** 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=1 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 = 1 auto_increment_increment = 2 #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 = 3000 max_connect_errors = 30 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=1800 #请求的最大连接时间 interactive_timeout=1800 #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 statusG;
*************************** 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 = 2 log-bin=mysql-binlog log-slave-updates=true max_binlog_size=1024M auto_increment_offset = 2 auto_increment_increment = 2 #偶数ID replicate-ignore-db = information_schema replicate-ignore-db = performance_schema replicate-ignore-db = test replicate-ignore-db = mysql max_connections = 3000 max_connect_errors = 30 skip-character-set-client-handshake init-connect='SET NAMES utf8' character-set-server=utf8 wait_timeout=1800 interactive_timeout=1800 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 statusG;
*************************** 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 2 weight -5 fall 2 rise 1 } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 100 nopreempt advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { mysql } virtual_ipaddress { 192.168.200.254 } }
[root@localhost ~]# vim /opt/mysql.sh
#!/bin/bash counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l) if [ "${counter}" -eq 0 ]; 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 2 weight -5 fall 2 rise 1 } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 99 advert_int 1 authentication { auth_type PASS auth_pass 1111 } track_script { mysql } virtual_ipaddress { 192.168.200.254 } }
[root@localhost ~]# vim /opt/mysql.sh
#!/bin/bash counter=$(netstat -na|grep "LISTEN"|grep "3306"|wc -l) if [ "${counter}" -eq 0 ]; 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)