We have compiled some of the commonly asked JMeter interview questions and answers below. You may come across these questions if you are interviewing for performance testing or load testing positions / roles.
What is JMeter?
JMeter is a performance testing tool, which is written in Java. It is an open source software. JMeter has become one of the most popular testing tool in the world. It is usually used to perform load testing and stress testing of an application.
Who created JMeter?
JMeter is an Apache project that can be used as a load testing tool for analyzing and measuring the performance of a variety of services. It was first developed by Stefano Mazzocchi of the Apache Software Foundation.
How can I install JMeter?
You can install JMeter by downloading the latest version of JMeter from the Apache website. It just needs to be extracted and run. However, your computer needs to have Java SDK installed on it before you run JMeter.
What are the protocols supported by JMeter?
There are many protocols supported by JMeter. Some of the popular protocols it supports are:
- Web: HTTP
- Web Services: SOAP / XML-RPC
- Database: Via JDBC drivers
- Directory: LDAP
- Service: POP3, IMAP, SMTP
What is a Test Plan in JMeter?
Test Plan is the biggest element of JMeter and is the top most element in the hierarchy. It is at the same level as WorkBench. It defines what to test and how to test. A Test Plan in JMeter consists of all elements of JMeter such as Thread Group, Controller, Listeners, etc.
What is the extension of a Test Plan file?
The Test Plan file has .JMX extension
How many types of processor are there in JMeter?
What is a timer in JMeter?
Timer creates a delay between threads in JMeter. There are many kinds of timer such as Constant Timer, Gaussian Random Timer, Synchronizing Timer, Uniform Random Timer and so on.
What are Listeners?
Listeners in JMeter let you view the results of Samplers in the form of tables, graphs, trees or simple text in some log files.
Can I launch JMeter in command line mode?
Yes, you can. JMeter supports launching in command line mode and GUI mode.
What are Config Elements?
Config Elements are used to create default settings for Samplers (Example: HTTP Request Defaults for HTTP Request) and other configurations to be used in the Test Plan (Example: DNS Cache Manager, Keystore Configuration etc). Users can add Config Elements to add to or modify requests.
Config Elements are used to save common configuration setting without repeating them several times in Samplers. This helps in maintenance of the Test Plan, since changes need to be made in only in the Config Element, if the configuration is changed.
Can I record the testing in JMeter?
Yes, you can. JMeter provides an element called HTTP(S) Test Script Recorder to record the user operation and play back next time.
How many Listeners does JMeter have?
JMeter has many Listeners. At present, there are 20 and new ones may be added in future releases. Some of the popular Listeners are:
- Aggregate Report
- View Result Tree
- View Result in Table
- Monitor Results
- Distribution Graph
- BeanShell Listener
- Summary Report
- Spline Visualizer
- Simple Data Writer
- Save Responses to a file