MTSQL主主同步方案

** MySQL主主+Keepalived

**MySQL+DRBD+Heartbeat

在企业中，数据库高可用一直是企业的重中之重，中小企业很多都是使用mysql主主方案，一主多从，读写分离等，但是单主存在单点故障，从库切换成主库需要作改动。因此，如果是双主或者多主，就会增加mysql入口，增加高可用。不过多主需要考虑自增长ID问题，这个需要特别设置配置文件，比如双主，可以使用奇偶，总之，主之间设置自增长ID相互不冲突就能完美解决自增长ID冲突问题。

主主方案实现思路

1、 两台mysql都可读写，互为主备。默认只使用一台masterA负责数据的写入，另一台masterB备用处于备用状态；

2、 masterA是masterB的主库，masterB又是masterA的主库，它们互为主从；

3、 两台主库之间做高可用,可以采用keepalived等方案，使用VIP对外提供服务；

4、所有提供服务的从服务器与masterB进行主从同步（双主多从）;

5、建议采用高可用策略的时候，masterA或masterB均不因宕机恢复后而抢占VIP（非抢占模式）；

这样做可以在一定程度上保证主库的高可用,在一台主库down掉之后,可以在极短的时间内切换到另一台主库上，尽可能减少主库宕机对业务造成的影响，减少了主从同步给生产主库带来的压力；

但是也有几个不足的地方:

• masterB可能会一直处于空闲状态（可以用它当从库，负责部分查询）；
• 主库后面提供服务的从库要等masterB先同步完了数据后才能去masterB上去同步数据，这样可能会造成一定程度的同步延时；

设备两台MARIADB机器：

masterA：IP为192.168.200.124

masterB：IP为192.168.200.125

masterA：

[root@localhost ~]# yum install mariadb mariadb-server -y

[root@localhost ~]#systemc restart mariadb

1：修改主配置文件

[root@localhost ~]#vim /etc/my.cnf

server-id=
log-bin=mysql-binlog                            #打开二进制功能
log-slave-updates=true
max_binlog_size=1024M                   #binlog单文件最大值
auto_increment_offset =
auto_increment_increment =             #奇数ID

replicate-ignore-db = information_schema        #忽略不同步主从的数据库
replicate-ignore-db = performance_schema
replicate-ignore-db = test
replicate-ignore-db = mysql

max_connections =
max_connect_errors = 

skip-character-set-client-handshake     #忽略应用程序想要设置的其他字符集
init-connect='SET NAMES utf8'           #连接时执行的SQL
character-set-server=utf8                       #服务端默认字符集
wait_timeout=                               #请求的最大连接时间
interactive_timeout=                        #和上一参数同时修改才会生效
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES     #sql模式

relay-log=relay-log-bin                         #开启中继日志
relay-log-index=slave-relay-bin.index

MariaDB [(none)]> grant replication slave on *.* to 'repl'@'192.168.200.125' identified by '123456';

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> flush privileges;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show master status;
+---------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+---------------------+----------+--------------+------------------+
| mysql-binlog.000001 | 911 | | |
+---------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

2：测试环境，可以保证没数据写入。否则需要的步骤是：先masterA锁表-->masterA备份数据-->masterA解锁表 -->masterB导入数据-->masterB设置主从-->查看主从

MariaDB [(none)]> stop slave;

Query OK, 0 rows affected, 1 warning (0.00 sec)

MariaDB [(none)]> change master to master_host='192.168.200.125',master_port=3306,master_user='repl',master_password='123456',master_log_file='mysql-binlog.000004',master_log_pos=670;

Query OK, 0 rows affected (0.04 sec)

 
MariaDB [(none)]> start slave;

MariaDB [(none)]> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.200.125
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-binlog.000004
Read_Master_Log_Pos: 670
Relay_Log_File: relay-log-bin.000002
Relay_Log_Pos: 624
Relay_Master_Log_File: mysql-binlog.000004
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: information_schema,performance_schema,test,mysql
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: 670
Relay_Log_Space: 916
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: 2
1 row in set (0.00 sec)

ERROR: No query specified

masterB：

[root@localhost ~]# yum install mariadb mariadb-server -y

[root@localhost ~]#systemc restart mariadb

1：修改主配置文件

[root@localhost ~]#vim /etc/my.cnf

server-id       =
log-bin=mysql-binlog
log-slave-updates=true
max_binlog_size=1024M
auto_increment_offset =
auto_increment_increment =                             #偶数ID

replicate-ignore-db = information_schema
replicate-ignore-db = performance_schema
replicate-ignore-db = test
replicate-ignore-db = mysql

max_connections =
max_connect_errors = 

skip-character-set-client-handshake
init-connect='SET NAMES utf8'
character-set-server=utf8
wait_timeout=
interactive_timeout=
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

relay-log=relay-log-bin
relay-log-index=slave-relay-bin.index

MariaDB [(none)]> grant replication slave on *.* to 'repl'@'192.168.200.124' identified by '123456';

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> flush privileges;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show master status;
+---------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+---------------------+----------+--------------+------------------+
| mysql-binlog.000004 | 670 | | |
+---------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

2：测试环境，可以保证没数据写入。否则需要的步骤是：先masterA锁表-->masterA备份数据-->masterA解锁表 -->masterB导入数据-->masterB设置主从-->查看主从

MariaDB [(none)]> stop slave;

Query OK, 0 rows affected (0.01 sec)

MariaDB [(none)]> change master to master_host='192.168.200.111',master_port=3306,master_user='repl',master_password='123456',master_log_file='mysql-binlog.000001',master_log_pos=911;

Query OK, 0 rows affected (0.13 sec)

MariaDB [(none)]> start slave;

Query OK, 0 rows affected (0.01 sec)

MariaDB [(none)]> show slave status\G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.200.124
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-binlog.000001
Read_Master_Log_Pos: 911
Relay_Log_File: relay-log-bin.000002
Relay_Log_Pos: 624
Relay_Master_Log_File: mysql-binlog.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB: information_schema,performance_schema,test,mysql
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: 911
Relay_Log_Space: 916
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
1 row in set (0.00 sec)

ERROR: No query specified

masterA测试：

MariaDB [(none)]> create database test01;

MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| client |
| cmx |
| db_test |
| liuxiang |
| mydb |
| mysql |
| performance_schema |
| shiqi |
| shiqishou |
| shuifei |
| test01 |

| test02 |
| var |
| yg |
| yqx |
+--------------------+
16 rows in set (0.00 sec)

masterB测试：

MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| cmx |
| db_test |
| liuxiang |
| mysql |
| performance_schema |
| shiqi |
| shiqishou |
| test01 |
| yqx |
+--------------------+
11 rows in set (0.00 sec)

MariaDB [(none)]> create database test02;

MariaDB [(none)]> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| cmx |
| db_test |
| liuxiang |
| mysql |
| performance_schema |
| shiqi |
| shiqishou |
| test01 |

| test02 |
| yqx |

MYSQL主主高可用方案：

masterA：

[root@localhost ~]# yum -y install keepalived

[root@localhost ~]# vim /etc/keepalived/keepalived.conf 

! Configuration File for keepalived

global_defs {

   router_id LVS_MASTER-A

}

vrrp_script mysql {                      

    script "/opt/mysql.sh"

    interval 

    weight -                 

    fall                  

    rise 

}

vrrp_instance VI_1 {

    state BACKUP

    interface ens33

    virtual_router_id 

priority 

nopreempt

    advert_int 

    authentication {

        auth_type PASS

        auth_pass 

    }

    track_script {

        mysql

    }

    virtual_ipaddress {

        192.168.200.254

    }

}

[root@localhost ~]# vim /opt/mysql.sh

#!/bin/bash

counter=$(netstat -na|grep "LISTEN"|grep ""|wc -l)

if [ "${counter}" -eq  ]; then

    systemctl stop keepalived

fi

[root@localhost ~]# chmod +x /opt/mysql.sh

[root@localhost ~]# systemctl start keepalived

[root@localhost ~]# ip a | grep ens33

2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

inet 192.168.200.124/24 brd 192.168.200.255 scope global ens33

inet 192.168.200.254/32 scope global ens33

masterB：

[root@localhost ~]# yum -y install keepalived

[root@localhost ~]# vim /etc/keepalived/keepalived.conf 

! Configuration File for keepalived

global_defs {

   router_id LVS_MASTER-B

}

vrrp_script mysql {

    script "/opt/mysql.sh"

    interval 

    weight -                 

    fall                  

    rise 

}

vrrp_instance VI_1 {

    state BACKUP

    interface ens33

    virtual_router_id 

    priority 

    advert_int 

    authentication {

        auth_type PASS

        auth_pass 

    }

    track_script {

        mysql

    }

    virtual_ipaddress {

        192.168.200.254

    }

}

[root@localhost ~]# vim /opt/mysql.sh

#!/bin/bash

counter=$(netstat -na|grep "LISTEN"|grep ""|wc -l)

if [ "${counter}" -eq  ]; then

    systemctl stop keepalived

fi

[root@localhost ~]# chmod +x /opt/mysql.sh

[root@localhost ~]# systemctl start keepalived

[root@localhost ~]# ip a | grep ens33

2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

inet 192.168.200.125/24 brd 192.168.200.255 scope global ens33

inet 192.168.200.254/32 scope global ens33

测试VIP的漂移：

masterA：

[root@localhost ~]# systemctl stop mariadb

[root@localhost ~]# ip a | grep ens33

2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

inet 192.168.200.124/24 brd 192.168.200.255 scope global ens33

masterB:

[root@localhost ~]# ip a | grep ens33

2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000

inet 192.168.200.125/24 brd 192.168.200.255 scope global ens33

inet 192.168.200.254/32 scope global ens33

远程客户端测试：

mysql服务器授权

[root@localhost ~]#systemctl start mariadb

[root@localhost ~]# mysql -uroot -p123123

MariaDB [(none)]> grant all on *.* to 'root'@'192.168.200.%' identified by '123456';             #授权200网段的客户机通过密码登入mysql

MariaDB [(none)]> flush privileges;                                                                                            #刷新授权列表

通过vip登陆测试：masterA与masterB都需要关闭防火墙

[root@localhost ~]# systemctl stop firewalld
[root@localhost ~]# iptables -F
[root@localhost ~]# setenforce 0

[root@localhost ~]# mysql -uroot -p123456 -h 192.168.200.254                                             #通过授权用户及密码登录Mysql

Welcome to the MariaDB monitor.  Commands end with ; or \g.

Your MariaDB connection id is 5796

Server version: 5.5.56-MariaDB MariaDB Server

Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> show databases;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| mysql              |

| performance_schema |

| test               |

| test01             |

| test02             |

+--------------------+

6 rows in set (0.00 sec)