MySQL配置慢查询日志

mysql> show variables like 'slow_query_log';
+----------------+-------+
| Variable_name  | Value |
+----------------+-------+
| slow_query_log | OFF   |
+----------------+-------+
1 row in set (0.00 sec)

慢日志查询没有开启，可以开启一下。

找到my.cnf，添加如下内容sudo vim /usr/local/mysql/my.cnf

# 添加慢查询日志
log_output=file
slow_query_log=on
slow_query_log_file = /tmp/mysql-slow.log
log_queries_not_using_indexes=on
long_query_time = 1

重启mysql。

mysql> show variables like 'slow_query_log';
+----------------+-------+
| Variable_name  | Value |
+----------------+-------+
| slow_query_log | ON    |
+----------------+-------+
1 row in set (0.00 sec)

mysql> show variables like '%quer%';
+----------------------------------------+------------------------------------+
| Variable_name                          | Value                              |
+----------------------------------------+------------------------------------+
| binlog_rows_query_log_events           | OFF                                |
| ft_query_expansion_limit               | 20                                 |
| have_query_cache                       | YES                                |
| log_queries_not_using_indexes          | ON                                 |
| log_throttle_queries_not_using_indexes | 0                                  |
| long_query_time                        | 1.000000                           |
| query_alloc_block_size                 | 8192                               |
| query_cache_limit                      | 1048576                            |
| query_cache_min_res_unit               | 4096                               |
| query_cache_size                       | 8388608                            |
| query_cache_type                       | OFF                                |
| query_cache_wlock_invalidate           | OFF                                |
| query_prealloc_size                    | 8192                               |
| slow_query_log                         | ON                                 |
| slow_query_log_file                    | /tmp/mysql-slow.log |
+----------------------------------------+------------------------------------+

注意：如果log目录不是mysql用户权限，将无法生成日志文件，mysql用户无权写入数据。

如果慢查询日志中有没有超过时间的查询记录，则关闭

mysql> show variables like 'log_queries_not_using_indexes';
+-------------------------------+-------+
| Variable_name                 | Value |
+-------------------------------+-------+
| log_queries_not_using_indexes | ON    |
+-------------------------------+-------+

log_queries_not_using_indexes = 0

然后重启MySQL，这样没有超过时间的查询就不会记录