查看一下mariadb是否开启慢查询：
show variables like 'slow_query%';查看慢查询时间设置为多少秒：
show variables like 'long_query_%';设置配置文件：
vim /etc/my.cnf.d/server.cnf [mysqld] slow_query_log = ON slow_query_log_file = /usr/local/mysql/data/slow.log long_query_time = 1 MariaDB [(none)]> show variables like 'long_query_%'; +-----------------+----------+ | Variable_name | Value | +-----------------+----------+ | long_query_time | 1.000000 | +-----------------+----------+ 1 row in set (0.00 sec)测试慢查询：
MariaDB [(none)]> select sleep(2);查看慢查询日志：
[root@localhost vhosts]# tailf /var/lib/mysql/localhost-slow.log /usr/sbin/mysqld, Version: 10.2.6-MariaDB (MariaDB Server). started with: Tcp port: 3306 Unix socket: /var/lib/mysql/mysql.sock Time Id Command Argument /usr/sbin/mysqld, Version: 10.2.6-MariaDB-log (MariaDB Server). started with: Tcp port: 0 Unix socket: /var/lib/mysql/mysql.sock Time Id Command Argument # Time: 170711 17:54:13 # User@Host: root[root] @ localhost [] # Thread_id: 8 Schema: QC_hit: No # Query_time: 2.001172 Lock_time: 0.000000 Rows_sent: 1 Rows_examined: 0 # Rows_affected: 0 SET timestamp=1499766853; select sleep(2);