故障解析 | 主从数据不一致竟然不报错？

MySQL [xuzong]> show master status;
+------------------+----------+--------------+------------------+--------------------------------------------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                             |
+------------------+----------+--------------+------------------+--------------------------------------------------------------------------+
| mysql-bin.000008 | 39349641 |              |                  | c233aec0-58d3-11ec-a74a-a0a33ba8b3ff:1-104345 |
+------------------+----------+--------------+------------------+--------------------------------------------------------------------------+

mysql> stop slave;
Query OK, 0 rows affected (0.00 sec)

mysql> reset slave all;
Query OK, 0 rows affected (0.01 sec)

mysql> reset master;
Query OK, 0 rows affected (0.01 sec)

mysql> set @@GLOBAL.GTID_PURGED='c233aec0-58d3-11ec-a74a-a0a33ba8b3ff:1-1000000'; #1000000>104345
Query OK, 0 rows affected (0.00 sec)

 Slave_IO_Running: Yes
 Slave_SQL_Running: Yes 
 ......
 Last_IO_Error_Timestamp: 
 Last_SQL_Error_Timestamp: 
           Master_SSL_Crl: 
       Master_SSL_Crlpath: 
       Retrieved_Gtid_Set: c233aec0-58d3-11ec-a74a-a0a33ba8b3ff:104221-104345
        Executed_Gtid_Set: c233aec0-58d3-11ec-a74a-a0a33ba8b3ff:1-1000000
            Auto_Position: 0
     Replicate_Rewrite_DB: 

MySQL [xuzong]> insert into test(passtext) values('test');
Query OK, 1 row affected (0.00 sec)

mysql> select * from xuzong.test;
+----+--------------------------------------------+
| id | passtext                         |
+----+--------------------------------------------+
|  1 | 7e5a44af63552be3f2f819cebbe0832a |
|  2 | 7e5a44af63552be3f2f819cebbe0832a |
|  3 | 7e5a44af63552be3f2f819cebbe0832a |
|  4 | d13baf7019431e0c75dee85bc923a91b |
|  5 | 11                               |
+----+--------------------------------------------+
5 rows in set (0.00 sec)

# 从库能看出来 Retrieved_Gtid_Set 在变化
mysql> show slave status \G
           Retrieved_Gtid_Set: c233aec0-58d3-11ec-a74a-a0a33ba8b3ff:104221-104367
            Executed_Gtid_Set: c233aec0-58d3-11ec-a74a-a0a33ba8b3ff:1-1000000

                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Slave has more GTIDs than the master has, using the master's SERVER_UUID. This may indicate that the end of the binary log was truncated or that the last binary log file was lost, e.g., after a power or disk failure when sync_binlog != 1. The master may or may not have rolled back transactions that were already replicated to the slave. Suggest to replicate any transactions that master has rolled back from slave to master, and/or commit empty transactions on master to account for transactions that have been'
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 1362229455
                  Master_UUID: c233aec0-58d3-11ec-a74a-a0a33ba8b3ff
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 230817 11:11:44
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: c233aec0-58d3-11ec-a74a-a0a33ba8b3ff:1-1000000
                Auto_Position: 1

rel_slave.cc
    --> request_dump

# 部分源码：
.....
  enum_server_command command= mi->is_auto_position() ?
    COM_BINLOG_DUMP_GTID : COM_BINLOG_DUMP;
......
  if (command == COM_BINLOG_DUMP_GTID)
  {
    if (gtid_executed.add_gtid_set(mi->rli->get_gtid_set()) != RETURN_STATUS_OK || // 加Retrieved_Gtid_Set
        gtid_executed.add_gtid_set(gtid_state->get_executed_gtids()) !=
        RETURN_STATUS_OK) // 加Executed_Gtid_Set
......
    int2store(ptr_buffer, binlog_flags);
    ptr_buffer+= ::BINLOG_FLAGS_INFO_SIZE;
    int4store(ptr_buffer, server_id);
    ptr_buffer+= ::BINLOG_SERVER_ID_INFO_SIZE;
    int4store(ptr_buffer, static_cast<uint32>(BINLOG_NAME_INFO_SIZE));
    ptr_buffer+= ::BINLOG_NAME_SIZE_INFO_SIZE;
    memset(ptr_buffer, 0, BINLOG_NAME_INFO_SIZE); // 设置 MASTER_LOG_FILE为0
    ptr_buffer+= BINLOG_NAME_INFO_SIZE;
    int8store(ptr_buffer, 4LL); // 设置 MASTER_LOG_POS为4
    ptr_buffer+= ::BINLOG_POS_INFO_SIZE; // 存 gtid_set

    /*
      In the init_gtid_set below we pass the mi->transaction_parser.
      This will be useful to ensure that we only add a GTID to
      the Retrieved_Gtid_Set for fully retrieved transactions. Also, it will
      be useful to ensure the Retrieved_Gtid_Set behavior when auto
      positioning is disabled (we could have transactions spanning multiple
      relay log files in this case).
      We will skip this initialization if relay_log_recovery is set in order
      to save time, as neither the GTIDs nor the transaction_parser state
      would be useful when the relay log will be cleaned up later when calling
      init_recovery.
    */ // 注释解释的很清楚，relay_log_recovery=1 会跳过初始化 gtid_retrieved_initialized
    if (!is_relay_log_recovery &&
        !gtid_retrieved_initialized &&
        relay_log.init_gtid_sets(&gtid_set, NULL,
                                 opt_slave_sql_verify_checksum,
                                 true/*true=need lock*/,
                                 &mi->transaction_parser, &gtid_partial_trx))
    {
      sql_print_error("Failed in init_gtid_sets() called from Relay_log_info::rli_init_info().");
      DBUG_RETURN(1);
    }
    gtid_retrieved_initialized= true;
#ifndef NDEBUG
    global_sid_lock->wrlock();
    gtid_set.dbug_print("set of GTIDs in relay log after initialization");
    global_sid_lock->unlock();
#endif