dubbo2.7.x升级到3.2.x后 应用跑两三天后就发生内存泄漏。

在 org.apache.dubbo.remoting.transport.netty4.NettyChannel的劝酒的私有的静态成员变量CHANNEL_MAP里的。
里面55多万个元素，1.1G的大小。 

到后面AbstractInvoker.waitForResultIfSync(底层是threadlessExecutor.waitAndDrain)会卡住，比如： 某个服务正常调用不到100ms就返回了，应用跑两三天后就开始 那个正常的服务调用开始20%的概率出现一次两三秒的卡顿。  


protected void initChannel(SocketChannel ch) throws Exception {
                    
                    final ChannelPipeline p = ch.pipeline();
                    final NettyPortUnificationServerHandler puHandler;
                    puHandler = new NettyPortUnificationServerHandler(getUrl(), true, getProtocols(),
                        NettyPortUnificationServer.this, NettyPortUnificationServer.this.dubboChannels,
                        getSupportedUrls(), getSupportedHandlers());
                    p.addLast("negotiation-protocol", puHandler);
                }
            });
        
        String bindIp = getUrl().getParameter(Constants.BIND_IP_KEY, getUrl().getHost());
        int bindPort = getUrl().getParameter(Constants.BIND_PORT_KEY, getUrl().getPort());
        if (getUrl().getParameter(ANYHOST_KEY, false) || NetUtils.isInvalidLocalHost(bindIp)) {
            bindIp = ANYHOST_VALUE;
        }
        InetSocketAddress bindAddress = new InetSocketAddress(bindIp, bindPort);
        ChannelFuture channelFuture = bootstrap.bind(bindAddress);
        channelFuture.syncUninterruptibly();
        channel = channelFuture.channel();
    }
    @Override
    public void doClose() {
        try {
            if (channel != null) {
                
                channel.close();
                channel = null;
            }
        } catch (Throwable e) {