Tech Notes:- Got fatal error 1236 from master when reading data from binary log: 'Cannot replicate anonymous transaction when AUTO_POSITION = 1

 Last_IO_Errno: 1236
                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Cannot replicate anonymous transaction when AUTO_POSITION = 1, at file ../binlogs/mysql-bin.000006, position 194.; the first event '' at 4, the last event read from '../binlogs/mysql-bin.000006' at 259, the last byte read from '../binlogs/mysql-bin.000006' at 259.'
               Last_SQL_Errno: 1396
 Master_UUID: ab7c6739-be64-11ea-b478-080027fd2c56

Retrieved_Gtid_Set: ab7c6739-be64-11ea-b478-080027fd2c56:1-29

            Executed_Gtid_Set: 846dc749-bf34-11ea-852d-08002749f9b4:1-1032,

ab7c6739-be64-11ea-b478-080027fd2c56:1-4:30-114202

On master check the binary log 'mysql-bin.000006' at position 194

mysql> show binlog events in 'mysql-bin.000006' from 4 limit 5;
+------------------+-----+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------+
| Log_name         | Pos | Event_type     | Server_id | End_log_pos | Info                                                                                                          |
+------------------+-----+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------+
| mysql-bin.000006 |   4 | Format_desc    |        55 |         123 | Server ver: 5.7.30-33-log, Binlog ver: 4                                                                      |
| mysql-bin.000006 | 123 | Previous_gtids |        55 |         194 | ab7c6739-be64-11ea-b478-080027fd2c56:1-29                                                                                                    |

+------------------+-----+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------+

The solution is to skip the transactions associated with GTID ab7c6739-be64-11ea-b478-080027fd2c56:1-29 
after making sure that this has been replicated already if not, we need to find and apply the transactions manually.

SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:1';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:2';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:3';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:4';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:5';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:6';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:7';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:8';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:9';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:10';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:11';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:12';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:13';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:14';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:15';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:16';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:17';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:18';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:19';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:20';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:21';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:22';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:23';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:24';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:25';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:26';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:27';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:28';
BEGIN;COMMIT;
SET GTID_NEXT='ab7c6739-be64-11ea-b478-080027fd2c56:29';
BEGIN;COMMIT;
SET GTID_NEXT='AUTOMATIC';

A script may be programmed to generate the above statements
Now we should be able to start the slave
start slave;

Tech Notes:- Enabling back GTID based replication on-line on a server which was started with GTID mode on , did some transactions and then switched it to GTID mode off

This is a special scenario were two  MySQL 5.7 servers were started with GTID_MODE=ON, executed some transactions like creating users and granting privileges, and then the GTID_MODE was switched off on both.

Now we want to configure these servers as master-slave, enable the traditional method of replication and then later switch to GTID based replication.

Here are the challenges.

1. We already created some transactions(creating users) on the master which means we have some GTID based transactions already logged in the binary logs as you can see below from the master binary logs
mysql> show binary logs;
+------------------+-----------+
| Log_name         | File_size |
+------------------+-----------+
| mysql-bin.000001 |       177 |
| mysql-bin.000002 |      1037 |
| mysql-bin.000003 |      6798 |
| mysql-bin.000004 |       217 |
| mysql-bin.000005 |       217 |
| mysql-bin.000006 |       825 |
| mysql-bin.000007 |       217 |
| mysql-bin.000008 |       378 |
| mysql-bin.000009 |  11592653 |
| mysql-bin.000010 |  36338956 |
| mysql-bin.000011 |  68473681 |
| mysql-bin.000012 | 198652424 |
+------------------+-----------+
12 rows in set (0.04 sec)

mysql> show binlog events in 'mysql-bin.000001';

+------------------+-----+----------------+-----------+-------------+------------------------------------------+

| Log_name         | Pos | Event_type     | Server_id | End_log_pos | Info                                     |

+------------------+-----+----------------+-----------+-------------+------------------------------------------+

| mysql-bin.000001 |   4 | Format_desc    |        55 |         123 | Server ver: 5.7.30-33-log, Binlog ver: 4 |

| mysql-bin.000001 | 123 | Previous_gtids |        55 |         154 |                                          |

| mysql-bin.000001 | 154 | Stop           |        55 |         177 |                                          |

+------------------+-----+----------------+-----------+-------------+------------------------------------------+

3 rows in set (0.02 sec)

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    |        55 |         123 | Server ver: 5.7.30-33-log, Binlog ver: 4                          |

| mysql-bin.000002 |  123 | Previous_gtids |        55 |         154 |                                                                   |

| mysql-bin.000002 |  154 | Gtid           |        55 |         219 | SET @@SESSION.GTID_NEXT= 'ab7c6739-be64-11ea-b478-080027fd2c56:1' |

| mysql-bin.000002 |  219 | Query          |        55 |         287 | BEGIN                                                             |

| mysql-bin.000002 |  287 | Table_map      |        55 |         459 | table_id: 99 (mysql.user)                                         |

| mysql-bin.000002 |  459 | Update_rows    |        55 |         793 | table_id: 99 flags: STMT_END_F                                    |

| mysql-bin.000002 |  793 | Query          |        55 |         862 | COMMIT                                                            |

| mysql-bin.000002 |  862 | Gtid           |        55 |         927 | SET @@SESSION.GTID_NEXT= 'ab7c6739-be64-11ea-b478-080027fd2c56:2' |

| mysql-bin.000002 |  927 | Query          |        55 |        1014 | FLUSH PRIVILEGES                                                  |

| mysql-bin.000002 | 1014 | Stop           |        55 |        1037 |                                                                   |

+------------------+------+----------------+-----------+-------------+-------------------------------------------------------------------+

10 rows in set (0.00 sec)

mysql> show binlog events in 'mysql-bin.000003';

+------------------+------+----------------+-----------+-------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+

| Log_name         | Pos  | Event_type     | Server_id | End_log_pos | Info                                                                                                                                                   |

+------------------+------+----------------+-----------+-------------+--------------------------------------------------------------------------------------------------------------------------------------------------------+

| mysql-bin.000003 |    4 | Format_desc    |        55 |         123 | Server ver: 5.7.30-33-log, Binlog ver: 4                                                                                                               |

| mysql-bin.000003 |  123 | Previous_gtids |        55 |         194 | ab7c6739-be64-11ea-b478-080027fd2c56:1-2                                                                                                               |

| mysql-bin.000003 |  194 | Gtid           |        55 |         259 | SET @@SESSION.GTID_NEXT= 'ab7c6739-be64-11ea-b478-080027fd2c56:3'                                                                                      |

| mysql-bin.000003 |  259 | Query          |        55 |         464 | CREATE USER 'slave'@'db-%.example.com' IDENTIFIED WITH 'mysql_native_password' AS '*B60C3C82CCEBA73F2BDC69601B65DFBAB435A2DA'                 |

| mysql-bin.000003 |  464 | Gtid           |        55 |         529 | SET @@SESSION.GTID_NEXT= 'ab7c6739-be64-11ea-b478-080027fd2c56:4'                                                                                      |

| mysql-bin.000003 |  529 | Query          |        55 |         685 | GRANT REPLICATION SLAVE ON *.* TO 'slave'@'db-%.example.com'                                                                                  |

2. After we switched the GTID mode to off, we have anonymous transactions in the binlogs on master

mysql> show binlog events in 'mysql-bin.000006';

+------------------+-----+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------+

| Log_name         | Pos | Event_type     | Server_id | End_log_pos | Info                                                                                                          |

+------------------+-----+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------+

| mysql-bin.000006 |   4 | Format_desc    |        55 |         123 | Server ver: 5.7.30-33-log, Binlog ver: 4                                                                      |

| mysql-bin.000006 | 123 | Previous_gtids |        55 |         194 | ab7c6739-be64-11ea-b478-080027fd2c56:1-29                                                                     |

| mysql-bin.000006 | 194 | Anonymous_Gtid |        55 |         259 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS'                                                                          |

| mysql-bin.000006 | 259 | Query          |        55 |         444 | CREATE USER 'repl'@'%' IDENTIFIED WITH 'mysql_native_password' AS '*0E840B1E4D3B2DDE222EA13524CA92099785A3E4' |

| mysql-bin.000006 | 444 | Anonymous_Gtid |        55 |         509 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS'                                                                          |

| mysql-bin.000006 | 509 | Query          |        55 |         645 | GRANT REPLICATION SLAVE ON *.* TO 'repl'@'%'                                                                  |

| mysql-bin.000006 | 645 | Anonymous_Gtid |        55 |         710 | SET @@SESSION.GTID_NEXT= 'ANONYMOUS'                                                                          |

| mysql-bin.000006 | 710 | Query          |        55 |         802 | flush privileges                                                                                              |

| mysql-bin.000006 | 802 | Stop           |        55 |         825 |    

                                                                                                           |

+------------------+-----+----------------+-----------+-------------+---------------------------------------------------------------------------------------------------------------+

9 rows in set (0.00 sec)

3. At this point, we are adding a slave which will connect and replicate using the traditional approach (MASTER_AUTO_POSITION = 0)

4. Now on both master and slave, we enable GTID mode

mysql> show slave status\G

*************************** 1. row ***************************

               Slave_IO_State: Waiting for master to send event

                  Master_Host: db-55.example.com

                  Master_User: repl

                  Master_Port: 3306

                Connect_Retry: 60

              Master_Log_File: mysql-bin.000011

          Read_Master_Log_Pos: 16689209

               Relay_Log_File: mysqld-relay-bin.000001

                Relay_Log_Pos: 4

        Relay_Master_Log_File: mysql-bin.000011

             Slave_IO_Running: Yes

            Slave_SQL_Running: Yes

Please note that the slave is now at mysql-bin.000011

5.Switch the method of replication to use GTID(MASTER_AUTO_POSITION = 1)

At this stage, we get an error in the slave

 Last_IO_Errno: 1236

                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Cannot replicate anonymous transaction when AUTO_POSITION = 1, at file ../binlogs/mysql-bin.000006, position 194.; the first event '' at 4, the last event read from '../binlogs/mysql-bin.000006' at 259, the last byte read from '../binlogs/mysql-bin.000006' at 259.'

               Last_SQL_Errno: 1396

               Last_SQL_Error: Error 'Operation CREATE USER failed for 'test@'127.0.0.1'' on query. Default database: ''. Query: 'CREATE USER 'test'@'127.0.0.1' IDENTIFIED WITH 'mysql_native_password' AS '*47FFA1D679CD8C02395ED76C3640A48AA3C3411C''

The reason for this error is that when we tried to switch to GTID based replication, the slave started reading all the binlogs and started with the transactions from binlogs which were already replicated using the traditional method(note that the slave was at mysql-bin.000011 before switching.

Now, how do we fix this?

First find out the UUID of the master by issuing the below command on the master which should match the master UUID in show slave status

mysql> show variables like '%uuid%';

+---------------+--------------------------------------+

| Variable_name | Value                                |

+---------------+--------------------------------------+

| server_uuid   | ab7c6739-be64-11ea-b478-080027fd2c56 |

+---------------+--------------------------------------+

1 row in set (0.01 sec)

Now, look at the show slave status

mysql> show slave status\G

*************************** 1. row ***************************

               Slave_IO_State:

                  Master_Host: db-55.example.com

                  Master_User: repl

                  Master_Port: 3306

                Connect_Retry: 60

              Master_Log_File: mysql-bin.000006

          Read_Master_Log_Pos: 194

               Relay_Log_File: mysqld-relay-bin.000003

                Relay_Log_Pos: 898

        Relay_Master_Log_File: mysql-bin.000003

             Slave_IO_Running: No

            Slave_SQL_Running: No

              Replicate_Do_DB:

          Replicate_Ignore_DB: mysql,information_schema

           Replicate_Do_Table:

       Replicate_Ignore_Table:

      Replicate_Wild_Do_Table:

  Replicate_Wild_Ignore_Table:

                   Last_Errno: 1396

                   Last_Error: Error 'Operation CREATE USER failed for 'test'@'127.0.0.1'' on query. Default database: ''. Query: 'CREATE USER 'test'@'127.0.0.1' IDENTIFIED WITH 'mysql_native_password' AS '*47FFA1D679CD8C02395ED76C3640A48AA3C3411C''

                 Skip_Counter: 0

          Exec_Master_Log_Pos: 685

              Relay_Log_Space: 9652

              Until_Condition: None

               Until_Log_File:

                Until_Log_Pos: 0

           Master_SSL_Allowed: No

           Master_SSL_CA_File:

           Master_SSL_CA_Path:

              Master_SSL_Cert:

            Master_SSL_Cipher:

               Master_SSL_Key:

        Seconds_Behind_Master: NULL

Master_SSL_Verify_Server_Cert: No

                Last_IO_Errno: 1236

                Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Cannot replicate anonymous transaction when AUTO_POSITION = 1, at file ../binlogs/mysql-bin.000006, position 194.; the first event '' at 4, the last event read from '../binlogs/mysql-bin.000006' at 259, the last byte read from '../binlogs/mysql-bin.000006' at 259.'

               Last_SQL_Errno: 1396

               Last_SQL_Error: Error 'Operation CREATE USER failed for 'test@'127.0.0.1'' on query. Default database: ''. Query: 'CREATE USER 'test'@'127.0.0.1' IDENTIFIED WITH 'mysql_native_password' AS '*47FFA1D679CD8C02395ED76C3640A48AA3C3411C''

  Replicate_Ignore_Server_Ids:

             Master_Server_Id: 55

                  Master_UUID: ab7c6739-be64-11ea-b478-080027fd2c56

             Master_Info_File: mysql.slave_master_info

                    SQL_Delay: 0

          SQL_Remaining_Delay: NULL

      Slave_SQL_Running_State:

           Master_Retry_Count: 86400

                  Master_Bind:

      Last_IO_Error_Timestamp: 200706 13:19:15

     Last_SQL_Error_Timestamp: 200706 13:19:15

               Master_SSL_Crl:

           Master_SSL_Crlpath:

           Retrieved_Gtid_Set: ab7c6739-be64-11ea-b478-080027fd2c56:1-29

            Executed_Gtid_Set: 846dc749-bf34-11ea-852d-08002749f9b4:1-29, 

ab7c6739-be64-11ea-b478-080027fd2c56:1-4:30-53010

                Auto_Position: 1

         Replicate_Rewrite_DB:

                 Channel_Name:

           Master_TLS_Version:

1 row in set (0.00 sec)

mysql> show master status;

+------------------+----------+--------------+--------------------------+----------------------------------------------------------------------------------------------+

| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB         | Executed_Gtid_Set                                                                            |

+------------------+----------+--------------+--------------------------+----------------------------------------------------------------------------------------------+

| mysql-bin.000010 |  2060774 |              | mysql,information_schema | 846dc749-bf34-11ea-852d-08002749f9b4:1-29,

ab7c6739-be64-11ea-b478-080027fd2c56:1-4:30-53010 |

+------------------+----------+--------------+--------------------------+----------------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

Here 846dc749-bf34-11ea-852d-08002749f9b4:1-29 --> Last slave GTID executed

           ab7c6739-be64-11ea-b478-080027fd2c56:1-4:30-53010 --> Last GTID executed on master

In order to fix the problem, we need to mark these as purged in slave.so that the slave continues with the next set of GTIDs. On slave run the below commands.

Please note that running reset master on slave would also delete all binary log files listed in the index file, resets the binary log index file to be empty, and creates a new binary log file.

mysql> reset master;

Query OK, 0 rows affected (0.01 sec)

mysql> set global GTID_PURGED='846dc749-bf34-11ea-852d-08002749f9b4:1-29,ab7c6739-be64-11ea-b478-080027fd2c56:1-53010';

Query OK, 0 rows affected (0.01 sec)

mysql> start slave;

Query OK, 0 rows affected (0.00 sec)

mysql> show slave status\G

*************************** 1. row ***************************

               Slave_IO_State: Queueing master event to the relay log

                  Master_Host: db-55.example.com

                  Master_User: repl

                  Master_Port: 3306

                Connect_Retry: 60

              Master_Log_File: mysql-bin.000011

          Read_Master_Log_Pos: 17944864

               Relay_Log_File: mysqld-relay-bin.000007

                Relay_Log_Pos: 781024

        Relay_Master_Log_File: mysql-bin.000011

             Slave_IO_Running: Yes

            Slave_SQL_Running: Yes

              Replicate_Do_DB:

          Replicate_Ignore_DB: mysql,information_schema

           Replicate_Do_Table:

       Replicate_Ignore_Table:

      Replicate_Wild_Do_Table:

  Replicate_Wild_Ignore_Table:

                   Last_Errno: 0

                   Last_Error:

                 Skip_Counter: 0

          Exec_Master_Log_Pos: 17469779

              Relay_Log_Space: 1256570

              Until_Condition: None

               Until_Log_File:

                Until_Log_Pos: 0

           Master_SSL_Allowed: No

           Master_SSL_CA_File:

           Master_SSL_CA_Path:

              Master_SSL_Cert:

            Master_SSL_Cipher:

               Master_SSL_Key:

        Seconds_Behind_Master: 955

Master_SSL_Verify_Server_Cert: No

                Last_IO_Errno: 0

                Last_IO_Error:

               Last_SQL_Errno: 0

               Last_SQL_Error:

  Replicate_Ignore_Server_Ids:

             Master_Server_Id: 55

                  Master_UUID: ab7c6739-be64-11ea-b478-080027fd2c56

             Master_Info_File: mysql.slave_master_info

                    SQL_Delay: 0

          SQL_Remaining_Delay: NULL

      Slave_SQL_Running_State: System lock

           Master_Retry_Count: 86400

                  Master_Bind:

      Last_IO_Error_Timestamp:

     Last_SQL_Error_Timestamp:

               Master_SSL_Crl:

           Master_SSL_Crlpath:

           Retrieved_Gtid_Set: ab7c6739-be64-11ea-b478-080027fd2c56:1-29:53011-56993

            Executed_Gtid_Set: 846dc749-bf34-11ea-852d-08002749f9b4:1-29,

ab7c6739-be64-11ea-b478-080027fd2c56:1-55487

                Auto_Position: 1

         Replicate_Rewrite_DB:

                 Channel_Name:

           Master_TLS_Version:

1 row in set (0.00 sec)

Tech Notes:- Mysql Replication Error 'Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file''

I kept my slave mysql db down for a week and then when I switched on the slave db server and checked the replication status, I started seeing this error.



Last_IO_Errno: 1236

Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'Could not find first log file name in binary log index file'



The most probable reason for this error is that the binary log required for the replication by slave servers no longer exists on the master database server. This could have happened because someone might have manually deleted the binary files on the MySQL master either by removing the files from the file system or using the purge binary logs command.

Another reason could be that a variable has been set in the conf file to expire the logs. In my case, it was this one and the variable was set to 2 days

expire_logs_days=2

Let's have a detailed look at SHOW SLAVE STATUS and SHOW BINARY LOGS on master

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State:
                  Master_Host: 172.25.1.20
                  Master_User: slave
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000023
          Read_Master_Log_Pos: 94955731
               Relay_Log_File: mysqld-relay-bin.000007
                Relay_Log_Pos: 4
        Relay_Master_Log_File: mysql-bin.000023
             Slave_IO_Running: No
            Slave_SQL_Running: Yes

mysql> SHOW BINARY LOGS;

+------------------+-----------+

| Log_name         | File_size |

+------------------+-----------+

| mysql-bin.000029 |      1315 |

+------------------+-----------+

1 row in set (0.21 sec)

So reading it all to gether, slave is looking for the master log file mysql-bin.000023 at position 94955731. But the master is at  mysql-bin.000029  and I dont have the file mysql-bin.000023. So this basically means that the mysql slave stopped replcation while at mysql-bin.000023.

How do we solve this?

The simplest way as well as the advisable approach is to dump the mysql from the master, restore it to slave and then restart the replication. But that may take time if the database is huge and there is no way to take the dump without impacting production performance.

If its a test system and you are ok with losing some data in replication, the best bet would be to set the position of the slave to the start of the new available master file.  

STOP SLAVE;

CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000029', MASTER_LOG_POS=4;

START SLAVE;

You may need to skip some positions sometimes. If you have patience and time, the best option is to examine the events in the log and point to the position accordingly. You can do it using the command below

sudo mysqlbinlog /var/lib/mysql/mysql-bin.000029 | more