面试英语（一）

LoadRunner interview questions

• 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 scripts 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, scripts, 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 script. 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 Script? - The Virtual User Generator (VuGen) component is used to record a script. It enables you to develop Vuser scripts for a variety of application types and communication protocols.
• What Component of LoadRunner would you use to play Back the script in multi user mode? - The Controller component is used to playback the script in multi-user mode. This is done during a scenario run where a vuser script is executed by a number of vusers in a group.
• What is a rendezvous point? - You insert rendezvous pointsinto Vuser scripts to emulate heavy user load on the server. Rendezvous pointsinstruct 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.
• 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.
• Explain the recording mode for web Vuser script? - We use VuGen to develop a Vuser script by recording a user performing typical business processes on a client application. VuGen creates the script 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 script.
• Why do you create parameters? - Parameters are like script 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 script is run. Better simulate the usage model for more accurate testing from the Controller; one script can emulate many different users on the system.
• 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 script 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.
• 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 becorrelated. From this we can pick a value to be correlated. Secondly, we can record two scripts 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 script. I did using scan for correlation.
• 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 script 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.
• What is a function to capture dynamic values in the web Vuser script? - Web_reg_save_param function saves dynamic data information to a parameter.
• When do you disable log in Virtual User Generator, When do you choose standard and extended logs? - Once we debug our script and verify that it is functional, we can enable logging for errors only. When we add a script 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 script execution to use for debugging. Disable this option for large load testing scenarios. When you copy a script to a scenario, logging is automatically disabledExtended 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 script 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.
• How do you debug a LoadRunner script? - VuGen contains two options to help debug Vuser scripts-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 script using the lr_set_debug_message function. This is useful if we want to receive debug information about a small section of the script only.
• 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.
• 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.
• 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.
• 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.
• 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’
• What is the advantage of running the Vuser as thread? - VuGen provides the facility to use multithreading. This enables more Vusers to be run per
  generator. If the Vuser is run as a process, the same driver program is loaded into memory for each Vuser, thus taking up a large amount of memory. This limits the number of Vusers that can be run on a single
  generator. If the Vuser is run as a thread, only one instance of the driver program is loaded into memory for the given number of
  Vusers (say 100). Each thread shares the memory of the parent driver program, thus enabling more Vusers to be run per generator.
• If you want to stop the execution of your script on error, how do you do that? - The lr_abort function aborts the execution of a Vuser script. It instructs the Vuser to stop executing the Actions section, execute the vuser_end section and end the execution. This function is useful when you need to manually abort a script execution as a result of a specific error condition. When you end a script using this function, the Vuser is assigned the status "Stopped". For this to take effect, we have to first uncheck the .Continue on error. option in Run-Time Settings.
• What is the relation between Response Time and Throughput? - The Throughput graph shows the amount of data in bytes that the Vusers received from the server in a second. When we compare this with the transaction response time, we will notice that as throughput decreased, the response time also decreased. Similarly, the peak throughput and highest response time would occur approximately at the same time.
• Explain the Configuration of your systems? - The configuration of our systems refers to that of the client machines on which we run the Vusers. The configuration of any client machine includes its hardware settings, memory, operating system, software applications, development tools, etc. This system component configuration should match with the overall system configuration that would include the network infrastructure, the web server, the database server, and any other components that go with this larger system so as to achieve the load testing objectives.
• How do you identify the performance bottlenecks? - Performance Bottlenecks can be detected by using monitors. These monitors might be application server monitors, web server monitors, database server monitors and network monitors. They help in finding out the troubled area in our scenario which causes increased response time. The measurements made are usually performance response time, throughput, hits/sec, network delay graphs, etc.
• If web server, database and Network are all fine where could be the problem? - The problem could be in the system itself or in the application server or in the code written for the application.
• How did you find web server related issues? - Using Web resource monitors we can find the performance of web servers. Using these monitors we can analyze throughput on the web server, number of hits per second that
  occurred during scenario, the number of http responses per second, the number of downloaded pages per second.
• How did you find database related issues? - By running .Database. monitor and help of .Data Resource Graph. we can find database related issues. E.g. You can specify the resource you want to measure on before running the controller and than you can see database related issues
• Explain all the web recording options?
• What is the difference between Overlay graph and Correlate graph? - Overlay Graph: It overlay the content of two graphs that shares a common x-axis. Left Y-axis on the merged graph show.s the current graph.s 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 graph.s Y-axis becomes X-axis of merged graph. Y-axis of the graph that was merged becomes merged graph.s Y-axis.
• How did you plan the Load? What are the Criteria? - Load test is planned to decide the number of users, what kind of machines we are going to use and from where they are run. It is based on 2 important documents, Task Distribution Diagram and Transaction profile. Task Distribution Diagram gives us the information on number of users for a particular transaction and the time of the load. The peak usage and off-usage are decided from this Diagram. Transaction profile gives us the information about the transactions name and their priority levels with regard to the scenario we are deciding.
• What does vuser_init action contain? - Vuser_init action contains procedures to login to a server.
• What does vuser_end action contain? - Vuser_end section contains log off procedures.
• What is think time? How do you change the threshold? -  Think time is the time that a real user waits between actions. Example: When a user receives data from a server, the user may wait several seconds to review the data before responding. This delay is known as the think time. Changing the Threshold: Threshold level is the level below which the recorded think time will be ignored. The default value is five (5) seconds. We can change the think time threshold in the Recording options of the Vugen.
• What is the difference between standard log and extended log? - The standard log sends a subset of functions and messages sent during script execution to a log. The subset depends on the Vuser type Extended log sends a detailed script execution messages to the output log. This is mainly used during debugging when we want information about: Parameter substitution. Data returned by the server. Advanced trace.
• Explain the following functions: - lr_debug_message - The lr_debug_message function sends a debug message to the output log when the specified message class is set. lr_output_message - The lr_output_message function sends notifications to the Controller Output window and the Vuser log file. lr_error_message - The lr_error_message function sends an error message to the LoadRunner Output window. lrd_stmt - The lrd_stmt function associates a character string (usually a SQL statement) with a cursor. This function sets a SQL statement to be processed. lrd_fetch - The lrd_fetch function fetches the next row from the result set.
• Throughput -  If the throughput scales upward as time progresses and the number of Vusers increase, this indicates that the bandwidth is sufficient. If the graphwere to remain relatively flat as the number of Vusers increased, it would
  be reasonable to conclude that the bandwidth is constraining the volume of
  data delivered.
• Types of Goals in Goal-Oriented Scenario -  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
• Analysis Scenario (Bottlenecks): In Running Vuser graph correlated with the response time graph you can see that as the number of Vusers increases, the average response time of the check itinerary transaction very gradually increases. In other words, the average response time steadily increases as the load
  increases. At 56 Vusers, there is a sudden, sharp increase in the average response
  time. We say that the test broke the server. That is the mean time before failure (MTBF). The response time clearly began to degrade when there were more than 56 Vusers running simultaneously.
• 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 script 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.
• 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 script 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.
• What is a function to capture dynamic values in the web vuser script? - Web_reg_save_param function saves dynamic data information to a parameter.

Software tester (SQA) interview questionsThese questions are used for software tester or SQA (Software Quality Assurance) positions. Refer to The Real World of Software Testing for more information in the field.

• The top management was feeling that when there are any changes in the technology being used, development schedules etc, it was a waste of time to update the Test Plan. Instead, they were emphasizing that you should put your time into testing than working on the test plan. Your Project Manager asked for your opinion. You have argued that Test Plan is very important and you need to update your test plan from time to time. It’s not a waste of time and testing activities would be more effective when you have your plan clear. Use some metrics. How you would support your argument to have the test plan consistently updated all the time.
• The QAI is starting a project to put the CSTE certification online. They will use an automated process for recording candidate information, scheduling candidates for exams, keeping track of results and sending out certificates. Write a brief test plan for this new project.
• The project had a very high cost of testing. After going in detail, someone found out that the testers are spending their time on software that doesn’t have too many defects. How will you make sure that this is correct?
• What are the disadvantages of overtesting?
• What happens to the test plan if the application has a functionality not mentioned in the requirements?
• You are given two scenarios to test. Scenario 1 has only one terminal for entry and processing whereas scenario 2 has several terminals where the data input can be made. Assuming that the processing work is the same, what would be the specific tests that you would perform in Scenario 2, which you would not carry on Scenario 1?
• Your customer does not have experience in writing Acceptance Test Plan. How will you do that in coordination with customer? What will be the contents of Acceptance Test Plan?
• How do you know when to stop testing?
• What can you do if the requirements are changing continuously?
• What is the need for Test Planning?
• What are the various status reports you will generate to Developers and Senior Management?
• Define and explain any three aspects of code review?
• Why do you need test planning?
• Explain 5 risks in an e-commerce project. Identify the personnel that must be involved in the risk analysis of a project and describe their duties. How will you prioritize the risks?
• What are the various status reports that you need generate for Developers and Senior Management?
• You have been asked to design a Defect Tracking system. Think about the fields you would specify in the defect tracking system?
• Write a sample Test Policy?
• Explain the various types of testing after arranging them in a chronological order?
• Explain what test tools you will need for client-server testing and why?
• Explain what test tools you will need for Web app testing and why?
• Explain pros and cons of testing done development team and testing by an independent team?
• Differentiate Validation and Verification?
• Explain Stress, Load and Performance testing?
• Describe automated capture/playback tools and list their benefits?
• How can software QA processes be implemented without stifling productivity?
• How is testing affected by object-oriented designs?
• What is extreme programming and what does it have to do with testing?
• Write a test transaction for a scenario where 6.2% of tax deduction for the first $62,000 of income has to be done?
• What would be the Test Objective for Unit Testing? What are the quality measurements to assure that unit testing is complete?
• Prepare a checklist for the developers on Unit Testing before the application comes to testing department.
• Draw a pictorial diagram of a report you would create for developers to determine project status.
• Draw a pictorial diagram of a report you would create for users and management to determine project status.
• What 3 tools would you purchase for your company for use in testing? Justify the need?
• Put the following concepts, put them in order, and provide a brief description of each:
  • system testing
  • acceptance testing
  • unit testing
  • integration testing
  • benefits realization testing
• What are two primary goals of testing?
• If your company is going to conduct a review meeting, who should be on the review committe and why?
• Write any three attributes which will impact the Testing Process?
• What activity is done in Acceptance Testing, which is not done in System testing?
• You are a tester for testing a large system. The system data model is very large with many attributes and there are a lot of inter-dependencies within the fields. What steps would you use to test the system and also what are the effects of the steps you have taken on the test plan?
• Explain and provide examples for the following black box techniques?
  • Boundary Value testing
  • Equivalence testing
  • Error Guessing
• What are the product standards for?
  • Test Plan
  • Test Script and Test Report
• You are the test manager starting on system testing. The development team says that due to a change in the requirements, they will be able to deliver the system for SQA 5 days past the deadline. You cannot change the resources (work hours, days, or test tools). What steps will you take to be able to finish the testing in time?
• Your company is about to roll out an e-commerce application. It’s not possible to test the application on all types of browsers on all platforms and operating systems. What steps would you take in the testing environment to reduce the business risks and commercial risks?
• In your organization, testers are delivering code for system testing without performing unit testing. Give an example of test policy:
  • Policy statement
  • Methodology
  • Measurement
• Testers in your organization are performing tests on the deliverables even after significant defects have been found. This has resulted in unnecessary testing of little value, because re-testing needs to be done after defects have been rectified. You are going to update the test plan with recommendations on when to halt testing. Wwhat recommendations are you going to make?
• How do you measure:
  • Test Effectiveness
  • Test Efficiency
• You found out the senior testers are making more mistakes then junior testers; you need to communicate this aspect to the senior tester. Also, you don’t want to lose this tester. How should one go about constructive criticism?
• You are assigned to be the test lead for a new program that will automate take-offs and landings at an airport. How would you write a test strategy for this new program?