MySQL日志管理

最近在配置主从服务器，对接触的一些日志文件，进行一下总结。

是否开启

首先就是确定是否启用了二进制日志

mysql> show variables like '%log_bin%';
+---------------------------------+--------------------------------------------------------+
| Variable_name                   | Value                                                  |
+---------------------------------+--------------------------------------------------------+
| log_bin                         | ON                                                     |
| log_bin_basename                | /usr/local/var/mysql/dingjiacaideMacBook-Pro-bin       |
| log_bin_index                   | /usr/local/var/mysql/dingjiacaideMacBook-Pro-bin.index |
| log_bin_trust_function_creators | OFF                                                    |
| log_bin_use_v1_row_events       | OFF                                                    |
| sql_log_bin                     | ON                                                     |
+---------------------------------+--------------------------------------------------------+
6 rows in set (0.00 sec)

mysql>

上面的变量log_bin 值为on说明已经启用了，如果没有启用的话，就在my.cnf文件加入下面一行

[mysqld]
log_bin

查看二进制内容

方法一：

mysql> show binlog events;//当前在用的日志
+------------------------------------+-----+----------------+-----------+-------------+-------------------------------------------+
| Log_name                           | Pos | Event_type     | Server_id | End_log_pos | Info                                      |
+------------------------------------+-----+----------------+-----------+-------------+-------------------------------------------+
| dingjiacaideMacBook-Pro-bin.000001 |   4 | Format_desc    |         1 |         123 | Server ver: 5.7.12-log, Binlog ver: 4     |
| dingjiacaideMacBook-Pro-bin.000001 | 123 | Previous_gtids |         1 |         150 |                                           |
| dingjiacaideMacBook-Pro-bin.000001 | 150 | Anonymous_Gtid |         1 |         211 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS'      |
| dingjiacaideMacBook-Pro-bin.000001 | 211 | Query          |         1 |         281 | BEGIN                                     |
| dingjiacaideMacBook-Pro-bin.000001 | 281 | Table_map      |         1 |         323 | table_id: 108 (mysync.t)                  |
| dingjiacaideMacBook-Pro-bin.000001 | 323 | Write_rows     |         1 |         359 | table_id: 108 flags: STMT_END_F           |
| dingjiacaideMacBook-Pro-bin.000001 | 359 | Xid            |         1 |         386 | COMMIT /* xid=51 */                       |
+------------------------------------+-----+----------------+-----------+-------------+-------------------------------------------+
14 rows in set (0.00 sec)

方法二：

mysql $ sudo mysqlbinlog --start-position=150 /usr/local/var/mysql/dingjiacaideMacBook-Pro-bin.000001 // 从150开始查看二进制文件内容

mysqlbinlog具体有提供哪些参数，这里就不详细说明了，通过–help可以查看帮助，这个在主从服务器同步是出现错误的时候，用来查找问题很管用

显示二进制数目

mysql> show master logs;
+------------------------------------+-----------+
| Log_name                           | File_size |
+------------------------------------+-----------+
| dingjiacaideMacBook-Pro-bin.000001 |       784 |
+------------------------------------+-----------+
1 row in set (0.00 sec)

mysql>

查看当前状态

mysql> show master status\G // 查看从服务器的状态把master改为slave即可
*************************** 1. row ***************************
File: dingjiacaideMacBook-Pro-bin.000001
Position: 784
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)

mysql>

删除二进制日志

mysql> reset master;
Query OK, 0 rows affected (0.08 sec)
mysql>

刷新日志

mysql> flush logs;//刷新日志
Query OK, 0 rows affected (0.07 sec)

mysql> show master logs;//查看日志，从结果可知多了000002这个日志
+------------------------------------+-----------+
| Log_name                           | File_size |
+------------------------------------+-----------+
| dingjiacaideMacBook-Pro-bin.000001 |       211 |
| dingjiacaideMacBook-Pro-bin.000002 |       150 |
+------------------------------------+-----------+
2 rows in set (0.00 sec)

mysql>

上面提到的是在配主从服务器时，用到的二进制日志文件

除了上面提到日志文件之外，在平时用的比较多的就是错误日志了，如果在对MySQL不是很熟悉的情况下，怎样快速得知日志的路径，只要想下面进行操作：

方法一：

mysql $ ps -ef| grep mysql//查看进程
0 70529     1   0  1:30下午 ??         0:00.03 /bin/sh /usr/local/Cellar/mysql/5.7.12//bin/mysqld_safe --datadir=/usr/local/var/mysql --pid-file=/usr/local/var/mysql/dingjiacaideMacBook-Pro.local.pid
74 70735 70529   0  1:30下午 ??         0:03.38 /usr/local/Cellar/mysql/5.7.12/bin/mysqld --basedir=/usr/local/Cellar/mysql/5.7.12/ --datadir=/usr/local/var/mysql --plugin-dir=/usr/local/Cellar/mysql/5.7.12//lib/plugin --user=_mysql --log-error=/usr/local/var/mysql/dingjiacaideMacBook-Pro.local.err --pid-file=/usr/local/var/mysql/dingjiacaideMacBook-Pro.local.pid --socket=/tmp/mysql.sock --port=3306
501 79053 61539   0  5:06下午 ttys003    0:00.00 grep mysql
mysql $

方法二：

mysql> show variables like '%log_error%';//全局变量查看
+---------------------+--------------------------------------------------------+
| Variable_name       | Value                                                  |
+---------------------+--------------------------------------------------------+
| binlog_error_action | ABORT_SERVER                                           |
| log_error           | /usr/local/var/mysql/dingjiacaideMacBook-Pro.local.err |
| log_error_verbosity | 3                                                      |
+---------------------+--------------------------------------------------------+
3 rows in set (0.00 sec)
mysql>

当然了，还有其他的日志，这里就不一一说明了，想知道他们的所在位置就通过show variables like ‘%log_%’;这个命令查看