Qpid has a substantial server performance test suite based around the http://sourceforge.net/projects/junit-toolkit/ library.
The test cases fall into the following categories:
Throughput - straight line 0-600,000 messages/second in how long?
Latency - how quickly can I get a few messages?
Reliability - burn in, stress and soak tests
Building and running the tests
The performance tests live in qpid/java/perftests. When they are built the scripts are generated and placed into qpid/java/build/bin/perftests.