MySQL的二进制日志（binlog）使用分析（3）——使用show binlog events命令查看日志信息
binlog文件中存储的内容称之为二进制事件，简称事件。我们的每一个数据库更新操作(Insert、Update、Delete等)，都会对应的一个事件。使用show binlog events命令可以以列表的形式显示日志中的事件信息。
一、show binlog events命令的格式
show binlog events [IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count];
说明：
（1）IN ‘log_name’：指定要查询的binlog文件名（如果省略此参数，则默认指定第一个binlog文件）；
（2）FROM pos：指定从哪个pos起始点开始查起（如果省略此参数，则从整个文件的第一个pos点开始算）；
（3）LIMIT【offset】：偏移量（默认为0）；
（4）row_count：查询总条数（如果省略，则显示所有行）。
1、查看binlog文件信息
mysql> show master logs;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 923 |
| mysql-bin.000002 | 154 |
+------------------+-----------+
2 rows in set (0.00 sec)
2、查询第一个binlog日志
mysql> show binlog events;
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| mysql-bin.000001 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.27-log, Binlog ver: 4 |
| mysql-bin.000001 | 123 | Previous_gtids | 1 | 154 | |
| mysql-bin.000001 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 219 | Query | 1 | 291 | BEGIN |
| mysql-bin.000001 | 291 | Table_map | 1 | 339 | table_id: 113 (hist.t2) |
| mysql-bin.000001 | 339 | Write_rows | 1 | 413 | table_id: 113 flags: STMT_END_F |
| mysql-bin.000001 | 413 | Xid | 1 | 444 | COMMIT /* xid=16 */ |
| mysql-bin.000001 | 444 | Anonymous_Gtid | 1 | 509 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 509 | Query | 1 | 581 | BEGIN |
| mysql-bin.000001 | 581 | Table_map | 1 | 629 | table_id: 113 (hist.t2) |
| mysql-bin.000001 | 629 | Update_rows | 1 | 845 | table_id: 113 flags: STMT_END_F |
| mysql-bin.000001 | 845 | Xid | 1 | 876 | COMMIT /* xid=17 */ |
| mysql-bin.000001 | 876 | Rotate | 1 | 923 | mysql-bin.000002;pos=4 |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
13 rows in set (0.00 sec)
3、查询第二个binlog日志
mysql> show binlog events in 'mysql-bin.000002';
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| mysql-bin.000002 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.27-log, Binlog ver: 4 |
| mysql-bin.000002 | 123 | Previous_gtids | 1 | 154 | |
| mysql-bin.000002 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000002 | 219 | Query | 1 | 291 | BEGIN |
| mysql-bin.000002 | 291 | Table_map | 1 | 336 | table_id: 112 (hist.t1) |
| mysql-bin.000002 | 336 | Write_rows | 1 | 386 | table_id: 112 flags: STMT_END_F |
| mysql-bin.000002 | 386 | Xid | 1 | 417 | COMMIT /* xid=39 */ |
| mysql-bin.000002 | 417 | Anonymous_Gtid | 1 | 482 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000002 | 482 | Query | 1 | 554 | BEGIN |
| mysql-bin.000002 | 554 | Table_map | 1 | 599 | table_id: 112 (hist.t1) |
| mysql-bin.000002 | 599 | Write_rows | 1 | 649 | table_id: 112 flags: STMT_END_F |
| mysql-bin.000002 | 649 | Xid | 1 | 680 | COMMIT /* xid=40 */ |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
12 rows in set (0.00 sec)
4、查询mysql-bin.000002文件，从pos点417开始查询
mysql> show binlog events in 'mysql-bin.000002' from 417;
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
| mysql-bin.000002 | 417 | Anonymous_Gtid | 1 | 482 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000002 | 482 | Query | 1 | 554 | BEGIN |
| mysql-bin.000002 | 554 | Table_map | 1 | 599 | table_id: 112 (hist.t1) |
| mysql-bin.000002 | 599 | Write_rows | 1 | 649 | table_id: 112 flags: STMT_END_F |
| mysql-bin.000002 | 649 | Xid | 1 | 680 | COMMIT /* xid=40 */ |
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
5 rows in set (0.00 sec)
5、查询mysql-bin.000002文件，从pos点219开始查询，查询5条记录
mysql> show binlog events in 'mysql-bin.000002' from 219 limit 5;
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
| mysql-bin.000002 | 219 | Query | 1 | 291 | BEGIN |
| mysql-bin.000002 | 291 | Table_map | 1 | 336 | table_id: 112 (hist.t1) |
| mysql-bin.000002 | 336 | Write_rows | 1 | 386 | table_id: 112 flags: STMT_END_F |
| mysql-bin.000002 | 386 | Xid | 1 | 417 | COMMIT /* xid=39 */ |
| mysql-bin.000002 | 417 | Anonymous_Gtid | 1 | 482 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
5 rows in set (0.00 sec)
6、查询mysql-bin.000002文件，从pos点219开始查询，查询5条记录，偏移2行
mysql> show binlog events in 'mysql-bin.000002' from 219 limit 2,5;
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
| mysql-bin.000002 | 336 | Write_rows | 1 | 386 | table_id: 112 flags: STMT_END_F |
| mysql-bin.000002 | 386 | Xid | 1 | 417 | COMMIT /* xid=39 */ |
| mysql-bin.000002 | 417 | Anonymous_Gtid | 1 | 482 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000002 | 482 | Query | 1 | 554 | BEGIN |
| mysql-bin.000002 | 554 | Table_map | 1 | 599 | table_id: 112 (hist.t1) |
+------------------+-----+----------------+-----------+-------------+--------------------------------------+
5 rows in set (0.00 sec)
二、binlog管理事件
使用show binlog events命令查询到的每一行数据就是一个binlog管理事件。当使用mysqlbinlog查看日志信息时，每两个【at 数字】之间的信息就对应一个管理事件。
mysql> show binlog events in '/var/lib/mysql/mysql-bin.000002';
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| mysql-bin.000002 | 4 | Format_desc | 2 | 123 | Server ver: 5.7.27-log, Binlog ver: 4 |
| mysql-bin.000002 | 123 | Previous_gtids | 2 | 154 | |
| mysql-bin.000002 | 154 | Anonymous_Gtid | 2 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000002 | 219 | Query | 2 | 298 | BEGIN |
| mysql-bin.000002 | 298 | Query | 2 | 397 | use `hist`; update t2 set id=id+10000 |
| mysql-bin.000002 | 397 | Xid | 2 | 428 | COMMIT /* xid=11 */ |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
6 rows in set (0.00 sec)
1、每一个管理事件对应的信息说明
（1）Log_name：当前事件所在的binlog文件名称；
（2）Pos：当前事件的开始位置，每个事件都占用固定的字节大小，结束位置(End_log_position)减去Pos，就是这个事件占用的字节数。第一个事件位置并不是从0开始，而是从4。Mysql通过文件中的前4个字节，来判断这是不是一个binlog文件。这种方式很常见，很多格式的文件，如pdf、doc、jpg等，都会通常前几个特定字符判断是否是合法文件。
（3）Event_type：表示事件的类型；
（4）Server_id：表示产生这个事件的mysql server_id，通过设置my.cnf中的server-id选项进行配置；
（5）End_log_position：下一个事件的开始位置；
（6）Info：当前事件的描述信息。
2、Statement模式下的事件说明
以下是一个Statement日志格式的管理事件信息：
mysql> show binlog events in '/var/lib/mysql/mysql-bin.000001';
+------------------+------+----------------+-----------+-------------+-----------------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+------+----------------+-----------+-------------+-----------------------------------------------------------------------------+
| mysql-bin.000001 | 4 | Format_desc | 2 | 123 | Server ver: 5.7.27-log, Binlog ver: 4 |
| mysql-bin.000001 | 123 | Previous_gtids | 2 | 154 | |
| mysql-bin.000001 | 154 | Anonymous_Gtid | 2 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 219 | Query | 2 | 298 | BEGIN |
| mysql-bin.000001 | 298 | Intvar | 2 | 330 | INSERT_ID=2 |
| mysql-bin.000001 | 330 | Query | 2 | 456 | use `hist`; insert into t2(name) values('zhang'),('wang'),('li') |
| mysql-bin.000001 | 456 | Xid | 2 | 487 | COMMIT /* xid=31 */ |
| mysql-bin.000001 | 487 | Anonymous_Gtid | 2 | 552 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 552 | Query | 2 | 631 | BEGIN |
| mysql-bin.000001 | 631 | Intvar | 2 | 663 | INSERT_ID=5 |
| mysql-bin.000001 | 663 | Query | 2 | 789 | use `hist`; insert into t2(name) values('jack'),('tom'),('rose') |
| mysql-bin.000001 | 789 | Xid | 2 | 820 | COMMIT /* xid=32 */ |
| mysql-bin.000001 | 820 | Anonymous_Gtid | 2 | 885 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 885 | Query | 2 | 964 | BEGIN |
| mysql-bin.000001 | 964 | Query | 2 | 1063 | use `hist`; update t2 set id=id+10000 |
| mysql-bin.000001 | 1063 | Xid | 2 | 1094 | COMMIT /* xid=33 */ |
| mysql-bin.000001 | 1094 | Anonymous_Gtid | 2 | 1159 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 1159 | Query | 2 | 1250 | create database wgx |
| mysql-bin.000001 | 1250 | Anonymous_Gtid | 2 | 1315 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 1315 | Query | 2 | 1451 | use `wgx`; create table t1(id int primary key auto_increment,name char(20)) |
| mysql-bin.000001 | 1451 | Anonymous_Gtid | 2 | 1516 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 1516 | Query | 2 | 1593 | BEGIN |
| mysql-bin.000001 | 1593 | Intvar | 2 | 1625 | INSERT_ID=1 |
| mysql-bin.000001 | 1625 | Query | 2 | 1741 | use `wgx`; insert into t1(name) values('zhang'),('tom') |
| mysql-bin.000001 | 1741 | Xid | 2 | 1772 | COMMIT /* xid=44 */ |
| mysql-bin.000001 | 1772 | Stop | 2 | 1795 | |
+------------------+------+----------------+-----------+-------------+-----------------------------------------------------------------------------+
26 rows in set (0.01 sec)
说明：
（1）每个binlog文件总是以Format Description Event作为开始，以Rotate Event（Stop Event）作为结束。在开始和结束之间，穿插着其他各种事件。
（2）每个事务都是以Query Event作为开始，其INFO列内容为BEGIN，以Xid Event表示结束，其INFO列内容为COMMIT。即使对於单条更新SQL我们没有开启事务，Mysql也会默认的帮我们开启事务。
（3）Intvar Event事件：如果主键是自增（AUTO_INCREMENT）列，MySQL首先会自增一个值，这就是Intvar Event的作用。需要注意的是，该事件，只会在Statement模式下出现。
（4）Query Event：记录的就是插入的SQL。这也体现了Statement模式的作用，就是记录执行的SQL。
（5）Stop Event：表示日志文件的结束。
2、Row模式下的事件说明
以下是一个Row日志格式的管理事件信息：
mysql> show binlog events;
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
| mysql-bin.000001 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.27-log, Binlog ver: 4 |
| mysql-bin.000001 | 123 | Previous_gtids | 1 | 154 | |
| mysql-bin.000001 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 219 | Query | 1 | 291 | BEGIN |
| mysql-bin.000001 | 291 | Table_map | 1 | 339 | table_id: 113 (hist.t2) |
| mysql-bin.000001 | 339 | Write_rows | 1 | 413 | table_id: 113 flags: STMT_END_F |
| mysql-bin.000001 | 413 | Xid | 1 | 444 | COMMIT /* xid=16 */ |
| mysql-bin.000001 | 444 | Anonymous_Gtid | 1 | 509 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000001 | 509 | Query | 1 | 581 | BEGIN |
| mysql-bin.000001 | 581 | Table_map | 1 | 629 | table_id: 113 (hist.t2) |
| mysql-bin.000001 | 629 | Update_rows | 1 | 845 | table_id: 113 flags: STMT_END_F |
| mysql-bin.000001 | 845 | Xid | 1 | 876 | COMMIT /* xid=17 */ |
| mysql-bin.000001 | 876 | Rotate | 1 | 923 | mysql-bin.000002;pos=4 |
+------------------+-----+----------------+-----------+-------------+---------------------------------------+
13 rows in set (0.00 sec)
说明：
（1）每个binlog文件总是以Format Description Event作为开始，以Rotate Event（Stop Event）作为结束。在开始和结束之间，穿插着其他各种事件。
（2）TABLE_MAP EVENT：其作用是记录INSERT、DELETE、UPDATE操作的表结构。
（3）Write_rows：插入记录。
（4）Update_rows：更新记录。
（5）Rotate Event：表示日志文件的结束。
三、binlog日志的优化
1、binlog_row_image参数
在ROW模式下，即使我们只更新了一条记录的其中某个字段，也会记录每个字段变更前后的值，binlog日志就会变大，带来磁盘IO上的开销，以及网络开销。这个行为可以通过binlog_row_image参数控制，该参数的取值如下：
FULL（默认值）：记录列的所有修改，即使字段没有发生变更也会记录。
MINIMAL：只记录修改的列。
NOBLOB：如果是text类型或clob字段，不记录这些日志。
（1）binlog_row_image参数为FULL的binlog日志信息
[root@Mysql11 ~]# mysqlbinlog -v /var/lib/mysql/mysql-bin.000004
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
.............
'/*!*/;
### UPDATE `hist`.`stu`
### WHERE
### @1=3
### @2='jack'
### @3=20
### @4='Zhengzhou'
### @5='13675871454'
### @6=1
### SET
### @1=3
### @2='jack'
### @3=21
### @4='Zhengzhou'
### @5='13675871454'
### @6=1
# at 464
#200704 11:04:54 server id 1 end_log_pos 495 CRC32 0xc311dbb6 Xid = 18
COMMIT/*!*/;
SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;
DELIMITER ;
# End of log file
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
（2）binlog_row_image参数为MINIMAL的binlog日志信息
[root@Mysql11 ~]# mysqlbinlog -v /var/lib/mysql/mysql-bin.000007
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=1*/;
/*!50003 SET @OLD_COMPLETION_TYPE=@@COMPLETION_TYPE,COMPLETION_TYPE=0*/;
..............
'/*!*/;
### UPDATE `hist`.`stu`
### WHERE
### @1=1
### SET
### @3=21
# at 394
#200704 11:14:45 server id 1 end_log_pos 425 CRC32 0x54f07b19 Xid = 17
COMMIT/*!*/;
SET @@SESSION.GTID_NEXT= 'AUTOMATIC' /* added by mysqlbinlog */ /*!*/;
DELIMITER ;
# End of log file
/*!50003 SET COMPLETION_TYPE=@OLD_COMPLETION_TYPE*/;
/*!50530 SET @@SESSION.PSEUDO_SLAVE_MODE=0*/;
3、在Row模式下记录sql语句
在Statement模式下，直接记录SQL比较直观。在Row模式下，使用binlog_rows_query_log_events参数也可以记录SQL。参数的默认为值为FALSE，如果为true的情况下，会通过Rows Query Event来记录SQL。
在my.cnf中添加以下配置，来开启row模式下的SQL记录：
binlog-rows-query-log_events=1
结果如下：
mysql> show binlog events in '/var/lib/mysql/mysql-bin.000009';
+------------------+------+----------------+-----------+-------------+-------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+------------------+------+----------------+-----------+-------------+-------------------------------------------+
| mysql-bin.000009 | 4 | Format_desc | 1 | 123 | Server ver: 5.7.27-log, Binlog ver: 4 |
| mysql-bin.000009 | 123 | Previous_gtids | 1 | 154 | |
| mysql-bin.000009 | 154 | Anonymous_Gtid | 1 | 219 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000009 | 219 | Query | 1 | 291 | BEGIN |
| mysql-bin.000009 | 291 | Rows_query | 1 | 354 | # insert into t2(name) values('zhangfei') |
| mysql-bin.000009 | 354 | Table_map | 1 | 402 | table_id: 113 (hist.t2) |
| mysql-bin.000009 | 402 | Write_rows | 1 | 451 | table_id: 113 flags: STMT_END_F |
| mysql-bin.000009 | 451 | Xid | 1 | 482 | COMMIT /* xid=17 */ |
| mysql-bin.000009 | 482 | Anonymous_Gtid | 1 | 547 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000009 | 547 | Query | 1 | 619 | BEGIN |
| mysql-bin.000009 | 619 | Rows_query | 1 | 666 | # update t2 set id=id+100 |
| mysql-bin.000009 | 666 | Table_map | 1 | 714 | table_id: 113 (hist.t2) |
| mysql-bin.000009 | 714 | Update_rows | 1 | 850 | table_id: 113 flags: STMT_END_F |
| mysql-bin.000009 | 850 | Xid | 1 | 881 | COMMIT /* xid=18 */ |
| mysql-bin.000009 | 881 | Anonymous_Gtid | 1 | 946 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS' |
| mysql-bin.000009 | 946 | Query | 1 | 1018 | BEGIN |
| mysql-bin.000009 | 1018 | Rows_query | 1 | 1069 | # delete from t2 where id=201 |
| mysql-bin.000009 | 1069 | Table_map | 1 | 1117 | table_id: 113 (hist.t2) |
| mysql-bin.000009 | 1117 | Delete_rows | 1 | 1157 | table_id: 113 flags: STMT_END_F |
| mysql-bin.000009 | 1157 | Xid | 1 | 1188 | COMMIT /* xid=34 */ |
+------------------+------+----------------+-----------+-------------+-------------------------------------------+
20 rows in set (0.00 sec)