mysql使用binlog进行数据恢复

日期：2022-07-16 栏目：数据库浏览：1184 次

从整库备份的sql文件中导出某个表的sql语句时，vim查找到表的第一条INSERT语句后，按上下换行键计数INSERT语句的条数，然后按n yy复制，退出vim后，
再新建一个文件，按p粘贴刚才的n条INSERT语句，再进行source导入。

一、登录数据库刷新binlog

1.1)查看当前的binlog

MySQL> show master status;
+---------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------------+----------+--------------+------------------+-------------------+
| test-150-bin.000003 | 2895377 | | | |
+---------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

1.2)刷新binlog

mysql> flush logs;
Query OK, 0 rows affected (0.01 sec)

1.3)确认刷新binlog成功

mysql> show master status;
+---------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+---------------------+----------+--------------+------------------+-------------------+
| test-150-bin.000004 | 120 | | | |
+---------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

用show master status 命令查看当前的binlog已经由test-150-bin.000003变为test-150-bin.000004，
证明binlog已经刷新成功。

二、查询二进制日志位置

mysql> show variables like'log_bin%';
+---------------------------------+------------------------------------------+
| Variable_name                   | Value                                    |
+---------------------------------+------------------------------------------+
| log_bin                             | ON                                       |
| log_bin_basename             | /db/mysql5.6/data/test-150-bin       |
| log_bin_index                    | /db/mysql5.6/data/test-150-bin.index |
| log_bin_trust_function_creators | ON                                       |
| log_bin_use_v1_row_events       | OFF                                      |
+---------------------------------+------------------------------------------+

三、从二进制日志中获取表被删除的时间

$ mysqlbinlog test-150-bin.000003 | grep -i DROP -A3 -B4
COMMIT/*!*/;
# at 122869
#140126 17:03:35 server id 150 end_log_pos 122989 CRC32 0x8707c4c4 Query thread_id=12519 exec_time=0 error_code=0
SET TIMESTAMP=1390727015/*!*/;
DROP TABLE `test` /* generated by server */
/*!*/;
# at 122989
#140126 17:04:06 server id 150 end_log_pos 123039 CRC32 0x43476aad Rotate to test-150-bin.000004 pos: 4

drop语句的前两行表名drop语句的执行时间是在 17:03:35

mysql> SELECT from_unixtime('1390727015');
+-----------------------------+
| from_unixtime('1390727015') |
+-----------------------------+
| 2014-01-26 17:03:35.000000 |
+-----------------------------+
1 row in set

四、从binlog中获取指定数据库的改变数据
用mysqlbinlog 恢复ivr数据库在二进制日志test-150-bin.000003中的数据
假设从上一次mysql备份后，只有一个binlog产生，即登录数据库时查询到binlog test-150-bin.000003

mysqlbinlog -d ivr --stop-datetime='2014-01-26 17:03:35' test-150-bin.000003 > recover_ivr.sql

如果从上次备份刷新binlog，到发现表被删掉的过程中产生了多个binlog。则要按照binlog产生的顺序进行恢复，那
么恢复的次序应该是按照binglog的产生的序号，从小到大依次恢复。
假如从上次备份，到发现表被删除，共有两个binlog文件，分别是test-150-bin.000002，test-150-bin.000003 ，
则按照binlog序号从小到大的排列，恢复的顺序应该是：

mysqlbinlog -d ivr test-150-bin.000002 > recover_ivr.sql

mysqlbinlog -d ivr --stop-datetime='2014-01-26 17:03:35' test-150-bin.000003 >> recover_ivr.sql

由于恢复的文件recover_ivr.sql中包含了整个ivr数据库的所有表，我们只要恢复指定的表mytable，还要对恢复出来的sql进行过滤。

cat recover_ivr.sql | grep -A1 -B3 -i -E '^insert|^update|^delete|^replace|^alter' | grep -A1 -B3 mytable > mytable.sql

可以先使用more确认一下

/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!40019 SET @@session.max_insert_delayed_threads=0*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
DELIMITER /*!*/;
--
# at 122721
#140126 17:03:28 server id 150 end_log_pos 122721 CRC32 0xe0f851bb Intvar
SET INSERT_ID=4/*!*/;
#140126 17:03:28 server id 150 end_log_pos 122838 CRC32 0x9efcc7b2 Query thread_id=12578 exec_time=0 error_code=0
use `ivr`/*!*/;
SET TIMESTAMP=1390727008/*!*/;
INSERT INTO `testtuo` (`name`) VALUES ('d')
/*!*/;
# at 122838