RestEasy does not respect Keep-Alive header in HTTP requests, when using NettyHttpRequest.resume(Object entity).

Even if header contains "Connection: Keep-Alive", connection is closed. The reason why connection is closed, comes from call of nettyFlush(), where ctx.close() is called in finally block without verifying whether Keep-Alive should be respected or not. That's why async response will close connection, regardless Keep-Alive.