Wildfly leaks half-open sockets if the client closes the connection before all data was sent to the client. This only happens when the HTTP header field "Content-Length" was manually set.

The leaked sockets can be determined by "lsof -p <process-id> | grep identify". The relevant sockets are listed with "Can't identify protocol".

The leak occurs if the client connection is closed (on the client side) before the server could send the complete response.

It does not happen every time. I have attached an example application using a web browser as client. One button click sends the request 500 times. The socket does not leak on every button click.

Another interesting fact is, that the socket will also leak if a Content-Length larger than the actual response data is set. This is independent from the client's behavior.