Abstract:
A system and method for testing the reliability of a target module is presented. A reliability testing module executes a testing script by directing the target module to perform various functions, and by further consuming system resources by executing test applications. The behaviors of the target module are recorded and evaluated, and a reliability score is generated for the target module. The reliability score enables a user to compare the reliability of a first target module to that of a second.

Description:
FIELD OF THE INVENTION 
     The present invention relates to testing computer system software, and more particularly, to testing the reliability of software modules on a computer system. 
     BACKGROUND OF THE INVENTION 
     Most computers today, especially the ubiquitous personal computers, can be configured with any number of devices from a variety of vendors. For example, the typical personal computer can be configured from a variety of graphic display systems, scanners, input devices such as a mouse or digitizing pad, network interface cards, and Web cameras, to name just a few. Indeed, the possibilities often seem endless. 
     Competition among the various vendors is often quite fierce. In order to attract buyers, vendors frequently promote their products according to the speed with which they can complete a certain task or tasks on a given computer system. For example, with respect to graphic display systems, third-party vendors often promote their graphic display systems according to speed-related benchmarks achieved by their product when run against a benchmark suite. Industry-related magazines and publications often review, promote, and/or endorse products based on these benchmark results. Correspondingly, many users purchase third-party devices based on the various benchmarks published or associated with a device. Almost universally, benchmarks are speed-related evaluations. 
     As those familiar with the computer industry will recognize, third-party vendors often analyze the benchmark suite, examining and analyzing the methodologies by which the benchmarks are derived. Such analysis provides the vendors with invaluable insight as to what exactly is sought by reviewers (and presumably customers), and also provides insight as to how they may improve their products to achieve better benchmark scores. Unfortunately, this information often leads a vendor to optimize their product for benchmark purposes, frequently turning to complex processing, short-cuts, and raising (even exceeding) operating limits. Whether or not a vendor intentionally does so, these “optimizations” tend to sacrifice operating stability for benchmark performance, i.e., speed. 
     One area that is often sacrificed to optimization for performance sake is the interface between a computer&#39;s operating system and the hardware device, hereafter referred to as the “device driver.” Indeed, the device driver is a logical choice for optimization, as its modification represents the least expensive course, and one that could yield substantial results, for a vendor. Unfortunately, device driver failures account for a substantial percentage of computer system crashes. According to some statistics, at least one out of every four system crashes is attributable to a device driver malfunction. 
     While market forces typically drive vendors to optimize their products for improved speed, there is an unfortunate lack of a complimentary force that encourages vendors to produce stable products, i.e., those that will not cause system crashes. In other words, there is currently no system available that benchmarks or measures the stability of a product in the same way that benchmarks are available for speed/performance. It should be noted that many operating system providers provide a compatibility certification for third party products, including devices. In other words, if a vendor meets the established baseline of compatibility with an operating system, the operating system provider will permit the vendor to advertise that its product has been certified as compatible with the operating system. Unfortunately, such certification simply indicates that a product has met some minimum level of compatibility, and does not provide a consumer with any information by which a comparison may be made between products. In fact, there is a general need in the computer industry for a stability benchmark rating of products. The present invention addresses these needs and other issues found in the prior art. 
     SUMMARY OF THE INVENTION 
     In accordance with aspects of the present invention, computer system for generating a reliability rating for a target module is presented. The computer system comprises a processor that executes the target module; a memory, the memory storing the target module; and a reliability testing module configured to test the reliability of the target module. To determine a reliability rating for the target module, the reliability testing module executes a testing script in conjunction with the operation of the target module. The reliability testing module evaluates the behavior of the target module in response to the execution of the testing script. The reliability testing module then generates a reliability rating according to the evaluated behavior of the target module. The reliability rating is a value by which the reliability of the target module may be compared to the reliability of a second target module to determine which target module is more reliable. 
     In accordance with additional aspects of the present invention, a method for determining the reliability of a target module is presented. A target module is executed on a computing device. A testing script to test the reliability of the target module is executed. The behavior of the target module is monitored in response to executing the testing script. A reliability rating is generated according to the monitored behavior of the target module. The reliability rating is a value by which the reliability of the target module may be compared to the reliability of a second target module to determine which target module is more reliable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a pictorial diagram illustrating an exemplary computer system suitable for implementing aspects of the present invention; 
         FIGS. 2A and 2B  are pictorial diagrams illustrating exemplary system load/time graphs of varying the system load to test a target module; 
         FIG. 3  is a pictorial diagram illustrating an alternative, exemplary network computer system suitable for implementing aspects of the present invention; 
         FIG. 4  is a flow diagram illustrating an exemplary routine for testing the reliability of target module and generating a reliability score for the target module; and 
         FIG. 5  is a flow diagram illustrating an exemplary routine for varying the test applications running on the computer system during the software reliability testing of a target module. 
     
    
    
     DETAILED DESCRIPTION 
     As mentioned above,  FIG. 1  is a pictorial diagram illustrating an exemplary computer system  100  suitable for implementing aspects of the present invention. The computer system  100  includes a processor  102  and memory  104 . As those skilled in the art will appreciate, the memory comprises both volatile and non-volatile memory for storing a variety of items, including an operating system, software applications, data files, and the like. As shown in exemplary  FIG. 1 , the memory  104  includes an operating system  106  which, as those skilled in the art will appreciate, provides an environment in which other applications and modules may operate. 
     The computer system also includes, typically in the memory  104 , a target module  108  which is the subject matter to be tested for reliability. The computer system  100  tests the target module  108  using a reliability test module  110 . The reliability test module  110  may be running/executing prior to the execution of the target module  108  and load the target module as part of the reliability test process, or alternatively, may commence the test process on an already executing target module. 
     Those skilled in the art will recognize that application start-up and shut-down procedures, both with a target module as well as other applications, account for a substantial portion of reliability issues, such as system crashes, program crashes, malfunctions, and the like. Thus, one way to test a target module is to launch other test applications during the testing of the test module. Accordingly, the computer system  100  may also include a set of test applications  114 , including a set of test applications, such as test applications  116 - 124 . As described below, the timing of starting and stopping test applications  114  is controlled according to a predetermined testing script. 
     According to aspects of the present invention, the reliability test module  110  exercises the target module  108  according to one or more predetermined testing scripts  112 . The testing scripts  112  include instructions which the reliability test module  110  cause to occur, including causing the target module to perform various functions. In addition, the testing scripts  112  may also include instructions to the reliability test module  110  to perform various actions that affect the computer system  100  generally. For example, a testing script may include instructions to load any number of test applications  114  to consume system resources, compete for processing time, interact with the target module  108 , and the like. It should be noted that a testing script may be embodied in various forms. For example, a testing script may be a document or file written in a computer readable format, such as an HTML, XML, JavaScript, or other formatted files. Alternatively, a testing script may be encoded in computer readable format. As still another alternative, the testing script may be generated on the fly, such as by a random selection of instructions for the target module. Still further, the testing script may be hard coded into the reliability test module  110 , or some other application supplying instructions to the reliability test module. It should be appreciated, however, that the above examples are illustrative only, and should not be construed as limiting upon the present invention. Another item included in the computer system  100  is a test log  128 . As the reliability test module  110  exercises the target module  108 , the actions taken by the reliability test module are recorded in the test log  128 . Similarly, the behavior of the target module, as well as computer system conditions, are also recorded into the test log  128 . By recording the various actions taken, computer system conditions, and target module  108  results, reliability issues related to the target module  108  can be identified, and a reliability score for the target module can be determined. According to aspects of the present invention, the reliability test module  110  records information into the test log  128  on a predetermined periodic basis. Alternatively, the reliability test module  110  records information into the test log  128  as testing script actions are executed. As yet another alternative, the reliability test module  110  records information into the test log  128  as actions are executed, and on a periodic basis. 
     As indicated above, a test script may be configured to perform a variety of actions, actions directed to manipulate various functionality of the test module  108 , as well as actions that indirectly impact the test module.  FIGS. 2A and 2B  are pictorial diagrams illustrating exemplary system load/time graphs  200  and  212  of varying the computer system load to test the target module  108 , with the system load represented by line  202  and time represented by line  204 . 
     In particular, with respect to  FIG. 2A , a test script may be configured such that the system load  210 , including both computer system resources consumed by the test module  108  due to the actions taken by the test script, as well as test applications loaded into the computer system by the test script, may fluctuate between a maximum system load level  206  and minimum system load level  208 . Additionally, the maximum system load level  206  and minimum system load level  208  may increase or decrease over time  204 . As shown in  FIG. 2A , the system load  210  can be configured to fluctuate sinusoidally between the maximum and minimum load levels. However, the system load level may be configured to any particular levels over time, such as system load level  214  of graph  212  of  FIG. 2B . Still further, while not shown, a testing script may be configured to maintain a constant system load, anywhere between a maximum system load  206  or a minimum system load  208  over a given period of time, or for the entire duration of the testing script process. 
     With reference to  FIG. 1 , it should be noted that while the present discussion has been directed at a single computer system, and more particularly at computer system  100 , aspects of the invention may be suitably applied in a multi-computer environment, including a networked environment.  FIG. 3  is a pictorial diagram illustrating an exemplary networked computing environment  300  suitable for implementing aspects of the present invention. As illustrated in  FIG. 3 , the exemplary computing environment includes a target computer  302  upon which the target module  108  is executed. The exemplary computing environment also includes a test computer  304 , coupled to the target computer  302  via a communication network  306 . 
     According to the exemplary networked environment  300 , the test computer includes a master test module  310  that reads one or more test scripts  114  and sends the test instructions from the test script over the network  306  to a corresponding slave test module  308 . The slave test module  308  carries out the instructions of the test scripts  114 , both on the target module  116  as well as the computing environment of the target computer  302 . For example, the slave test module  308  may direct the test module to perform various functions, as well as launch various test applications, such as test applications  120  and  122 . As events occur, or on a periodic basis, or both, the slave test module  308  reports the actions back to the master test module  310  on the test computer  304 , which records the various reports sent back by the slave test module  308  in the test log  112  for subsequent evaluation. 
     In evaluating the information in the test log  112  to determine a reliability score, any number of factors may be considered. For example, weight may be given to the length of time that the target module  116  continuously runs before failure/crash. Weight may also be given to the behavior of the target module  116  during high system load times. Still additionally weight may be given, if the target module crashes, as to whether the computer system, such as computer system  102 , can continue to operate or whether the target module&#39;s crash caused a fatal system error. Other factors may also be given weight in determining a reliability score. Of course, as those skilled in the art will appreciate, should there be a crash, either of the target module  116  or the computer system, an evaluation must be made as to whether the target module was at least partially the cause of the crash, and only consider those instances where target module  108  is a direct contributor. 
     Another aspect of evaluating the information in the test log  112  to determine a reliability score is to aggregate or average the scores of multiple test passes, i.e., running a test script repeatedly, and generating an average reliability score based on the multiple passes. 
       FIG. 4  is a flow diagram illustrating an exemplary routine  400  for testing the reliability of target module  108  and generating a reliability score for that target module. Beginning at block  402 , the reliability test module  110  loads a testing script  112 . At decision block  404 , a determination is made as to whether any pre-execution requirements must be established/satisfied before the testing script  112  can be executed. These requirements may include establishing a baseline system load level, ensuring that a particular hardware device is operational, connecting to a network, and the like. If there are pre-executing requirements, at block  406 , the pre-execution requirements are satisfied and/or established. 
     At block  408 , the target module  108  is executed. Alternatively, it should be noted that executing the target module may be specified as a pre-execution setting, or further alternatively, the target module  108  may be executing prior to loading the testing script. Thus, the order of loading the target module  108  as shown in  FIG. 4  should be viewed as illustrative only, and not construed as limiting upon the present invention. 
     At block  410 , the testing script  112  is executed. As mentioned above, executing a testing script  112  may involve sending instructions to the target module  108  to perform various functions, consuming computer system resources such as memory or disk space, launching one or more test applications  114 . Commensurate with executing the test script  112  numerous factors are recorded in the test log  126 . These factors include the behavior of the target module  108  in response to the test script  112 , which test applications  114  were executed, the time that a particular event occurred, and the like. 
     At block  412 , after having executed the test script, the information recorded in the test log is evaluated, thereby generating a preliminary reliability score for the test module  108 . However, as mentioned above, the ultimate reliability score generated for the test module  108  may be an aggregation of multiple passes through the testing script  112 . Accordingly, at block  414 , a determination is made as to whether the testing script  112  should be repeated. If the testing script  112 , or alternatively another testing script, should be repeated, at block  418 , the computer system is optionally reset to the conditions when the testing started. At block  420 , any variables or settings associated with the testing script  112  are reset. Thereafter, the routine  400  returns again to decision block  404  to determine whether an pre-execution requirements must be established, as described above. 
     Alternatively, if the test script  112 , or another testing script, is not to be repeated, at block  416  a cumulative reliability score is generated for the target module  108 . As indicated above, this may be an average of the scores generated from individual passes, and/or be a function of any number of factors identified during the execution of the testing script or scripts. Thereafter, the routine  400  terminates. 
     The reliability score is not simply a pass/fail score that indicates a minimum of compatibility. Instead, the reliability score, typically a numeric value, corresponds to the results of the reliability of the target module with respect to the testing scripts executed. Using this reliability score, a user can evaluate the reliability of the target module  108  in comparison to other, similar modules and determine which module is more likely to be reliable based on that score. 
     As previously mentioned, testing the reliability of the target module  108  may involve concurrently executing test applications  114  to provide an overall system load on the computer resources. However, just as with any testing environment, a static pattern does not always find problems with a test module  108  that a randomized pattern might. Thus, selecting the same test applications to provide an overall system load might not locate problems that could be found by randomizing or rotating the test applications executed to provide overall system load. Thus, according to aspects of the present invention, the test module  110 , in addition to processing a test script to test the target module, rotates and/or randomizes the selection of test applications from the set of test applications  114  when directed to provide various levels of system load. 
     According to one embodiment, the test applications in the set of test applications  114  are executed in a queue fashion, i.e., first executed, first terminated. Thus, when the overall system load is to decrease by terminating a test application, the test application that has been executing for the longest amount of time is terminated. Similarly, when the overall system load is to be increased by executing a test application, a test application that has not yet been executed, or if all have been executed, the test application whose inactivity has been the longest is selected. 
     Additionally, to provide further alternation between test applications, according to one embodiment, test applications are replaced on a periodic basis. In other words, in addition to executing or terminating test applications to provide a desired level of a overall system load, on a periodic basis a currently executing test application is terminated and is replaced by executing another test application in the set of test applications  114 . 
       FIG. 5  is a flow diagram illustrating an exemplary routine  500  for varying the test applications  114  executing on the computer system during the software reliability testing of a target module  108 . Beginning at block  502 , a test application timer is set. Setting the test application timer ensures that test applications are cycled as the timer expires. Thereafter, at event block  504 , the routine  500  waits for an event to occur. Events for which this routine monitors include both load request events from a reliability test module  110 , or a timer event indicating a time to change one or more test applications executing on the computer system. 
     Upon detecting an event, at decision block  506  a determination is made as to the type of event that was detected. If the event was a load event from the reliability test module  110 , at decision block  508  another determination is made as to whether the load event was to increase or decrease the system load. If the load event indicated a decrease to the overall system load, at block  510 , a test application that is currently executing is selected. As mentioned above, selecting a test application to terminate may be based on a queue basis, i.e., the longest executing test application is the selected test application to be terminated. At block  512 , the selected test application is terminated, and the routine  500  proceeds to block  526 , where the test application timer is reset. Thereafter, the routine  500  returns again to event block  504  to await another event. 
     If, at decision block  508 , the load request is to increase the system load, at block  514  one or more additional test applications are selected to satisfy the load request. At block  516 , the selected test applications are launched. At block  526 , the test application timer is reset and the process  500  returns again to event block  504 . 
     At decision block  506 , if the detected event is a timer event, at block  518  a currently executing test application is selected for replacement/rotation. As mentioned above, test applications may be alternated according to a longest executing/first terminated manner. At block  520 , the selected test application is terminated. At block  522 , a replacement test application is selected. Selecting a replacement test application may be performed according to a variety of criteria including the particular resources that a test application may use, the amount of time since the test application has been executed, the amount of resources that a test application consumes, and the like. After selecting the replacement test application, at block  524  the selected test application is launched/executed. The routine  500  then proceeds to block  526 , where the test application timer is reset. Thereafter, the routine  500  returns to event block  504  to await another event. 
     No ending block is identified in the exemplary routine  500 . It is anticipated that the exemplary routine  500  terminates when the reliability testing terminates. 
     While various embodiments, including the preferred embodiment, of the invention have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.