@@connections The number of logins since the server was last started
自服务器上次启动后的登录数
@@max_connections For the personal server, the maximum number of simultaneous connections that can be made to the server, which is 10. For the network server, the maximum number of active clients (not database connections, as each client can support multiple connections).
对于个人服务器,数目是10
对于网络服务器,为活动客户端(而非数据库连接,因为每个客户端可以支持多个连接)的最大数目