HP LoadRunner Questions Bank: Q. 1 to 10
Learn “Controller” Module of HP LoadRunner through FAQs:
Q. 1: What is the purpose of using HP – LoadRunner?
In real world scenario, it is not possible to create situation involving say one thousand users using a system simultaneously so as to test the behavior of the system under such stressful conditions. LoadRunner can create such a situation.
LoadRunner artificially simulates several thousand users – which are called Virtual Users. These artificial / digitally created users are simultaneously forced to operate on the same task, thereby loading the system in a way it is expected to be loaded by real human users in actual practice.
With LoadRunner we can simulate situation with hundreds or thousands of artificial users & we can impose definite, consistent and repeatable loads on the system thereby stressing it from end-to-end. This way we can emulate several business processes & production conditions,
which a deployed application is going to encounter.LoadRunner accurately measures, monitors, and analyzes a system’s performance and functionality.
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Q. 2: What are the essential capabilities we look in a typical application performance-testing Tool?
Essential capabilities of an application performance testing tool are that:
1) It must be able to test a system which combines many software applications and hardware platforms.
2) It must be able to determine the suitability of a server for any given application.
3) It must be able to test the server before the necessary client software has been developed.
4) It must be able to emulate an environment where multiple clients interact with a single server application.
5) It must be able to test an application under the load of tens, hundreds, or even thousands of potential users.
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Q. 3: What are the drawbacks of manual load testing processes?
Load testing of a complete system can be done manually by building an environment where many users work simultaneously on the system. Each user is made to work on his standalone machine and every individual submits input to the system. However due to complexity of such a system, following drawbacks are there
1) Manual testing methods offer only a partial solution to the load testing.
2) Manual testing is expensive & requires large amounts of manpower & equipment.
3) Manual testing is complicated, especially while coordinating and synchronizing multiple testers.
4) Manual testing involves a high degree of organization, especially to record and analyze results meaningfully.
5)The repeatability of the manual tests is limited.
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Q. 4: How LoadRunner takes care of the shortcomings of manual performance testing?
1) LoadRunner reduces manpower requirements by replacing human users with virtual users or Vusers. These Vusers emulate the behavior of real users operating real applications.
2) Since several Vusers can run on a single computer, LoadRunner reduces the amount of hardware required for testing.
3) LoadRunner Controller allows us to easily and effectively control all the Vusers from a single point of control.
4) LoadRunner monitors the application performance online, enabling us to fine-tune the system during test execution.
5) LoadRunner automatically records the performance of the application during a test. We can choose from a wide variety of graphs and reports to view the performance data.
6) 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 us improve performance.
7) Because LoadRunner tests are fully automated, we can easily repeat them as often as we need.
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Q. 5: What are the process elements of using LoadRunner?
Process elements of LoadRunner are :
1) Scenario: Before using LoadRunner, we divide the application performance testing requirements into various scenarios. A scenario defines the events which 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.
2) Vusers: In the scenario, LoadRunner replaces human users with virtual users or Vusers. When we run a scenario, Vusers emulate the actions of human users working with our application. 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.
3) Vuser Scripts: The actions that a Vuser performs during the scenario are described in a Vuser script. When we run a scenario, each Vuser executes a Vuser script. The Vuser scripts include functions that measure and record the performance of our application�s components.
4) Transactions: To measure the performance of the server, we define transactions. A transaction represents an action or a set of actions that we are interested in measuring. We define transactions within our Vuser script by enclosing the appropriate sections of the script with start and end transaction statements. For example, we can define a transaction that measures the time it takes for the server to process a request to view the balance of an account and for the information to be displayed at the ATM.
5) Rendezvous points: We 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, so that they may simultaneously perform a task. For example, to emulate peak load on the bank server, we can insert a rendezvous point instructing 100 Vusers to deposit cash into their accounts at the same time.
6) Controller: We use the LoadRunner Controller to manage and maintain our scenarios. Using the Controller, we control all the Vusers in a scenario from a single workstation.
7) Load Generator: When we execute a scenario, the Controller distributes each Vuser in the scenario to a load generator. The load generator is the machine that executes the Vuser script, enabling the Vuser to emulate the actions of a human user.
8) Performance analysis: Vuser scripts include functions that measure and record system performance during load-testing sessions. During a scenario run, we can monitor the network and server resources. Following a scenario run, we can view performance analysis data in reports and graphs.
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Q. 6: What are our expectations from a scenario load testing an application Server?
The scenario would define the following actions which would be required to be performed on the server during the load test.
1) Emulating the conditions of controlled load on the server.
2) Emulating the conditions of maximum load on the server.
3) Measuring the server performance under load.
4) Check where performance delays occur: network or client delays, CPU performance, I/O delays, database locking, or other issues at the server.
5) Monitoring the network and server resources under load.
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Q. 7: What is the role of Remote Agent Dispatcher in LoadRunner?
The role of Remote Agent Dispatcher is to enable the Controller to start applications on the load generator.
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Q. 8: What is the role of LoadRunner Agent?
1) LoadRunner Agent enables the Controller and the load generator to communicate with each other.
2) When we run a scenario, the Controller instructs the Remote Agent Dispatcher to launch the LoadRunner agent.
3) The agent receives instructions from the Controller to initialize, run, pause, and stop Vusers.
4) The agent relays data on the status of the Vusers back to the Controller.
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Q. 9: What type of actions a Vuser can perform during database server testing?
A Vuser script can perform following actions while testing a database server:
1) Logging in to the Web application.
2) Connecting to the database server.
3) Submitting an SQL query.
4) Retrieving and processing the server response.
5) Disconnecting from the server and the Web.
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Q. 10: What are the broad steps involved in testing process by LoadRunner?
LoadRunner follows a Six step process for testing the application under the load:
Step – 1: Planning the Test: Involves development of a thorough test plan for the success of the load testing effort.
Step – 2: Creating the Vuser Scripts: Vusers emulate human users interacting with our application. A Vuser script contains the actions which each Vuser performs during scenario execution.
Step – 3: Creating the Scenario: A scenario describes the events that occur during a testing session. A scenario includes a list of machines on which Vusers run, a list of scripts that the Vusers run, and a specified number of Vusers or Vuser groups that run during the scenario. We can create scenarios using the Controller.
Step – 4: Running the Scenario: User load is emulated on the server by instructing multiple Vusers to perform tasks simultaneously. We can set the level of load by increasing and decreasing the number of Vusers that perform tasks at the same time.
Step – 5: Monitoring a Scenario: This can be done by executing scenario monitoring with the help of LoadRunner’s set of many resources.
Step – 6: Analyzing Test Results: During scenario execution, LoadRunner records the performance of the application under different loads. We can use LoadRunner’s graphs and reports to analyze the application’s performance.
Continue to Next Part : Q 11 to 20
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