Load Runner interview Question & Answers-5


Q201. What Is The Parameterization?
Answer :
Parameterization is script variables which are used to pass many values to server. It emulates the actions of human user.
Q202. What Is The Load Runner End-transaction And Its Syntax?
Answer :
It end the Transaction on the script and its syntax is that lr-end-transaction.
Q203. What Is The Automatic Correlation?
Answer :
Automatic Correlation is set some rules for correlation.
Q204. What Is The Difference Between Overlay Graph And Correlate Graph?
Answer :
Overlay Graph: It overlay the content of two graphs that shares a common x-axis. Left Y-axis on the merged graph shows the current graphs value & Right Y-axis show the value of Y-axis of the graph that was merged.
Correlate Graph: Plot the Y-axis of two graphs against each other. The active graphs Y-axis becomes X-axis of merged graph. Y-axis of the graph that was merged becomes merged graphs Y-axis.

Q205. Types Of Goals In Goal-oriented Scenario?
Answer :
Load Runner provides you with five different types of goals in a goal oriented scenario:
The number of concurrent Vusers
The number of hits per second
The number of transactions per second
The number of pages per minute
The transaction response time that you want your scenario

Q206. What Is Performance Testing?
Answer:
Performance Testing is performed to determine response time of the some components of the system perform under a particular workload. It is generally measured in terms of response time for the user activity. It is designed to test the overall performance of the system at high load and stress condition It identifies the drawback of the architectural design which helps to tune the application.
It includes the following:
Increasing number of users interacting with the system.
Determine the Response time.
Repeating the load consistently.
Monitoring the system components under controlled load.
Providing robust analysis and reporting engines.

Q207. What Is Concurrent User Hits In Load Testing?

Answer:
When the multiple users, without any time difference, hits on a same event of the application under the load test is called a concurrent user hit. The concurrency point is added so that multiple Virtual User can work on a single event of the application. By adding concurrency point, the virtual users will wait for the other Virtual users which are running the scripts, if they reach early. When all the users reached to the concurrency point, only then they start hitting the requests.
Q208. What Is The Life-cycle Of Testing?
Answer:
Planning the Test
Developing the Test
Execution of the Test
Analysis of Results
Q209. List Out Some Common Performance Bottlenecks?
Answer:
Some common performance bottlenecks include:
CPU Utilization
Memory Utilization
Networking Utilization
S limitation
Disk Usage
Q210. What Drawbacks Do Manual Load Tests Have?
Answer:
The manual load testing drawbacks are:
It is very expensive to do Manual Testing, as real users charge by the hour.
With manual load testing, load testing for longer durations like for 7 days won’t be possible, as users really work a maximum of eight hours daily.
You will not get accuracy for results correlation as there are delays between actions of users.
It is hard to do results collection as the results capture each other.
It is hard to do.
Q210. What Is The Difference Between Baseline And Benchmark Testing?
Answer:
The differences between baseline and benchmark testing are:
Baseline testing is the process of running a set of tests to capture performance information. This information can be used as a point of reference when in future changes are made to the application where as Benchmarking is the process of comparing your system performance against an industry standard that is given by some other organization.
Example: We can run baseline test of an application, collect and analyze results, and then modify several indexes on a SQL Server database and run the same test again, using the previous results to determine whether or not the new results were better, worse, or about the same.
Q211. What Is The Difference Between Performance Testing And Performance Engineering?
Answer:
Performance testing:
In Performance testing, testing cycle includes requirement gathering, scripting, execution, result sharing and report generation.
Performance engineering:
Performance Engineering is a step ahead of Performance testing where after execution; results are analyzed with the aim to find the performance bottlenecks and the solution is provided to resolve the identified issues.
Q212. What Are The Automated Performance Testing Phases?
Answer:
The phases involved in automated performance testing are:
Planning/Design: This is the primary phase where team will be gathering the requirements of the performance testing. Requirements can be Business, Technical, System and Team requirements.
Build: This phase consists of automating the requirements collected during the design phase.
Execution: it is done in multiple phases. It consists of various types of testing like baseline, benchmarking testing.
Analyzing and tuning: During the performance testing we will be capturing all the details related to the system like Response time and System Resources for identifying the major bottlenecks of the system. After the bottlenecks are identified we have to tune the system to improve the overall performance.
Q213. What Is Distributed Load Testing?
Answer:
Distributed load testing: in this we test the application for a number of users accessing the application at a same time. In distributed load testing test cases are execute to determine the application behavior. Now application behavior is monitored, recorded and analyzed when multiple users concurrently use the system. Distributed load testing is the process using which multiple systems can be used for simulating load of large number of users. The reason for doing the distributed load testing is that to overcome the limitation single system to generate large number of threads.
Q214. What Is Profiling?
Answer:
Profiling is a process of pinpointing a bottleneck performance at minute levels. This is done by performance teams for engineering which includes developers or performance testers. You can profile in any application layer getting tested. If you need to do application profiling you might need to use tools for performance profiling of application servers. When profiling an application server, you identify issues at the level of code such as memory intensive API’s If the database is what you are profiling using the tools for database profiling, you can identify a number of things such as a full table scan query, high cost queries and the number of executed SQLs.
Q215. List Down Any Challenge You Faced In Your Performance Career And How Did You Overcome It?
Answer:
Yes, I faced many challenges like defining the scope of application, break points which I over came by studying the historical data of application and based on them I decided the values, setting up the performance environment including proxy bypassing, connecting to Server under test.
Q216. What Is Ip Spoofing And Why Is It Used?
Answer:
IP spoofing is used to spoof the system so that each host machine can use many different IPs to create hypothetical environment where system believes that request are coming from different locations.
Q217. How Do You Identify Which Protocol To Use For Any Application?
Answer:
Previously Performance tester had to depend much on the development team to know about the protocol that application is using to interact with the server. Sometimes, it also used to be speculative.
However, Load Runner provides a great help in form of Protocol Advisor from version 9.5 onwards. Protocol advisor detects the protocols that application uses and suggest us the possible protocols in which script can be created to simulate the real user.
Q218. How Do You Do The Analysis Of The System For Identifying Issues?
Answer:
We can study the various graphs generated by the tool such as Response time, throughput graph, running Vusers graph etc. and also we can see the server logs to identify the issues in system.
Q219. What Is Performance Engineering, How Its Different Form Performance Testing?
Answer:
Performance testing is the process where we identify the issues in the system.
Performance engineering is the process where we address the issues and rectify them.
Q220. How You Can Calculate Pacing For Your Application?
Answer:
We can calculate pacing by the formula as
No. of users = (Response Time in seconds + Pacing in seconds) * TPS
TPS is transaction per Second.
Q221. How Do You Find Out The Performance Bottlenecks?
Answer:
Performance Bottlenecks can be identified by using different counters such as response time, throughput, hits/sec, network delay graph. We can analyze them and tell where the suspected performance bottleneck is.
Q222. What Is Think Time?
Answer:
Think time can be defined as the real time wait between 2 consecutive transactions. For Example a real time user waits to evaluate the data he received before performing the next step, that wait time he takes can be stated as think time.
Q223. Can You Tell A Scenario Where Throughput Is Increasing With Response Time Means When They Are Directly Proportional?
Answer:
Yes it can be possible when you have lots of CSS (Cascading Style Sheet) in your application which takes a lot of time to display. We can expect this type of situation where throughput will be increasing as well as the response time.
Q224. What Is The Reason Behind Performing Automated Load Testing?
Answer:
Difficult to measure the performance of the application accurately.
Difficult to do synchronization between the users.
Number of real time users are required to involve in Performance Testing.
Difficult to analyze and identify the results & bottlenecks.
Increases the infrastructure cost.
Q225. What Is Performance Tuning?
Answer:
To improve the system performance we follow a mechanism, known as Performance tuning.
To improve the systems performance there are two types of tuning performed:
Hardware tuning: Optimizing, adding or replacing the hardware components of the system and changes in the infrastructure level to improve the systems performance is called hardware tuning.
Software tuning: Identifying the software level bottlenecks by profiling the code, database etc. Fine tuning or modifying the software to fix the bottlenecks is called software tuning.
Q226. What Is A Protocol And How Many You Have Worked On?
Answer:
A protocol is a set of rules for information communication between 2 or more systems. There are many protocols such as Http/Https, FTP, Web Services, Citrix.Mostly used protocols are Http/Https and Web Services.
Q227. What Is Difference Between Simultaneous User And Concurrent User?
Answer:
Simultaneous users wait for other user to complete then it starts its activity whereas in concurrent users, it can be like 2 users log into the system and perform different activities at the same time.
Q228. What Is Performance Tuning? How Many Types Are There?
Answer:
Performance tuning is done for improving the system performance:
Hardware Tuning: Optimizing, adding or replacing hardware components of the system and changes done in the infrastructure level to improve system performance is called hardware tuning.
Software Tuning: Identifying the software level bottlenecks by profiling the code, database etc. Fine tuning or modifying the software to fix the bottlenecks is called software tuning.
Q229. What Activities Are Performed During Performance Testing Of Any Application?
Answer:
Following activities are performed during testing of application:
Create user scenarios
User Distribution
Scripting
Dry run of the application
Running load test and analyzing the result
Q230. Explain The Sub-genres Of Performance Testing?
Answer:
Following are the sub-genres of Performance Testing:
Load Testing: it is conducted to examine the performance of application for a specific expected load. Load can be increased by increasing the number of user performing a specific task on the application in a specific time period.
Stress Testing: is conducted to evaluate a system performance by increasing the number of user more than the limits of its specified requirements. It is performed to understand at which level application crash.
Volume Testing: test an application in order to determine how much amount of data it can handle efficiently and effectively.
Spike Testing: what changes happens on the application when suddenly large number of user increased or decreased.
Soak Testing: is performed to understand the application behavior when we apply load for a long period of time what happens on the stability and response time of application.
Q231. Mention What Is The Difference Between Performance Testing And Functional Testing?
Answer:
Functional Testing
To verify the accuracy of the software with definite inputs against expected output, functional testing is done
This testing can be done manually or automated
One user performs all the operations
Customer, Tester and Development involvement is required
Production sized test environment is not necessary, and H/W requirements are minimal.
Performance Testing
To validate the behavior of the system at various load conditions performance testing is done.
It gives the best result if automated
Several user performs desired operations
Customer, Tester, Developer, DBA and N/W management team
Requires close to production test environment and several H/W facilities to populate the load.
Q232. What is performance testing?
Answer:
Performance testing is done for quality assurance. It involves testing Software application to make sure that the software is working well under their expected workload.
Q233. What are the common performance problem does user’s face?
Answer:
Longer loading time
Poor response time
Poor Scalability
Bottlenecking (coding errors or hardware issues)
Q234. What are the Important performance testing tool?
Answer:
HP Loader
HTTP Load
Proxy Sniffer
Rational Performance Tester
JMeter
Borland Silk Performer
Q235. Why does JMeter become a natural choice of the tester when it comes to performance testing?
Answer:
JMeter tool has benefits like
It can be used for testing both static resources like HTML and JavaScript, as well as dynamic resources like Servlets, Ajax, JSP, etc.
JMeter has a tendency to determine the maximum number of concurrent users that your website can handle
It provides a variety of graphical analyses of performance reports
Q236. Name important parameters considered for performance testing?
Answer:
Memory usage
Processor usage
Bandwidth
Memory pages
Network output queue length
Response time
CPU interruption per second
Committed memory
Thread counts
Top waits, etc.
Q237. What are the important factors you must consider before selecting performance tools?
Answer:
Customer preference tool
Availability of license within customer machine
Availability of test environment
Additional protocol support
License cost
Efficiency of tool
User options for Manual Testing
Vendor support
Q238. What is the difference between JMeter and SOAPUI?
Answer:
JMeter
It is used for load and performance testing HTTP, JDBC, JMS, Web Service(SOAP), etc.
It supports distributed load testing
SoapUI
It is specific for web services and has a more user-friendly IDE
It does not support distributed load testing
For most IDE, it has plugin support
Q239. What is the difference between performance testing and Functional Testing?
Functional Testing
Answer:
It helps to verify the accuracy of the software with definite inputs against expected output, and functional Testing is done.
This Testing can be done manually or automated
One user performs all the operations
Customer, Tester and Development involvement is required
Production sized test environment is not necessary, and H/W requirements are minimal
Performance Testing
To validate the behavior of the system at various load conditions performance testing is done.
It gives the best result if automated
Several users perform desired operations
Customer, Tester, Developer, DBA, and N/W management team
Requires close to a production test environment and several H/W facilities to populate the load
Q240. Tell me the file extensions of RTS?
Answer:
Extension of RTS is “.cfg” & “.usp”.
Q241. Tell me the file extensions of ANALYZER?
Answer:
The file extensions of ANALYZER is “.lra”.
Q242. What are the benefits of Load Runner on testing tools?
Answer:
Benefits of Load Runner testing tools is
Versatility
Test Cases Results
Easy Integrations
Robust reports
Enterprise Package
Q243. What are the common mistakes done in Performance Testing?
Answer:
The common mistakes done in Performance Testing are
  • Direct jump to multi-user tests
  • Test results not validated
  • Unknown workload details
  • Too small run durations
  • Lacking long duration sustainability test
  • Confusion on a definition of concurrent users
  • Data not populated sufficiently
  • The significant difference between test and production environment
  • Network bandwidth not simulated
  • Underestimating software testing schedules
  • Incorrect extrapolation of pilots
  • Inappropriate base-lining of configurations
Q244. Explain the steps required in JMeter to create a performance test plan?
Answer:
To create a performance test plan in JMeter
step 1:Add thread group
step 2:Add JMeter elements
step 3:Add Graph result
step 4:Run test & get the result
Q245. How you can execute spike testing in Jmeter?
Answer:
In JMeter, spike testing can be done by using Synchronizing Timer. The threads are jammed by synchronizing the timer until a specific number of threads have been blocked and then release at once, creating a large instantaneous load.
Q246. What is the throughput in Performance Testing?
Answer:
In performance testing, throughput is referred to the amount of data transported to the server in response to the client request at a given period of time. It is calculated in terms of requests per second, calls per day, reports per year, hits per second, etc. Performance of application depends on throughput value, higher the value of throughput -higher the performance of the application.
Q247. What is concurrent user hits in load testing?
Answer:
In load testing, without any time difference when multiple users hit on the same event of an application under the load test is called a concurrent user hit.
Q248. What are the different sections of the script? In what sequence do these sections run?
Answer:
Load Runner script has three sections vuser_init, Action and vuser_end.
vuser_init has requests/actions to login to the application/server.
Action has actual code to test the functionality of the application. This can be played many times in iterations.
Vuser_end has requests/actions to login out the application/server.
The sequence in which these sections get executed is vuser_init is at the very beginning and vuser_end at the very end. The action is executed in between the two.
Q249. How do you identify which protocol to use for any application?
Answer:
Previously Performance tester had to depend much on the development team to know about the protocol that application is using to interact with the server. Sometimes, it also used to be speculative.
However, Load Runner provides a great help in form of Protocol Advisor from version 9.5 onwards. Protocol advisor detects the protocols that application uses and suggest us the possible protocols in which script can be created to simulate the real user.
Q250. What is parameterization & why is parameterization necessary in the script?
Answer:
Replacing hard-coded values within the script with a parameter is called Parameterization. This helps a single virtual user (vuser) to use different data on each run. This simulates real-life usage of an application as it avoids server from caching results.




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