HP LoadRunner Questions Bank: Q. 11 to 20
Learn “Controller” Module of HP LoadRunner through FAQs:
Q. 11: What are the benefits of a test plan for a successful load testing?
A well-defined test plan is the first essential step to successful testing.
Planning of load testing helps us in:
1) Building test scenarios which accurately emulate our working environment. Load testing means testing our application under typical working conditions, and checking for system performance, reliability, capacity, and so forth.
2) Understanding as to which resources are required for testing. Application testing requires hardware, software, and human resources. Before we begin testing, we need to know which resources are available and decide how to use them effectively.
3) Defining success criteria in measurable terms. Focused testing goals and test
criteria ensure successful testing. For example, it’s not enough to define vague objectives like “Check server response time under heavy load.” A more focused success criterion would be “Check that 100 customers can check their account balance simultaneously, and that the server response time will not exceed one minute.”
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Q. 12: What are the elements of Load Test Planning Process using LoadRunner?
Load test planning is a three-step process:
Step -1: Analyzing the Application: Involves becoming thoroughly familiar with the hardware and software components, the system configuration, and the typical usage model. This step ensures that the testing environment created by us will accurately reflect the environment and configuration of the application under test.
Step -2: Defining Testing Objectives: Before starting the testing process, we need to define exactly what we want to achieve.
Step -3: Planning LoadRunner Implementation: Involves decision making on how to use LoadRunner to achieve our testing goals.
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Q. 13: What factors do we consider while planning the system configuration before its load testing?
We describe the configuration of every system component like client machines, network, middleware, and servers in ample detail giving answers to the following:
1) How many users are anticipated to connect to the system?
2) What is the configuration of application client machine. Configuration includes information on hardware, memory, operating system, software, development tool etc.?
3) What types of database and Web servers are used with the information of hardware, database type, operating system, file server etc.?
4) How does the server communicate with the application client?
5) What is the middleware configuration and application server between the front-end client and back-end server?
6) What other network components are used like modems etc. which may affect response time?
7) What is the throughput of the communications devices & How many concurrent users can each device handle?
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Q. 14: What factors do we consider regarding system usage while planning the load testing?
1) Consideration as to how the system is typically used, and decide which functions are important to test.
2) Consideration as to who uses the system, what are the number of each type of user and what are the common tasks performed by each user.
3) Consideration of any background load which might affect the system response time.
For example, say 500 persons log on to the accounting system every morning, and the same office network has a constant background load of 100 users performing various word processing and printing tasks. We would create a LoadRunner scenario with 600 virtual users signing in to the accounting database, and check the server response time.
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Q. 15: What are the broad objectives before planning load testing?
Before starting testing, we need to define our objectives precisely as to what we want to achieve.
Broad application testing objectives for load testing with LoadRunner can be:
1) Measuring end-user response time: To know how long does it take to complete a business process?
2) Defining optimal hardware configuration: To know which hardware configuration provides the best performance?
3) Checking reliability: To know how hard or long can the system work without errors or failures?
4) Checking hardware or software upgrades: To know how does the upgrade affect performance or reliability?
5) Evaluating new products: To know which server hardware or software should we choose?
6) Measuring system capacity: To know how much load can the system handle without significant performance degradation?
7) Identifying problem areas: To know which element is slowing down the response time?
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Q. 16: Load Testing is applicable during which stages of product life cycle?
Load testing is necessary throughout the product life cycle.
Load Testing activities performed during various stages of product life cycle are:
1) During Planning and Design stage: Evaluation of new products & measurement of response time of every activity.
2) During Product Development stage: Measurement of response time of every activity, checking of optimum hardware configuration, checking of hardware and software upgrades and checking of reliability.
3) During Product Deployment stage: Checking of reliability, measurement of response time of every activity and measurement of system capacity.
4) During Production stage: Measurement of response time of every activity and Identification of various problem areas.
5) During Evolution stage: Checking of hardware and software upgrades and measurement of system capacity.
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Q. 17: At which points we use LoadRunner to measure the response time in our application?
Following type of response times are measured to decide as to where to run the Vusers and which Vusers to run, according to our predefined test objectives:
1) Measurement of end-to-end response time: We can measure the response time which a user experiences by running a GUI Vuser at the front end. GUI Vusers emulate real users by submitting input to and receiving output from the client application.
We can run GUI Vusers at the front end to measure the response time across the entire network, including a terminal emulator or GUI front end, network, and server.
2) Measurement of network and server response times: We can measure network and server response time, excluding response time of the GUI front end, by running Vusers on the client machine. Vusers emulate client calls to the server without the user interface. When we run many Vusers from the client machine, we can measure how the load affects network and server response time.
3) Measurement of GUI response time: We can find out as to how the client application interface affects response time by calculating the difference among the previous two measurements i.e.
GUI response time = (End-to-end response time) – (Network and server response time)
4) Measurement of server response time: We can measure the time it takes for the server to respond to a request without going across the network. When we run Vusers on a machine directly connected to the server, we can measure the server performance.
5) Measurement of middleware-to-server response time: We can measure response time from the server to middleware if we have access to the middleware and its API. We can create Vusers with the middleware API and measure the middleware-server performance.
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Q. 18: What are the broad basis for creating Vuser scripts?
Since Vusers emulate the actions of a typical enduser, the Vuser scripts are created with a consideration of end-user tasks.
Vuser scripts are created based on the following:
1) Analysis of Vuser types: For finding out the number and type of Vusers expected to be created.
2) Activities expected to be performed by the Vusers: For example, for load testing a banking application, we would create a Vuser script which performs typical banking related activities.
3) Test objectives: Form the basis of taking decision on tasks to be measured and defining their transactions.
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Q. 19: What factors do we consider while selecting hardware for using LoadRunner?
For running the desired number of Vusers the hardware and Operating system must be adequately powerful and fast.
Following factors are given due consideration while deciding the number of machines and their configuration:
1) Make a provision of running LoadRunner Controller on a separate machine.
2) Make a provision of a separate Windows-based machine for every GUI Vuser. However one UNIX machine can take care of running of several GUI Vusers.
3) Keep the configuration of GUI Vusers testing machine same like the actual user�s machine.
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Q. 20: How LoadRunner can be helpful in checking the reliability of a hardware system?
LoadRunner can provide good pointers to decision making in following areas pertaining to hardware:
1) Finding out the level of system stability under heavy or continuous work loads, by creating stress on the system.
2) Testing the system by forcing it to handle the extended activity in a compressed time period to simulate the kind of activity a system would normally experience over a period of weeks or months.
Continue to Next Part : Q 21 to 30
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