Apache JMeter is a 100% pure Java desktop application designed to load test functional behavior and measure performance. It was originally designed for testing Web Applications but has since expanded to other test functions.

What can I do with it?

Apache JMeter may be used to test 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.

Using JMeter

What does it do?

 *Apache JMeter features include:
 *Can load and performance test HTTP and FTP servers as well as arbitrary database queries (via JDBC)
 *Complete portability and 100% Java purity .
 *Full Swing and lightweight component support (precompiled JAR uses packages javax.swing.* ).
 *Full multithreading framework allows concurrent sampling by many threads and simultaneous sampling of different functions by seperate 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 extendibility as well as personalization.

Vendor Site:- Jakarta Apache Project