http://docs.codehaus.org/display/JETTY/Stress+Testing+Cometd
Jetty comes with cometd installed in $JETTY_HOME/webapps/cometd.war.To run the server with additional memory needed for the test, use:
java -Xmx2048m -jar start.jar etc/jetty.xml
While the test is executing, a series of digits is output to show progress. The digits represent the current average latency in units of 100ms. So a 0 represent <100ms latency from
the time the message was publish by the client to when it has been received on the client. 1 represents a latency >=100ms and <200ms etc.
Also a real chat room server implementation would probably be backed by JMS so that multiple nodes would still represent a single chat space.(意味着可以利用JMS来做集群？)
