mysql 遭遇系统limit 参数影响

mysql 的error log 如下：

130525  9:26:13 [ERROR] /home/mysql/libexec/mysqld: Can't open file: './mysql/user.frm' (errno: 24)

130525  9:27:25 [ERROR] Error in accept: Too many open files

查看系统当前的连接数:

[root@app_db ~]# ulimit -n

512000

查看mysql 当前的连接数:

information_schema> show variables like 'open_files_limit';

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

| Variable_name    | Value |

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

| open_files_limit | 1500  |

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

1 row in set (0.00 sec)

应该是 MySQL启动前，文件打开数上限为1500，之后才改为 512000 。重启MySQL，再次查看：

information_schema> show variables like 'open_files_limit';

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

| Variable_name    | Value  |

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

| open_files_limit | 512000 |

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

数据库恢复正常。