Step‑by‑Step Guide to MySQL 8.0 Master‑Slave Replication with GTID

Prerequisites

Prepare 3–5 virtual machines.

Install MySQL 8.0 on each machine.

Master‑Slave Architecture

Two common patterns are used: “one master many slaves” and “cascading replication”. Both rely on the binary log (binlog) to record DDL and certain DML statements; slaves replay these statements to stay synchronized.

Step 1: Configure server_id

Set a unique server_id for each MySQL instance. You can query the current value with: SHOW VARIABLES LIKE 'server_id'; Edit /etc/mysql/my.cnf (or /etc/mysql/my.conf) and add the following under [mysqld]:

[mysqld]
server-id=1   # master

[mysqld]
server-id=2   # slave

Restart MySQL after editing:

systemctl restart mysql

Step 2 (Optional): Check master status

On the master run: SHOW MASTER STATUS; This displays the current binlog file name (File) and position (Position) as well as other replication‑related variables such as Binlog_Do_DB, Binlog_Ignore_DB, and Executed_Gtid_Set.

Step 3: Configure the slave

On the slave execute the CHANGE REPLICATION SOURCE command, filling in the master’s address and credentials:

CHANGE REPLICATION SOURCE TO
  SOURCE_HOST='192.168.3.107',
  SOURCE_USER='root',
  SOURCE_PASSWORD='1234',
  SOURCE_LOG_FILE='binlog.000009',
  SOURCE_LOG_POS=0;

Key fields: SOURCE_HOST: master IP or hostname SOURCE_USER: replication user SOURCE_PASSWORD: password SOURCE_LOG_FILE: current binlog file on master SOURCE_LOG_POS: position within the binlog

After running the command, verify the replica status: SHOW REPLICA STATUS; Common replica management commands:

SHOW REPLICA STATUS;   # view status
START REPLICA;         # begin replication
STOP REPLICA;          # pause replication
RESET REPLICA ALL;     # remove all replication settings

GTID Mode (Recommended)

Check GTID mode on the master: SHOW GLOBAL VARIABLES LIKE 'gtid_mode'; Enable GTID in the configuration:

[mysqld]
server-id=1
gtid_mode=ON
enforce_gtid_consistency=TRUE

On the slave, use GTID‑based replication which eliminates the need to specify SOURCE_LOG_FILE and SOURCE_LOG_POS:

CHANGE REPLICATION SOURCE TO
  SOURCE_HOST='192.168.3.107',
  SOURCE_USER='root',
  SOURCE_PASSWORD='123',
  SOURCE_AUTO_POSITION=1;

Common Commands

Master:

SHOW MASTER STATUS;   # view master status
RESET MASTER;         # reset binlog (starts from 000001)

Slave:

SHOW REPLICA STATUS;   # view slave status
START REPLICA;         # start replication
STOP REPLICA;          # stop replication
RESET REPLICA ALL;     # delete replication configuration
SELECT * FROM performance_schema.replication_applier_status_by_worker; # view thread info

Additional utilities:

SHOW VARIABLES LIKE 'server_id';   # check server_id
SHOW GLOBAL VARIABLES LIKE 'gtid_mode'; # check GTID status