private ServerSocketChannel openServerSocket(int port) throws IOException {
    InetSocketAddress address = new InetSocketAddress(port);
    ServerSocketChannel serverChannel = ServerSocketChannel.open();
    serverChannel.configureBlocking(false);
    serverChannel.socket().bind(address);
    logger.info("Awaiting socket connections on {}:{}", address.getHostName(), port);
    return serverChannel;
  }
Accept loop that checks for new connection attempts for a plain text port
ambry-network/src/main/java/com/github/ambry/network/SocketServer.java