I'm running wildfly-8.0.0.Final, I set "<connection-limit name="connection-limit-1" max-concurrent-requests="3000" queue-size="30000"/>" in undertow subsystem and reference it in host section. When I did an performance testing (long-polling API, server will hold it until http timeout), I found once the created connections reach 3000, client just received 200 OK response immediately, and there's no access log of these response.

I found undertow-1.0.0.Final/core/src/main/java/io/undertow/server/handlers/RequestLimit.java is related to it, the above described behavior doesn't match the javadoc, so I posted it here.