针对MySQL5 二进制日志（binary logs）常用命令

最近频繁接到数据库服务器磁盘空间不足的告警，实际上数据库文件本身不大，主要是半年多累积的binary logs大，尤其是有主从配置的DB。查看了很多资料，总结了一下常用的专门针对binary logs的mysql命令：

1. Binary logs 位置：

1）查看/etc/my.cnf (Windows下为my.ini）, 例如：

log_bin=/var/mydb/bin-log

如果该设置没带路径，就放在datadir=/var/lib/mysql 下

2） 到数据库查看是否开启binary log 功能：

mysql> show variables like 'log_bin';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| log_bin | ON |

+---------------+-------+

1 row in set (0.00 sec)

mysql> show variables like 'log_bin';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| log_bin | OFF |

+---------------+-------+

1 row in set (0.01 sec)

如果是OFF就没有以下工作了：）

2. 查看当前工作的logfile名及大小： show binary logs /show master logs;

mysql> show binary logs;

+-----------------+-----------+

| Log_name | File_size |

+-----------------+-----------+

| bin-log.000011 | 148329 |

+-----------------+-----------+

mysql> show master logs;

+-----------------+-----------+

| Log_name | File_size |

+-----------------+-----------+

| bin-log.000011 | 148329 |

+-----------------+-----------+

mysql> show binary logs;

ERROR 1381 (HY000): You are not using binary logging ###没有开启binary logs

3. 清除所有binary logs;

1)

mysql> show master logs;

+-----------------+-----------+

| Log_name | File_size |

+-----------------+-----------+

| log-bin.000001 | 259548 |

| log-bin.000002 | 37200 |

| log-bin.000003 | 74219 |

+-----------------+-----------+

3 rows in set (0.00 sec)

mysql> reset master; (在slave上，用reset slave，之前应stop slave，之后再start slave）

Query OK, 0 rows affected (0.00 sec)

mysql> show master logs;

+-----------------+-----------+

| Log_name | File_size |

+-----------------+-----------+

| log-bin.000001 | 98 |

+-----------------+-----------+

1 row in set (0.00 sec)

4. 清除指定部分logs：

mysql>purge binary logs to 'log-bin.000012';

将log-bin.000012之前的binary logs清掉；

mysql>purge binary logs before '2011-05-28 12:05:38';

将指定时间之前的binary logs清掉；

5.查看当前binary log的情况：

mysql>show master status;

6. 查看binary logs的内容：

mysql>show binlog events;

命令行下：

#mysqlbinlog /var/log/mysql/log-bin.000140; 或者

#mysqlbinlog --start-datetime='2011-07-01 00:00:00' --stop-datetime='2010-07-15 00:00:00' /var/log/mysql/log-bin.000020 > ./tmp.log

7. 在my.cnf/my.ini中设定binary logs回滚天数：

expire_logs_days = 7