We are assuming these:

1. Same version and same setup of MySQL is installed on SOURCE (Master) host and TARGET (AKA Replica or Slave) host.
   
2. In our example our Source/Master is 192.168.100.1
   
3. In our example our Target/Slave is 192.168.100.2
   
4. For username for replication, we'll use 'replicator' as example.

1. Backup MySQL config

cp /etc/mysql/my.cnf /etc/mysql/my.cnf.BACKUP_`date +%Y%m%s_%H%M%S`

2. Edit /etc/mysql/my.cnf

Add:

[mysqld]
server-id = 1
log_bin = mysql-bin
binlog_format = ROW
gtid_mode = ON
enforce_gtid_consistency = ON
binlog_row_image = FULL
log_slave_updates = ON
binlog_expire_logs_seconds = 604800   # optional, keep binlogs 7 days

Save changes.

3. Restart MySQL on Source/Master

sudo systemctl restart mysql

Save changes

1. Login to MySQL:

mysql -u root -p

2. Create the replication user:

mysql> CREATE USER 'replicator'@'<SLAVE_IP>' IDENTIFIED BY '<password>';

OR

mysql> CREATE USER 'replicator'@'<SLAVE_IP>' IDENTIFIED WITH mysql_native_password BY '<password>';

NOTE: Replace <SLAVE_IP> with the IP address of your slave host, and <password> with actual password.  

Example:
mysql> CREATE USER 'replicator'@'192.168.100.2' IDENTIFIED BY 'mySecretpw%489';

OR

mysql> CREATE USER 'replicator'@'%' IDENTIFIED BY '12345678';

3. Grant access:

mysql> GRANT REPLICATION SLAVE ON *.* TO 'replicator'@'<SLAVE_IP>';

Example:

mysql> GRANT REPLICATION SLAVE ON *.* TO 'replicator'@'192.168.100.2';

mysql> FLUSH PRIVILEGES;

4. Exit:

mysql > exit;

1. Login to MySQL:

mysql -u root -p

2. Flush:

mysql> FLUSH TABLES WITH READ LOCK;

NOTE, this lock prevent changes to be made to all tables.  To unlock, use:  

mysql> UNLOCK TABLES;

3. Get master status:

mysql> SHOW MASTER STATUS;

+------------------+----------+--------------+------------------+------------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                        |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000001 |      896 |              |                  | c1a85a0a-4afc-11f0-b090-bc2411487311:1-3 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)

4. List all GTIDs processed

mysql> SELECT @@GLOBAL.GTID_EXECUTED;

+------------------------------------------+
| @@GLOBAL.GTID_EXECUTED                   |
+------------------------------------------+
| c1a85a0a-4afc-11f0-b090-bc2411487311:1-3 |
+------------------------------------------+
1 row in set (0.00 sec)

Keep this terminal open so the lock stays in place

3. Configure replication (SQL):

mysql>STOP SLAVE;

mysql> RESET SLAVE ALL;

NON-SSL:

mysql> CHANGE MASTER TO

  MASTER_HOST='192.168.100.1',

  MASTER_USER='replicator',

  MASTER_PASSWORD='replicaPass@123',

  MASTER_AUTO_POSITION=1;

SSL-ENABLED:

CHANGE MASTER TO
  MASTER_HOST='192.168.100.1',
  MASTER_USER='replicator',
  MASTER_PASSWORD='replicaPass@123',
  MASTER_AUTO_POSITION=1,
  MASTER_SSL=1,
  MASTER_SSL_CA='/etc/mysql/certs/self-ca.pem',
  MASTER_SSL_CERT='/etc/mysql/certs/self-slave-cert.pem',
  MASTER_SSL_KEY='/etc/mysql/certs/self-slave-key.pem';

mysql> START SLAVE;

4. See status:

mysql> SHOW SLAVE STATUS\G

On MASTER

Create a test database on On master (test_replica):

mysql> CREATE DATABASE IF NOT EXISTS test_replica;

mysql> use test_replica;

mysql> CREATE TABLE IF NOT EXISTS replication_test (
  id INT PRIMARY KEY AUTO_INCREMENT,
  message VARCHAR(255),
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

mysql> INSERT INTO replication_test (message) VALUES ('Hello from master!');

mysql> FLUSH TABLES WITH READ LOCK;

On SLAVE

Check if the test datanase created on Master, is also on the Slave:

mysql> show databases;

+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
| test_replica       |
| testdb             |
+--------------------+
6 rows in set (0.00 sec)

NOTE: 'test_replica' should replicate over to the slave as seen above.

mysql> use test_replica;

mysql> SELECT * FROM replication_test;

+----+--------------------+---------------------+
| id | message            | created_at          |
+----+--------------------+---------------------+
|  1 | Hello from master! | 2025-06-17 15:15:56 |
+----+--------------------+---------------------+
1 row in set (0.00 sec)