Patent Publication Number: US-2023155916-A1

Title: Accurately identifying execution time of performance test

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to performance testing, such as performance regression testing, and more particularly to accurately identifying the execution time of a performance test, such as a performance regression test. 
     BACKGROUND 
     Performance regression testing is a comparative approach that examines how a software application performs in successive builds. For experts in intelligent test automation, this is performed by simulating a variety of usage scenarios, many of which are tests that place the application into adverse performance conditions. Simplistically, performance regression testing provides feedback on how the performance of the application varies according to recent changes in development. 
     SUMMARY 
     In one embodiment of the present disclosure, a computer-implemented method for accurately identifying an execution time of a performance test comprises determining compensation times based on obtained performance test execution times for a group of performance tests run in a remote cluster environment and obtained performance test execution times for the group of performance tests run in a local cluster environment, where each of the compensation times comprises a test execution time impacted by network latency. The method further comprises grouping the compensation times into clustered groups of compensation times using a cluster algorithm. The method additionally comprises building a regression model to predict a performance test execution time impacted by network latency using the clustered groups of compensation times. Furthermore, the method comprises generating the execution time of the performance test run in the remote cluster environment that takes into consideration the performance test execution time impacted by network latency predicted by the regression model. 
     Other forms of the embodiment of the computer-implemented method described above are in a system and in a computer program product. 
     The foregoing has outlined rather generally the features and technical advantages of one or more embodiments of the present disclosure in order that the detailed description of the present disclosure that follows may be better understood. Additional features and advantages of the present disclosure will be described hereinafter which may form the subject of the claims of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A better understanding of the present disclosure can be obtained when the following detailed description is considered in conjunction with the following drawings, in which: 
         FIG.  1    illustrates a communication system for practicing the principles of the present disclosure in accordance with an embodiment of the present disclosure; 
         FIG.  2    is a diagram of the software components of the performance analyzer for accurately identifying the execution time of the performance test run in the remote cluster environment in accordance with an embodiment of the present disclosure; 
         FIG.  3    illustrates an embodiment of the present disclosure of the hardware configuration of the performance analyzer which is representative of a hardware environment for practicing the present disclosure; 
         FIG.  4    is a flowchart of a method for predicting the performance test execution time impacted by network latency in accordance with an embodiment of the present disclosure; 
         FIG.  5    illustrates the grouping of network latency data into clustered groups of network latency data using a cluster algorithm in accordance with an embodiment of the present disclosure; 
         FIG.  6    illustrates the grouping of compensation times into clustered groups of compensation times using a cluster algorithm in accordance with an embodiment of the present disclosure; 
         FIG.  7    illustrates the information from the clustered groups of network latency data and the clustered groups of compensation times, which is used by the regression algorithm to build the regression model in accordance with an embodiment of the present disclosure; 
         FIG.  8    is a graph illustrating the prediction of the execution time impacted by the network latency (compensation time) by the regression model in accordance with an embodiment of the present disclosure; and 
         FIG.  9    is a flowchart of a method for accurately identifying the execution time of the performance test run on the server cluster in the remote cluster environment by taking into consideration the impact of network latency in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     As stated in the Background section, performance regression testing is a comparative approach that examines how a software application performs in successive builds. For experts in intelligent test automation, this is performed by simulating a variety of usage scenarios, many of which are tests that place the application into adverse performance conditions. Simplistically, performance regression testing provides feedback on how the performance of the application varies according to recent changes in development. 
     When a tester observes a performance regression in the latest build of an application, such as slower page load times, it is typically the result of a recent change to that application. Typically, higher page load time is a negative effect on application performance. A tester will confirm this by comparing the performance of the previous build with the current build. 
     Such performance regression testing may be performed on a server cluster in a network environment, such as remote network environment, which is used to handle big data (extremely large data sets that may be analyzed computationally to reveal patterns, trends, and associations, especially relating to human behavior and interactions). A “server cluster,” as used herein, refers to two or more servers working together. Even though each sever in the server cluster has its own resources, it is displayed in the network under one host name and has only a single Internet Protocol (IP) address. Performance regression tests on such server clusters often require the need to test certain data many times. Such repetitive tests may span a long time for big data. 
     At times, the running ability of the server cluster will be affected by the network performance, such as network latency, during different periods of time. Furthermore, at times, the tester will observe an increase in the duration of the execution time of the performance test, such as a performance regression test, running on the server cluster. Such an increase in the execution time may be attributed to network performance, such as network latency, which may cause the tester to improperly conclude that the performance test was invalid. 
     Unfortunately, there is not currently a means for determining the extent of network latency affecting the execution time of the performance test, which may provide clarity as to whether or not the performance test was truly invalid. Additionally, there is not currently a means for obtaining an accurate execution time of the performance test, such as the performance regression test, that takes into account the network latency. 
     The embodiments of the present disclosure provide a means for determining the extent of network latency affecting the execution time of the performance test thereby accurately identifying the execution time of the performance test, such as the performance regression test. 
     In some embodiments of the present disclosure, the present disclosure comprises a computer-implemented method, system and computer program product for accurately identifying an execution time of a performance test. In one embodiment of the present disclosure, network latency data is grouped into clustered groups of network latency data using a first cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. Furthermore, the performance test execution times for a group of performance tests run in a remote cluster environment are obtained at different times. That is, the performance test execution times of running the performance tests on a server cluster in the remote cluster environment are obtained at different times. Additionally, the performance test execution times for the same group of performance tests run in a local cluster environment are obtained. The test execution times impacted by network latency (“compensation times”) are then determined based on such obtained performance test execution times in the local and remote cluster environments. In one embodiment, the compensation time (test execution time impacted by network latency) is equal to the performance test execution time for the performance test run in the remote cluster environment minus the performance test execution time for the same performance test run in the local cluster environment. Such compensation times are then grouped into clustered groups of compensation times using a second cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. A regression model is then built to predict a performance test execution time impacted by network latency using the clustered groups of network latency data and the clustered groups of compensation times. The execution time of a performance test run in the remote cluster environment is then generated that takes into consideration the performance test execution time impacted by network latency predicted by the regression model. In this manner, the execution time of the performance test, such as the performance regression test, is more accurate as the network latency is taken into account. Furthermore, in this manner, a tester is able to more correctly determine whether the performance test was valid or invalid. 
     In the following description, numerous specific details are set forth to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without such specific details. In other instances, well-known circuits have been shown in block diagram form in order not to obscure the present disclosure in unnecessary detail. For the most part, details considering timing considerations and the like have been omitted inasmuch as such details are not necessary to obtain a complete understanding of the present disclosure and are within the skills of persons of ordinary skill in the relevant art. 
     Referring now to the Figures in detail,  FIG.  1    illustrates an embodiment of the present disclosure of a communication system  100  for practicing the principles of the present disclosure. Communication system  100  includes a performance analyzer  101  configured to perform a performance test, such as a performance regression test, on a server cluster. Such a performance test may be performed on a server cluster  102  in a local cluster environment  103 . A “local cluster environment,” as used herein, refers to an environment in which server cluster  102  is directly connected to performance analyzer  101 . That is, a “local cluster environment,” refers to an environment in which server cluster  102  is not connected to performance analyzer  101  via a network. Furthermore, as shown in  FIG.  1   , such a performance test may be performed on a server cluster  104  in a remote cluster environment  105 , such as via a network  106 . A “remote cluster environment,” as used herein, refers to an environment in which server cluster  104  is remotely connected to performance analyzer  101 , such as via a network (e.g., network  106 ). 
     Network  106  may be, for example, a local area network, a wide area network, a wireless wide area network, a circuit-switched telephone network, a Global System for Mobile Communications (GSM) network, a Wireless Application Protocol (WAP) network, a WiFi network, an IEEE 802.11 standards network, various combinations thereof, etc. Other networks, whose descriptions are omitted here for brevity, may also be used in conjunction with system  100  of  FIG.  1    without departing from the scope of the present disclosure. 
     As previously discussed, a “server cluster,” as used herein, refers to two or more servers working together. As shown in  FIG.  1   , local cluster environment  103  includes a server cluster  102 , such as servers  107 A- 107 C (identified as “Server A,” “Server B,” and “Server C,” respectively in  FIG.  1   ). Servers  107 A- 107 C may collectively or individually be referred to as servers  107  or server  107 , respectively. While  FIG.  1    illustrates server cluster  102  in local cluster environment  103  including three servers  107 , it is noted that server cluster  102  in local cluster environment  103  may include any number of servers  107 . 
     Furthermore, as shown in  FIG.  1   , remote cluster environment  105  includes a server cluster  104 , such as servers  108 A- 108 C (identified as “Server D,” “Server E,” and “Server F,” respectively in  FIG.  1   ). Servers  108 A- 108 C may collectively or individually be referred to as servers  108  or server  108 , respectively. While  FIG.  1    illustrates server cluster  104  in remote cluster environment  105  including three servers  108 , it is noted that server cluster  104  in remote cluster environment  105  may include any number of servers  108 . 
     In one embodiment, servers  107  in local cluster environment  103  possess substantially the same amount of resources (e.g., same amount of disk space (e.g., 50 GB), same amount of memory size (e.g., 4 GB), same processor speed (e.g., 3 GHz)) as servers  108  in remote cluster environment  105 . 
     In one embodiment, performance analyzer  101  is configured to accurately identify the execution time of a performance test, such as the performance regression test, run on server cluster  104  in remote cluster environment  105 , such as by taking into consideration the impact, if any, of network latency. A more detailed description of these and other features will be provided below. Furthermore, a description of the software components of performance analyzer  101  is provided below in connection with  FIG.  2    and a description of the hardware configuration of performance analyzer  101  is provided further below in connection with  FIG.  3   . 
     System  100  is not to be limited in scope to any one particular network architecture. System  100  may include any number of performance analyzers  101 , server clusters  102 ,  104 , environments  103 ,  105 , and networks  106 . 
     A discussion regarding the software components used by performance analyzer  101  for accurately identifying the execution of the performance test, such as the performance regression test, run in remote cluster environment  105  is provided below in connection with  FIG.  2   . 
       FIG.  2    is a diagram of the software components of performance analyzer  101  ( FIG.  1   ) for accurately identifying the execution time of the performance test, such as the performance regression test, run in remote cluster environment  105  ( FIG.  1   ) in accordance with an embodiment of the present disclosure. 
     Referring to  FIG.  2   , in conjunction with  FIG.  1   , performance analyzer  101  includes a monitor engine  201 . Monitor engine  201  is configured to monitor and collect the network latency data during different periods of time, such as the network latency in remote cluster environment  105 . 
     “Network latency,” as used herein, refers to delays in communication over a network (e.g., network  106 ), such as the delay in the amount of time it takes for a packet of data to be captured, transmitted, processed and received at its destination. Such latency may be caused by a variety of reasons, such as insufficient bandwidth, firewall blocking traffic, signal conversion, etc. 
     In one embodiment, monitor engine  201  monitors and collects the network latency data in remote cluster environment  105  during different periods of time by applying an applet (small application that performs one specific task that runs within the scope of a dedicated engine ( 201 ) or a larger program, such as a plug-in) in the test environment  105  to obtain a large number of random network delay data in different time periods. In one embodiment, the applet collects such network latency data via ping (software utility used to test the reachability of a host on an Internet Protocol (IP) network). Ping measures the round trip time for messages sent from the originating host to a destination that are echoed back to the source. In one embodiment, ping operates by sending Internet Control Message Protocol (ICMP) echo request packets to the target host and waiting for an ICMP echo reply. The applet may then report errors, packet loss and a statistical summary of the results, such as the minimum, maximum, the mean route trip times and standard deviation of the mean. 
     Examples of collecting the network latency data in remote cluster environment  105  using ping include collecting the latency between a client and a master, collecting the latency between master and slaves, etc. 
     In one embodiment, monitor engine  201  monitors and collects the network latency data during different periods of time, such as the network latency in remote cluster environment  105 , using various software tools, including, but not limited to, SolarWinds® Network Performance Monitor, Paessler® Router Traffic Grapher, NetScan Tools, NetworkLatencyView from NirSoft, PingPlotter®, SolarWinds® NetFlow Traffic Analyzer, SolarWinds® Network Bandwidth Analyzer Pack, SolarWinds® Engineer&#39;s Toolset™, etc. 
     Performance analyzer  101  further includes a cluster module  202  configured to group collected network latency data using a cluster algorithm and configured to group compensation times using a cluster algorithm. “Compensation time,” as used herein, refers to the amount of the test execution time of the performance test, such as the performance regression test, impacted by the network latency. 
     In one embodiment, cluster module  202  groups the network latency data collected by monitor engine  201  using a cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. 
     In one embodiment, cluster module  202  groups the compensation times, which are determined by execution time module  203  (discussed below), using a cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. 
     Performance analyzer  101  additionally includes an execution time module  203  configured to obtain the performance test execution times for a group of performance tests run in remote cluster environment  105  at different times and obtain the performance test execution times for the same performance tests run in local cluster environment  103 . In one embodiment, execution time module  203  runs the same performance test, such as the performance regression test, on server cluster  102  of local cluster environment  103  as on server cluster  104  of remote cluster environment  105  at the same time. In one embodiment, an original version of the performance test is run in either the local cluster environment  103  or the remote cluster environment  105  and a duplicate copy of the performance test is run in the other environment. In this manner, the same performance test is run at the same time in both local cluster environment  103  and remote cluster environment  105 . 
     When such performance tests are run, execution time module  203  obtains the execution time of such performance tests (referred to herein as the “performance test execution time”). In one embodiment, execution time module  203  obtains such execution times using various software tools, including, but not limited to, Linux® Trace Toolkit, worst-case execution time (WCET) tools, Timing Profiler, aiT, Bound-T, METAMOC, OTAWA developed by the University of Toulouse, TuBound, etc. 
     The performance execution time in local cluster environment  103  should not be affected by network latency since server cluster  102  is directly connected to performance analyzer  101  (not connected to performance analyzer  101  via a network). As a result, such a performance execution time reflects the true performance execution time (execution time of the performance test) when there is no network latency. 
     By obtaining the performance test execution time in both local cluster environment  103  and remote cluster environment  105  pertaining to the execution of the same performance test in both local cluster environment  103  and remote cluster environment  105 , the network latency affecting the execution time for such a performance test (“compensation time”) in remote cluster environment  105  may now be determined by subtracting the performance execution time in local cluster environment  103  (not affected with network latency) from the performance execution time in remote cluster environment  105  (affected with network latency). 
     As a result, execution time module  203  is configured to determine test execution times impacted by network latency (referred to herein as the “compensation times”) based on such obtained performance test execution times in both the local and remote cluster environments  103 ,  105 . That is, execution time module  203  determines the compensation times based on the obtained performance test execution times in remote cluster environment  105  and the obtained performance test execution times in local cluster environment  103  for the same performance tests. Each of these compensation times represents a test execution time impacted by network latency as discussed above. 
     In one embodiment, the compensation time (test execution time impacted by network latency) is equal to the performance test execution time in remote cluster environment  105  minus the performance test execution time in local cluster environment  103  for the same performance test run at the same time in both local cluster environment  103  and remote cluster environment  105 . In one embodiment, an original version of the performance test is run in either the local cluster environment  103  or the remote cluster environment  105  and a duplicate copy of the performance test is run in the other environment at the same time. In this manner, the same performance test is run at the same time in both the local cluster environment  103  and remote cluster environment  105 . 
     Furthermore, performance analyzer  101  includes a regression model builder  204  configured to build a regression model to predict the performance test execution time impacted by the network latency (compensation time) using a regression algorithm that uses the clustered groups of network latency data and the clustered groups of compensation times. 
     For example, in one embodiment, regression model builder  204  builds a regression model using a regression algorithm that uses the clustered groups of network latency data (e.g., network latency between master and slave in seconds) and the clustered groups of compensation times (e.g., compensation times from network latency in seconds). Such clustered groups are then used by a regression algorithm to build a regression model to predict the execution time impacted by the network latency. Examples of such regression algorithms include, but not limited to, linear regression, support vector regression, regression trees, decision tree, lasso regression, random forest, etc. 
     After the regression model is built, the execution time of a performance test run in remote cluster environment  105  is collected by execution time module  203  as discussed above. For example, execution time module  203  obtains such execution times using various software tools, including, but not limited to, Linux® Trace Toolkit, worst-case execution time (WCET) tools, Timing Profiler, aiT, Bound-T, METAMOC, OTAWA developed by the University of Toulouse, TuBound, etc. 
     Furthermore, after the regression model is built, monitor engine  201  collects real-time network latency when running the performance test in remote cluster environment  105  as discussed above. For example, monitor engine  201  collects such real-time network latency using various software tools, including, but not limited to, SolarWinds® Network Performance Monitor, Paessler® Router Traffic Grapher, NetScan Tools, NetworkLatencyView from NirSoft, PingPlotter®, SolarWinds® NetFlow Traffic Analyzer, SolarWinds® Network Bandwidth Analyzer Pack, SolarWinds® Engineer&#39;s Toolset™, etc. 
     In one embodiment, regression model builder  204  is configured to predict the amount of execution time of the performance test (“compensation time”) that is impacted by the network latency using the regression model using the collected real-time network latency discussed above. Such an amount of execution time of the performance test that is impacted by the network latency that is predicted by the regression model is then subtracted from the collected execution time of the performance test run in remote cluster environment  105 , as discussed above, by execution time generator  205  of performance analyzer  101  in order to obtain the accurate execution time of the performance test. Such an execution time of the performance test, such as the performance regression test, generated by execution time generator  205  is now more accurate as the network latency is taken into account. In this manner, a tester may be able to more correctly determine whether the performance test was valid or invalid. 
     Software tools utilized by execution time generator  205  to obtain the accurate execution time of the performance test run in remote cluster environment  105  by subtracting the compensation time predicted by the regression model from the collected execution time of the performance test run in remote cluster environment  105  include, but not limited to, Time Calc, EZ Time Calculator, Time Calculator by Nummolt, etc. 
     A further description of these and other functions is provided below in connection with the discussion of the method for accurately identifying the execution time of the performance test (e.g., performance regression test) run in remote cluster environment  105 . 
     Prior to the discussion of the method for accurately identifying the execution time of the performance test (e.g., performance regression test) run in remote cluster environment  105 , a description of the hardware configuration of performance analyzer  101  is provided below in connection with  FIG.  3   . 
     Referring now to  FIG.  3   ,  FIG.  3    illustrates an embodiment of the present disclosure of the hardware configuration of performance analyzer  101  ( FIG.  1   ) which is representative of a hardware environment for practicing the present disclosure. 
     Performance analyzer  101  has a processor  301  connected to various other components by system bus  302 . An operating system  303  runs on processor  301  and provides control and coordinates the functions of the various components of  FIG.  3   . An application  304  in accordance with the principles of the present disclosure runs in conjunction with operating system  303  and provides calls to operating system  303  where the calls implement the various functions or services to be performed by application  304 . Application  304  may include, for example, monitor engine  201  ( FIG.  1   ), cluster module  202  ( FIG.  2   ), execution time module  203  ( FIG.  2   ), regression model builder  204  ( FIG.  2   ) and execution time generator  205  ( FIG.  2   ). Furthermore, application  304  may include, for example, a program for accurately identifying the execution time of the performance test (e.g., performance regression test) run in remote cluster environment  105  ( FIG.  1   ) as discussed further below in connection with  FIGS.  4 - 9   . 
     Referring again to  FIG.  3   , read-only memory (“ROM”)  305  is connected to system bus  302  and includes a basic input/output system (“BIOS”) that controls certain basic functions of performance analyzer  101 . Random access memory (“RAM”)  306  and disk adapter  307  are also connected to system bus  302 . It should be noted that software components including operating system  303  and application  304  may be loaded into RAM  306 , which may be performance analyzer&#39;s  101  main memory for execution. Disk adapter  307  may be an integrated drive electronics (“IDE”) adapter that communicates with a disk unit  308 , e.g., disk drive. It is noted that the program for accurately identifying the execution time of the performance test run in remote cluster environment  105 , as discussed further below in connection with  FIGS.  4 - 9   , may reside in disk unit  308  or in application  304 . 
     Performance analyzer  101  may further include a communications adapter  309  connected to bus  302 . Communications adapter  309  interconnects bus  302  with an outside network (e.g., network  106  of  FIG.  1   ) to communicate with other devices, such as server cluster  102 ,  104  ( FIG.  1   ). 
     In one embodiment, application  304  of performance analyzer  101  includes the software components of monitor engine  201 , cluster module  202 , execution time module  203 , regression model builder  204  and execution time generator  205 . In one embodiment, such components may be implemented in hardware, where such hardware components would be connected to bus  302 . The functions discussed above performed by such components are not generic computer functions. As a result, performance analyzer  101  is a particular machine that is the result of implementing specific, non-generic computer functions. 
     In one embodiment, the functionality of such software components (e.g., monitor engine  201 , cluster module  202 , execution time module  203 , regression model builder  204  and execution time generator  205 ) of performance analyzer  101 , including the functionality for accurately identifying the execution time of the performance test run in remote cluster environment  105 , may be embodied in an application specific integrated circuit. 
     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. 
     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. 
     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. 
     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&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;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&#39;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. 
     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. 
     These computer readable program instructions may be provided to a processor of a computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     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. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be accomplished as one step, executed concurrently, substantially concurrently, in a partially or wholly temporally overlapping manner, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     As stated above, performance regression testing may be performed on a server cluster in a network environment, such as remote network environment, which is used to handle big data (extremely large data sets that may be analyzed computationally to reveal patterns, trends, and associations, especially relating to human behavior and interactions). A “server cluster,” as used herein, refers to two or more servers working together. Even though each sever in the server cluster has its own resources, it is displayed in the network under one host name and has only a single Internet Protocol (IP) address. Performance regression tests on such server clusters often require the need to test certain data many times. Such repetitive tests may span a long time for big data. At times, the running ability of the server cluster will be affected by the network performance, such as network latency, during different periods of time. Furthermore, at times, the tester will observe an increase in the duration of the execution time of the performance test, such as a performance regression test, running on the server cluster. Such an increase in the execution time may be attributed to network performance, such as network latency, which may cause the tester to improperly conclude that the performance test was invalid. Unfortunately, there is not currently a means for determining the extent of network latency affecting the execution time of the performance test, which may provide clarity as to whether or not the performance test was truly invalid. Additionally, there is not currently a means for obtaining an accurate execution time of the performance test, such as the performance regression test, that takes into account the network latency. 
     The embodiments of the present disclosure provide a means for determining the extent of network latency affecting the execution time of the performance test thereby accurately identifying the execution time of the performance test, such as the performance regression test, as discussed below in connection with  FIGS.  4 - 9   .  FIG.  4    is a flowchart of a method for predicting the performance test execution time impacted by network latency.  FIG.  5    illustrates the grouping of network latency data into clustered groups of network latency data using a cluster algorithm.  FIG.  6    illustrates the grouping of compensation times into clustered groups of compensation times using a cluster algorithm.  FIG.  7    illustrates the information from the clustered groups of network latency data and the clustered groups of compensation times, which is used by the regression algorithm to build the regression model.  FIG.  8    is a graph illustrating the prediction of the execution time impacted by the network latency (compensation time) by the regression model.  FIG.  9    is a flowchart of a method for accurately identifying the execution time of the performance test run on the server cluster in the remote cluster environment by taking into consideration the impact of network latency. 
     As stated above,  FIG.  4    is a flowchart of a method  400  for predicting the performance test execution time impacted by network latency in accordance with an embodiment of the present disclosure. 
     Referring to  FIG.  4   , in conjunction with  FIGS.  1 - 3   , in operation  401 , monitor engine  201  of performance analyzer  101  collects the network latency data during different periods of time, such as the network latency in remote cluster environment  105 . 
     As stated above, “network latency,” as used herein, refers to delays in communication over a network (e.g., network  106 ), such as the delay in the amount of time it takes for a packet of data to be captured, transmitted, processed and received at its destination. Such latency may be caused by a variety of reasons, such as insufficient bandwidth, firewall blocking traffic, signal conversion, etc. 
     In one embodiment, monitor engine  201  monitors and collects the network latency data in remote cluster environment  105  during different periods of time by applying an applet (small application that performs one specific task that runs within the scope of a dedicated engine ( 201 ) or a larger program, such as a plug-in) in the test environment  105  to obtain a large number of random network delay data in different time periods. In one embodiment, the applet collects such network latency data via ping (software utility used to test the reachability of a host on an Internet Protocol (IP) network). Ping measures the round trip time for messages sent from the originating host to a destination that are echoed back to the source. In one embodiment, ping operates by sending Internet Control Message Protocol (ICMP) echo request packets to the target host and waiting for an ICMP echo reply. The applet may then report errors, packet loss and a statistical summary of the results, such as the minimum, maximum, the mean route trip times and standard deviation of the mean. 
     Examples of collecting the network latency data in remote cluster environment  105  using ping include collecting the latency between a client and a master, collecting the latency between master and slaves, etc. 
     In one embodiment, monitor engine  201  monitors and collects the network latency data during different periods of time, such as the network latency in remote cluster environment  105 , using various software tools, including, but not limited to, SolarWinds® Network Performance Monitor, Paessler® Router Traffic Grapher, NetScan Tools, NetworkLatencyView from NirSoft, PingPlotter®, SolarWinds® NetFlow Traffic Analyzer, SolarWinds® Network Bandwidth Analyzer Pack, SolarWinds® Engineer&#39;s Toolset™, etc. 
     In operation  402 , cluster module  202  of performance analyzer  101  groups the collected network latency data using a cluster algorithm. 
     As stated above, in one embodiment, cluster module  202  groups the network latency data collected by monitor engine  201  using a cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. 
     An example of grouping the network latency data collected by monitor engine  201  is shown in  FIG.  5   . 
     Referring to  FIG.  5   ,  FIG.  5    illustrates the grouping of network latency data into clustered groups of network latency data using a cluster algorithm in accordance with an embodiment of the present disclosure. 
     As shown in  FIG.  5   ,  FIG.  5    is a graph  500  illustrating network latency  501  versus time  502  which depicts the distribution or groups of network latency data that was collected by monitor engine  201 . 
     Returning to  FIG.  4   , in conjunction with  FIGS.  1 - 3  and  5   , in operation  403 , execution time module  203  of performance analyzer  101  obtains the performance test execution times for a group of performance tests run in remote cluster environment  105  at different times. That is, execution time module  203  of performance analyzer  101  obtains the performance test execution times of running the performance tests on server cluster  104  in remote cluster environment  105  at different times. 
     When such performance tests are run, execution time module  203  obtains the execution time of such performance tests (referred to herein as the “performance test execution time”). In one embodiment, execution time module  203  obtains such execution times using various software tools, including, but not limited to, Linux® Trace Toolkit, worst-case execution time (WCET) tools, Timing Profiler, aiT, Bound-T, METAMOC, OTAWA developed by the University of Toulouse, TuBound, etc. 
     In operation  404 , execution time module  203  of performance analyzer  101  obtains the performance test execution times for the same group of performance tests run in local cluster environment  103 . That is, execution time module  203  of performance analyzer  101  obtains the performance test execution times for the same performance tests that are run on server cluster  102  of local cluster environment  103  as well as run on server cluster  104  of remote cluster environment  105 . 
     In one embodiment, an original version of the performance test is run in either the local cluster environment  103  or the remote cluster environment  105  and a duplicate copy of the performance test is run in the other environment. In this manner, the same performance test is run at the same time in both local cluster environment  103  and remote cluster environment  105 . 
     As discussed above, the performance execution time in local cluster environment  103  should not be affected by network latency since server cluster  102  is directly connected to performance analyzer  101  (not connected to performance analyzer  101  via a network). As a result, such a performance execution time reflects the true performance execution time (execution time of the performance test) when there is no network latency. 
     By obtaining the performance test execution time in both the local cluster environment  103  and the remote cluster environment  105 , the network latency affecting such a performance test execution time (“compensation time”) in remote cluster environment  105  may now be determined by comparing the performance execution time in remote cluster environment  105  (affected with network latency) with the performance execution time in local cluster environment  103  (not affected with network latency). 
     In operation  405 , execution time module  203  of performance analyzer  101  determines the test execution times impacted by network latency (compensation times) based on the obtained performance execution times in local and remote cluster environments  103 ,  105 . 
     As stated above, execution time module  203  is configured to determine test execution times impacted by network latency (referred to herein as the “compensation times”) based on such obtained performance test execution times in both the local and remote cluster environments  103 ,  105 . That is, execution time module  203  determines the compensation times based on the obtained performance test execution times in remote cluster environment  105  and the obtained performance test execution times in local cluster environment  103  for the same performance tests. Each of these compensation times represents a test execution time impacted by network latency as discussed above. 
     In one embodiment, the compensation time (test execution time impacted by network latency) is equal to the performance test execution time in remote cluster environment  105  minus the performance test execution time in local cluster environment  103  for the same performance test run in both local cluster environment  103  and remote cluster environment  105 . In one embodiment, an original version of the performance test is run in either the local cluster environment  103  or the remote cluster environment  105  and a duplicate copy of the performance test is run in the other environment at the same time. In this manner, the same performance test is run at the same time in both local cluster environment  103  and remote cluster environment  105 . 
     In operation  406 , cluster module  202  of performance analyzer  101  groups the compensation times (determined in operation  405 ) using a cluster algorithm. 
     As discussed above, in one embodiment, cluster module  202  groups the compensation times, which are determined by execution time module  203 , using a cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. 
     An example of grouping the compensation times determined by execution time module  203  is shown in  FIG.  6   . 
     Referring to  FIG.  6   ,  FIG.  6    illustrates the grouping of compensation times into clustered groups of compensation times using a cluster algorithm in accordance with an embodiment of the present disclosure. 
     As shown in  FIG.  6   ,  FIG.  6    is a graph  600  illustrating the evaluation times impacted by network latency (compensation time)  601  versus the performance tests  602 , where graph  600  depicts the distribution or groups of compensation times that was determined by execution time module  203 . 
     Returning to  FIG.  4   , in conjunction with  FIGS.  1 - 3  and  5 - 6   , in operation  407 , regression model builder  204  of performance analyzer  101  builds a regression model to predict the performance test execution time impacted by network latency (compensation time) using a regression algorithm that uses the clustered groups of network latency data and the clustered groups of compensation times. 
     As stated above, in one embodiment, regression model builder  204  builds a regression model using a regression algorithm that uses the clustered groups of network latency data (e.g., network latency between master and slave in seconds) and the clustered groups of compensation times (e.g., compensation times from network latency in seconds). Such clustered groups are then used by a regression algorithm to build a regression model to predict the execution time impacted by the network latency. Examples of such regression algorithms include, but not limited to, linear regression, support vector regression, regression trees, decision tree, lasso regression, random forest, etc. 
     An example of using information from such clustered groups (clustered groups of network latency data as shown in  FIG.  5    and clustered groups of compensation times as shown in  FIG.  6   ) to build a regression model by the regression algorithm is shown in  FIG.  7   . 
       FIG.  7    illustrates the information from the clustered groups of network latency data and the clustered groups of compensation times, which is used by the regression algorithm to build the regression model in accordance with an embodiment of the present disclosure. 
     Referring to  FIG.  7   , in conjunction with  FIGS.  5 - 6   , such information from the clustered groups of network latency data and the clustered groups of compensation times may be stored in a data structure  700  (e.g., table) as shown in  FIG.  7   . In one embodiment, data structure  700  may be stored in a storage device (e.g., memory  305 , disk unit  308 ) of performance analyzer  101 . 
     As shown in  FIG.  7   , data structure  700  includes information pertaining to the clustered groups of network latency data, such as network latency with the master  701  (in seconds), network latency between the master and slave #1  702  (in seconds), network latency between the master and slave #2  703  (in seconds), network latency between the master and slave #3  704  (in seconds), and so forth. 
     Furthermore, as shown in  FIG.  7   , data structure  700  includes information pertaining to the clustered groups of compensation times, such as the compensation time from the network latency  705  (in minutes). 
     Additionally, as shown in  FIG.  7   , each of such information may be associated with an identifier  706  (identified as “ID” in  FIG.  7   ). 
     In one embodiment, the information stored in data structure  700  may then be used to build a regression model by a regression algorithm, where the regression model is configured to predict the execution time impacted by the network latency (compensation time) as shown in  FIG.  8   . 
     Referring to  FIG.  8   ,  FIG.  8    is a graph illustrating the prediction of the execution time impacted by the network latency (compensation time) by the regression model in accordance with an embodiment of the present disclosure. 
     As shown in  FIG.  8   ,  FIG.  8    is a graph  800  illustrating the linkage between the average network latency  801  (in seconds) and the execution time impacted by network latency  802  (in minutes). 
     After the regression model is built, an accurate execution time of a performance test (e.g., performance regression test) run on server cluster  104  ( FIG.  1   ) in remote cluster environment  105  ( FIG.  1   ) will be able to be identified by taking into consideration the impact, if any, of the network latency as discussed below in connection with  FIG.  9   . 
       FIG.  9    is a flowchart of a method  900  for accurately identifying the execution time of the performance test (e.g., performance regression test) run on server cluster  104  ( FIG.  1   ) in remote cluster environment  105  ( FIG.  1   ) by taking into consideration the impact of network latency in accordance with an embodiment of the present disclosure. 
     Referring to  FIG.  9   , in conjunction with  FIGS.  1 - 8   , in operation  901 , execution time module  203  of performance analyzer  101  collects the execution time of the performance test (e.g., performance regression test) run in remote cluster environment  105 . That is, execution time module  203  collects the execution time of the performance test (e.g., performance regression test) run on server cluster  104  of remote cluster environment  105 . 
     As discussed above, execution time module  203  obtains or collects the execution time of the performance test run in remote cluster environment  105  using various software tools, including, but not limited to, Linux® Trace Toolkit, worst-case execution time (WCET) tools, Timing Profiler, aiT, Bound-T, METAMOC, OTAWA developed by the University of Toulouse, TuBound, etc. 
     In operation  902 , monitor engine  201  of performance analyzer  101  collects the real-time network latency when running the performance test in remote cluster environment  105 . That is, monitor engine  201  collects the real-time network latency when running the performance test on server cluster  104  of remote cluster environment  105 . 
     As stated above, monitor engine  201  monitors and collects the network latency data in remote cluster environment  105 , using various software tools, including, but not limited to, SolarWinds® Network Performance Monitor, Paessler® Router Traffic Grapher, NetScan Tools, NetworkLatencyView from NirSoft, PingPlotter®, SolarWinds® NetFlow Traffic Analyzer, SolarWinds® Network Bandwidth Analyzer Pack, SolarWinds® Engineer&#39;s Toolset™, etc. 
     In operation  903 , regression model builder  204  of performance analyzer  101  predicts the amount of the execution time of the performance test impacted by network latency (compensation time) using the built regression model. 
     As discussed above, in one embodiment, regression model builder  204  is configured to predict the amount of execution time of the performance test (“compensation time”) that is impacted by the network latency using the regression model using the collected real-time network latency discussed above. 
     In operation  904 , execution time generator  205  of performance analyzer  101  generates the accurate execution time of the performance test by subtracting compensation time predicted by the regression model (see operation  903 ) from the execution time of the performance test run in remote cluster environment  105  (see operation  901 ). 
     As stated above, in one embodiment, execution time generator  205  subtracts the amount of execution time of the performance test that is impacted by the network latency that is predicted by the regression model from the collected execution time of the performance test run in remote cluster environment  105  in order to obtain the accurate execution time of the performance test. Such an execution time of the performance test, such as the performance regression test, generated by execution time generator  205  is now more accurate as the network latency is taken into account. In this manner, a tester may be able to more correctly determine whether the performance test was valid or invalid. 
     As a result of the foregoing, embodiments of the present disclosure accurately identify the execution time of a performance test, such as a performance regression test, by taking into consideration the impact of network latency. By taking into consideration the performance impact from network latency, a more accurate execution time of the performance test is obtained thereby enabling the tester to more accurately determine whether the performance test was valid or invalid. 
     Furthermore, the principles of the present disclosure improve the technology or technical field involving performance testing, such as performance regression testing. As discussed above, performance regression testing may be performed on a server cluster in a network environment, such as remote network environment, which is used to handle big data (extremely large data sets that may be analyzed computationally to reveal patterns, trends, and associations, especially relating to human behavior and interactions). A “server cluster,” as used herein, refers to two or more servers working together. Even though each sever in the server cluster has its own resources, it is displayed in the network under one host name and has only a single Internet Protocol (IP) address. Performance regression tests on such server clusters often require the need to test certain data many times. Such repetitive tests may span a long time for big data. At times, the running ability of the server cluster will be affected by the network performance, such as network latency, during different periods of time. Furthermore, at times, the tester will observe an increase in the duration of the execution time of the performance test, such as a performance regression test, running on the server cluster. Such an increase in the execution time may be attributed to network performance, such as network latency, which may cause the tester to improperly conclude that the performance test was invalid. Unfortunately, there is not currently a means for determining the extent of network latency affecting the execution time of the performance test, which may provide clarity as to whether or not the performance test was truly invalid. Additionally, there is not currently a means for obtaining an accurate execution time of the performance test, such as the performance regression test, that takes into account the network latency. 
     Embodiments of the present disclosure improve such technology by grouping network latency data into clustered groups of network latency data using a first cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. Furthermore, the performance test execution times for a group of performance tests run in a remote cluster environment are obtained at different times. That is, the performance test execution times of running the performance tests on a server cluster in the remote cluster environment are obtained at different times. Additionally, the performance test execution times for the same group of performance tests run in a local cluster environment are obtained. The test execution times impacted by network latency (“compensation times”) are then determined based on such obtained performance test execution times in the local and remote cluster environments. In one embodiment, the compensation time (test execution time impacted by network latency) is equal to the performance test execution time for the performance test run in the remote cluster environment minus the performance test execution time for the same performance test run in the local cluster environment. Such compensation times are then grouped into clustered groups of compensation times using a second cluster algorithm, such as the k-means clustering algorithm, mean-shift clustering algorithm, density-based spatial clustering of applications with noise, expectation-maximization clustering using Gaussian mixture models, agglomerative hierarchical clustering, etc. A regression model is then built to predict a performance test execution time impacted by network latency using the clustered groups of network latency data and the clustered groups of compensation times. The execution time of a performance test run in the remote cluster environment is then generated that takes into consideration the performance test execution time impacted by network latency predicted by the regression model. In this manner, the execution time of the performance test, such as the performance regression test, is more accurate as the network latency is taken into account. Furthermore, in this manner, a tester is able to more correctly determine whether the performance test was valid or invalid. Additionally, in this manner, there is an improvement in the technical field involving performance testing, such as performance regression testing. 
     The technical solution provided by the present disclosure cannot be performed in the human mind or by a human using a pen and paper. That is, the technical solution provided by the present disclosure could not be accomplished in the human mind or by a human using a pen and paper in any reasonable amount of time and with any reasonable expectation of accuracy without the use of a computer. 
     The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.