Hi all 现状：
Dubbo 在应用层面发送心跳包保证连接的可用性，使用了定时器的设计，在客户端和服务端分别设置一个定时器，发送心跳，当发现连接断开时，客户端负责重连，服务端负责 close。使用定时器并不是一个好的设计，在忙通信时，心跳是不必要的。建议使用 Netty 的 IdleStateHandler，仅仅在检测到空闲连接时发送心跳。 修改建议： 使用 IdleStateHandler 代替 Timer 发送心跳 关闭 ChannelOption.SO_KEEPALIVE，网络层面的 TCP 断连需要在机器级别设置，默认是 2 小时，几乎没有必要存在，却发出了无必要的 TCP 探测包，仅仅依赖于应用层的心跳来给连接保活即可。 For now: Dubbo sends a heartbeat packet at the application level to ensure the availability of the connection. A timer is set on the client and the server to send a heartbeat. When the connection is found to be disconnected, the client is responsible for reconnection and the server is responsible for close. Using a timer is not a good design, and the heartbeat is unnecessary when communicating busy. It is recommended to use Netty's IdleStateHandler to send a heartbeat only when an idle connection is detected. Proposed changes: Send heartbeats using IdleStateHandler instead of Timer Close ChannelOption.SO_KEEPALIVE, TCP disconnection at the network level needs to be set at the machine level. The default is 2 hours. There is almost no need to exist, but an unnecessary TCP probe packet is issued. It only depends on the heartbeat of the application layer to keep the connection alive. Just fine.
