Tech Notes:- Mysql replication error 1236 for GTID based replication

For GTID based MySQL replication we sometimes end up with below error

Slave_IO_Running: No
Slave_SQL_Running: Yes
Last_IO_Errno: 1236

Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: 'The slave is connecting using CHANGE MASTER TO MASTER_AUTO_POSITION = 1, but the master has purged binary lo
gs containing GTIDs that the slave requires. Replicate the missing transactions from elsewhere, or provision a new slave from backup. Consider increasing the master's binary log expiration period. 

The way to solve this is outlines below

On Master

--------------
Take a mysqldump from the master and then copy it to the slave. Say your dump file is  mysqldump_db-01_2020-05-13.sql.gz

On Slave

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

[sudeep@db-slave ~]$ gunzip mysqldump_db-01_2020-05-13.sql.gz

Record the gtid_purged value that mysqldump added to the dump file.
[sudeep@db-slave~]$ cat mysqldump_db-01_$(date +%F).sql | grep GTID_PURGED | cut -f2 -d'=' | cut -f2 -d$'\''
a21bbd99-935e-11ea-a7c0-080027677b11:1-100 

Remove the line from the dump file that contains the SET @@GLOBAL.gtid_purged statement

[sudeep@db-slave~]$ sed '/GTID_PURGED/d' mysqldump_db-01_$(date +%F).sql > mysqldump_db-01_gtid_nopurge_$(date +%F).sql

[sudeep@db-slave~]$sudo mysql  -e "source mysqldump_db-01_gtid_nopurge_$(date +%F).sql"

[sudeep@db-slave ~]$ sudo mysql -e "RESET MASTER"

The reset master command should clear the GTID_EXECUTED on slave

[sudeep@db-slave ~]$  sudo mysql -e "show global variables like '%GTID_EXECUTED%'"

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

| Variable_name | Value |

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

| gtid_executed |            |

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

[sudeep@db-slave ~]$ sudo mysql -e "set global GTID_PURGED='a21bbd99-935e-11ea-a7c0-080027677b11:1-100'"
[sudeep@db-slave ~]$ sudo mysql -e "START SLAVE io_thread"
[sudeep@db-slave ~]$ sudo mysql -e "SHOW SLAVE STATUS\G" | grep -i yes
         Slave_IO_Running: Yes
         Slave_SQL_Running: Yes