server.maxConnections
设置此属性以在服务器的连接计数变高时拒绝连接。
¥Set this property to reject connections when the server's connection count gets high.
一旦将套接字发送给具有 child_process.fork() 的子级，不建议使用此选项。
¥It is not recommended to use this option once a socket has been sent to a child
with child_process.fork().