Abstract:
A usage metering system for determining computer resource utilization is described herein. Computer resource utilization is determined by accumulating instances of computer resource utilization based on array of counters. This enables an accurate determination of instances of when a predetermined threshold baseline of computer resource utilization is exceeded over an accumulated period of time. By using an array of counters to collect data rather than averaging values over time, a more accurate indication of computer resource utilization is determined. The usage metering system has little impact on computer system resources, because snapshots can be taken on a fairly infrequent basis, and any computer resource utilization calculations can be performed on computer platforms separated from the system being monitored.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates generally to monitoring utilization of computer resources in a computer system, and more specifically, to usage metering technology.  
       BACKGROUND  
       [0002]     A new model for purchasing a computer system has emerged in the computer industry, referred to as capacity-on-demand billing. According to this model, the customer agrees to purchase a computer system with a fixed baseline performance capability level based on a quantity of computer resources installed on the computer system (i.e., the number of Central Processing Units (CPUs), memory units, and/or Input/Output (I/O) modules, available in the computer system). In return, the manufacturer of the computer system agrees to install extra computer resources on the computer system at no upfront expense to the customer, and the customer is entitled to use the extra computer resources, but on a pay-per-use basis. Automated usage metering technology employed with the computer system detects when the customer&#39;s resource usage exceeds a threshold level, i.e., the fixed baseline performance capability level, and the customer is charged a usage fee for excessive usage over the threshold. Typically, the usage metering technology operates in the background recording computer resource utilization data and transmitting the data to a billing site for invoicing.  
         [0003]     An advantage of the capacity-on-demand billing model is that it allows the customer to purchase a computer system with reserve capacity, but at no additional upfront costs. This means a customer may have additional resources instantly available during periods of high computing demand, but without the penalty of having to purchase extra computer resources that lay dormant during slower demand periods.  
         [0004]     Ensuring the customer is accurately charged for using computer resources above an agreed threshold is a challenge with the capacity-on-demand billing model. For instance, some usage metering technologies rely on averaging methods that tend to record the resource utilization of a computer system over relatively long periods and often fail to account for the moment-by-moment operation of a typical computer system performing real-world tasks. For example, suppose a customer purchased a computer system with an agreed to maximum threshold of four CPUs, but in actuality, resident with the computer system are 16 CPUs. Now suppose that for three hours out of the day the customer uses 12 CPUs worth of processing power and for the remaining 21 hours the customer uses only two CPUs worth of processing power. If the usage metering technology uses an averaging method, it would appear that the customer only used 3.2 CPUs worth of CPU resources, which is well within the customer&#39;s baseline threshold of four CPUs. In reality, for three hours out of the day during peak usage, 12 CPUs were used and the customer should have been charged for using eight additional CPUs over their four base CPUs. In other words, but for the ability to use the additional CPU resources during peak usage times, the customer&#39;s work would not have been completed in a timely fashion, and the customer ought to have been charged for using extra resources, but was not in this scenario. Thus, a drawback with sampling usage data on an averaging basis is the likelihood that the metering usage tool may fail to capture short-lived events, and may produce results with a lower computer resource utilization level than actually occurring in a computer system.  
         [0005]     To compensate for averaging problems, some usage metering tools attempt to collect system resource data metrics, such as CPU and I/O performance data, at high frequencies to accurately reflect system resource utilization. A drawback, however, of sampling performance data at high frequencies is a tendency to consume a substantial amount of system resources, which skews computer resource consumption measurements, is expensive, and burdensome.  
       SUMMARY  
       [0006]     A usage metering system for determining computer resource utilization is described herein. The usage metering system collects iterative snapshots of computer resource utilization. Each snapshot provides a value indicative of the amount of specific computer resource utilized during a particular duration of time. Each value of a snapshot is used to select a particular counter from an array of counters corresponding to the value of the snapshot. The particular counter is incremented and the process repeats itself for a next snapshot. After a particular duration of time, the values of each counter are collected from the array of counters, and a usage report can be generated showing actual computer resource utilization accumulated over the particular duration of time, and more particularly, the number of instances computer resource utilization exceeded a threshold level of computer resource utilization over the particular duration of time. Based the usage report it is possible to bill for usage that exceeded the threshold levels, and the quantity and extent of usage that exceed the threshold levels.  
         [0007]     In an exemplary implementation, the usage metering system uses a collection module to collect the snapshots from the computer system and increment the counters. To reduce impacting computer resource utilization, the collector module may pass resource utilization data to a reporter module that resides on a separate system (although both the collector module and reporter module may reside on the same system in an alternative implementation). The reporter module receives the utilization data from the collector module, consolidates and formats the data for billing purposes and/or other purposes, such as health monitoring and assessment. The reporter module may also monitor the health of a collector module and send an alert if problems are detected with the collector module. Redundant collector modules and reporter modules may also be used to protect against a loss of utilization data or failures that may preclude monitoring of computer resource utilization.  
         [0008]     The usage metering system, therefore, introduces the broad concept of determining computer resource utilization by accumulating instances of computer resource utilization based on an array of counters. This enables an accurate determination of instances of when a predetermined threshold baseline of computer resource utilization is exceeded over an accumulated period of time. By using an array to collect data rather than averaging values overtime, a more accurate indication of computer resource utilization is determined. The usage metering system has little impact on computer system resources, because the snapshot process is very lightweight, and any computer resource utilization calculations can be performed on computer platforms separated from the system being monitored.  
         [0009]     Various other features and advantages shall become more apparent from the following description.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The detailed description is explained with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears.  
         [0011]      FIG. 1  illustrates an exemplary computing environment within which an innovative usage metering system and methodologies can be either fully or partially implemented.  
         [0012]      FIG. 2  is a block diagram of an exemplary collector module.  
         [0013]      FIG. 3  shows an exemplary array in which utilization data is maintained.  
         [0014]      FIG. 4  is a block diagram of an exemplary reporter module.  
         [0015]      FIG. 5  is a flow diagram illustrating an exemplary method of operation associated with collecting computer resource utilization data.  
         [0016]      FIG. 6  is a flow diagram illustrating an exemplary method of operation associated with recording and reporting computer resource utilization data.  
     
    
     DETAILED DESCRIPTION  
     Computing Environment  
       [0017]      FIG. 1  illustrates an exemplary computing environment  100  within which an innovative usage metering system  102  and methodologies can be either fully or partially implemented. The innovative systems and methods described herein are operational with numerous other general purpose or special purpose computing system environments or configurations. The exemplary computing environment is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of systems and methods described herein. Additionally, the exemplary computing environment should not be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the computing environment.  
         [0018]     According to one exemplary implementation, computing environment  100  includes a computer system  104 , a supervision computer  105 , and a network  106 .  
         [0019]     Computer system  104  can be any of a variety of computer devices, including workstations, multiprocessor systems, mainframe computers, enterprise systems, and a combination of any of the above example devices. Each computer system  104  includes computer resources such as processors  120 , memory units  122 , and I/O modules  121 .  
         [0020]     For example, each processor or group of processors comprise a CPU, which is typically responsible for controlling the interpretation and execution of computer-executable instructions (program instructions) in the form of software or logic, performs arithmetic and logical operations on data, and controls I/O functions.  
         [0021]     Memory units  122  represent any part of a computer system where data and instructions are stored, such as main memory, central memory, immediate access memory, cache, registers, discs, and related storage devices. Memory units  122  may include volatile memory (e.g., RAM) and/or non-volatile memory (e.g., ROM, PCMCIA cards, etc.).  
         [0022]     I/O modules  121  provide communication interfaces with other devices such as networks, printers, disks, computers, terminals, and other various devices able to connect to and communicate with a computer system.  
         [0023]     Resident in the memory units  122  is one or more operating systems  123 , and software applications  124  that execute on the one or more processors  120 . For purposes of illustration, programs and other executable program modules are illustrated herein as discrete blocks, although it is recognized that such programs and components reside at various times in different storage components of the computer systems  104 , and are executed by the one or more processors  120 . Example of software applications  124  include, but are not limited to, application programs, email programs, word processing programs, spreadsheets programs, Internet browser programs, Web services and so forth.  
         [0024]     In one implementation, operating system  123  is produced by Microsoft Corporation of Redmond, Washington, USA, such a Microsoft® Window® related operating system, which commonly implements high-level application-program interfaces (APIs), file systems, communications protocols, input/output data conversions, and other functions to enable software applications  124  to operate. Although the exemplary implementations will generally be described in the context of Microsoft operating systems, it is possible that other operating systems, such as Linux, UNIX, OS/400, AIX, and others, could be used in accordance with the principles and illustrations described herein.  
         [0025]     Operating system  123  generally maintains a process utilization manager  126 , such as the Windows NT Performance Monitoring API, present in the Windows operating system environment, and most commonly known through its well-known client programs as the Windows Task Manager, System Monitor, or Performance Monitor (Perfmon). Process utilization manager  126  generally maintains raw data, such as processes, sub-process, components, and threads (hereinafter processes) consuming computer resources associated with computer system  104 . The process utilization manager  126  maintains utilization data indicating CPU, memory, and I/O utilization in computer system  104 .  
         [0026]     Other elements such as power supplies, keyboards, touch pads, I/O interfaces, displays, LEDs, audio generators, and so forth are not shown as being a part of computer systems  104 , but could easily be a part of the computer systems  104 . Additionally, although not shown, a system bus or point-to-point connections typically connects the various components within computer systems  104 .  
         [0027]     Network  106  represents any of a variety of networks and may include the Internet, or one or more other networks (e.g., a local area network (LAN) or wide area network (WAN). Additionally, it may also be possible for various devices to communicate directly with other devices without using network  106  as a communication link in the form of a point-to-point connection.  
         [0028]     Supervision computer  105  is a computer system capable of communicating with computer system  104 . Supervision computer  105  may refer to, but is not limited to, a personal computer, a workstation, a server, a mainframe computer, an enterprise server, and potentially other devices that communicate with and provide services to end users and/or other computer devices. Although only one supervision computer  105  is shown in  FIG. 1 , it is readily appreciated that environment  100  may include more than one supervision computer  105 .  
         [0029]     Supervision computer  105  also includes at least one processor  130  and memory  132 . Resident in memory  132  are one or more operating systems (not shown), and programs  134  that execute on the one or more processor  130 . Other elements such as power supplies, keyboards, touch pads, I/O interfaces, displays, LEDs, and so forth are not shown in supervision computer  105 , but could easily be a part of the exemplary supervision computer  105 . Additionally, although not shown, a system bus or point-to-point connections typically connects the various components within supervision computer  105 .  
         [0030]     Having introduced an exemplary environment  100  in which usage metering system  102  functions, it is now possible to describe usage metering system  102  in detail.  
       Exemplary Usage Metering System  
       [0031]     Usage metering system  102  is a software-based tool that collects computer resource utilization data from process utilization manager  126  and reports the amount of computer resources used on the computer system  104  to a monitoring facility, such as a billing center  180 . Computer resource utilization data may include CPU utilization, memory utilization, I/O metrics, and potentially other process utilization metrics and units of execution.  
         [0032]     Usage metering system  102  is composed of two primary software components: a collector module  160  and a reporter module  136 . The collector module  160  is responsible for low level collection of utilization data from process utilization manager  126 . The reporter module  136  is responsible for receiving utilization data transferred from the collector module  160  via network  106  or other communication path. The reporter module  136  is also responsible for formatting and forwarding the utilization data to a collection point, such as billing center  180 , customer service center (not shown), Information Technology department (not shown), and so forth. The reporter module  136  may also monitor the status of one or more collectors operating on a computer system  104 , such as for monitoring the health of computer system  104  and for reporting anomalies with computer system  104 .  
         [0033]     In one implementation, collector module  160  and reporter module  136 , operate on computer systems  104  and supervision computer  105 , respectively, and communicate programmatically with each other as well as other program processes. Alternatively, collector module  160  and reporter module  136  could reside on the same platform. Typically, collector module  160  and reporter module  136  communicate with each other using at least one of a variety of communication protocols. For example, on one implementation, collector module  160  uses Transmission Control Protocol/Internet Protocol (TCP/IP) sockets to communicate with reporter module  136 .  
         [0034]     Collector module  160  operates as a system level process. Although only one collector module  160  is shown in  FIG. 1 , it is appreciated that more than collector module  160  may be employed. For instance, if computer system  104  has logical partitions such that sets of resources can be operated independently with its own operating system instance than a collector module can be targeted to collect utilization data from each particular OS instance. Each collector module, such as collector module  160 , typically samples computer resource utilization data directly from the OS performance counters (not shown), which are part of the process utilization manager  126 .  
         [0035]     Collector module  160  is designed to be extremely lightweight so that its impact on overall system utilization is negligible. Collector module  160  measures peak instances of computer resource utilization observed on an iterative basis, and records the measurements in an array (to be described). Each element of the array represents a count of how many times a corresponding computer utilization value was observed. At user defined intervals, collector module  160  transmits the utilization data (the counts comprising the array of counters) to the reporter module  136  for consolidation and report generation. Accordingly, only minimal work is performed by collector module  160 , and the more process intense analysis and consolidation of data is offloaded and performed on the supervision computer  105  by reporter module  136  minimizing any impact on computer resource utilization levels measured on computer system  104 .  
         [0036]     The reporter module  136  may also execute as system level process on supervision computer  105 , although it is possible for reporter module  136  to execute on computer system  104 . When the reporter module  136  receives the utilization data from one or more collector modules, the data is consolidated and formatted as a report for transmission to a user designated location. For instance, in one implementation, the data is transmitted to a recipient center in the form of an electronic message (e-mail); however, other forms of transfer may be used. The report may indicate how many times a computer resource was utilized and the extent to which the utilization exceeded a particular threshold. For example, information maintained by the array of counters can easily be consolidated over a defined period of time, such as a week, month or a quarter, and a report can be generated at prescribed times summarizing computer resource utilization over a period of time. The report may be used for purposes of generating a bill, in the event it is determined that the customer utilized more computer resources than the customer&#39;s agreed threshold performance capability level. Reporter module  136  may maintain an archive of data in a memory  132  to guard against loss of data at collection site.  
         [0037]     The reporter module  136  may also monitor the health of computer system  104  by reporting if any particular collector module  160  fails to communicate with reporter module  136 , or fails to communicate in a prescribed fashion, which may indicate that a OS instance or computer system  104  is experiencing a malfunction. If a prescribed period elapses and reporter module  136  fails to receive utilization data from collector module  160  or communicate in a acceptable manner with a collector module, reporter module  136  can send an alert message (such as an e-mail) to a user designated location to report the potential anomaly.  
         [0038]     Although  FIG. 1  shows a single system topology for discussion purposes, those skilled in the art should appreciate that usage metering system  102  may be deployed in various forms. For example, in one implementation several collector modules and reporter modules may be deployed as part of usage metering system  102 . A collector module and a reporter module may be deployed for each system partition requiring monitoring. Each collector and reporter module pair acts as an independent unit and may not communicate with other collector and reporter modules that may be deployed on the same network.  
         [0039]     In another implementation, a collector module is installed on each system/partition to be monitored. A reporter module is installed to service the collector modules. The reporter module may reside on a system/partition with a collector or it may be installed on a stand-alone system such as supervision computer  105 . In such an implementation, collector modules and the reporter module are usually located on the same Local Area Network (LAN) segment.  
         [0040]     In still another implementation, one collector module is installed on each system/partition to be monitored. Two or more reporter modules are installed to service the collector modules. Again, the reporter modules may reside on the same system/partitions as the collector modules or be installed on a standalone system. Using redundant reporter modules ensures that if one reporter module fails (or its platform fails), another reporter module can take over the task of collecting utilization data from collector modules and reporting the data.  
         [0041]     Collector module  160  and reporter module  136  of  FIG. 1  shall now be described in more detail as follows.  
       Exemplary Collector Module  
       [0042]      FIG. 2  is a block diagram of a collector module  160  residing in memory  122  ( FIG. 1 ) of a computer system  104  ( FIG. 1 ). Collector module  160  typically operates as a background module and may operate in a secure mode, to prevent being tampered with by users of computer system  104 . The collector module  160  is usually automatically activated when computer system  104  is functioning. In one implementation, collector module  160  comprises a communications module  202 , an array manager  204 , and an array  206 . Although it is appreciated that collector module may comprise program modules and data. Program modules typically include routines, programs, objects, threads, components, and so on, for performing particular tasks or implementing particular abstract data types.  
         [0043]     Communication module  202  communicates with reporter module  136  ( FIG. 1 ). For example, communication module  202  transmits performance data for storage and manipulation by reporter module  136 . Communications module  202  may also record other descriptive data, such as the date/time of the snapshots as well as identification indicia, indicating the particular computer system (or partition) on which the information was recorded. The identification indicia enable the reporter module  136  when it receives data from different collector modules to associate the particular data with a particular system or partition. Communications module  202  can also receive rules/instructions from reporter module  136  ( FIG. 1 ), such as when to take snapshots, how often to transmit data to supervision computer  105  ( FIG. 1 ), where to send data including whether to send data to redundant reporter modules, etc. In the exemplary implementation, communication module  202  communicates with reporter module  136  ( FIG. 1 ) using TCP/IP protocols over network  106  ( FIG. 1 ), but other communication protocols could be used such as RPC, COM+, DCOM, and Multicast.  
         [0044]     Array manager  204  collects performance data from process utilization manager  126  on an iterative basis. That is, array manager  204  samples (i.e., takes a “snapshot” of) process utilization manager  126  on a continuous basis over prescribed period of time and stores the utilization data in an array  206  for eventual transmission to reporter module  136  ( FIG. 1 ) via communication module  202 . Array manager  204  uses the communication module  202  to transmit utilization data.  
         [0045]     Array manager  204  uses a timer (not shown) to manage the overall period of time (minutes, hours, days, weeks, months) continuous snapshots are taken. Array manager  204  also uses a timer to control the amount of time between two consecutive readings are taken from the process utilization manager  126  ( FIG. 1 ) i.e., the delay intervals between snapshots. In one implementation, array manager  204  takes a reading (also referred to as a snapshot) of the process utilization manager  126  ( FIG. 1 ) every five seconds. However, the amount of time between snapshots is configurable. Preferably the time interval selected between snapshots should be frequent enough to capture real-time computer utilization events but not too frequent so as to impact computer utilization measurements on a particular computer system  104  ( FIG. 1 ).  
         [0046]     Each snapshot provides a value indicative of a peak amount of a computer resource utilized at a particular time interval. Each value of a snapshot is used by array manager  204  to select a particular element (also referred to as a “bucket”) from an array  206  corresponding to the value of the snapshot. Each element corresponding to the value of the snapshot contains a count indicating the number of times the particular computer resource level (value) was observed. So each time a particular value is observed, a corresponding bucket with the same value is selected and the count associated with that bucket is incremented by one.  
         [0047]     For example, suppose array manager  204  reads a CPU resource utilization value of 10% for each of its first two readings from process utilization manager  126  ( FIG. 1 ). In this case, array manager  204  selects the 10 th  bucket of an array and increments the counter associated with the 10 th  bucket twice, so the value contained in the 10 th  bucket would equal two.  
         [0048]      FIG. 3  shows an exemplary array  206 . Array  206  includes 101 buckets labeled at the bottom of each bucket, 0 through 100. The number of each bucket corresponds to a metric value (i.e., a particular computer resource level value). For example, suppose a CPU value of 90% is read from process utilization manager  126  by array manager  204  ( FIG. 2 ), then that value of 90% would correspond to bucket  90 . In each bucket is a counter value indicating the number of times the particular computer resource level value was observed over a particular duration of time. For example, in bucket  90  there is a count value 10, which indicates that there ten instances over a particular duration of time a computer resource was 90% utilized. If during another instance of time a snapshot is taken of the process utilization manager  126 , which indicates that a computer resource was again 90% utilized, then the count value contained in bucket  90  is incremented by one and the count value would read  11  (not shown) instead of  10  (shown). Thus, each bucket contains a count value which indicates the number of times a particular computer resource utilization percentage was reached over a particular duration of time. For example, bucket  1  of array  206  shows that there were 90 instances over a particular duration of time that a particular computer resource was utilized at a peak utilization level of 1%; and so forth.  
         [0049]     As shown in  FIG. 3 , the array  206  may be stored in memory  122  ( FIG. 1 ) as part of a log  302  or file.  
         [0050]     Referring back to  FIG. 2  again, after a configurable duration of time (e.g., seconds, minutes, hours or even days), utilization data from array  206  (i.e., count values from buckets 0 through 100) are transmitted to reporter module  136  ( FIG. 1 ) via communication module  202  ( FIG. 2 ) and network  106  ( FIG. 1 ). Once there is a confirmation from reporter module  136  that the data was successfully received, array module  204  resets all the counters in array  206  and the process repeats itself for the next duration of time.  
       Exemplary Reporter Module  
       [0051]     A portion of usage metering system  102  may also reside in memory in the form of an innovative reporter module  136 , such as in memory  132  of supervision computer  105 . Reporter module  136  is a program module that communicates with collection module  160  and uploads information forwarded by (or pulled by) collection module  160  to determine workload utilization of computer resources executing on computer system  104 . That is, reporter module  136  is configured to collect utilization data (counter values from the array and other potential information) from collection module  160  and consolidate and format the data to construct a billing record which can be transmitted to a billing center  180  if the billing center  180  resides separately from supervision computer  105 . Reporter module  136  may also be responsible for monitoring the status of one or more collection modules  160  and send an alert message if abnormalities are observed. As such the health of computer system  104  may be monitored.  
         [0052]      FIG. 4  is a block diagram of a reporter module  136  residing in memory  132  of supervision computer  105 . In this example, reporter module  136  comprises program modules and program data. Program modules typically include routines, programs, objects, threads, components, and so on, for performing particular tasks or implementing particular abstract data types. The processor  130  is configured to fetch and execute computer program instructions from the program modules in memory  132 , and is further configured to fetch data from program data while executing the reporter module  136 .  
         [0053]     In the exemplary implementation, reporter module  136  comprises a front end  402 , a communication module  404 , a calculation module  406 , a report module  408 , and data files  410 .  
         [0054]     Front end  402  is a module that allows a user to connect (i.e., login) into the supervision computer  105  (directly or over a network  106 ) and access a user interface (not shown). Using the user interface, the user can control the characteristics of the usage metering system and monitor computer resource utilization on computer systems  104 . For example, network accessible front end  402  comprises a display module  420  and a rule composer module  422 .  
         [0055]     Display module  420  view information about collector modules  160  ( FIG. 1 ), including how often data is forwarded from each collector module  160  ( FIG. 1 ), which instance or system is being monitored, etc. Display module  220  also enables the user, to view precise information detailing computer resource utilization in computer systems  104 .  
         [0056]     Rule composer module  422  enables a user to: install reporter modules on supervision systems  105 , install collector modules on computer system  104 , configure and deploy rules that instruct how information is sent from collector modules (such as how often), configure and deploy rules of how and when to generate reports indicating a quantity of computer system resources utilized over select period of time (such as month, week, quarter, etc.). This information may be further utilized by billing software or other applications for billing a department responsible for the software application that operates on the computer systems  104 .  
         [0057]     Communications module  404  connects the supervision computer  105  to the computer systems  104  over network  106  ( FIG. 1 ) to transmit and receive various data required by collection agents  160  ( FIG. 1 ) and reporter module  136 . The communication module  404  accepts transmission of data files, including logs containing arrays from collector module  160  for storage on the supervision computer  105  in data files  410 .  
         [0058]     The communication module  404  also facilitates transmission of instructions and rules for collecting utilization data and information from computer systems  104 . This enables the computer systems  104  (via collector modules  160 ) to store the instructions, data, and rules as indicated by reporter module  136 .  
         [0059]     Communications module  404  also transmits information to collector modules  160  to ensure that each module (if more than one) is collecting utilization data at precise intervals and forwarding the data from arrays  206  at prescribed periods of time.  
         [0060]     Reporter module  136  through communications module  404  also may participate in health monitoring of computer system  104  ( FIG. 1 ). This is accomplished by pinging each collector module  160  ( FIG. 1 ) to monitor the status of the collector module, i.e., make sure it is still functioning. Malfunctions with collector modules, or a loss of communication with computer system  104  ensures that reporter module  136  will send an alert message to a center, such as service center, bill center, etc. or other designated site.  
         [0061]     Calculation module  406  periodically retrieves data from collector modules  160  such as counts from array  106 , which are stored in data files  410 . Calculation module  406  also maintains a master array which mirrors array  106 , but includes a cumulative count of all buckets from a time period. Once a report is shipped to accounting, however, the master array can be reset to zero, and the accumulation of counts can be restarted for a next duration of time, such as a week, a month, a quarter, etc.  
         [0062]     Calculation module  406  also compares the data in each bucket of the array to a threshold to determine how many times the customer&#39;s computer resource utilization exceeded the threshold. This is accomplished by sending the array data to the billing center where the threshold data is processed according to the terms of the customer&#39;s service contract. For example: if a customer has contracted for the use of 8 processors in a 16 processor system and utilization of the system exceeding 50 percent indicates the use of processors in excess of 8. The actual billing rate for utilization beyond the contracted base of 8 processors is negotiated by the vendor and customer when the service contract is created  
         [0063]     Once calculation module  406  computes the computer resource utilization over a specific threshold, report module  408  generates a usage report which indicates exactly how many resources were utilized the amount that exceeded the agreed threshold. It is possible to use information from the report for charging a customer for utilization of computer resources above an agreed quantity threshold quantity, or for other purposes such as analyzing, monitoring, and predicting computer system performance.  
         [0064]     Redundant reporter modules may be linked together, with one reporter module designated as the primary reporter module for receiving information and data from one or more collector modules, and the other reporter module designated as a secondary reporter module that maintains a duplicate copy of information stored by the primary reporter module, in the event the primary reporter module fails. Typically, secondary reporter modules will ping the primary reporter module on a periodic basis, such as when requesting duplicate copies of data for backup, and will takeover the role of the primary reporter module, if the primary reporter module fails to respond in a prescribed period of time. A particular secondary reporter module will notify the one or more collector modules  160  to transfer data to it instead of the primary reporter module in such a scenario.  
         [0065]     In another implementation, if multiple reporter modules are configured as part of usage metering system  102  to function in a primary module and a secondary standby mode relationship, and primary reporter module fails to respond to a collector module&#39;s request to push data to it, one of the secondary reporter modules will designate itself as the primary module and resume the process of receiving data from collector modules and data consolidation and monitoring. If eventually the reporter module, which failed again, becomes function, through restart or user intervention, the failed reporter module will designate itself as standby or secondary reporter module.  
       Methods of Operation  
       [0066]     Methods for collecting computer resource utilization data from process utilization manager  126  may be described in the general context of computer-executable instructions. Generally, computer-executable instructions include routines, programs, objects, threads, components, data structures, etc. and the like that perform particular functions or implement particular abstract data types. The described methods may also be practiced in distributed computing environments where functions are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, computer-executable instructions may be located in both local and remote computer storage media, including memory storage devices (computer-readable media).  
         [0067]      FIG. 5  is a flow diagram illustrating an exemplary method  500  of operation associated with collecting computer resource utilization data. The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Each of the operations and blocks may be optional and do not necessarily have to be implemented. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof. Exemplary method  500  includes blocks  502 ,  504 ,  506 ,  508 ,  510 ,  512 ,  514 , and  516 .  
         [0068]     In block  502 , a snapshot of the process utilization manager is taken providing a value indicative of peak amount of computer resource utilized at a particular time. For example, array manager  204  ( FIG. 2 ) of collector module  160  ( FIGS. 1 and 2 ) reads the value indicated process utilization manager  126  ( FIG. 1 ).  
         [0069]     In block  504 , a bucket corresponding to the value is selected from an array. For example, array manager  204  selects a bucket 0 through 100 from array  106  corresponding to the value obtained from taking the snapshot.  
         [0070]     In block  506 , a counter associated with selected bucket is incremented. For example, array manager  204  increments the counter associated with the selected bucket by one.  
         [0071]     In a decisional block  508 , a determination is made whether an interval time between snapshots has elapsed. For example, a timer (not shown) within array manager  204  determines how long to wait between each successive snapshot. If enough time has not elapsed, then process  500  shall wait the prescribed period of time according to the No branch of decisional block  508 . If enough time has elapsed, the process  500  proceeds to decisional block  510 .  
         [0072]     In decisional block  510 , a determination is made whether a second and longer duration of time has elapsed, such as minutes, hours, weeks or days. If such second duration of time has not elapsed, then according the No branch of decisional block  510 , process  500  proceeds back to block  502  and process  500  repeats itself for the next snapshot or iterations of snapshots. If the second duration of time has elapsed, then according the Yes branch of decisional block  510 , process  500  process proceeds to block  512 .  
         [0073]     In block  512 , the array or values associated with each counter of the array is forwarded to a reporter module. For example, communication module  202  ( FIG. 2 ) transmits an array  206  ( FIG. 2 ) to reporter module  136  ( FIG. 1 ).  
         [0074]     In a decisional block  514 , a determination is made whether the array was successfully received by the reporter module. For example, unless an acknowledgement is received from a reporter module that it successfully received the data contained in the array maintained by the collector module, according the No branch of decisional block  514 , the collector module will attempt to resend the message (block  512 ) after a prescribe period of time or take other corrective action such as notifying a secondary reporter module that it is having problems communicating with the a primary reporter module. If the array was successfully received process  500  proceeds to block  516 .  
         [0075]     In block  516 , the counters comprising the array are reset to zero. For example, array manager  204  resets all the counters in array  206 . Alternatively, it is noted that array manager could also start a new array or continue keep counting and let the reporter module worry about where the counts left off. Process  500  repeats itself for the next duration of time.  
         [0076]      FIG. 6  is a flow diagram illustrating an exemplary method  600  of operation associated with recording and reporting computer resource utilization data. The order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Each of the operations and blocks may be optional and do not necessarily have to be implemented. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof. Exemplary method  600  includes blocks  602 ,  604 ,  606 , and  608 .  
         [0077]     In a decisional block  602 , a reporter module attempts to retrieve data from a collector module (in a pull strategy) or waits to receive data from a collector module (in push module). If in either case, the reporter module is unable to receive data after a prescribed period of time or number of attempts to communicate with the collector module, then according to the No branch of decisional block  602  process  600  proceeds to block  604  and a alert is send to a designated site, person or service center, that there is a problem with the health of an instance partition, computer system, and/or collector module. If according to the Yes branch of decisional block  602 , the reporter module receives utilization data (typically in the form of an array), then process  600  proceeds to block  606 .  
         [0078]     In block  606 , the data from the array is consolidated and formatted based on the data record format required by the billing center. At a minimum the data is formatted into a comma separated data file and a human readable text file. Additional data files are created using the data record templates of the target billing systems. These templates are provided to the reporter module at the time of software installation. All data files transmitted from the reporter are processed to generate an encrypted digital signature. This signature is used at the receiving billing center to ensure the integrity of the received files.  
         [0079]     In block  608 , a report is sent to a designated site, such as billing center  180  ( FIG. 1 ) for analysis or generation of bill, in the event the customer utilized more computer resources than an agreed upon threshold level.  
         [0080]     Although the invention has been described in language specific to structural features and/or methodological acts, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific features or acts described. Rather, the specific features and acts are disclosed as exemplary forms of implementing the claimed invention.