Software Testing Interview Questions – Part 1
1. What is the difference between lr_error_message and lr_debug _message?
lr_error_message:- Sends an error message to the LoadRunner Controller’s Output window.
lr_debug _message:- Sends a debug message to the LoadRunner Controller’s Output window.
2. What Are the Important Aspects of Website Load Testing?
When testing websites, it is critically important to test from outside the firewall. In addition, web-based load testing services, based outside the firewall, can identify bottlenecks that are only found by testing in this manner.
Web-based stress testing of web sites are therefore more accurate when it comes to measuring a site’s capacity constraints.
Web traffic is rarely uniformly distributed, and most Web sites exhibit very noticeable peaks in their volume patterns. Typically, there are a few points in time (one or two days out of the week, or a couple of hours each day) when the traffic to the Web site is highest.
3. How to test performance of the application manualy?
To do manual performace testing , one way could be as follows :
4. Decide for how many user your are going to performace testing.
Ask them to open a login window or the module on which testing to be done , if in case login window is open ask them to put id and passward , and ask them to login at a time , along with stop watch on at same moment and note down the time to , how much time did the application tooked to open .Here one has to follow the above method for each module and has to note down the time taken and compare this actual time with expected one.
And in case if some module is to be tested , then ask them to enter proper data and ask all of them to press SAVE button and check how much time application takes time to Save .
5. What is Load,Stress,Volume and Performence testing.
Performance testing is a class of tests implemented and executed to characterize and evaluate the performance related characteristics of the target-of-test such as the timing profiles, execution flow, response times,and operational reliability and limits
Load testing – Verifies the acceptability of the target-of-test’s performance behavior under varying operational conditions (such as number of users, number of transactions, etc.) while the configuration remains constant.
Stress testing – Verifies the acceptability of the target-of-test’s performance behavior when abnormal or extreme conditions are encountered, such as diminished resources or extremely high number of users.
6. What is the difference between Load testing and Performace Testing?
The concept and exercise of Load testing is after the performance testing. The Performance testing is something where we find the response time of the appication, Look out the Bootlenecks & Tune it. This testing includes in different layers Like Application Layer, Network Layer, Database Layer & OS Layer After fixing the defects from the Above layers then comes an exercise to perform a Load Testing.
A Load testing is done once if the functional and Performance testing is up and done to check the minumum and maximum load the Application can handle.
7. Why Scalability and Load Testing is Important?
Some very high profile websites have suffered from serious outages and/or performance issues due to the number of people hitting their website.
E-commerce sites that spent heavily on advertising but not nearly enough on ensuring the quality or reliability of their service have ended up with poor web-site performance, system downtime and/or serious errors, with the predictable result that customers are being lost.
In the case of toysrus, its web site couldn’t handle the approximately 1000 percent increase in traffic that their advertising campaign generated. Similarly, Encyclopaedia Britannica was unable to keep up with the amount of users during the immediate weeks following their promotion of free access to its online database.
The truth is, these problems could probably have been prevented, had adequate load testing taken place. When creating an eCommerce portal, companies will want to know whether their infrastructure can handle the predicted levels of traffic, to measure performance and verify stability.
These types of services include Scalability / Load / Stress testing, as well as Live Performance Monitoring. Load testing tools can be used to test the system behaviour and performance under stressful conditions by emulating thousands of virtual users.
These virtual users stress the application even harder than real users would, while monitoring the behaviour and response times of the different components.
This enables companies to minimise test cycles and optimise performance, hence accelerating deployment, while providing a level of confidence in the system.
Once launched, the site can be regularly checked using Live Performance Monitoring tools to monitor site performance in real time, in order to detect and report any performance problems – before users can experience them.
8. Estimating Test Duration?
The duration of the peak is also very important-a Web site that may deal very well with a peak level for five or ten minutes may crumble if that same load level is sustained longer than that. You should use the length of the average user session as a base for determining the load test duration.
9. What are the reasons why parameterization is necessary when load testing the Web server and the database server?
Parameterization is done to check how your application performs the same operation with different data. In load runner it is necessary to make a single user to refer the page for several times similar in case of database server. In General load testers will try to generate the load with the real time scenario. In order to over come this we(Load Tester) will try to send the different data to server(Web Server) to get the response.
10. What is difference between load testing and intersystem testing?
Inter systems testing : This type of testing is also called as end to end testing. In this testing test engineer validates that whether our application build co-exitance with other s/w applications or not?
Load testing : Also called as scalability testing. In this testing we have to run our application under customer expected load and customer expected configuration to estinate the load performace. Means that no. of concurent users can access your application.