MYSQL-- binlog事件详解

Posted 2020-07-07 zengkefu

mysqlbinlog  -vvv log.000001

# at 154
#160517 15:09:13 server id 100  end_log_pos 219 CRC32 0x7439a004        GTID   last_committed=0 sequence_number=1
SET @@SESSION.GTID_NEXT= ‘191f7a9f-ffa2-11e5-a825-00163e00242a:1‘/*!*/;
# at 219
#160517 15:09:13 server id 100  end_log_pos 291 CRC32 0x0839a8df        Query  thread_id=22     exec_time=0     error_code=0
SET TIMESTAMP=1463468953/*!*/;
SET @@session.pseudo_thread_id=22/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=1436549152/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8 *//*!*/;
SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=8/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
BEGIN
/*!*/;
# at 291
#160517 15:09:13 server id 100  end_log_pos 336 CRC32 0x738c7c74        Table_map: `test`.`tt` mapped to number 113
# at 336
#160517 15:09:13 server id 100  end_log_pos 376 CRC32 0x1949e971        Write_rows: table id 113 flags: STMT_END_F

BINLOG ‘
mcM6VxNkAAAALQAAAFABAAAAAHEAAAAAAAEABHRlc3QAAnR0AAEDAAF0fIxz
mcM6Vx5kAAAAKAAAAHgBAAAAAHEAAAAAAAEAAgAB//4KAAAAcelJGQ==
‘/*!*/;
### INSERT INTO `test`.`tt`
### SET
###   @1=10 /* INT meta=0 nullable=1 is_null=0 */
# at 376
#160517 15:09:13 server id 100  end_log_pos 407 CRC32 0x63b03fee        Xid = 132
COMMIT/*!*/;

| log.000001 |  154 | Gtid           |       100 |         219 | SET @@SESSION.GTID_NEXT= ‘191f7a9f-ffa2-11e5-a825-00163e00242a:1‘ |
| log.000001 |  219 | Query          |       100 |         291 | BEGIN                                                             |
| log.000001 |  291 | Table_map      |       100 |         336 | table_id: 113 (test.tt)                                           |
| log.000001 |  336 | Write_rows     |       100 |         376 | table_id: 113 flags: STMT_END_F                                   |
| log.000001 |  376 | Xid            |       100 |         407 | COMMIT /* xid=1

mysqlbinlog --base64-output=decode-rows -vvv log.000001


# at 154
#160517 15:09:13 server id 100  end_log_pos 219 CRC32 0x7439a004        GTID   last_committed=0 sequence_number=1
SET @@SESSION.GTID_NEXT= ‘191f7a9f-ffa2-11e5-a825-00163e00242a:1‘/*!*/;
# at 219
#160517 15:09:13 server id 100  end_log_pos 291 CRC32 0x0839a8df        Query  thread_id=22     exec_time=0     error_code=0
SET TIMESTAMP=1463468953/*!*/;
SET @@session.pseudo_thread_id=22/*!*/;
SET @@session.foreign_key_checks=1, @@session.sql_auto_is_null=0, @@session.unique_checks=1, @@session.autocommit=1/*!*/;
SET @@session.sql_mode=1436549152/*!*/;
SET @@session.auto_increment_increment=1, @@session.auto_increment_offset=1/*!*/;
/*!\C utf8 *//*!*/;
SET @@session.character_set_client=33,@@session.collation_connection=33,@@session.collation_server=8/*!*/;
SET @@session.lc_time_names=0/*!*/;
SET @@session.collation_database=DEFAULT/*!*/;
BEGIN
/*!*/;
# at 291
#160517 15:09:13 server id 100  end_log_pos 336 CRC32 0x738c7c74        Table_map: `test`.`tt` mapped to number 113
# at 336
#160517 15:09:13 server id 100  end_log_pos 376 CRC32 0x1949e971        Write_rows: table id 113 flags: STMT_END_F
### INSERT INTO `test`.`tt`
### SET
###   @1=10 /* INT meta=0 nullable=1 is_null=0 */
# at 376
#160517 15:09:13 server id 100  end_log_pos 407 CRC32 0x63b03fee        Xid = 132
COMMIT/*!*/;

binlog事件：由<公有事件头>+[私有事件头]+[事件体]三部分组成

           所有的binlog事件都包含公有事件头,另外两个部分是根据事件类型可选

公有事件头：

http://dev.mysql.com/doc/internals/en/event-structure.html


v4 event structure:

+=====================================+
| event  | timestamp         0 : 4    |
| header +----------------------------+
|        | type_code         4 : 1    |
|        +----------------------------+
|        | server_id         5 : 4    |
|        +----------------------------+
|        | event_length      9 : 4    |
|        +----------------------------+
|        | next_position    13 : 4    |
|        +----------------------------+
|        | flags            17 : 2    |
|        +----------------------------+
|        | extra_headers    19 : x-19 |
+=====================================+
| event  | fixed part        x : y    |
| data   +----------------------------+
|        | variable part              |
+=====================================+
header length = x bytes

data length = (event_length - x) bytes


timestamp:包含了该项事件的开始的时间
event type:指是该事件的类型
serer_id :产生该事件的服务器的server-id
event_length :(包括了 公有事件头,私有事件头,事件体三部分的长度)

-------------------------------------------------------------------------

binlog事件类型：

FORMAT_DESCRIPTION_EVENT
MYSQL根据其定义的来解析其他事件 


QUERY_EVENT：
事物开始 BEGIN事件
binlog_format=‘STATEMENT‘ ,具体执行的语句保存在QUERY_EVENT事件中
对于ROW 格式的BINLOG,所有DDL以文本格式的记录在QUERY_EVENT中


ROW_EVENT 分三类：（binlog_format=‘ROW‘)
1.WRITE_ROWS_EVENT   ->insert
包含了要插入的数据
2.UPDATE_ROWS_EVENT  ->update
包含了行修改前的值,也包含了修改后的值
3.DELETE_ROWS_EVENT  ->delete
包含了需要删除行的主键值/行号


TABLE_MAP_EVENT
每个ROWS_EVENT事件之前有一个TABLE_MAP_EVENT用于描述内部ID和结构定义

XID_EVENT:                   
MYSQL进行崩溃恢复时间,根据事务在binlog中的提交情况来决定是否提交存储引擎中状态为prepared的事物

BINLOG_CHECKPOINT_EVENT
mysql执行崩溃恢的过程中，会根据读取的BINLOG_CHECKPOINT_EVENT来决定那些binlog文件是可以不用扫描的

ROTATE_EVENT
当BINLOG 文件大小达到max_binlog_size参数设置值时或者flush logs命令时，binlog发生切换，在文件尾添加ROTATE_EVENT事件

STOP_EVENT
MYSQL停止时,在文件尾加入STOP_EVENT