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.
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)
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