while a different partition can run another instance of 0S/400,
possibly a different release, or with different environment settings
(e. g., time zone). The operating systems in the logical partitions could
even be different than 0S/400, provided it is compatible with the hardware
(such as AIX or Linux). In this manner the logical partitions can provide
completely different computing environments on the same physical computer
system.
The partition manager 121 preferably includes capacity manager 122
that manages temporary resources. Note that the "temporary resources"
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discussed herein may be provided using "temporary capacity on demand",
"metered capacity on demand", or "activate immediate" discussed in the
Background Art section above. In addition, the preferred embodiments also
extend to any and all ways to provide temporary resources in a computer
system, whether currently known or developed in the future. The capacity
manager 122 includes a minimum resource enforcement mechanism 123 that
assures the sum of all minimum resource specifications on apparatus 100
does not exceed a level that is satisfied by the base resources of
apparatus 100. The term "base resources" as used herein refers to the
resources that are permanently enabled on apparatus 100, and includes all
resources that are enabled when the computer system is acquired, and
includes all additional resources that are subsequently permanently
enabled. By assuring the minimum resource specification for computer
system 100 does not exceed the level of base resources, the capacity
manager 122 will always be able to recover temporary resources when the
corresponding resource-time expires.
The partitions 125A-125N are shown in FIG. 1 to reside within the
main memory 120. However, one skilled in the art will recognize that a
partition is a logical construct that includes resources other than
memory. A logical partition typically specifies a portion of memory,
along with an assignment of processor capacity and other system resources,
such as memory 120 or I/0 slots 180. Thus, one partition could be defined.
to include two processors and a portion of memory 120, along with one or
more I/0 processors and/or slots that can provide the functions of mass
storage interface 130, display interface 140, network interface 150, or
interfaces to I/0 devices plugged into I/0 slots 180. Another partition
could then be defined to include three other processors, a different
portion of memory 120, and one or more I/~ processors. The partitions are
shown in FIG. 1 to symbolically represent logical partitions, which would
include system resources outside of memory 120 within computer system 100.
Note also that the partition manager 121 preferably resides in memory and
hardware separate from the partitions and include facilities and
mechanisms that are not directly available to the partitions.
Computer system 100 utilizes well known virtual addressing
mechanisms that allow the programs of computer system 100 to behave as if
they only have access to a large, single storage entity instead of access
to multiple, smaller storage entities such as main memory 120 and DASD
device 155. Therefore, while partition manager 121 and the partitions
125A-125N are shown to reside in main memory 120, those skilled in the art
will recognize that these items are not necessarily all completely
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contained in main memory 120 at the same time. It should also be noted
that the term "memory" is used herein to generically refer to the entire
virtual memory of computer system 100.
Each processor 110 may be constructed from one or more
microprocessors and/or integrated circuits. A processor 110 executes
program instructions stored in main memory 120. Main memory 120 stores
programs and data that a processor 110 may access. When computer system
100 starts up, a processor 110 initially executes the program instructions
that make up the partition manager 121, which initializes the operating
systems in the logical partitions.
Although computer system 100 is shown to contain only a single
system bus, those skilled in the art will appreciate that the present
invention may be practiced using a computer system that has multiple
buses. In addition, the I/0 interfaces that are used in the preferred
embodiment each may include separate, fully programmed microprocessors
that are used to off-load compute-intensive processing from processor 110,
as in iSeries input/output processors, or may be simple industry standard
I/0 adapters (I~As).
Display interface 140 is used to directly connect one or more
displays 165 to computer system 100. These displays 165, which may be
non-intelligent (i.e., dumb) terminals or fully programmable workstations,
are used to allow system administrators and users to communicate with
computer system 100. Note, however, that while display interface 140 is
provided to support communication with one or more displays 165, computer
system 100 does not necessarily require a display 165, because all needed
interaction with users and other processes may occur via network interface
150.
Network interface 150 is used to connect other computer systems
and/or workstations (e.g., 175 in FIG. 1) to computer system 100 across a
network 170. The present invention applies equally no matter how computer
system 100 may be connected to other computer systems and/or workstations,
regardless of whether the network connection 170 is made using present-day
analog and/or digital techniques or via some networking mechanism of the
future. In addition, many different network protocols can be used to
implement a network. These protocols are specialized computer programs
that allow computers to communicate across network 170. TCP/IP
(Transmission Control Protocol/Internet Protocol) is an example of a
suitable network protocol.
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At this point, it is important to note that while the present
invention has been and will continue to be described in the context of a
fully functional computer system, those skilled in the art will appreciate
that the present invention is capable of being distributed as a program
product in a variety of forms, and that the present invention applies
equally regardless of the particular type of computer readable signal
bearing media used to actually carry out the distribution. Examples of
suitable signal bearing media include: recordable type media such as
floppy disks and CD RW (e. g., 195 of FIG. 1), and transmission type media
such as digital and analog communications links.
A more detailed view of the partition manager 121 in FIG. 1 is shown
in FIG. 2. Partition manager 121 includes a minimum resource
specification 210, a current resource specification 220, and a maximum
resource specification 230 for each logical partition. The minimum
resource specification 210 specifies the minimum resources defined by the
customer that must be available for the logical partition to function
correctly. The current resource specification 220 specifies the resources
that are currently allocated to the logical partition. The maximum
resource specification 230 specifies the maximum resources that may be
allocated to the logical partition. The partition manager manages and
controls access to the minimum resource specification 210, current
resource specification 220 and maximum resource specification 230.
The capacity manager 122 manages temporary resources, whether
requested through temporary capacity on demand, metered capacity on
demand, activate immediate, or some other scheme. The capacity manager
122 includes an enablement code mechanism 240, which is used to determine
whether an enablement code 242 is valid, and to enable one or more
resources when the enablement code is determined to be valid. The
capacity manager 122 also includes a resource allocator 250, which is the
mechanism that allocates resources for use. Thus, when the enablement
mechanism 240 determines that an enablement code 242 is valid, the
resource allocator 250 makes the corresponding resources) available for
use.
The minimum resource enforcement mechanism 123 in capacity manager
122 controls access to the minimum resource specification 210 in each
logical partition to assure the sum of all minimum resource specifications
210 for all logical partitions does not exceed the base resources in the
system. If the sum of minimum resource specifications 210 is maintained
at a level that can always be satisfied by the base resources of the
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computer system, the temporary resources can always be recovered without
impacting the level of service defined by the customer.
While FIG.1 shows a sample computer system that includes some of the
salient features of both hardware and software in accordance with the
preferred embodiments, a more detailed logical view of some of the
components in FIG. 1 is shown as system 300 in FIG. 3. In system 300, N
logical partitions 125A-125N are shown executing their respective
operating systems 126A-126N. The logical partitions are managed by a
partition manager 121. Partition manager 121 manages resources 350, shown
in FIG. 3 as resource 350A through resource 350X. A "resource" in this
context may be any hardware or software that may be controlled by
partition manager 340. Examples of hardware resources include processors,
memory, and hard disk drives. Examples of software resources include a .
database, internal communications (such as a logical LAN), or applications
(such as word processors, e-mail, etc.). The partition manager 121
controls which resources 350 may be used by the logical partitions. A
resource, once made available to the partition manager 121, is categorized
as an available resource 360 if it has not yet been assigned to a logical
partition, is categorized as a shared resource 370 if multiple logical
partitions may access the resource, and is categorized as a dedicated
resource 380 if it has been exclusively assigned to a logical partition.
FIG. 3 shows dedicated resources 380A . . . 380N that correspond to each
logical partition 125A . . . 125N.
Referring to FIG. 4, a flow diagram of one suitable method 400 for
providing temporary resources on demand begins lay the customer requesting
an enablement code from the manufacturer (step 410). The customer
receives the enablement code, which includes a specification of
resource-time (step 420). The term °'resource-time'° is a
general term that
allows specifying any resource or combination of resources for any
suitable period of time. One example of resource-time is processor-days.
The customer enters the enablement code, which enables the resources on
the computer system (step 430). A timer is then started (step 440). The
user may then use the resources (step 450) as long as the resource-time
has not expired (step 460=N0). Once the resource-time expires (step
460=YES), the resources are disabled (step 470).
A simple example will show the usefulness of method 400. Let's
assume that a company that sells goods via catalog sales experiences peak
demand in November and December of each year due to holiday shopping. The
company could purchase a computer system that has one or more additional
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processors that are installed but initially disabled. The company could
then contract with the provider of the computer system to enable the
additional processors) for a set period of time. Let's assume that the
computer system has two additional processors, and let's assume that the
peak buying period runs for the thirty day period from November 15t'' to
December 14t''. The customer could purchase sixty processor-days of
additional capacity beginning on November 15th. These two additional
processors will then be enabled for the thirty day period (providing the
sixty processor-days of additional capacity). Once the sixty
processor-days have elapsed, the two additional processors are disabled.
When the usage of temporary resources is monitored by the
manufacturer, the manufacturer can assure the customer is appropriately
billed for the temporary resources. However, in an activate immediate
scenario, the system is not monitored by the manufacturer. This could
lead to loss of revenue due to abuses by customers that use temporary
capacity for a period of time that is greater than the specified
resource-time. This could happen, for example, if the sum of minimum
resource specifications for the logical partitions is increased to a level
that can only be satisfied by using temporary resources (i.e., that cannot
be satisfied by only base resources). When the resource-time expires
(step 460=YES), method 400 will attempt to disable the temporary resources
(step 470). However, if the sum of minimum resource specifications
requires use of temporary resources, the capacity manager may be unable to
disable (or recover) all of the temporary resources. For this reason,
some mechanism is needed to assure that temporary resources can always be
recovered. This is the subject matter of the preferred embodiments.
A method 500 in accordance with the preferred embodiments includes
all of the steps in method 400 discussed above with reference to FIG. 4.
Note, however, that method 500 additionally includes step 510, which
controls access to minimum resource specifications corresponding to the
logical partitions to assure temporary resources may be recovered. By
controlling access to the minimum resource specifications for the logical
partitions, method 500 assures the minimum resource specifications may be
satisfied by only base resources, thereby creating a state where the
temporary resources can always be recovered. Some examples will follow to
illustrate these concepts.
We assume for this example that a computer system has three logical
partitions, designated 1, 2 and 3. We assume that the base system
includes eight processors, all of which have been allocated to the logical
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partitions, as shown by the current processor specification column in FIG.
6, which shows that partition 1 has 2 processors, partition 2 has 5
processors, and partition 3 has 1 processor. Let's assume that a customer
now pays for the temporary use of eight additional processors using the
activate immediate scenario described above. As shown in FIG. 7, these
additional processors may then be made available to the partition manager
by designating these eight temporary processors as available resources 360
shown in FIG. 3. Once these eight temporary processors are designated as
available resources 360, they may be allocated to the logical partitions,
either as shared resources 370 or as dedicated processors 380. We assume
for this example these eight temporary processors are allocated as
dedicated processors 380, as shown in FIG. 8, which shows logical
partition 1 with 6 processors, partition 2 with 9 processors, and
partition 3 with 1 processor. The problem with prior art implementations
is shown in FIG. 8, where the minimum processor capacity for the logical
partitions has been increased to a level where the sum exceeds the base
system processors. The total of processors in the minimum processor
specification for the three partitions equals nine. Note, however, that
only eight of the sixteen processors currently in use are base processors.
As a result, when the specified processor-time that was purchased by the
customer expires, the system will attempt to recover the eight temporary
processors. But the problem lies in the sum of minimum processor
specifications, which now equals nine in FIG. 8, in excess of the eight
base processors. As a result, the prior art would succeed in recovering
only seven of the eight temporary processors. The eighth would remain
available for the customer to use because it is required according to the
sum of minimum processor specifications. This could lead to a customer
using a temporary resource on a permanent basis without paying the
manufacturer for continued use of that resource.
The preferred embodiments eliminates this problem in the prior art
by controlling access to the minimum resource specifications so the sum of
the minimum resource specifications never exceeds the level of base
resources on the system. Thus, for the example in FIGS. 6 and 7, the
minimum processor specifications may be changed, as shown in FIG. 9, but
the sum of these minimum processor specifications cannot exceed the eight
base system processors. Thus, we see in FIG. 9 that the minimum processor
specification for partition 1 has increased from 1 to 3, but the total
processors in the minimum processor specifications (3 for partition 1, 4
for partition 2, and 1 for partition 3) is still less than or equal to the
eight base processors.
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Now let's assume that the customer decides to make three of the
temporary processor permanent by paying the manufacturer for permanent
usage of three processors. The customer receives a key that, once entered
into the system, permanently enables three of the eight temporary
processors. In this example, the number of base processors has increased
from eight to eleven. As a result, the sum of minimum processor
specifications may now increase to eleven. Thus, in FIG. 10, partition 1
has a minimum processor specification of 6, partition 2 has a minimum
processor specification of 4, and partition 3 has a minimum processor
specification of 1, for a total of eleven processors, which still equals
the number of base processors in the system. In the preferred
embodiments, the partition manager is inhibited from changing a minimum
resource specification to a value that would cause the sum of minimum
resource specifications for all partitions to exceed the base resources in
the system.
By controlling access to minimum resource specifications so their
sum does not exceed the base resources of the system, the preferred
embodiments achieve a system where temporary resources may always be
recovered after a specified resource-time expires. This eliminates
potential loss of revenue and thus enhances the revenue generation of
providing computer systems with the ability to provide temporary resources
on demand.
~ne skilled in the art will appreciate that many variations are
possible within the scope of the present invention. Thus, while the
invention has been particularly shown and described with reference to
preferred embodiments thereof, it will be understood by those skilled in
the art that these and other changes in form and details may be made.
The scope of the present disclosure includes any novel feature or
combination of features disclosed herein. The applicant hereby gives
notice that new claims may be formulated to such features or combination
of features during prosecution of this application or of any such further
applications derived therefrom. In particular, with reference to the
appended claims, features from dependent claims may be combined with those
of the independent claims and features from respective independent claims
may be combined in any appropriate manner and not merely in the specific
combinations enumerated in the claims.
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For the avoidance of doubt, the term "comprising", as used herein
throughout the description and claims is not to be construed as meaning
"consisting only of".
