LoadRunner-Introduction Chapter 1

Krish Hegde1LoadRunner•To load your application, LoadRunner emulates an environment where multiple users work concurrently. •While the application is under load, LoadRunner accurately measures, monitors, and analyzes a system’s performance and functionality.Krish Hegde2Architecture OverviewKrish Hegde3Client-Server Paradigm•Client Server applications deliver higher functionalities and power, but also introduce new risks:–Higher Performance risks due to large number of users accessing the system simultaneously.–Impossible to manually simulate load on applicationKrish Hegde4Manual Load Testing• It is expensive, requiring large amounts of both personnel and machinery• It is complicated, especially coordinating and synchronizing multiple testers• It involves a high degree of organization, especially to record and analyze results meaningfully• The repeatability of the manual tests is limitedKrish Hegde5Load Testing with LoadRunner•LoadRunner reduces the personnel requirements by replacing human users with virtual users or Vusers. These Vusers emulate the behavior of real users—operating real applications.•Because numerous Vusers can run on a single computer, LoadRunner reduces the hardware requirements.•The LoadRunner Controller allows you to easily and effectively control all the Vusers—from a single point of control.Krish Hegde6Load Testing with LoadRunner•LoadRunner monitors the application performance online, enabling you to fine-tune your system during test execution.• LoadRunner automatically records the performance of the application during a test. You can choose from a wide variety of graphs and reports to view the performance data.Krish Hegde7Load Testing with LoadRunner•LoadRunner checks where performance delays occur: network or client delays, CPU performance, I/O delays, database locking, or other issues at the database server.•LoadRunner monitors the network and server resources to help you improve performance.• Because LoadRunner tests are fully automated, you can easily repeat them as often as you need.Krish Hegde8Load & Stress Testing•Objectives:–Check Scalability–Check Performance ie Transactions/minute,–Draw Memory Profile–Check CPU performance–Check Network performanceKrish Hegde9Load & Stress Testing•Load & Stress testing are two different but related forms of testing.•Stress Testing: Involves testing a system under extreme cases, which may rarely occur under normal conditions.•Such testing can involve scenarios like:–Running many users concurrently for short times–Short transactions repeated quickly and extraordinarily long transactions.Krish Hegde10Load & Stress Testing•Load testing places a more realistic load on the system•Load testing starts by placing a low demand on the system and gradually increasing the load.•This process allows measuring the performance of the system under loads, as well as determining the maximum load, under which the AUT can respond acceptably.Krish Hegde11Load & Stress Testing•Load and stress testing are clearly two inter related processes, generally performed concurrently.•They do not conduct functional tests.•In order to perform performance testing, it must be assumed that a reasonably stable and functional system is in use, otherwise results are meaningless.Krish Hegde12Load & Stress Testing•It is essential to know that the bottleneck of a system is due to the server /Client/Database/Network performance issues.•Performance issues could be related to:–Lack of sufficient Memory–Lack of CPU performance–poor algorithms–Poor design. Krish Hegde13LoadRunner-Scenarios•Using LoadRunner, you divide your application performance testing requirements into scenarios. •A Scenario could be running a UseCase. In ideal condition there may be 20~50 usecases /Scenarios in a AUT.•A scenario defines the events that occur during each testing session. Thus, for example, a scenario defines and controls the number of users to emulate, the actions that they perform, and the machines on which they run their emulations.Krish Hegde14VUsers•In the scenario, LoadRunner replaces human users with virtual users or Vusers. When you run a scenario, Vusers emulate the actions of human users—submitting input to the server. •While a workstation accommodates only a singlehuman user, many Vuserscan run concurrently on a single workstation. In fact, a scenario can contain tens, hundreds, or even thousands of Vusers.Krish Hegde15Vuser Scripts•The actions that a Vuser performs during the scenario are described in a Vuser script. When you run a scenario, each Vuser executes a Vuser script. •The Vuser scripts include functions that measure and record the performance of the server during the scenario.Krish Hegde16Transactions•To measure the performance of the server, you define transactions. A transaction represents an action or a set of actions that you are interested in measuring. •You define transactions within your Vuser script by enclosing the appropriate sections of the script with start and end transaction statements.Krish Hegde17Rendezvous points•You insert rendezvous points into Vuser scripts to emulate heavy user load on the server. Rendezvous points instruct Vusers to wait during test execution for multiple Vusers to arrive at a certain point, in order that they may simultaneously perform a task. •For example, to emulate peak load on the bank server, you can insert a rendezvous point instructing 100 Vusers to deposit cash into their accounts at the same time.Krish Hegde18Controller•You use the LoadRunner Controller to manage and maintain your scenarios.•Using the Controller, you control all the Vusers in a scenario from a single workstation.•When you execute a scenario, the LoadRunner Controller distributes each Vuser in the scenario to a host. The host is the machine that executes the Vuser script, enabling the Vuser to emulate the actions of a human user.•Ideally, the LoadRunner Controller must be installed in a separate system outside the test bed.Krish Hegde19LoadRunner Vuser TechnologyKrish Hegde20LoadRunner Vuser Technology•LoadRunner has various types of Vusers. Each type is designed to handle different aspects of today’s system architectures.Vuser Types:1.E-business Vuser : For Web (HTTP,HTML), Corba-Java, General-Java, LDAP, POP3, COM/DCOM, Jolt, LDAP, POP3 and FTP protocols.2.Middleware Vuser : For Jolt, and Tuxedo(6.0, 6.3) protocols.3.ERP Vuser : For SAP, Baan, Oracle NCA, Peoplesoft (Tuxedo or Web) and Siebel protocols.4.Client/Server Vuser : For Informix, MSSQLServer, ODBC, Oracle (2-tier), Sybase Ctlib, Sybase Dblib, and Windows Sockets protocols.5.LegacyVuser: For Terminal Emulation (RTE).6.GeneralVuser: For C template, Java template, and Windows Sockets type scripts.Krish Hegde21GUI VuserKrish Hegde22GUI Vuser•A GUI Vuser running on a Windows host uses WinRunner to execute its Vuser script. To enable the LoadRunner Controller to open WinRunner, you must specify the location of the appropriate WinRunner configuration file (wrun.ini).Krish Hegde23DB VuserKrish Hegde24RTE VuserKrish Hegde25LoadRunner Testing ProcessKrish Hegde26•Questions?