MHA部署实现高可用（2）

三、修改密码后，配置主从

1、c731主服务器操作

vim /etc/my.cnf

[mysqld]
server-id=1
log-bin=mysql-bin　　
relay_log_purge=0　　//禁止mysql自动删除relaylog功能
gtid_mode = on　　　　//mysql 5.6的特性，开启gtid，必须主从全开
enforce_gtid_consistency = 1
log_slave_updates = 1

重启mysql

systemctl restart mysql

创建同步的用户

mysql -p123456
mysql> grant all privileges on *.* to mha@'192.168.37.%' identified by 'mha';
mysql> flush privileges;

查看mysql主库的master状态

mysql> show master statusG
*************************** 1. row ***************************
             File: mysql-bin.000001
         Position: 151

查看GTID状态

mysql> show global variables like '%gtid%';
+---------------------------------+------------------------------------------+
| Variable_name                   | Value                                    |
+---------------------------------+------------------------------------------+
| binlog_gtid_simple_recovery     | OFF                                      |
| enforce_gtid_consistency        | ON                                       |
| gtid_executed                   | f27d0522-4e44-11ea-a692-000c2918e47a:1-2 |
| gtid_mode                       | ON                                       |
| gtid_owned                      |                                          |
| gtid_purged                     |                                          |
| simplified_binlog_gtid_recovery | OFF                                      |
+---------------------------------+------------------------------------------+
7 rows in set (0.00 sec)

2、c732从服务器操作

vim /etc/my.cnf

[mysqld]
server-id=2
log-bin=mysql-bin
relay_log_purge = 0
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = 1

重启mysql
systemctl restart mysql

创建同步的用户

mysql -uroot -p123456

mysql> grant replication slave on *.* to 'rep'@'192.168.37.%' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

关闭从服务器的复制功能

mysql -p123456
mysql> stop slave;

配置从服务器指向master

mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> change master to master_host='192.168.37.31',
    -> master_user='rep',
    -> master_password='123456',
    -> master_log_file='mysql-bin.000001',
    -> master_log_pos=534;
Query OK, 0 rows affected, 2 warnings (0.01 sec)

开启从服务器的复制功能
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)

开启slave后，默认有relay-log日志了

 查看从服务器的状态

mysql> show slave status G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.37.31
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 534
               Relay_Log_File: mysqld-relay-bin.000002
                Relay_Log_Pos: 314
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

其中启动slave时可能会出现MySQL的ERROR 1872，导致slave无法正常启动

解决办法：

使用RESET SLAVE 语句，清除master信息和relay日志的信息，删除所有relay日志文件，并开始创建一个全新的中继日志

mysql>stop slave;
mysql>reset slave;

3、c733从服务器操作

vim /etc/my.cnf

[mysqld]
server-id=3
log-bin=mysql-bin
relay_log_purge = 0
gtid_mode = on
enforce_gtid_consistency = 1
log_slave_updates = 1

重启mysql
systemctl restart mysql

创建同步的用户

mysql> grant replication slave on *.* to 'rep'@'192.168.37.31' identified by '123456';
Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

关闭从服务器的复制功能
mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)

配置从服务器指向master
mysql> change master to master_host='192.168.37.31',
    -> master_user='rep',
    -> master_password='123456',
    -> master_log_file='mysql-bin.000001',
    -> master_log_pos=534;
Query OK, 0 rows affected, 2 warnings (0.02 sec)

mysql> start slave ;
Query OK, 0 rows affected (0.00 sec)

查看状态

mysql> show slave status G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.37.31
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 534
               Relay_Log_File: mysqld-relay-bin.000002
                Relay_Log_Pos: 314
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

GTID讲解：

 四、准备MHA，首先下载rpm包，其次配置环境

　　！！！三台机器同时操作以下步骤

1.1、安装依赖

yum install perl-DBD-MySQL -y
yum install -y perl-Config-Tiny epel-release perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes

1.2、授权MHA管理用户

grant all privileges on *.* to mha@'192.168.37.%' identified by 'mha';
flush privileges;

1.3、安装MHA node节点

上传mha4mysql-node-0.58-0.el7.centos.noarch.rpm ，然后安装
rpm -ivh mha4mysql-node-0.58-0.el7.centos.noarch.rpm 

切记安装依赖，也可以使用nodeps （不推荐使用）

rpm -ivh mha4mysql-manager-0.58-0.el7.centos.noarch.rpm --nodeps --force

2.1、安装MHA管理节点

安装MHA管理端，这里选择c733（永远不会切换为主库的节点）　　

注意：MHA不要安装到mysql主从库上，否则会在后面出现vip无法漂移等情况

rpm -ivh mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

2.2、配置MHA

创建两个文件夹

mkdir  -p /etc/mha

mkdir -p /var/log/mha/app1

编辑MHA配置文件

[server default]
manager_log=/var/log/mha/app1/manager.log
manager_workdir=/var/log/mha/app1
master_binlog_dir=/var/lib/mysql #binlog的目录，如果说miysql的环境不一样，binlog位置不同，每台服务器的binlog的位置写在server标签里面即可
user=mha
password=mha
ping_interval=2
repl_password=123456
repl_user=rep
ssh_user=root

[server1]
hostname=192.168.37.31
port=3306

[server2]
hostname=192.168.37.32
port=3306

[server3]
hostname=192.168.37.33
port=3306
ignore_fail=1  #如果这个节点挂了，mha将不可用，加上这个参数，slave挂了一样可以用
no_master=1  #从不将这台主机转换为master
#candidate_master=1 #如果候选master有延迟的话，relay日志超过100m，failover切换不能成功，加上此参数后会忽略延迟日志大小。
#check_repl_delay=0 #用防止master故障时,切换时slave有延迟,卡在那里切不过来

在配置文件后面不要有空格和注释，推荐用  d+$ 删除行后所有字符

2.3、启动测试

ssh检查检测

[root@c733 ~]# masterha_check_ssh --conf=/etc/mha/app1.cnf 

 主从复制检测

[root@c733 ~]# masterha_check_repl --conf=/etc/mha/app1.cnf