MySQL抑制binlog日志中的BINLOG部分

冷不防 2022-08-06 04:07 209阅读 0赞

MySQL通过binlog来记录整个数据的变更过程，因此我们只要有MySQL的binlog日志即可完整的还原数据库。MySQL binlog日志记录有3种不同的方式，即：STATEMENT，MIXED，ROW。对于不同的日志模式，生成的binlog有不同的记录方式。对于MIXED(部分SQL语句)和ROW模式是以base-64方式记录，会以BINLOG开头，是一段伪SQL，我们可以用使用base64-output参数来抑制其显示。本文对此给出了描述及演示。

有关mysqlbinlog的用法，请参考：[使用mysqlbinlog提取二进制日志][mysqlbinlog]

1、mysqlbinlog之base64-output参数

[\--base64-output=***value***][--base64-output_value]

This option determines when events should be displayed encoded as base-64 strings using [**BINLOG**][BINLOG] statements. The option has these permissible values (not case sensitive):

*   **AUTO** ("automatic") or **UNSPEC** ("unspecified") displays  [**BINLOG**][BINLOG]  statements automatically when necessary (that is, for format description events and row events). If no  [\--base64-output][--base64-output_value]  option is given, the effect is the same as  [\--base64-output=AUTO][--base64-output_value] .
 *   **NEVER** causes  [**BINLOG**][BINLOG]  statements not to be displayed.  [**mysqlbinlog**][mysqlbinlog 1]  exits with an error if a row event is found that must be displayed using  [**BINLOG**][BINLOG] .
 *  **DECODE-ROWS** specifies to  [**mysqlbinlog**][mysqlbinlog 1]  that you intend for row events to be decoded and displayed as commented SQL statements by also specifying the  [\--verbose][--verbose]  option. Like **NEVER**, **DECODE-ROWS** suppresses display of  [**BINLOG**][BINLOG]  statements, but unlike **NEVER**, it does not exit with an error if a row event is found.

以上描述对于binlog日志中的BINLOG部分，如果要过虑掉需要指定**DECODE-ROWS** 以及[\--verbose][--verbose]选项。

The SQL statements produced by [\--verbose][--verbose] for row events are much more readable than the corresponding [**BINLOG**][BINLOG] statements. However, they do not correspond exactly to the original SQL statements that generated the events. The following limitations apply:

[\--verbose][--verbose]选项可以获取更多的可读信息，但是并不是一个原始的SQL语句(类似的)。

·         The original column names are lost and replaced by **@*N***, where ***N*** is a column number.

·         Character set information is not available in the binary log, which affects string column display:

*  There is no distinction made between corresponding binary and nonbinary string types ( [**BINARY**][BINARY]  and  [**CHAR**][CHAR] , [**VARBINARY**][BINARY]  and  [**VARCHAR**][CHAR] ,  [**BLOB**][BLOB]  and  [**TEXT**][BLOB] ). The output uses a data type of **STRING** for fixed-length strings and**VARSTRING** for variable-length strings.
 *  For multibyte character sets, the maximum number of bytes per character is not present in the binary log, so the length for string types is displayed in bytes rather than in characters. For example, **STRING(4)** will be used as the data type for values from either of these column types:

CHAR(4) CHARACTER SET latin1

CHAR(2) CHARACTER SET ucs2

*  Due to the storage format for events of type **UPDATE\_ROWS\_EVENT**,  [**UPDATE**][UPDATE]  statements are displayed with the**WHERE** clause preceding the **SET** clause.

Proper interpretation of row events requires the information from the format description event at the beginning of the binary log. Because [**mysqlbinlog**][mysqlbinlog 1] does not know in advance whether the rest of the log contains row events, by default it displays the format description event using a [**BINLOG**][BINLOG] statement in the initial part of the output.

If the binary log is known not to contain any events requiring a [**BINLOG**][BINLOG] statement (that is, no row events), the [\--base64-output=NEVER][--base64-output_value] option can be used to prevent this header from being written.

2、演示生成binlog日志

--环境
    mysql> show variables like 'version';
    +---------------+------------+
    | Variable_name | Value      |
    +---------------+------------+
    | version       | 5.6.12-log |
    +---------------+------------+
    
    --如下查询binlog为row记录模式
    mysql> show variables like 'binlog_for%';
    +---------------+-------+
    | Variable_name | Value |
    +---------------+-------+
    | binlog_format | ROW   |
    +---------------+-------+
    
    mysql> reset master;
    Query OK, 0 rows affected (0.01 sec)
    
    mysql> show master status;
    +-----------------+----------+--------------+------------------+-------------------+
    | File            | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
    +-----------------+----------+--------------+------------------+-------------------+
    | APP01bin.000001 |      120 |              |                  |                   |
    +-----------------+----------+--------------+------------------+-------------------+
    
    mysql> use test;
    Database changed
    
    --创建表t1
    mysql> create table t1(id smallint,val varchar(20));
    Query OK, 0 rows affected (0.01 sec)
    
    --插入单条记录
    mysql> insert into t1 values(1,'robin');
    Query OK, 1 row affected (0.00 sec)
    
    --清空表
    mysql> truncate table t1;
    Query OK, 0 rows affected (0.01 sec)
    
    --查看binlog events
    mysql> show binlog events;
    +-----------------+-----+-------------+-----------+-------------+----------------------------------------------------------+
    | Log_name        | Pos | Event_type  | Server_id | End_log_pos | Info                                                     |
    +-----------------+-----+-------------+-----------+-------------+----------------------------------------------------------+
    | APP01bin.000001 |   4 | Format_desc |        11 |         120 | Server ver: 5.6.12-log, Binlog ver: 4                    |
    | APP01bin.000001 | 120 | Query       |        11 |         238 | use `test`; create table t1(id smallint,val varchar(20)) |
    | APP01bin.000001 | 238 | Query       |        11 |         310 | BEGIN                                                    |
    | APP01bin.000001 | 310 | Table_map   |        11 |         358 | table_id: 74 (test.t1)                                   |
    | APP01bin.000001 | 358 | Write_rows  |        11 |         402 | table_id: 74 flags: STMT_END_F                           |
    | APP01bin.000001 | 402 | Xid         |        11 |         433 | COMMIT /* xid=30 */                                      |
    | APP01bin.000001 | 433 | Query       |        11 |         517 | use `test`; truncate table t1                            |
    +-----------------+-----+-------------+-----------+-------------+----------------------------------------------------------+
    7 rows in set (0.00 sec)
    
    --获取binlog位置
    mysql> show variables like 'log_bin_basename';
    +------------------+--------------------+
    | Variable_name    | Value              |
    +------------------+--------------------+
    | log_bin_basename | /opt/data/APP01bin |
    +------------------+--------------------+

3、演示提取binlog日志  
\#未使用base64-output选项的情形，即缺省值为AUTO  
SHELL>  mysqlbinlog /opt/data/APP01bin.000001|grep truncate -B15  
\# at 310  
\#141218 16:28:05 server id 11  end\_log\_pos 358 CRC32 0xe0025004         Table\_map: \`test\`.\`t1\` mapped to number 74  
\# at 358  
\#141218 16:28:05 server id 11  end\_log\_pos 402 CRC32 0x3452dcfe         Write\_rows: table id 74 flags: STMT\_END\_F

BINLOG '                               \#这个BINLOG部分是真实的SQL语句，无法看到具体内容  
FZCSVBMLAAAAMAAAAGYBAAAAAEoAAAAAAAEABHRlc3QAAnQxAAICDwI8AAMEUALg  
FZCSVB4LAAAALAAAAJIBAAAAAEoAAAAAAAEAAgAC//wBAAVyb2Jpbv7cUjQ=  
'/\*!\*/;  
\# at 402  
\#141218 16:28:05 server id 11  end\_log\_pos 433 CRC32 0xbe26740a         Xid = 30  
COMMIT/\*!\*/;  
\# at 433  
\#141218 16:29:00 server id 11  end\_log\_pos 517 CRC32 0x89c52d6a         Query   thread\_id=1     exec\_time=0     error\_code=0  
SET TIMESTAMP=1418891340/\*!\*/;  
truncate table t1

\#使用-v参数的情形，可以看到我们操作生成的SQL语句了，为insert into [..@1][.._1]之类的形式，如果-vv则输出列的描述信息  
\#BINLOG部分依旧被显示出来  
SHELL>  mysqlbinlog -v /opt/data/APP01bin.000001|grep truncate -B20  
/\*!\*/;  
\# at 310  
\#141218 16:28:05 server id 11  end\_log\_pos 358 CRC32 0xe0025004         Table\_map: \`test\`.\`t1\` mapped to number 74  
\# at 358  
\#141218 16:28:05 server id 11  end\_log\_pos 402 CRC32 0x3452dcfe         Write\_rows: table id 74 flags: STMT\_END\_F

BINLOG '  
FZCSVBMLAAAAMAAAAGYBAAAAAEoAAAAAAAEABHRlc3QAAnQxAAICDwI8AAMEUALg  
FZCSVB4LAAAALAAAAJIBAAAAAEoAAAAAAAEAAgAC//wBAAVyb2Jpbv7cUjQ=  
'/\*!\*/;  
\#\#\# INSERT INTO \`test\`.\`t1\`  
\#\#\# SET  
\#\#\#   @1=1  
\#\#\#   @2='robin'  
\# at 402  
\#141218 16:28:05 server id 11  end\_log\_pos 433 CRC32 0xbe26740a         Xid = 30  
COMMIT/\*!\*/;  
\# at 433  
\#141218 16:29:00 server id 11  end\_log\_pos 517 CRC32 0x89c52d6a         Query   thread\_id=1     exec\_time=0     error\_code=0  
SET TIMESTAMP=1418891340/\*!\*/;  
truncate table t1

\#添加--base64-output=DECODE-ROWS选项来抑制BINLOG的显示，如下我们看不到了BINLOG部分  
SHELL>  mysqlbinlog --base64-output=DECODE-ROWS -v /opt/data/APP01bin.000001|grep truncate -B20  
/\*!\*/;  
\# at 238  
\#141218 16:28:05 server id 11  end\_log\_pos 310 CRC32 0x60507739         Query   thread\_id=1     exec\_time=0     error\_code=0  
SET TIMESTAMP=1418891285/\*!\*/;  
BEGIN  
/\*!\*/;  
\# at 310  
\#141218 16:28:05 server id 11  end\_log\_pos 358 CRC32 0xe0025004         Table\_map: \`test\`.\`t1\` mapped to number 74  
\# at 358  
\#141218 16:28:05 server id 11  end\_log\_pos 402 CRC32 0x3452dcfe         Write\_rows: table id 74 flags: STMT\_END\_F  
\#\#\# INSERT INTO \`test\`.\`t1\`  
\#\#\# SET  
\#\#\#   @1=1  
\#\#\#   @2='robin'  
\# at 402  
\#141218 16:28:05 server id 11  end\_log\_pos 433 CRC32 0xbe26740a         Xid = 30  
COMMIT/\*!\*/;  
\# at 433  
\#141218 16:29:00 server id 11  end\_log\_pos 517 CRC32 0x89c52d6a         Query   thread\_id=1     exec\_time=0     error\_code=0  
SET TIMESTAMP=1418891340/\*!\*/;  
truncate table t1

\#此时使用mysqlbinlog做一个不完全恢复  
SHELL>  mysqlbinlog --database=test --start-position="238" --stop-position="433" /opt/data/APP01bin.000001 |mysql -uroot -p --database=test  
Enter password:

\#查看恢复后的结果  
SHELL>  mysql -uroot -p -e "select \* from test.t1"  
Enter password:  
\+------+-------+  
| id   | val   |  
\+------+-------+  
|    1 | robin |  
\+------+-------+

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[mysqlbinlog]: http://blog.csdn.net/leshami/article/details/41962243
[--base64-output_value]: http://dev.mysql.com/doc/refman/5.6/en/mysqlbinlog.html#option_mysqlbinlog_base64-output
[BINLOG]: http://dev.mysql.com/doc/refman/5.6/en/binlog.html
[mysqlbinlog 1]: http://dev.mysql.com/doc/refman/5.6/en/mysqlbinlog.html
[--verbose]: http://dev.mysql.com/doc/refman/5.6/en/mysqlbinlog.html#option_mysqlbinlog_verbose
[BINARY]: http://dev.mysql.com/doc/refman/5.6/en/binary-varbinary.html
[CHAR]: http://dev.mysql.com/doc/refman/5.6/en/char.html
[BLOB]: http://dev.mysql.com/doc/refman/5.6/en/blob.html
[UPDATE]: http://dev.mysql.com/doc/refman/5.6/en/update.html
[.._1]: mailto:..@1
[DBA]: http://pub.idqqimg.com/wpa/images/group.png
[DBA_DBA]: /images/20220806/af63b0632c41488d97fb0b31911c7033.png