mysql主从复制，server 或 Docker容器

mysql set up replication refer to Mysql doc

On master check if logging binary enabled:
show variables like 'log_bin', refer to how to know if mysql binary log is enable through sql command?

1.Config my.cnf
Master:

[mysqld]
log-bin=mysql-bin
server-id=1

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Slave:

[mysqld]
server-id=2
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2. Create user and grant privileges for replication: (On Master create user, which will be used by the slave)
   For example, to set up a new user, repl, that can connect for replication from any host within the example.com domain, issue these statements on the master:

mysql> CREATE USER 'repl'@'%.example.com' IDENTIFIED BY 'password';
mysql> GRANT REPLICATION SLAVE ON . TO 'repl'@'%.example.com';
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If needed run FLUSH PRIVILEGES; to load the pasword table after update or grant

3. Obtaining the replication master binary log coordinates(On Master)
   Start a session and lock the mysql with read lock,
   mysql> FLUSH TABLES WITH READ LOCK;
   In another session,get current binary log file name and position

mysql > SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000003 | 73 | test | manual,mysql |
+------------------+----------+--------------+------------------+
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4. Creating a data snapshot using mysqldump(On Master)
   shell> mysqldump -u root -p --all-databases --master-data > dbdump.db or shell> mysqldump -u root -p database_name --master-data >database_name.db

note: –master-data doc, when use --master-data=2

cat backup.db | more

-- Host: localhost Database: xxxxx

---

-- Server version 5.5.60-MariaD

--
-- Position to start replication or point-in-time recovery from

-- CHANGE MASTER TO MASTER_LOG_FILE='master-bin.000011', MASTER_LOG_POS=107962617;

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5. Release the lock(On Master)
   mysql> UNLOCK TABLES;

6. Load db(On Slave)
   shell> mysql -u root -p < dbdump.db
   or
   shell> mysql -u root -p database_name < database_name.db (here maybe need create database_name first)
   then start slave mysql> start slave
   Here maybe get this error ERROR 1200 (HY000): The server is not configured as slave; fix in config file or with CHANGE MASTER TO
   Setting the master Configuration on the slave to solve it.

mysql> CHANGE MASTER TO
-> MASTER_HOST='master_host_name',
-> MASTER_USER='replication_user_name',
-> MASTER_PASSWORD='replication_password',
-> MASTER_LOG_FILE='recorded_log_file_name',
-> MASTER_LOG_POS=recorded_log_position;
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If you need to restart mysql:/etc/init.d/mysql restart or /etc/init.d/mariadb restart

7. If you want to run the replication in docker container, refer to mysql-replication for DOCKER mysql master and slave.

8. You also can just run a mysql slave in docker

9. install and config docker
   install docker

sudo yum install -y yum-utils device-mapper-persistent-data lvm2
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
sudo yum install docker-ce
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uninstall docker sudo yum remove docker-ce
start docker sudo systemctl start docker
auto start docker when os on sudo systemctl enable docker
auto start container docker run -dit --restart unless-stopped redis, refer to start containers automatically
restart container docker restart containername
check running container docker ps
check images docker images
issues:

Warning: failed to get default registry endpoint from daemon (Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?)
Solution: `su && service docker start && docker images;`

Warning: failed to get default registry endpoint from daemon (Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.38/info: dial unix /var/run/docker.sock: connect: permission denied)
Solution: run with `sudo`

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10. start mysql slave in docker container
    pull image docker pull mysql:5.5 refer to docker mysql
    run container from docker run --name mysql-slave -e MYSQL_ROOT_PASSWORD=password -d mysql:5.5

copy the dump db to container docker cp database_name.db container:/root
loginto the container docker exec -it mysql_slaves /bin/bash
then config mysql as above.
You may be need to install vim, to edit the my.cnf with apt update and apt install vim

11. check slave status

mysql> show slave status \G
1. row
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.1.186
Master_User: replication
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000051
Read_Master_Log_Pos: 245
Relay_Log_File: 80b47762156a-relay-bin.000015
Relay_Log_Pos: 391
Relay_Master_Log_File: mysql-bin.000051
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
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: 245
Relay_Log_Space: 554
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: 0
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: 2
1 row in set (0.00 sec)