开启MySQL慢查询
- 2018-10-17
- 242 人已阅读
一、参数说明
slow_query_log 慢查询开启状态
slow_query_log_file 慢查询日志存放的位置(这个目录需要MySQL的运行帐号的可写权限,一般设置为MySQL的数据存放目录)
long_query_time 查询超过多少秒才记录
二、设置步骤
1.查看慢查询相关参数
mysql> show variables like 'slow_query%'; +---------------------------+----------------------------------+ | Variable_name | Value | +---------------------------+----------------------------------+ | slow_query_log | OFF | | slow_query_log_file | /var/lib/mysql/sws-slow.log | +---------------------------+----------------------------------+ mysql> show variables like 'long_query_time'; +-----------------+-----------+ | Variable_name | Value | +-----------------+-----------+ | long_query_time | 10.000000 | +-----------------+-----------+
2.设置方法
修改配置文件my.cnf,在[mysqld]下的下方加入
[mysqld] slow_query_log = ON slow_query_log_file = /var/lib/mysql/sws-slow.log long_query_time = 1
3.重启MySQL服务
service mysqld restart
4.查看设置后的参数
mysql> show variables like 'slow_query%'; +---------------------+--------------------------------+ | Variable_name | Value | +---------------------+--------------------------------+ | slow_query_log | ON | | slow_query_log_file | /var/lib/mysql/sws-slow.log | +---------------------+--------------------------------+ mysql> show variables like 'long_query_time'; +-----------------+----------+ | Variable_name | Value | +-----------------+----------+ | long_query_time | 1.000000 | +-----------------+----------+
三、测试
1.执行一条慢查询SQL语句
mysql> select sleep(2);
2.查看是否生成慢查询日志
ls /var/lib/mysql/sws-slow.log