分类：1.show status
Threads_connected 当前的连接数
Connections 试图连接到(不管是否成功)MySQL服务器的连接数。
Max_used_connections 服务器启动后已经同时使用的连接的最大数量。
2.set GLOBAL max_connections=连接数;
flush privileges
3.修改/etc/my.cnf中的max_connections
4.show processlist 显示当前正在执行的mysql连接
5.mysqladmin -u<user> -p<pwd> -h<host> status
显示当前mysql状态
Uptime: 13131 Threads: 1 Questions: 22 Slow queries: 0 Opens: 16 Flush tables: 1 Open tables: 1 Queries per second avg: 0.1
mysqladmin -u<user> -p<pwd> -h<host> extended-status
显示mysql的其他状态
+-----------------------------------+----------+
| Variable_name | Value |
+-----------------------------------+----------+
| Aborted_clients | 0 |
| Aborted_connects | 1 |
| Binlog_cache_disk_use | 0 |
| Binlog_cache_use | 0 |
| Bytes_received | 1152 |
| Bytes_sent | 10400 |
| Com_admin_commands | 0 |
| Com_assign_to_keycache | 0 |
.............................................................
.............................................................
| Threads_cached | 2 |
| Threads_connected | 1 |
| Threads_created | 3 |
| Threads_running | 1 |
| Uptime | 13509 |
| Uptime_since_flush_status | 13509 |
+-----------------------------------+----------+