MySQL之主从复制搭建

文章目录

• • 主从复制
  • • 主从搭建
    • • 配置主从复制的命令
      • 测试
• 总结

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，

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