2 案例2：准备MHA集群环境
2.1 问题
准备6台虚拟机，并按照本节规划配置好IP参数
在这些虚拟机之间实现SSH免密登录
在相应节点上安装好MHA相关的软件包
2.2 方案
使用6台RHEL 7虚拟机，如图-1所示。准备集群环境，安装依赖包，授权用户，配置ssh密钥对认证登陆，所有节点之间互相以root秘钥对认证登录，管理主机以root密钥对认证登录所有数据节点主机，配置mha集群。
图－1
IP规划，如图-2所示：
图-2
2.3 步骤
实现此案例需要按照如下步骤进行。
步骤一： 准备集群环境
1）修改主机名，配置IP（其余几台请按照图-2修改IP和主机名，这里以master51为例）
[root@localhost ~]# echo master51 > /etc/hostname
[root@localhost ~]# nmcli connection modify eth0 ipv4.method manual ipv4.addresses 192.168.4.51/24 connection.autoconnect yes
[root@localhost ~]# nmcli connection up eth0
2在所有主机上安装Perl依赖包（51-56操作）
[root@master51 ~]# cd mysql/mha-soft-student/
[root@master51 ~]# yum -y install perl-*.rpm
3）在所有数据库服务器上安装mha-node包（51-55操作）
[root@master51 mha-soft-student]# yum -y install perl-DBD-mysql perl-DBI
[root@master51 mha-soft-student]# rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm
Preparing... ################################# [100%]
Updating / installing...
1:mha4mysql-node-0.56-0.el6 ################################# [100%]
4）在管理主机上安装mha_node 和 mha-manager包（56操作）
[root@mgm56 mha-soft-student]# yum -y install perl-DBD-mysql perl-DBI
[root@mgm56 mha-soft-student]# rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm
Preparing... ################################# [100%]
Updating / installing...
1:mha4mysql-node-0.56-0.el6 ################################# [100%]
[root@mgm56 mha-soft-student]# yum -y install perl-ExtUtils-* perl-CPAN-*
[root@mgm56 mha-soft-student]# tar -zxf mha4mysql-manager-0.56.tar.gz
[root@mgm56 mha-soft-student]# cd mha4mysql-manager-0.56/
[root@mgm56 mha4mysql-manager-0.56]# perl Makefile.PL
*** Module::AutoInstall version 1.03
*** Checking for Perl dependencies...
[Core Features]
- DBI ...loaded. (1.627)
- DBD::mysql ...loaded. (4.023)
- Time::HiRes ...loaded. (1.9725)
- Config::Tiny ...loaded. (2.14)
- Log::Dispatch ...loaded. (2.41)
- Parallel::ForkManager ...loaded. (1.18)
- MHA::NodeConst ...loaded. (0.56)
*** Module::AutoInstall configuration finished. //配置完成
Checking if your kit is complete...
Looks good
Writing Makefile for mha4mysql::manager
Writing MYMETA.yml and MYMETA.json
[root@mgm56 mha4mysql-manager-0.56]# make
[root@mgm56 mha4mysql-manager-0.56]# make install
步骤二： 配置ssh密钥对认证登陆
1）所有节点之间可以互相以ssh密钥对方式认证登陆以（以51为例）
[root@master51 mha-soft-student]# ssh-keygen
[root@master51 mha-soft-student]# ssh-copy-id 192.168.4.52
//除了传给52外，53，54，55也要传，52-55主机也是一样的
6）配置56主机 无密码ssh登录所有数据节点主机
[root@mgm56 mha4mysql-manager-0.56]# ssh-keygen
[root@mgm56 mha4mysql-manager-0.56]# ssh-copy-id 192.168.4.51
//除传给51外，还要传给52-55
3 案例3：配置MHA集群环境
3.1 问题
配置主节点 master51
配置两个备用主节点 master52、master53
配置两个从节点 slave54、slave55
配置管理节点 mgm56
3.2 步骤
实现此案例需要按照如下步骤进行。
步骤一：配置mha集群环境
1）安装数据库（51-55同样操作，以51为例）
[root@master51 ~]# cd /root/mysql
[root@master51 mysql]# tar -xf mysql-5.7.17.tar
[root@master51 mysql]# yum -y install perl-JSON
[root@master51 mysql]# rpm -Uvh mysql-community-*.rpm
[root@master51 mysql]# rpm -qa | grep -i mysql
2）master51 数据库服务器配置文件
[root@master51 mysql]# vim /etc/my.cnf
plugin-load = "rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so"
rpl-semi-sync-master-enabled = 1
rpl-semi-sync-slave-enabled = 1
server_id=51
log-bin=master51
binlog-format="mixed"
[root@master51 mysql]# systemctl restart mysqld
[root@master51 mysql]# mysql -u root -p123456
mysql> set global relay_log_purge=off; //不自动删除本机的中继日志文件
Query OK, 0 rows affected (0.00 sec)
mysql> grant replication slave on *.* to repluser@"%" identified by "123456";
//添加主从同步授权用户
Query OK, 0 rows affected, 1 warning (10.01 sec)
mysql> show master status;
+-----------------+----------+--------------+------------------+-------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-----------------+----------+--------------+------------------+--------------+
| master51.000003 | 441 | | | |
+-----------------+----------+--------------+------------------+--------------+
1 row in set (0.00 sec)
3）master52数据库服务器配置文件
[root@master52 mysql]# vim /etc/my.cnf
plugin-load ="rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so"
rpl-semi-sync-master-enabled = 1
rpl-semi-sync-slave-enabled = 1
server_id=52
log-bin=master52
binlog-format="mixed"
[root@master52 mysql]# systemctl restart mysqld
[root@master52 mysql]# mysql -u root -p123456
mysql> set global relay_log_purge=off;
mysql> change master to
-> master_host="192.168.4.51",
-> master_user="repluser",
-> master_password="123456",
-> master_log_file="master51.000003",
-> master_log_pos=441;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)
mysql> show slave status\G;
...
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
...
4）master53数据库服务器配置文件
[root@master53 mysql]# vim /etc/my.cnf
plugin-load ="rpl_semi_sync_master=semisync_master.so;rpl_semi_sync_slave=semisync_slave.so"
rpl-semi-sync-master-enabled = 1
rpl-semi-sync-slave-enabled = 1
server_id=53
log-bin=master53
binlog-format="mixed"
[root@master53 mysql]# systemctl restart mysqld
[root@master53 mysql]# mysql -u root -p123456
mysql> set global relay_log_purge=off;
Query OK, 0 rows affected (0.00 sec)
mysql> change master to
-> master_host="192.168.4.51",
-> master_user="repluser",
-> master_password="123456",
-> master_log_file="master51.000003",
-> master_log_pos=441;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G;
...
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
...
5）slave54 数据库服务器配置文件
[root@slave54 mysql]# vim /etc/my.cnf
server_id=54
[root@master54 mysql]# systemctl restart mysqld
[root@master54 mysql]# mysql -u root -p123456
mysql> change master to
-> master_host="192.168.4.51",
-> master_user="repluser",
-> master_password="123456",
-> master_log_file="master51.000003",
-> master_log_pos=441;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G;
...
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
...
6）slave55 数据库服务器配置文件
[root@slave55 mysql]# vim /etc/my.cnf
server_id=55
[root@master55 mysql]# systemctl restart mysqld
[root@master55 mysql]# mysql -u root -p123456
mysql> change master to
-> master_host="192.168.4.51",
-> master_user="repluser",
-> master_password="123456",
-> master_log_file="master51.000003",
-> master_log_pos=441;
Query OK, 0 rows affected, 2 warnings (0.01 sec)
mysql> start slave;
Query OK, 0 rows affected (0.00 sec)
mysql> show slave status\G;
...
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
...
7）配置管理主机4.56
[root@mgm56 ~]# cd mysql/mha-soft-student/mha4mysql-manager-0.56/
[root@mgm56 mha4mysql-manager-0.56]# cp bin/* /usr/local/bin/
//提示覆盖，说明安装的时候有，没有可以拷贝过来
[root@mgm56 mha4mysql-manager-0.56]# mkdir /etc/mha_manager //创建工作目录
[root@mgm56 mha4mysql-manager-0.56]# cp samples/conf/app1.cnf /etc/mha_manager
//建立样板文件
[root@mgm56 mha4mysql-manager-0.56]# vim /etc/mha_manager/app1.cnf
//编辑主配置文件app1.cnf
[server default]
manager_workdir=/etc/mha_manager
manager_log=/etc/mha_manager/manager.log
master_ip_failover_script=/usr/local/bin/master_ip_failover
ssh_user=root
ssh_port=22
repl_user=repluser
repl_password=123456
user=root
password=123456
[server1]
hostname=192.168.4.51
port=3306
[server2]
hostname=192.168.4.52
port=3306
candidate_master=1
[server3]
hostname=192.168.4.53
port=3306
candidate_master=1
[server4]
hostname=192.168.4.54
no_master=1
[server5]
hostname=192.168.4.55
no_master=1
[root@mgm56 mha4mysql-manager-0.56]# cp samples/scripts/master_ip_failover
/usr/local/bin/ //创建故障切换的脚本
