What is you exact platform (OS) and JDK used?
Also how many resources(ram,cpu) does your system have.
Undertow is by default NIO2, and error you are getting looks related to native OS / JDK impl of NIO.
is this complete stacktrace or is there some other caused by?
thank you, I solved, it was a problem of application.
they had customized for another application server
I have create an application that use websocket and it's have not problem .
thanks a lot