多主一從，也稱爲多源複製，數據流向：mysql

主庫1 -> 從庫s
主庫2 -> 從庫s
主庫n -> 從庫s

應用場景

數據彙總，可將多個主數據庫同步彙總到一個從數據庫中，方便數據統計分析。
讀寫分離，從庫只用於查詢，提升數據庫總體性能。

部署環境

注：使用docker部署mysql實例，方便快速搭建演示環境。但本文重點是講解主從配置，所以簡略描述docker環境構建mysql容器實例。linux

數據庫：MySQL 5.7.x （相比5.5，5.6而言，5.7同步性能更好，支持多源複製，可實現多主一從，主從庫版本應保證一致）
操做系統：CentOS 7.x
容器：Docker 17.09.0-ce
鏡像：mysql:5.7
主庫300：IP=192.168.10.212; PORT=4300; server-id=300; database=test3; table=user
主庫400：IP=192.168.10.212; PORT=4400; server-id=400; database=test4; table=user
主庫500：IP=192.168.10.212; PORT=4500; server-id=500; database=test5; table=user
從庫10345：IP=192.168.10.212; PORT=4345; server-id=10345; database=test3,test4,test5; table=user

配置約束

主從庫必須保證網絡暢通可訪問
主庫必須開啓binlog日誌
主從庫的server-id必須不一樣

事前準備

關閉selinux

setenforce 0
vim /etc/sysconfig/selinux 
SELINUX=disabled

# 若不關閉，使用docker啓動mysql5.7鏡像容器時啓動不起來，查看日誌會有以下錯誤顯示：
ERROR: mysqld failed while attempting to check config
command was: "mysqld --verbose --help"
mysqld: Can't read dir of '/etc/mysql/conf.d/' (Errcode: 13 - Permission denied)
mysqld: [ERROR] Fatal error in defaults handling. Program aborted!
ERROR: mysqld failed while attempting to check config
command was: "mysqld --verbose --help"
mysqld: Can't read dir of '/etc/mysql/conf.d/' (Errcode: 13 - Permission denied)
mysqld: [ERROR] Fatal error in defaults handling. Program aborted!

安裝並啓動docker

yum install epel-release
yum -y install docker
systemctl start docker.service

mkdir -p /datavol/mysql-300/{mysql,conf}
mkdir -p /datavol/mysql-400/{mysql,conf}
mkdir -p /datavol/mysql-500/{mysql,conf}
mkdir -p /datavol/mysql-10345/{mysql,conf}

【主庫300】操做及配置

配置my.cnf

把該文件放到主庫所在配置文件路徑下：/datavol/mysql-300/confsql

[client]
port = 3306
default-character-set = utf8mb4

[mysql]
port = 3306
default-character-set = utf8mb4

[mysqld]
##########################
# summary
##########################
#bind-address = 0.0.0.0
#port = 3306
#datadir=/datavol/mysql/data #數據存儲目錄

##########################
# log bin
##########################
server-id = 300			#必須惟一
log_bin = mysql-bin 	#開啓及設置二進制日誌文件名稱
binlog_format = MIXED
sync_binlog = 1
expire_logs_days =7		#二進制日誌自動刪除/過時的天數。默認值爲0，表示不自動刪除。

#binlog_cache_size = 128m
#max_binlog_cache_size = 512m
#max_binlog_size = 256M

binlog-do-db = test3 	#要同步的數據庫

binlog-ignore-db = mysql 	#不須要同步的數據庫 
binlog_ignore_db = information_schema
binlog_ignore_db = performation_schema
binlog_ignore_db = sys
			

##########################
# character set
##########################
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci

安裝啓動

[root@localhost ~]# docker run -d -p 4300:3306 --name=mysql-300 -v /datavol/mysql-300/conf:/etc/mysql/conf.d -v /datavol/mysql-300/mysql:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
5691bac538e646db00273e3cad5b350dbe6cce0bd176346b7eefd9a6f9e3a9ad
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE                               COMMAND                  CREATED             STATUS              PORTS                                                NAMES
5691bac538e6        mysql:5.7                           "docker-entrypoint..."   44 seconds ago      Up 43 seconds       33060/tcp, 0.0.0.0:4300->3306/tcp                    mysql-300
[root@localhost ~]# docker exec -it mysql-300 /bin/bash
root@5691bac538e6:/# mysql -u root -p
Enter password:

注：若不熟悉docker，可以使用傳統方式安裝mysql，效果相同。docker

建立受權用戶

鏈接mysql主數據庫，鍵入命令mysql -u root -p，輸入密碼後登陸數據庫。建立用戶用於從庫同步複製，授予複製、同步訪問的權限數據庫

mysql> CREATE USER 'slave'@'%' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.00 sec)

mysql> grant replication slave on *.* to 'slave'@'%' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

log_bin是否開啓

mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin       | ON    |
+---------------+-------+
1 row in set

查看master狀態

mysql> show master status \G
*************************** 1. row ***************************
             File: mysql-bin.000003
         Position: 438
     Binlog_Do_DB: test3
 Binlog_Ignore_DB: mysql,information_schema,performation_schema,sys

【主庫400】配置及操做

配置my.cnf

把該文件放到主庫所在配置文件路徑下：/datavol/mysql-400/confvim

[client]
port = 3306
default-character-set = utf8mb4

[mysql]
port = 3306
default-character-set = utf8mb4

[mysqld]
##########################
# summary
##########################
#bind-address = 0.0.0.0
#port = 3306
#datadir=/datavol/mysql/data #數據存儲目錄

##########################
# log bin
##########################
server-id = 400			#必須惟一
log_bin = mysql-bin 	#開啓及設置二進制日誌文件名稱
binlog_format = MIXED
sync_binlog = 1
expire_logs_days =7		#二進制日誌自動刪除/過時的天數。默認值爲0，表示不自動刪除。

#binlog_cache_size = 128m
#max_binlog_cache_size = 512m
#max_binlog_size = 256M

binlog-do-db = test4 		#要同步的數據庫

binlog-ignore-db = mysql 	#不須要同步的數據庫 
binlog_ignore_db = information_schema
binlog_ignore_db = performation_schema
binlog_ignore_db = sys
			

##########################
# character set
##########################
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci

安裝啓動

[root@localhost ~]# docker run -d -p 4400:3306 --name=mysql-400 -v /datavol/mysql-400/conf:/etc/mysql/conf.d -v /datavol/mysql-400/mysql:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
19e93b6d93ca4e6ca0d540e3f6c831b835cdbb35362733867c3977aee4d33bf7
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE                               COMMAND                  CREATED             STATUS              PORTS                                                NAMES
19e93b6d93ca        mysql:5.7                           "docker-entrypoint..."   4 seconds ago       Up 3 seconds        33060/tcp, 0.0.0.0:4400->3306/tcp                    mysql-400
[root@localhost ~]# docker exec -it mysql-400 /bin/bash
root@19e93b6d93ca:/# mysql -u root -p
Enter password:

建立受權用戶

建立用戶用於從庫同步複製，授予複製、同步訪問的權限bash

mysql> CREATE USER 'slave'@'%' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.00 sec)

mysql> grant replication slave on *.* to 'slave'@'%' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

log_bin是否開啓

mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin       | ON    |
+---------------+-------+
1 row in set

查看master狀態

mysql> show master status \G;
*************************** 1. row ***************************
             File: mysql-bin.000003
         Position: 438
     Binlog_Do_DB: test4
 Binlog_Ignore_DB: mysql,information_schema,performation_schema,sys

【主庫500】配置及操做

配置my.cnf

把該文件放到主庫所在配置文件路徑下：/datavol/mysql-500/conf服務器

[client]
port = 3306
default-character-set = utf8mb4

[mysql]
port = 3306
default-character-set = utf8mb4

[mysqld]
##########################
# summary
##########################
#bind-address = 0.0.0.0
#port = 3306
#datadir=/datavol/mysql/data #數據存儲目錄

##########################
# log bin
##########################
server-id = 500			#必須惟一
log_bin = mysql-bin 	#開啓及設置二進制日誌文件名稱
binlog_format = MIXED
sync_binlog = 1
expire_logs_days =7		#二進制日誌自動刪除/過時的天數。默認值爲0，表示不自動刪除。

#binlog_cache_size = 128m
#max_binlog_cache_size = 512m
#max_binlog_size = 256M

binlog-do-db = test5 		#要同步的數據庫

binlog-ignore-db = mysql 	#不須要同步的數據庫 
binlog_ignore_db = information_schema
binlog_ignore_db = performation_schema
binlog_ignore_db = sys
			

##########################
# character set
##########################
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci

安裝啓動

[root@localhost ~]# docker run -d -p 4500:3306 --name=mysql-500 -v /datavol/mysql-500/conf:/etc/mysql/conf.d -v /datavol/mysql-500/mysql:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
19e93b6d93ca4e6ca0d540e3f6c831b835cdbb35362733867c3977aee4d33bf7
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE                               COMMAND                  CREATED             STATUS              PORTS                                                NAMES
19e93b6d93ca        mysql:5.7                           "docker-entrypoint..."   4 seconds ago       Up 3 seconds        33060/tcp, 0.0.0.0:4500->3306/tcp                    mysql-500
[root@localhost ~]# docker exec -it mysql-500 /bin/bash
root@19e93b6d93ca:/# mysql -u root -p
Enter password:

建立受權用戶

建立用戶用於從庫同步複製，授予複製、同步訪問的權限網絡

mysql> CREATE USER 'slave'@'%' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.00 sec)

mysql> grant replication slave on *.* to 'slave'@'%' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

log_bin是否開啓

mysql> show variables like 'log_bin';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin       | ON    |
+---------------+-------+
1 row in set

查看master狀態

mysql> show master status \G
*************************** 1. row ***************************
             File: mysql-bin.000003
         Position: 438
     Binlog_Do_DB: test5
 Binlog_Ignore_DB: mysql,information_schema,performation_schema,sys

【從庫10345】配置及操做

配置my.cnf

把該文件放到主庫所在配置文件路徑下：/datavol/mysql-10345/conftcp

[client]
port = 3306
default-character-set = utf8mb4

[mysql]
port = 3306
default-character-set = utf8mb4

[mysqld]
##########################
# summary
##########################
#bind-address = 0.0.0.0
#port = 3306
#datadir=/datavol/mysql/data 	#數據存儲目錄

##########################
# log bin
##########################
server-id = 10345
master_info_repository      = table
relay_log_info_repository   = table		

##########################
# character set
##########################
character-set-server = utf8mb4
collation-server = utf8mb4_unicode_ci

安裝啓動

[root@localhost ~]# docker run -d -p 4345:3306 --name=mysql-10345 -v /datavol/mysql-10345/conf:/etc/mysql/conf.d -v /datavol/mysql-10345/mysql:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 mysql:5.7
19e93b6d93ca4e6ca0d540e3f6c831b835cdbb35362733867c3977aee4d33bf7
[root@localhost ~]# docker ps
CONTAINER ID        IMAGE                               COMMAND                  CREATED             STATUS              PORTS                                                NAMES
19e93b6d93ca        mysql:5.7                           "docker-entrypoint..."   4 seconds ago       Up 3 seconds        33060/tcp, 0.0.0.0:4345->3306/tcp                    mysql-10345
[root@localhost ~]# docker exec -it mysql-10345 /bin/bash
root@19e93b6d93ca:/# mysql -u root -p
Enter password:

設置【主庫】信息

登陸【從庫10345】，進入mysql命令行。

mysql> stop slave;
Query OK, 0 rows affected

mysql> CHANGE MASTER TO 
MASTER_HOST='192.168.10.212',
MASTER_PORT=4300,
MASTER_USER='slave',
MASTER_PASSWORD='123456',
MASTER_LOG_FILE='mysql-bin.000003',
MASTER_LOG_POS=438 
for channel '300';
Query OK, 0 rows affected

mysql> CHANGE MASTER TO 
MASTER_HOST='192.168.10.212',
MASTER_PORT=4400,
MASTER_USER='slave',
MASTER_PASSWORD='123456',
MASTER_LOG_FILE='mysql-bin.000003',
MASTER_LOG_POS=438 
for channel '400';
Query OK, 0 rows affected

mysql> CHANGE MASTER TO 
MASTER_HOST='192.168.10.212',
MASTER_PORT=4500,
MASTER_USER='slave',
MASTER_PASSWORD='123456',
MASTER_LOG_FILE='mysql-bin.000003',
MASTER_LOG_POS=438 
for channel '500';
Query OK, 0 rows affected

mysql> start slave;
Query OK, 0 rows affected

stop slave; //中止同步 start slave; //開始同步 //必須和【主庫】的信息匹配。 CHANGE MASTER TO MASTER_HOST='192.168.10.212', //主庫IP MASTER_PORT=4300, //主庫端口 MASTER_USER='slave', //訪問主庫且有同步複製權限的用戶 MASTER_PASSWORD='123456', //登陸密碼 //【關鍵處】從主庫的該log_bin文件開始讀取同步信息，主庫show master status返回結果 MASTER_LOG_FILE='mysql-bin.000003', //【關鍵處】從文件中指定位置開始讀取，主庫show master status返回結果 MASTER_LOG_POS=438 **for channel '300'; //定義通道名稱 **

查看同步狀態

mysql> show slave status \G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.10.212
                  Master_User: slave
                  Master_Port: 4300
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 1860
               Relay_Log_File: 0ad84f013600-relay-bin-300.000002
                Relay_Log_Pos: 1742
        Relay_Master_Log_File: mysql-bin.000003
             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: 1860
              Relay_Log_Space: 1960
              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: 300
                  Master_UUID: 4efae154-ebd4-11e8-bf7d-0242ac110007
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave 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: 300
           Master_TLS_Version: 
*************************** 2. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.10.212
                  Master_User: slave
                  Master_Port: 4400
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 2461
               Relay_Log_File: 0ad84f013600-relay-bin-400.000002
                Relay_Log_Pos: 1187
        Relay_Master_Log_File: mysql-bin.000003
             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: 2461
              Relay_Log_Space: 1405
              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: 400
                  Master_UUID: 8fb0aa81-ebd4-11e8-ac5b-0242ac110009
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave 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: 400
           Master_TLS_Version: 
*************************** 3. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.10.212
                  Master_User: slave
                  Master_Port: 4500
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 2151
               Relay_Log_File: 0ad84f013600-relay-bin-500.000002
                Relay_Log_Pos: 626
        Relay_Master_Log_File: mysql-bin.000003
             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: 2151
              Relay_Log_Space: 844
              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: 500
                  Master_UUID: b87704d2-ebd5-11e8-a90c-0242ac11000a
             Master_Info_File: mysql.slave_master_info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave 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: 500
           Master_TLS_Version: 
3 rows in set (0.00 sec)

能夠看見設置三個的主從同步通道的全部狀態信息。 只有【Slave_IO_Running】和【Slave_SQL_Running】都是Yes，則同步是正常的。 若是是No或者Connecting都不行，可查看mysql-error.log，以排查問題。

mysql> show variables like 'log_error%';
+---------------------+--------+
| Variable_name       | Value  |
+---------------------+--------+
| log_error           | stderr |
| log_error_verbosity | 3      |
+---------------------+--------+
2 rows in set

配置完成，則【從庫10345】開始自動同步。

若須要單獨啓動或中止某個同步通道，可以使用以下命令： start slave for channel '300'; //啓動名稱爲300的同步通道 stop slave for channel '300'; //中止名稱爲300的同步通道

驗證數據同步

建庫

使用root帳號登陸【主庫300】，建立test3數據庫

mysql> CREATE DATABASE test3;
Query OK, 1 row affected (0.00 sec)

mysql> USE test3;
Database changed

建表

在【主庫300】中建立user表

CREATE TABLE `user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) COLLATE utf8mb4_unicode_ci NOT NULL,
  `age` tinyint(3) unsigned NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

新增

在【主庫300】中向user表插入一條數據：

mysql> use test3;
Database changed
mysql> INSERT INTO user (id, name, age) VALUES (300, 'Tom', 18);
Database changed
mysql> SELECT * FROM user;
+-----+------+-----+
| id  | name | age |
+-----+------+-----+
| 300 | Tom  |  18 |
+-----+------+-----+
1 row in set (0.00 sec)

在【從庫10345】中查詢user表數據：

mysql> use test3;
Database changed
mysql> SELECT * FROM user;
+-----+------+-----+
| id  | name | age |
+-----+------+-----+
| 300 | Tom  |  18 |
+-----+------+-----+
1 row in set (0.00 sec)

新增記錄同步成功。

更新

在【主庫300】中修改剛纔插入的數據：

mysql> UPDATE user SET name='Peter' where id=300;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from user;
+-----+-------+-----+
| id  | name  | age |
+-----+-------+-----+
| 300 | Peter |  18 |
+-----+-------+-----+
1 row in set (0.00 sec)

在【從庫10345】中查詢user表數據：

mysql> select * from user;
+-----+-------+-----+
| id  | name  | age |
+-----+-------+-----+
| 300 | Peter |  18 |
+-----+-------+-----+
1 row in set (0.00 sec)

更新記錄同步成功。

刪除

在【主庫300】中刪除剛纔更新的數據：

mysql> DELETE FROM user WHERE id=300;
Query OK, 1 row affected (0.00 sec)

mysql> select * from user;
Empty set (0.00 sec)

在【從庫10345】中查詢user表數據：

mysql> select * from user;
Empty set (0.00 sec)

刪除記錄同步成功。注：【主庫400】、【主庫500】的驗證操做與上述相似。

補充：

若是【主服務器】重啓mysql服務，【從服務器】會等待與【主服務器】重連。當主服務器恢復正常後，從服務器會自動從新鏈接上主服務器，並正常同步數據。
若是某段時間內，【從數據庫】服務器異常致使同步中斷（多是同步點位置不匹配），能夠嘗試如下恢復方法：進入【主數據庫】服務器（正常），在bin-log中找到【從數據庫】出錯前的position，而後在【從數據庫】上執行change master，將master_log_file和master_log_pos從新指定後，開始同步。
如果不須要同步，登陸從庫執行：stop slave;
若須要單獨啓動或中止某個同步通道，可以使用以下命令： start slave for channel '300'; //啓動名稱爲300的同步通道 stop slave for channel '300'; //中止名稱爲300的同步通道
一般多主一從，主庫之間儘可能不使用相同的databaseName，避免衝突。

MySQL5.7多主一從（多源複製）同步配置

應用場景

部署環境

配置約束

事前準備

【主庫300】操做及配置

配置my.cnf

安裝啓動

建立受權用戶

log_bin是否開啓

查看master狀態

【主庫400】配置及操做

配置my.cnf

安裝啓動

建立受權用戶

log_bin是否開啓

查看master狀態

【主庫500】配置及操做

配置my.cnf

安裝啓動

建立受權用戶

log_bin是否開啓

查看master狀態

【從庫10345】配置及操做

配置my.cnf

安裝啓動

設置【主庫】信息

查看同步狀態

驗證數據同步

建庫

建表

新增

更新

刪除