-
What
is load testing? - Load testing is to test that
if the application works fine with the loads that result from large number of simultaneous users, transactions and to determine weather it can handle peak usage periods. -
What
is Performance testing? - Timing for both read and update transactions should be gathered to determine whether system functions are being performed in an acceptable timeframe. This should be done standalone and then in a multi user environment to determine
the effect of multiple transactions on the timing of a single transaction. -
Did
u use LoadRunner?
What version? - Yes. Version 7.2. -
Explain
the Load testing process? -
Step 1: Planning the test. Here, we develop a clearly defined test plan to ensure the test scenarios we develop will accomplish load-testing objectives. Step 2: Creating Vusers. Here, we create Vuser scrīpts that contain tasks performed by each Vuser, tasks
performed by Vusers as a whole, and tasks measured as transactions. Step 3: Creating the scenario. A scenario describes the events that occur during a testing session. It includes a list of machines, scrīpts, and Vusers that run during the scenario. We create
scenarios using LoadRunner Controller. We can create manual scenarios as well as goal-oriented scenarios. In manual scenarios, we define the number of Vusers, the load generator machines, and percentage of Vusers to be assigned to each scrīpt. For web tests,
we may create a goal-oriented scenario where we define the goal that our test has to achieve. LoadRunner automatically builds a scenario for us. Step 4: Running the scenario.
We emulate load on the server by
instructing multiple Vusers to perform. tasks simultaneously. Before the testing, we set the scenario configuration and scheduling. We can run the entire scenario, Vuser groups, or individual Vusers. Step 5: Monitoring the scenario.
We monitor scenario execution using the LoadRunner online runtime, transaction, system resource, Web resource, Web server resource, Web application server resource, database server resource, network delay, streaming media resource, firewall server resource,
ERP server resource, and Java performance
monitors. Step 6: Analyzing test results. During scenario execution, LoadRunner records the performance of the application under different loads. We use LoadRunner’s graphs and reports to analyze the application’s performance. -
When
do you do load and performance Testing? - We perform. load testing once we are done with interface (GUI) testing. Modern system architectures are large and complex. Whereas single user testing primarily on functionality and user interface of a system component,
application testing focuses on performance and reliability of an entire system. For example, a typical application-testing scenario might depict 1000 users logging in simultaneously to a system. This gives rise to issues such as what is the response time of
the system, does it crash, will it go with different software applications and platforms, can it hold so many hundreds and thousands of users, etc. This is when we set do load and performance testing. -
What
are the components of LoadRunner? - The components of LoadRunner are The Virtual User Generator, Controller, and the Agent process, LoadRunner Analysis and Monitoring, LoadRunner Books Online. -
What
Component of LoadRunner would you use to record a scrīpt? - The Virtual User Generator (VuGen) component is used to record a scrīpt. It enables you to develop Vuser scrīpts for a variety of application types and communication protocols. -
What
Component of LoadRunner would you use to play Back the scrīpt in multi user mode? - The Controller component is used to playback the scrīpt in multi-user mode. This is done during a scenario run where a vuser scrīpt is executed by a number of vusers in a group. -
What
is a rendezvous point? - You insert rendezvous points into Vuser scrīpts 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.
10. What
is a scenario? - A scenario defines the events that occur during each testing session. For example, a scenario defines and controls the number of users to emulate, the actions to be performed, and the machines on which the virtual users run their emulations.
11. Explain
the recording mode for web Vuser scrīpt? - We use VuGen to develop a Vuser scrīpt by recording a user performing typical business processes on a client application. VuGen creates the scrīpt by recording the activity between the client and the server. For example,
in web based applications, VuGen monitors the client end of the database and traces all the requests sent to, and received from, the database server. We use VuGen to: Monitor the communication between the application and the server; Generate the required function
calls; and Insert the generated function calls into a Vuser scrīpt.
12. Why
do you create parameters? - Parameters are like scrīpt variables. They are used to vary input to the server and to emulate real users. Different sets of data are sent to the server each time the scrīpt is run. Better simulate the usage model for more accurate
testing from the Controller; one scrīpt can emulate many different users on the system.
13. What
is correlation? Explain the difference between automatic correlation and manual correlation? - Correlation is used to obtain data which are unique for each run of the scrīpt and which are generated by nested queries. Correlation provides the value to avoid
errors arising out of duplicate values and also optimizing the code (to avoid nested queries). Automatic correlation is where we set some rules for correlation. It can be application server specific. Here values are replaced by data which are created by these
rules. In manual correlation, the value we want to correlate is scanned and create correlation is used to correlate.
14. How
do you find out where correlation is required? Give few examples from your projects? - Two ways: First we can scan for correlations, and see the list of values which can be correlated. From this we can pick a value to be correlated. Secondly, we can record
two scrīpts and compare them. We can look up the difference file to see for the values which needed to be correlated. In my project, there was a unique id developed for each customer, it was nothing but Insurance Number, it was generated automatically and
it was sequential and this value was unique. I had to correlate this value, in order to avoid errors while running my scrīpt. I did using scan for correlation.
15. Where
do you set automatic correlation options? - Automatic correlation from web point of view can be set in recording options and correlation tab. Here we can enable correlation for the entire scrīpt and choose either issue online messages or offline actions, where
we can define rules for that correlation. Automatic correlation for database can be done using show output window and scan for correlation and picking the correlate query tab and choose which query value we want to correlate. If we know the specific value
to be correlated, we just do create correlation for the value and specify how the value to be created.
16. What
is a function to capture dynamic values in the web Vuser scrīpt? - Web_reg_save_param function saves dynamic data information to a parameter.
17. When
do you disable log in Virtual User Generator, When do you choose standard and extended logs? - Once we debug our scrīpt and verify that it is functional, we can enable logging for errors only. When we add a scrīpt to a scenario, logging is automatically disabled.
Standard Log Option: When you select
Standard log, it creates a standard log of functions and messages sent during scrīpt execution to use for debugging. Disable this option for large load testing scenarios. When you copy a scrīpt to a scenario, logging is automatically disabled Extended Log Option:
Select
extended log to create an extended log, including warnings and other messages. Disable this option for large load testing scenarios. When you copy a scrīpt to a scenario, logging is automatically disabled. We can specify which additional information should
be added to the extended log using the Extended log options.
18. How
do you debug a LoadRunner scrīpt? - VuGen contains two options to help debug Vuser scrīpts-the Run Step by Step command and breakpoints. The Debug settings in the Options dialog box allow us to determine the extent of the trace to be performed during scenario
execution. The debug information is written to the Output window. We can manually set the message class within your scrīpt using the lr_set_debug_message function. This is useful if we want to receive debug information about a small section of the scrīpt only.
19. How
do you write user defined functions in LR? Give me few functions you wrote in your previous project? - Before we create the User Defined functions we need to create the external
library (DLL) with the function. We add this library to VuGen bin directory. Once the library is added then we assign user defined function as a parameter. The function should have the following format: __declspec (dllexport) char* <function name>(char*, char*)Examples
of user defined functions are as follows:GetVersion, GetCurrentTime, GetPltform. are some of the user defined functions used in my earlier project.
20. What
are the changes you can make in run-time settings? - The Run Time Settings that we make are: a) Pacing - It has iteration count. b) Log - Under this we have Disable Logging Standard Log and c) Extended Think Time - In think time we have two options like Ignore
think time and Replay think time. d) General - Under general tab we can set the vusers as process or as multithreading and whether each step as a transaction.
21. Where
do you set Iteration for Vuser testing? - We set Iterations in the Run Time Settings of the VuGen. The navigation for this is Run time settings, Pacing tab, set number of iterations.
22. How
do you perform. functional testing under load? - Functionality under load can be tested by running several Vusers concurrently. By increasing the amount of Vusers, we can determine how much load the server can sustain.
23. What
is Ramp up? How do you set this? - This option is used to gradually increase the amount of Vusers/load on the server. An initial value is set and a value to wait between intervals can be
specified. To set Ramp Up, go to ‘Scenario Scheduling Options’