一、问题原因
UTC是世界统一时间，而我现在的系统为北京时间是东八区，比UTC早了8个小时，所以这里设置为SYSTEM
这是由于log_timestamps这个参数设置造成的，查询当前设置

mysql> show variables like ‘%log_time%‘;
+----------------+-------+
| Variable_name  | Value |
+----------------+-------+
| log_timestamps | UTC   |
+----------------+-------+
1 row in set (0.01 sec)

 
二、问题解决

mysql> set global log_timestamps=SYSTEM;
Query OK, 0 rows affected (0.00 sec)

mysql> show variables like ‘%log_time%‘;
+----------------+--------+
| Variable_name  | Value  |
+----------------+--------+
| log_timestamps | SYSTEM |
+----------------+--------+
1 row in set (0.01 sec)


在mysql里执行一条测试慢日志语句

mysql> select sleep(5);
+----------+
| sleep(5) |
+----------+
|        0 |
+----------+
1 row in set (4.99 sec)

mysql> 


再次查看慢日志是否正常