The Introduction to JMeter

What is JMeter

Jmeter is probably the only tool for load testing, which on the one hand is free and open source, on the other hand is sufficiently developed and has the ability to create load test simultaneously from multiple computers.

Tests for JMeter are created visually and have a tree structure in the editing test.

You can run the tests from the application window and from the command line, which in turn is useful if you run them on a schedule, for example, at night.

For What JMeter Is Best Suited

Tool positioning itself as a versatile, allowing to work with both http requests, and FTP, JDBC requests, SOAP, Web Services, TCP, LDAP, JMS, Mail testers. But, clearly, it is best suited for  Web applications testing.

If you create a multi-user web application, so you definitely have questions before its release:

• if the application works stable under heavy load
• What is the maximum possible number of users will withstand the application on a specific configuration
• How quickly the application went to work after the improving architecture code

JMeter will answer you all these issues with relatively little expenditure of time.

When you create a test JMeter offers several types of components:

1. Samplers - key elements that directly deal with the application under test, such as http sampler to access the Web application
2. Logic controllers - devices that allow to group other elements in the cycles of parallel running, etc.
3. Assertions - elements operating control. With their help, you can check the text that you would expect on a Web page or, for example, specify that you would expect a response from the server, no more than 2 seconds. If any Assert will not be satisfied, the test will have a negative result.

How Does The Report Look Like

You set by yourself what will be contained in the report. Conveniently that the report can include all sorts of charts and graphs. Here is a typical example of a report: 

Can We Extend JMeter

Possible and necessary. Jmeter itself is handy tool for running and monitoring tests and to view reports. So if you need special kinds of tests that you can write in Java, then all you need is to write the code of the test. Further, it must issue as Sampler, then JMeter helps you do all the rest of the work of the organization, configuration and implementation of tests (including those with multiple computers).