概述

mysql binlog物理存储格式详解。基于mysql 8.0.22

MagicNumber

每个binlog的开头是 4bytes magic number 0xfe 0x62 0x69 0x6e

EventHead

mysql binlog 是由多个event组成的，而每个event都有一个通用的head，结构如下

eventType

这里是所有的eventType

enum Log_event_type {
  /**
    Every time you add a type, you have to
    - Assign it a number explicitly. Otherwise it will cause trouble
      if a event type before is deprecated and removed directly from
      the enum.
    - Fix Format_description_event::Format_description_event().
  */
  UNKNOWN_EVENT = 0,
  /*
    Deprecated since mysql 8.0.2. It is just a placeholder,
    should not be used anywhere else.
  */
  START_EVENT_V3 = 1,
  QUERY_EVENT = 2,
  STOP_EVENT = 3,
  ROTATE_EVENT = 4,
  INTVAR_EVENT = 5,
 
  SLAVE_EVENT = 7,
 
  APPEND_BLOCK_EVENT = 9,
  DELETE_FILE_EVENT = 11,
 
  RAND_EVENT = 13,
  USER_VAR_EVENT = 14,
  FORMAT_DESCRIPTION_EVENT = 15,
  XID_EVENT = 16,
  BEGIN_LOAD_QUERY_EVENT = 17,
  EXECUTE_LOAD_QUERY_EVENT = 18,
 
  TABLE_MAP_EVENT = 19,
 
  /**
    The V1 event numbers are used from 5.1.16 until mysql-5.6.
  */
  WRITE_ROWS_EVENT_V1 = 23,
  UPDATE_ROWS_EVENT_V1 = 24,
  DELETE_ROWS_EVENT_V1 = 25,
 
  /**
    Something out of the ordinary happened on the master
   */
  INCIDENT_EVENT = 26,
 
  /**
    Heartbeat event to be send by master at its idle time
    to ensure master's online status to slave
  */
  HEARTBEAT_LOG_EVENT = 27,
 
  /**
    In some situations, it is necessary to send over ignorable
    data to the slave: data that a slave can handle in case there
    is code for handling it, but which can be ignored if it is not
    recognized.
  */
  IGNORABLE_LOG_EVENT = 28,
  ROWS_QUERY_LOG_EVENT = 29,
 
  /** Version 2 of the Row events */
  WRITE_ROWS_EVENT = 30,
  UPDATE_ROWS_EVENT = 31,
  DELETE_ROWS_EVENT = 32,
 
  GTID_LOG_EVENT = 33,
  ANONYMOUS_GTID_LOG_EVENT = 34,
 
  PREVIOUS_GTIDS_LOG_EVENT = 35,
 
  TRANSACTION_CONTEXT_EVENT = 36,
 
  VIEW_CHANGE_EVENT = 37,
 
  /* Prepared XA transaction terminal event similar to Xid */
  XA_PREPARE_LOG_EVENT = 38,
 
  /**
    Extension of UPDATE_ROWS_EVENT, allowing partial values according
    to binlog_row_value_options.
  */
  PARTIAL_UPDATE_ROWS_EVENT = 39,
 
  TRANSACTION_PAYLOAD_EVENT = 40,
 
  HEARTBEAT_LOG_EVENT_V2 = 41,
  /**
    Add new events here - right above this comment!
    Existing events (except ENUM_END_EVENT) should never change their numbers
  */
  ENUM_END_EVENT /* end marker */
};