一、試驗基礎環境配置

1、查看當前數據庫的最大連接數

mysql> show global variables like '%connect%';+--------------------------+-----------------+

| Variable_name | Value |

+--------------------------+-----------------+

| character_set_connection | utf8 |

| collation_connection | utf8_general_ci |

| connect_timeout | 10 |

| init_connect | |

| max_connect_errors | 10 |

| max_connections | 160 |

| max_user_connections | 0 |

+--------------------------+-----------------+

7 rows in set (0.00 sec)

2、設置全局變量max_connections為3(基于試驗目的，做測試)

mysql> set global max_connections=3;

Query OK,0 rows affected (0.01 sec)

3、查看設置是否生效.max_connections已經設置為3.

mysql> show global variables like '%connect%';+--------------------------+-----------------+

| Variable_name | Value |

+--------------------------+-----------------+

| character_set_connection | utf8 |

| collation_connection | utf8_general_ci |

| connect_timeout | 10 |

| init_connect | |

| max_connect_errors | 10 |

| max_connections |3 |

| max_user_connections | 0 |

+--------------------------+-----------------+

7 rows in set (0.00 sec)

4、退出當前登陸，再次登陸查看是否生效.

mysql> exitBye

C:\Users\ArcerZhang>mysql -uroot -parcerzhang

Welcometo the MySQL monitor. Commands end with ; or\g.

Your MySQL connection idis 3Server version:5.5.28MySQL Community Server (GPL)

Copyright (c)2000, 2012, Oracle and/or its affiliates. Allrights reserved.

Oracleis a registered trademark of Oracle Corporation and/orits

affiliates. Other names may be trademarksoftheir respective

owners.

Type'help;' or '\h' for help. Type '\c' to clear the currentinput statement.

mysql> show global variables like '%connect%';+--------------------------+-----------------+

| Variable_name | Value |

+--------------------------+-----------------+

| character_set_connection | utf8 |

| collation_connection | utf8_general_ci |

| connect_timeout | 10 |

| init_connect | |

| max_connect_errors | 10 |

| max_connections | 3 |

| max_user_connections | 0 |

+--------------------------+-----------------+

7 rows in set (0.00 sec)

二、查看當前數據庫連接數

mysql> usearcerzhangdb;Databasechanged

mysql>show processlist;+----+------+-----------------+--------------+---------+------+-------+------------------+

| Id | User | Host | db | Command | Time | State | Info |

+----+------+-----------------+--------------+---------+------+-------+------------------+

| 3 | root | localhost:53232 | arcerzhangdb | Query | 0 | NULL | show processlist |

+----+------+-----------------+--------------+---------+------+-------+------------------+

1 row in set (0.00 sec)

三、分別打開第二個、第三個、第四個、第五個CMD窗口登錄數據庫

C:\Users\ArcerZhang>mysql -uroot -parcerzhang

Welcometo the MySQL monitor. Commands end with ; or\g.

Your MySQL connection idis 4Server version:5.5.28MySQL Community Server (GPL)

Copyright (c)2000, 2012, Oracle and/or its affiliates. Allrights reserved.

Oracleis a registered trademark of Oracle Corporation and/orits

affiliates. Other names may be trademarksoftheir respective

owners.

Type'help;' or '\h' for help. Type '\c' to clear the currentinput statement.

mysql> usearcerzhangdb;Databasechanged

mysql>show tables;+------------------------+

| Tables_in_arcerzhangdb |

+------------------------+

| inno_tab |

| t |

| t_myisam |

| tablespace_test |

| tt |

| ttt |

+------------------------+

6 rows in set (0.00sec)

mysql> desct;+-------+-------------+------+-----+---------+-------+

| Field | Type | Null | Key | Default | Extra |

+-------+-------------+------+-----+---------+-------+

| id | int(11) | NO | PRI | 0 | |

| name | varchar(10) | YES | | NULL | |

+-------+-------------+------+-----+---------+-------+

2 rows in set (0.12 sec)

打開第二個窗口

mysql>show processlist;+----+------+-----------------+--------------+---------+------+-------+------------------+

| Id | User | Host | db | Command | Time | State | Info |

+----+------+-----------------+--------------+---------+------+-------+------------------+

| 3 | root | localhost:53232 | arcerzhangdb | Query | 0 | NULL | show processlist |

| 4 | root | localhost:53251 | arcerzhangdb | Sleep | 6 | | NULL |

+----+------+-----------------+--------------+---------+------+-------+------------------+

2 rows in set (0.00 sec)

查看數據庫連接

C:\Users\ArcerZhang>mysql -uroot -parcerzhang

Welcometo the MySQL monitor. Commands end with ; or\g.

Your MySQL connection idis 5Server version:5.5.28MySQL Community Server (GPL)

Copyright (c)2000, 2012, Oracle and/or its affiliates. Allrights reserved.

Oracleis a registered trademark of Oracle Corporation and/orits

affiliates. Other names may be trademarksoftheir respective

owners.

Type'help;' or '\h' for help. Type '\c' to clear the currentinput statement.

mysql> usearcerzhangdb;Databasechanged

mysql> select * fromtt;+------+------+

| id | msg |

+------+------+

| 1 | a |

| 2 | b |

| 3 | c |

| 4 | d |

| 5 | e |

| 1000 | f |

+------+------+

6 rows in set (0.06sec)

mysql>

打開第三個窗口

mysql>show processlist;+----+------+-----------------+--------------+---------+------+-------+------------------+

| Id | User | Host | db | Command | Time | State | Info |

+----+------+-----------------+--------------+---------+------+-------+------------------+

| 3 | root | localhost:53232 | arcerzhangdb | Query | 0 | NULL | show processlist |

| 4 | root | localhost:53251 | arcerzhangdb | Sleep | 43 | | NULL |

| 5 | root | localhost:53264 | arcerzhangdb | Sleep | 5 | | NULL |

+----+------+-----------------+--------------+---------+------+-------+------------------+

3 rows in set (0.00 sec)

查看數據庫連接

C:\Users\ArcerZhang>mysql -uroot -parcerzhang

Welcometo the MySQL monitor. Commands end with ; or\g.

Your MySQL connection idis 6Server version:5.5.28MySQL Community Server (GPL)

Copyright (c)2000, 2012, Oracle and/or its affiliates. Allrights reserved.

Oracleis a registered trademark of Oracle Corporation and/orits

affiliates. Other names may be trademarksoftheir respective

owners.

Type'help;' or '\h' for help. Type '\c' to clear the currentinput statement.

mysql> usearcerzhangdb;Databasechanged

mysql>show tables;+------------------------+

| Tables_in_arcerzhangdb |

+------------------------+

| inno_tab |

| t |

| t_myisam |

| tablespace_test |

| tt |

| ttt |

+------------------------+

6 rows in set (0.00sec)

mysql> select * fromttt;+----+------+

| id | msg |

+----+------+

| 1 | a |

+----+------+

1 row in set (0.07sec)

mysql>

打開第四個窗口

mysql>show processlist;+----+------+-----------------+--------------+---------+------+-------+------------------+

| Id | User | Host | db | Command | Time | State | Info |

+----+------+-----------------+--------------+---------+------+-------+------------------+

| 3 | root | localhost:53232 | arcerzhangdb | Query | 0 | NULL | show processlist |

| 4 | root | localhost:53251 | arcerzhangdb | Sleep | 97 | | NULL |

| 5 | root | localhost:53264 | arcerzhangdb | Sleep | 59 | | NULL |

| 6 | root | localhost:53274 | arcerzhangdb | Sleep | 5 | | NULL |

+----+------+-----------------+--------------+---------+------+-------+------------------+

4 rows in set (0.00 sec)

查看數據庫連接

Microsoft Windows [版本 10.0.10586](c)2015Microsoft Corporation。保留所有權利。

C:\Users\ArcerZhang>mysql -uroot -parcerzhang

ERROR1040(HY000): Too many connections

C:\Users\ArcerZhang>

打開第五個窗口

四、結論

第一個連接窗口為初始窗口，或者說叫做監控窗口.

第二個連接窗口應該算是我們設置max_connections=3后第一個真正意義上的連接用戶.

第三個連接窗口應該算是我們設置max_connections=3后第二個真正意義上的連接用戶.

第四個連接窗口應該算是我們設置max_connections=3后第三個真正意義上的連接用戶.

所以當打開第五個窗口的時候，會報如下錯誤:

C:\Users\ArcerZhang>mysql -uroot -parcerzhang

ERROR1040 (HY000): Too many connections

總結

以上是生活随笔為你收集整理的mysql 连接数测试_mysql最大连接数试验的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。