Implementation ideas and steps for MySQL master-slave construction (multiple masters and one slave)

[mysqld]
lower_case_table_names = 1 # Table names are case insensitive server-id = 100
log_bin = mysql-bin #Start binlog recording binlog_format = MIXED 
#Every time a transaction is committed, MySQL will flush the binlog. This is the safest setting but it has the greatest performance loss.
#In this case, the system may lose the data of one transaction only if the host operating system where the database is located is damaged or the power is suddenly lost. #However, although binlog is sequential IO, if sync_binlog=1 is set, multiple transactions are submitted at the same time.
#It also greatly affects MySQL and IO performance. Set as needed.
sync_binlog = 1 
# Number of days after which binary logs are automatically deleted/expired. The default value is 0, which means no automatic deletion.
expire_logs_days = 7
#binlog_cache_size = 128m
#max_binlog_cache_size = 512m
#max_binlog_size = 256M
# Need to synchronize the database binlog-do-db = dev
# No synchronization library is required binlog-ignore-db = mysql
binlog_ignore_db = information_schema
binlog_ignore_db = performance_schema
binlog_ignore_db = sys
datadir=/var/lib/mysql

#mysql -uroot -p 
# password: xxxxxx
# mysql> GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%' IDENTIFIED BY 'root1234';
# mysql> flush privileges;
# quit;
# systemctl restart mysqld;
# show master status \G
#*************************** 1. row ***************************
             File:mysql-bin.000001
         Position: 886
     Binlog_Do_DB: dev
 Binlog_Ignore_DB: mysql,information_schema,performance_schema,sys
Executed_Gtid_Set: 
1 row in set (0.00 sec)

[mysqld]
lower_case_table_names = 1 # Table names are case insensitive server-id = 200
log_bin = mysql-bin #Start binlog recording binlog_format = MIXED 
#Every time a transaction is committed, MySQL will flush the binlog. This is the safest setting but it has the greatest performance loss.
#In this case, the system may lose the data of one transaction only if the host operating system where the database is located is damaged or the power is suddenly lost. #However, although binlog is sequential IO, if sync_binlog=1 is set, multiple transactions are submitted at the same time.
#It also greatly affects MySQL and IO performance. Set as needed.
sync_binlog = 1 
# Number of days after which binary logs are automatically deleted/expired. The default value is 0, which means no automatic deletion.
expire_logs_days = 7
#binlog_cache_size = 128m
#max_binlog_cache_size = 512m
#max_binlog_size = 256M
# Need to synchronize the database binlog-do-db = dev
# No synchronization library is required binlog-ignore-db = mysql
binlog_ignore_db = information_schema
binlog_ignore_db = performance_schema
binlog_ignore_db = sys
datadir=/var/lib/mysql

#mysql -uroot -p 
# password: xxxxxx
# mysql> GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%' IDENTIFIED BY 'root1234';
# mysql> flush privileges;
# quit;
# systemctl restart mysqld;
# show master status \G
#*************************** 1. row ***************************
             File:mysql-bin.000001
         Position: 154
     Binlog_Do_DB: dev
 Binlog_Ignore_DB: mysql,information_schema,performance_schema,sys
Executed_Gtid_Set: 
1 row in set (0.00 sec)

[mysqld]
lower_case_table_names = 1 # Table names are case insensitive server-id = 300
master_info_repository = table
relay_log_info_repository = table 
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock  
symbolic-links=0 
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

#mysql -uroot -p 
# password: xxxxxx
# Set the master database information# mysql> CHANGE MASTER TO  
# ->MASTER_HOST='192.168.194.3',
# ->MASTER_PORT=3306, MASTER_USER='slave', 
# ->MASTER_PASSWORD='root1234',
# ->MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=886 for channel '100';
# mysql> CHANGE MASTER TO  
# ->MASTER_HOST='192.168.194.4',
# ->MASTER_PORT=3306, MASTER_USER='slave', 
# ->MASTER_PASSWORD='root1234',
# ->MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=154 for channel '200';
# Set the master database information# mysql> flush privileges;
# start slave;
# mysql>show slave status \G

CREATE TABLE `t_user` (
  `id` varchar(32) NOT NULL COMMENT 'Primary key ID',
  `name` varchar(32) CHARACTER SET utf8mb4 NULL COMMENT 'User name',
  `code` varchar(32) CHARACTER SET utf8mb4 NULL COMMENT 'User code',
  `phone_number` varchar(300) CHARACTER SET utf8mb4 NULL COMMENT 'Phone number',
  `create_date` datetime NULL COMMENT 'Creation time',
  `update_date` datetime NULL COMMENT 'Modification time',
  PRIMARY KEY (`id`)
) COMMENT = 'User information table';
INSERT INTO t_user (`id`, `name`, `code`, `phone_number`, `create_date`, `update_date`) 
VALUES ('userId_4', '张三', '123456789', '123456789632', '2020-04-27 22:05:00', '2020-04-27 22:05:00');

SELECT * FROM t_user;
------+--------+----------+--------------+---------------------+-------------+
| id | name | code | phone_number | create_date | update_date |
+-------+--------+----------+--------------+---------------------+----------+
| userId_4 | Zhang San|123456789|123456789632|2020-04-27 22:05:00|2020-04-27 22:05:00