娃哈哈好喝1、环境 centos7.X
192.168.6.6-主
192.168.6.5-从
mysql8.0：首先要创建好要用的数据库，如test，两台服务器都要先创建好。表会自动同步。
2、主-从配置 2.1主服务器配置：修改/etc/my.cnf，在[mysqld]模块中填写
[mysqld]
log-bin = mysql-bin #同步binlog文件
server-id = 1 #服务器id，同组服务器的id不要一样
binlog-do-db = test #同步的数据库名字
2.2主服务器创建账号并授权：
mysql> create user 'backupuser'@'%' identified by 'Aa123456';
mysql> grant replication slave,replication client on *.* to 'backupuser'@'%';
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000005 | 735 | test | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql>
记住mysql-bin.000005和735这两个东西，等会要用。
2.3从服务器配置：修改/etc/my.cnf，在[mysqld]模块中填写
[mysqld]
server-id = 2 #服务器id，同组服务器的id不要一样
replicate-do-db = test #同步的数据库名字
2.4从库配置主从关系：
# 配置master信息，注意master_log_file和master_log_pos为刚刚2.2中show master获取到的值，
mysql> change master to master_host='192.168.6.6',master_user='backupuser',master_password='Aa123456',master_log_file='mysql-bin.000005',master_log_pos=735;
# 开启主从
mysql> start slave;
mysql> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for source to send event
Master_Host: 192.168.6.6
Master_User: backupuser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000005
Read_Master_Log_Pos: 735
Relay_Log_File: slave-relay-bin.000008
Relay_Log_Pos: 659
Relay_Master_Log_File: mysql-bin.000005
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: 735
Relay_Log_Space: 1085
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: 1
Master_UUID: 96a324d7-e5b2-11ec-beed-000c292b5f3a
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State: Replica has read all relay log; waiting for more updates
Master_Retry_Count: 86400
Master_Bind:
Last_IO_Error_Timestamp:
Last_SQL_Error_Timestamp:
Master_SSL_Crl:
Master_SSL_Crlpath:
Retrieved_Gtid_Set:
Executed_Gtid_Set:
Auto_Position: 0
Replicate_Rewrite_DB:
Channel_Name:
Master_TLS_Version:
Master_public_key_path:
Get_master_public_key: 0
Network_Namespace:
1 row in set, 1 warning (0.00 sec)
ERROR:
No query specified
mysql>
主要看这两个服务的状态：
Slave_IO_Running: Yes Slave_SQL_Running: Yes
如果是这样的说明配置成功。
3、主-主配置 沿用上面的环境，那么主主的环境就是互为主从
3.1主库配置：修改/etc/my.cnf，在[mysqld]模块中填写，和上面的差不多，就是把不同的内容再互相对调填写一下就可以了
[mysqld]
log-bin = mysql-bin
server-id = 1
binlog-do-db = test
replicate-do-db = test
3.2从库配置：除了server-id不一样其他都一样
[mysqld]
log-bin = mysql-bin
server-id = 2
binlog-do-db = test
replicate-do-db = test
3.3两台服务器都要创建用户
mysql> create user 'backupuser'@'%' identified by 'Aa123456';
mysql> grant replication slave,replication client on *.* to 'backupuser'@'%';
mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000008 | 3804 | test | | |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysql>
3.4从库主从关系：
# 配置master信息，注意master_log_file和master_log_pos为刚刚2.2中show master获取到的值，
mysql> change master to master_host='192.168.6.5',master_user='backupuser',master_password='Aa123456',master_log_file='mysql-bin.000008',master_log_pos=3804;
# 开启主从
mysql> start slave;
和上面的主从一样
4、问题总结 4.1如果遇到从库中表的数据没更新或者更新不完整，报错信息：Last_SQL_Errno: 13124
mysql> reset slave;
Query OK, 0 rows affected, 1 warning (0.32 sec)
master_host='192.168.6.5',master_user='backupuser',master_password='Aa123456',master_log_file='mysql-bin.000008',master_log_pos=3804;
mysql> start slave;
可以通过reset来解决，但前提是要确保数据量不大或者从库丢失没影响的情况下操作。