The Apache JMeter™ desktop application is one of the best known open source software tools , a 100% pure Java application designed to load test functional behavior and measure software performance. It was originally designed for testing Web Applications but has since expanded to other test functions.
Conclusion
Apache Jmeter review Need to test your web service, database, FTP- or web server? Both performance and functional testing? Have a look at JMeter. It is free, very intuitive and has all the 
possibilities you need to automate your work. Another big advantage of JMeter: open source. You can download the source and make modifications to it if you like. Also direct contact with the developers through a mailing list is very handy.
Tip: Combine JMeter with Badboy (http://www.badboy.com.au/) to make it even more powerful! JMeter doesn’t have record & playback functionality. Badboy is the solution. Record the flow in your website, export the recording to a JMeter file, modify it to your needs and use JMeter to test the performance of your site.
Apache JMeter may be used to test application performance both on static and dynamic resources (files, Servlets, Perl scripts, Java Objects, Data Bases and Queries, FTP Servers and more). It can be used to simulate a heavy load on a server, network or object to test its strength or to analyze overall performance under different load types. You can use it to make a graphical analysis of performance or to test your server/script/object behavior under heavy concurrent load.
What does it do?
Apache JMeter features include:
- Can load and performance test many different server types:
- Web – HTTP, HTTPS
- SOAP
- Database via JDBC
- LDAP
- JMS
- Mail – POP3(S) and IMAP(S)
- Complete portability and 100% Java purity .
- Full multithreading framework allows concurrent sampling by many threads and simultaneous sampling of different functions by separate thread groups.
- Careful GUI design allows faster operation and more precise timings.
- Caching and offline analysis/replaying of test results.
- Highly Extensible:
- Pluggable Samplers allow unlimited testing capabilities.
- Several load statistics may be choosen with pluggable timers .
- Data analysis and visualization plugins allow great extensibility as well as personalization.
- Functions can be used to provide dynamic input to a test or provide data manipulation.
- Scriptable Samplers (BeanShell is fully supported; and there is a sampler which supports BSF-compatible languages)
