Before we look at the new features, we'll first cover the changes in compatibility. JMeter 2.4 now requires at least Java 1.5. The Apache Avalon file format for JMX and JTL is no longer supported and the XPath Assertion and XPath Extractor elements no longer fetch external DTDs by default (but you can change that in the GUI). Also, JMSConfigGui has been renamed JMSSamplerGui, but this doesn't effect testing plans.
Here are the main new features in JMeter 2.4:
- HTTP Proxy can now record HTTPS sessions.
- JUnit sampler now supports JUnit4 annotations.
- Added JSR223 (javax.script) test elements.
- MailReader Sampler can now use any protocol supported by the underlying implementation.
- An SMTP Sampler has been added.
- JMeter now allows users to provide their own Thread Group implementations.
- View Results Tree now supports more display options, including search and Regex Testing.
- StatCalculator performance is much improved; Aggregate Report etc. need far less memory.
- JMS samplers have been extensively reworked, and should no longer lose messages. Correlation processing is improved. JMS Publisher and Subscriber now support both Topics and Queues.
JMeter was originally designed to test only web apps, but now has expanded to other test functions. It tests performance on static and dynamic resources (Perl scripts, servlets, POJOs, etc.), and it can also simulate a heavy load on servers, networks, or objects. JMeter tests load and performance with HTTP, SOAP, DB via JDBC, LDAP, JMS, and many other server types. Along with a productivity-focused GUI, tools for graphical performance analysis, and a extensible architecture, JMeter also provides a full multithreading framework for concurrency testing.
JMeter comes from a strong umbrella of Apache projects. The list of ex-Jakarta projects is essentially a who's who of Apache success stories. Hall of Famers such as Ant, Maven, Commons, Lucene, Struts, and Tomcat were all part of Jakarta at one point.
Here are two video tutorials to help you get started with JMeter and harness its power:
You can find a complete list of the new features, bugfixes, and incompatible changes on JMeter's website.