Loadrunner-introduction Chapter 1

LoadRunner • 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.

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Architecture Overview

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Client-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 application Krish Hegde

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Manual 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 limited Krish Hegde

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Load 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 Hegde

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Load Testing with LoadRunner • LoadRunner monitors the application performance online, enabling you to finetune 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 Hegde

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Load 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 Hegde

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Load & Stress Testing • Objectives: – Check Scalability – Check Performance ie Transactions/minute, – Draw Memory Profile – Check CPU performance – Check Network performance

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Load & 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 Hegde

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Load & 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.

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Load & 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 Hegde

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Load & 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 Hegde

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LoadRunner-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 Hegde

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VUsers • 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 single human user, many Vusers can run concurrently on a single workstation. In fact, a scenario can contain tens, hundreds, or even thousands of Vusers. Krish Hegde

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Vuser 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.

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Transactions • 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 Hegde

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Rendezvous 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 Hegde

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Controller • 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 Hegde

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LoadRunner Vuser Technology

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LoadRunner Vuser Technology • • • • • • •

LoadRunner has various types of Vusers. Each type is designed to handle different aspects of today’s system architectures. Vuser Types: E-business Vuser : For Web (HTTP,HTML), Corba-Java, GeneralJava, LDAP, POP3, COM/DCOM, Jolt, LDAP, POP3 and FTP protocols. Middleware Vuser : For Jolt, and Tuxedo(6.0, 6.3) protocols. ERP Vuser : For SAP, Baan, Oracle NCA, Peoplesoft (Tuxedo or Web) and Siebel protocols. Client/Server Vuser : For Informix, MSSQLServer, ODBC, Oracle (2-tier), Sybase Ctlib, Sybase Dblib, and Windows Sockets protocols. Legacy Vuser : For Terminal Emulation (RTE). General Vuser : For C template, Java template, and Windows Sockets type scripts. Krish Hegde

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GUI Vuser

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GUI 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).

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DB Vuser

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RTE Vuser

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LoadRunner Testing Process

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• Questions?

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