## 1. 信息查詢 ### 1.1 最大連接數 #### 1.1.1 查詢 ~~~ mysql> show global variables like 'max_conn%'; +--------------------+-------+ | Variable_name | Value | +--------------------+-------+ | max_connect_errors | 100 | | max_connections | 5000 | +--------------------+-------+ 2 rows in set (0.00 sec) ~~~ #### 1.1.2 修改 1 my.conf，需要重啟！ ~~~ max_connection = 1000; ~~~ 2. 動態修改 還可以進入數據庫 ~~~ mysql> set GLOBAL max_connections=200 ~~~ 顯示當前運行的Query： ~~~ mysql> show processlist; +---------+--------+-----------+------+---------+------+-------+------------------+ | Id | User | Host | db | Command | Time | State | Info | +---------+--------+-----------+------+---------+------+-------+------------------+ | 2909679 | manage | localhost | NULL | Query | 0 | init | show processlist | +---------+--------+-----------+------+---------+------+-------+------------------+ 1 row in set (0.00 sec) ~~~ 顯示當前狀態：mysql> show status 退出客戶端：mysql> exit > 這種方法設置后，只是暫時的，數據庫重啟后，會變為原來的數值，要想永久，設置完后修改配置文件my.cnf，避免重啟后失效。 show variables like '%pid%'; ### 1.3 當前連接數 ~~~ mysql> show status like 'Threads%'; +-------------------+-------+ | Variable_name | Value | +-------------------+-------+ | Threads_cached | 13 | | Threads_connected | 51 | | Threads_created | 94 | | Threads_running | 1 | //當前連接數 +-------------------+-------+ 4 rows in set (0.01 sec) ) ~~~