Matching on the on theEventLoopGrouphere is not correct anymore since theIOUsingEventLoopGroup did not make it to the non incubator version. At the same time (see4.2 notes),io.netty.channel.epoll.EpollEventLoopGroup is now deprecated, as well asio.netty.channel.kqueue.KQueueEventLoopGroup .

I'd be happy to craft a PR. I'm thinking of changing the appropriate factories and to find a way to know which type of transport to instantiate (so far, I've no idea).