MySQL Master‑Slave Replication in Docker, Sync to Redis via Canal & Spring Boot

Environment: Spring Boot 2.7.8, MySQL 8, master IP 192.168.2.129, slave IP 192.168.2.130.

1. Install MySQL with Docker

Create directories, set permissions, create my.cnf with required settings, then run the Docker container:

mkdir -p /root/software/mysql/conf /root/software/mysql/data
chmod -R 777 /root/software/mysql/
# my.cnf content omitted for brevity

docker run --name mysql8 --restart=always --privileged=true -v /root/software/mysql/conf/my.cnf:/etc/mysql/my.cnf -v /root/software/mysql/data:/var/lib/mysql -v /etc/localtime:/etc/localtime:ro -p 3306:3306 -e MYSQL_ROOT_PASSWORD=123123 -d mysql --lower_case_table_names=1

2. Master‑Slave Configuration

On the master (192.168.2.129) add to my.cnf:

binlog_format=MIXED
log-bin=mysql-bin
server-id=1

On the slave (192.168.2.130) add:

log-bin=mysql-bin
server-id=2

Restart MySQL on both nodes.

3. Configure the Slave

Check master status to obtain File and Position values:

mysql> show master status;
+------------------+----------+...
| File             | Position |
| mysql-bin.000001| 156      |

Run CHANGE MASTER TO on the slave using those values:

CHANGE MASTER TO
MASTER_HOST='192.168.2.129',
MASTER_PORT=3306,
MASTER_USER='root',
MASTER_PASSWORD='123123',
master_log_file='mysql-bin.000003',
master_log_pos=156,
master_connect_retry=60,
GET_MASTER_PUBLIC_KEY=1;

If the slave is running, stop it first: STOP SLAVE; Verify replication with: show slave status\G Key fields Slave_IO_Running and Slave_SQL_Running should be Yes.

4. Test Replication

Creating databases or tables on the master automatically replicates to the slave.

5. Deploy Canal

docker run --name canal -p 11111:11111 -v /opt/canal/conf:/home/admin/canal-server/conf -v /opt/canal/logs:/home/admin/canal-server/logs -d canal/canal-server

6. Integrate Canal with Spring Boot

Add Maven dependencies for Redis, Web, and canal-spring-boot-starter (version 1.2.1‑RELEASE).

<dependencies>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
  </dependency>
  <dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
    <groupId>top.javatool</groupId>
    <artifactId>canal-spring-boot-starter</artifactId>
    <version>1.2.1-RELEASE</version>
  </dependency>
</dependencies>

Configure Redis and Canal in application.yml:

spring:
  redis:
    host: localhost
    port: 6379
    password: 123123
    database: 8
    lettuce:
      pool:
        maxActive: 8
        maxIdle: 100
        minIdle: 10
        maxWait: -1
---
canal:
  server: 192.168.2.130:11111
  destination: redis

Define a simple data model:

public class Users {
  private Integer id;
  private String name;
  private Integer age;
  @Override
  public String toString() {
    return "Users [id=" + id + ", name=" + name + ", age=" + age + "]";
  }
}

Implement a service component to handle Canal events and write them to Redis:

@Component
@CanalTable("users")
public class UserServiceImpl implements EntryHandler<Users> {

  private static final Logger logger = LoggerFactory.getLogger(UserServiceImpl.class);
  private final StringRedisTemplate stringRedisTemplate;

  public UserServiceImpl(StringRedisTemplate stringRedisTemplate) {
    this.stringRedisTemplate = stringRedisTemplate;
  }

  @Override
  public void insert(Users user) {
    logger.info("New data {}", user);
    try {
      stringRedisTemplate.opsForValue()
        .set("users:" + user.getId(), new ObjectMapper().writeValueAsString(user));
    } catch (JsonProcessingException e) {
      e.printStackTrace();
    }
  }

  @Override
  public void update(Users before, Users after) {
    logger.info("Before {}", before);
    logger.info("After {}", after);
    try {
      stringRedisTemplate.opsForValue()
        .set("users:" + after.getId(), new ObjectMapper().writeValueAsString(after));
    } catch (JsonProcessingException e) {
      e.printStackTrace();
    }
  }

  @Override
  public void delete(Users user) {
    logger.info("Delete {}", user);
    stringRedisTemplate.delete("users:" + user.getId());
  }
}

With these steps, any insert, update, or delete on the MySQL master is captured by Canal and instantly synchronized to Redis via the Spring Boot application.

Done.