LoadRunner Interview Questions
Your application is crashing again and again? A heavy load of users, data, etc. could be the reason. By performing load testing on that, one can be assured that the application is ready to work well with a large number of users and this can be done with the help of Loadrunner. To know in detail about this testing tool, we have prepared a list of LoadRunner Interview Questions and Answers which will help you to clear your concepts and to get the best fit in any organization. By gaining knowledge about it one can make a career in the performance testing industry. According to a recent assessment, LoadRunner is a market leader and holds 85% of the market share in the Performance Testing paradigm.
Today companies like Amazon, Myntra, Flipkart, etc. can lose sales worth $1200 per second if there is any web service outage. A few minutes of downtime of Google could cost the search giant $6,00,000. Every year there is a loss of 4.4 billion of revenue due to poor web performance. Imagine yourself waiting for 5-8 seconds when searching a page on google or making a friend request on applications like Facebook. This all will result only in shutting down that application and due to these factors, tools such as Jmeter, LoadRunner, etc. are getting widely used. Data of 9863 companies are recorded which are using LoadRunner and are most often found in the United States.
Most Frequently Asked LoadRunner Interview Questions
Here in this article, we will be listing frequently asked LoadRunner Interview Questions and Answers with the belief that they will be helpful for you to gain higher marks. Also, to let you know that this article has been written under the guidance of industry professionals and covered all the current competencies.
To plan the load user has to decide the number of users, the kind of machines that are to be used, and from where machines would run. There are two specific criteria for doing this-
- Task Distribution Diagram- It gives users the information about the total number of users for a specific transaction and time of load. Users can determine peak usage and off-usage from this diagram.
- Transaction Profile- Information about the transaction’s name and their levels of priority can be determined with these criteria.
- Test Planning: Creating a test plan to ensure LoadRunner test scenarios meets the objectives of load-testing.
- Creation of Vuser Scripts: This includes the tasks performed by Vuser during scenario execution.
- Creation of Scenarios: This tells about the events that occurred during the client/server testing session. It includes machines, scripts, Vusers, and a list of their scripts.
- Running the Scenario: As the name suggests, you can run the entire scenario and Vuser groups.
- Performance Monitoring: Monitoring of database resources, transaction resources, and firewall resources can be done using LoadRunner online run time.
- Analyzing Test Results: During execution, it records the performance of an application and its graphs and reports are used in the analysis of the server’s output.
It depends upon the protocol used in the creation of the scripts and configuration of the load generator machine. The memory print of each protocol is different and that ultimately defines how many virtual users can be generated from the load generator’s configuration.
The first thing to look into when such a situation arises is Log message window in the controller and then the identification of the thrown error. Sometimes VUser script in Vugen needs enhancements, after doing that, run the edited script in debug mode to ensure it doesn’t fail. Refresh the Vuser script in the controller and then again start the scenario.
- At the Network level, performance measures can be improved by optimizing the latency and bandwidth.
- At the App server level, running profilers to find memory leakage could help.
- At the Web server level, monitors can be used in optimizing the throughput and other related metrics.
- At the Database level, verification of all indexes and sequences should be done by running profilers. Optimization of database queries can also be done.
Load Runner provides multiple types of monitors such as Application Server Monitors, Database Monitors, Firewall Monitors, Java Performance Monitors, Network Monitors, and Web Server Monitors which are helpful in identifying the bottlenecks by monitoring the performance of an application and finding out the troubled area which leads to increased response time. Performance response time, hits per second, throughput, network delay graphs, etc all are included in the measurements.
VuGen gives users two options for debugging.
- By using Run Step by Step command
- By using breakpoints
If you want to receive debug information about a small section, then you can manually set the message class using the Ir_set_debug_message function within your script.
It’s always recommended to turn off caching as it affects the response time. To store information about browsing data a temporary memory known as Cache is used. When a user visits a web page for the second time it required less time to load the page than the first visit as most of the information is fetched from the cache instead of grabbing from the server.
- Two scripts need to be recorded with similar steps and comparison should be done using the WDiff utility.
- Now replay the recorded scripts and scan them as this process provides you a list of values that needs to be correlated.
Example:
When two similar scripts are recorded and compared, session ids in those scripts should always be different and WDiff can highlight these values. So Session ID could be a good example.
This can be done through the lr_abort function. It instructs the Vuser to prevent the execution of the Action section and end it with the vuser_end function. To handle a specific error this function is used.
In performance testing, Throughput is a key metric that is used to measure how many requests a software can handle per second, per minute, or per hour. If we talk about their relation, Throughput and response time are inversely proportional to each other. With the increase in Throughput (TP), Response Time (RT) decreases and vice versa.