Adaptive load generation

Abstract

A method provides for a series of procedural steps in the determination of the state of operation of a computer web application responding to requests by a multiplicity of client machines. The procedural steps are accomplished by use of a plurality of load generators which apply loading to the web application simulating the actual loading of any one of the client machines. One of the load generators is selected to increase its load by an incremental loading. A further load generator is employed in the place of a probing client machine for observation of the performance of the web application. At the probing client machine, there is an observing of the transactions per second (TPS) and response time of the web application, the observing taking place both before and after the application of the load increment to the web application. Thereupon, by logic analysis of the presence or absence of an increase in the TPS, as well as a presence or absence of an increase in the response time, a determination is made as to whether the web application has attained its full capacity or whether the load generator has attained full capacity, the latter case requiring a utilization of a further one of the load generators for further loading of the web application.

What is claimed is:  
     
         1 . A method, employing adaptive load generation, for measuring performance of a web application which processes requests by client machines, the method comprising procedural steps of: 
 providing a set of load generators for generating loads which simulate the loading on the web application of requests by client machines;    employing a plurality of load generators from said set of load generators to said web application with an initial amount of loading;    a first step of directing a first of said plurality of load generators to increase its load by a first load increment;    determining if there has been any increase in transactions per second (TPS) and response time of said web application resulting from said first load increment; and    applying a logic analysis to a determination of said determining step wherein an absence of increase in the TPS in conjunction with the presence of an increase in the response time is determinative of said web application being in an operating state of full capacity.    
     
     
         2 . A method according to  claim 1  wherein said determining step includes a first step of observing said TPS and said response time prior to said directing step, and a second step of observing said TPS and said response time subsequent to said determining step.  
     
     
         3 . A method according to  claim 2  further comprising steps of selecting an additional one of said generators to function as a probing client machine, and performing said first and said second steps of observing said (TPS) and said response time at said probing client machine, said plurality of load generators providing the true number of effective clients loading said web application.  
     
     
         4 . A method according to  claim 3  wherein there are a plurality of client machines accessing said web application, each of said client machines running respective threads concurrently, and wherein implementation of the method provides for a plurality of measurements of web application performance during the running of the threads of the respective clients.  
     
     
         5 . A method according to  claim 1  wherein, in said logic analysis, an increase in the TPS is taken as a determination that said web application and said first load generator are operating satisfactorily, the procedure of the method continuing with a second step of directing one of said load generators of said set of load generators to increase a loading of said web application by a second load increment, thereafter there is a repetition of said steps of determining and applying.  
     
     
         6 . A method according to  claim 5  wherein, in said second step of directing, there is a directing of a second load generator of said plurality of load generators to increase its load.  
     
     
         7 . A method according to  claim 1  wherein, in said logic analysis, an absence of an increase in said TPS in conjunction with an absence of an increase in said response is determinative of said first load generator having reached an operating state of full capacity, wherein the procedure of the method continues with: 
 selecting a second generator of said plurality of generators; and  
 a second step of directing said second load generator to increase a loading of said web application by a second load increment, thereafter, there is a repetition of said steps of determining and applying.  
 
     
     
         8 . A method according to  claim 1  further comprising a step, subsequent to said applying step, of assessing whether a performance goal of said web application has been attained, thereafter, in the event that the performance goal has not been attained, there is a repetition of said steps of determining and applying, and in the event that the performance goal has been attained, there is a terminating of the procedure of the method.  
     
     
         9 . A method according to  claim 1  further comprising a step, prior to said determining step, of assessing whether said web application has attained a performance goal, the procedure of the method terminating if the performance goal has been attained, the procedure of the method continuing with said determining step if the performance goal has not been attained.