MySQL之主从复制搭建
主从复制
主从也叫做(AB复制)，允许一个服务器从一个服务器数据库（主服务器）的数据复制到一个或者多个MySQL数据库服务器。
主从复制的优点有很多，包括横向扩展解决方案，数据安全性，数据分析，远程数据分发。
主从搭建
作为主服务器的服务器开启二进制日志（binlog);
下面我们来搭建主从复制的，采用3个节点来尝试；
| 节点角色 | 主机名 | Ip地址 | server-id |
|---|---|---|---|
| master | master | 192.168.246.132 | 1 |
| slave | salve | 192.168.246.134 | 2 |
| slave2 | salve2 | 192.168.246.136 | 3 |
首先需要在etc/hosts中添加IP地址和主机名之间的映射关系，启动节点的数据库，然后可以查看他们的server-id
show variables like 'server_id';
# 创建主从复制的账号
create user 'rep1'@'192.168.246.%' identified by '123456';
grant replication slave on * .* to 'rep1'@'192.168.246.%';
flush privileges;
创建管理账号
create user 'myadmin'@'192.168.246.%' identified by '123456';
grant all privileges on *.* to 'myadmin'@'192.168.246.%';
flush privileges;
在所有的节点上都启用GTID
set @@GLOBAL.ENFORCE_GTID_CONSISTENCY = WARN;
set global ENFORCE_GTID_CONSISTENCY = ON;
set global GTID_MODE = OFF_PERMISSIVE;
set global GTID_MODE = ON_PERMISSIVE;
set global GTID_MODE = ON;
GTID全称为Global Transaction Identifier, 即全局事务标识符。用于在binlog中标识唯一的事务，当MySQL Server在写binlog的时候，会写一个特殊的binlog Event，指定下一个事务的GTID。
配置主从复制的命令
注意，需要在所有的从节点都配置
change master to master_host='192.168.246.132',master_user='rep1',master_password='123456',master_auto_position=1;
在所有的从节点中开启主从复制
start salve;
然后在从节点上查看主从复制的状态，出现下面的就算成功了。
show slave status \G;
show slave status \G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for source to send event
Master_Host: 192.168.246.132
Master_User: rep1
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-binlog.000008
Read_Master_Log_Pos: 157
Relay_Log_File: salve-relay-bin.000002
Relay_Log_Pos: 379
Relay_Master_Log_File: mysql-binlog.000008
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: 157
Relay_Log_Space: 589
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: 71341b64-4450-11ed-90f4-000c29f2a7f4
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: 1
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 (0.01 sec)
ERROR:
No query specified
测试
我们现在主节点上创建一张表并且插入一些数据，来查看从节点是否有同步数据；
create database demo2;
use demo2;
create table test1 (tid int);
insert into test1 values(123);
这个时候我们去从节点上进行查询，这个时候我们可以看到数据已经同步过来了。
我们还可以到我们设置的data目录下面查看binlog，
![[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-vaMlOkh9-1664959386378)(C:\Users\大勇\AppData\Roaming\marktext\images\2022-10-05-16-40-12-image.png)]](https://img-blog.csdnimg.cn/9a3345fe10174b0b9468ce5601bed806.png)
再到数据库里面查看，就可以查看具体的binlog信息了。
mysql> show binlog events in 'mysql-binlog.000008';
+---------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+
| Log_name | Pos | Event_type | Server_id | End_log_pos | Info |
+---------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+
| mysql-binlog.000008 | 4 | Format_desc | 2 | 126 | Server ver: 8.0.30, Binlog ver: 4 |
| mysql-binlog.000008 | 126 | Previous_gtids | 2 | 157 | |
| mysql-binlog.000008 | 157 | Gtid | 1 | 241 | SET @@SESSION.GTID_NEXT= '71341b64-4450-11ed-90f4-000c29f2a7f4:1' |
| mysql-binlog.000008 | 241 | Query | 1 | 352 | create database demo2 /* xid=51 */ |
| mysql-binlog.000008 | 352 | Gtid | 1 | 436 | SET @@SESSION.GTID_NEXT= '71341b64-4450-11ed-90f4-000c29f2a7f4:2' |
| mysql-binlog.000008 | 436 | Query | 1 | 554 | use `demo2`; create table test1 (tid int) /* xid=64 */ |
| mysql-binlog.000008 | 554 | Gtid | 1 | 640 | SET @@SESSION.GTID_NEXT= '71341b64-4450-11ed-90f4-000c29f2a7f4:3' |
| mysql-binlog.000008 | 640 | Query | 1 | 711 | BEGIN |
| mysql-binlog.000008 | 711 | Table_map | 1 | 763 | table_id: 94 (demo2.test1) |
| mysql-binlog.000008 | 763 | Write_rows | 1 | 803 | table_id: 94 flags: STMT_END_F |
| mysql-binlog.000008 | 803 | Xid | 1 | 834 | COMMIT /* xid=66 */ |
+---------------------+-----+----------------+-----------+-------------+-------------------------------------------------------------------+
11 rows in set (0.00 sec)
总结
上述就是搭建主从复制的搭建过程，相信大家跟着教程一步步搭建起来应该也可以成功
