keepalive message
常见例句
- In order to maintain presence, the chat application can send keep-alive messages on the websocket to prevent it being closed due to an idle timeout.
为了保持存在的状态，聊天应用要发送“连接保持（Keep Alive）”的消息给WebSocket，来避免该连接因为闲置超时而关闭。 返回 keepalive message