During the recent airhacks workshops an attendee asked me a question about websocket stress testing tools.
You could create an own generator with jmeter.apache.org, but the websocket protocol is not directly supported.
Hellsocket is a 23kB WAR which can be installed as drop-in on a Java EE 7 server and was tested on GlassFish / Payara 4.1 and WildFly 8.2. Stress tests can be initiated and the statistics are available via: HTTP/REST.
Feedback is highly appreciated.