Mysql主从

安装Mysql

环境

[root@node1 ~]#  cat /etc/redhat-release
CentOS Linux release 7.1.1503 (Core)

[root@node1 ~]# uname -a
Linux node4 3.10.0-229.el7.x86_64 #1 SMP Fri Mar 6 11:36:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

主机

Master：10.0.0.10 node1
Slave：10.0.0.11 node2

检查系统是否自带安装mysql

[root@node1 ~]# yum list installed | grep mysql 
[root@node1 ~]# 

如果有将其删除

[root@node1 ~]# yum -y remove mysql-libs.x86_64
Loaded plugins: fastestmirror
No Match for argument: mysql-libs.x86_64
No Packages marked for removal

由于mysql的yum源服务器在国外，所以下载速度会比较慢，还好mysql5.6只有79M大，而mysql5.7就有182M了，所以这里想安装mysql5.6

下载rpm包

[root@node1 ~]# wget http://repo.mysql.com/mysql-community-release-el7-7.noarch.rpm

解压

[root@node1 ~]# rpm -ivh mysql-community-release-el7-7.noarch.rpm 

检查mysql源是否安装成功

[root@node2 ~]# yum repolist enabled | grep "mysql.*-community.*"
mysql-connectors-community/x86_64 MySQL Connectors Community                  42
mysql-tools-community/x86_64      MySQL Tools Community                       51
mysql56-community/x86_64          MySQL 5.6 Community Server              

查看是否已经有mysql可安装文件

root@node1 ~]#  yum repolist all | grep mysql
mysql-connectors-community/x86_64 MySQL Connectors Community     enabled:     42
mysql-connectors-community-source MySQL Connectors Community - S disabled
mysql-tools-community/x86_64      MySQL Tools Community          enabled:     51
mysql-tools-community-source      MySQL Tools Community - Source disabled
mysql55-community/x86_64          MySQL 5.5 Community Server     disabled
mysql55-community-source          MySQL 5.5 Community Server - S disabled
mysql56-community/x86_64          MySQL 5.6 Community Server     enabled:    344
mysql56-community-source          MySQL 5.6 Community Server - S disabled
mysql57-community/x86_64          MySQL 5.7 Community Server     disabled
mysql57-community-source          MySQL 5.7 Community Server - S disabled

可以修改 mysql-community.repo 源，更改默认安装的mysql版本比如要安装5.6版本，将5.7源的enabled=1改成enabled=0。然后再将5.6源的enabled=0改成enabled=1即可。改完之后的效果如下所示： 

[root@node2 ~]# vim /etc/yum.repos.d/mysql-community.repo

enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

[mysql-tools-community]
name=MySQL Tools Community
baseurl=http://repo.mysql.com/yum/mysql-tools-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

# Enable to use MySQL 5.5
[mysql55-community]
name=MySQL 5.5 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.5-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

# Enable to use MySQL 5.6
[mysql56-community]
name=MySQL 5.6 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.6-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

安装mysql 服务器（网速决定安装速度）

[root@node1 ~]# yum -y install mysql-community-server

启动 mysql 服务

[root@node1 ~]# systemctl start mysql

查看mysql 的启动状态

[root@node1 ~]# systemctl status mysqld
mysqld.service - MySQL Community Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled)
   Active: active (running) since Wed 2017-08-23 11:28:23 EDT; 38min ago
  Process: 2904 ExecStartPost=/usr/bin/mysql-systemd-start post (code=exited, status=0/SUCCESS)
  Process: 2843 ExecStartPre=/usr/bin/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
 Main PID: 2903 (mysqld_safe)

开机启动

[root@node1 ~]# systemctl enable mysqld
[root@node1 ~]# systemctl daemon-reload

以上操作在10.0.0.10和10.0.0.11 上做相同操作

配置主从

修改主服务器master

[root@node1 ~]# vim /etc/my.cnf
[mysqld]
log-bin=mysql-bin   #[不是必须]启用二进制日志
server-id=10     #[必须]服务器唯一ID，默认是1，一般取IP最后一段

修改从服务器Slave

[root@node2 ~]# vim /etc/my.cnf
[mysqld]
log-bin=mysql-bin   #[不是必须]启用二进制日志
server-id=11     #[必须]服务器唯一ID，默认是1，一般取IP最后一段

重启两台服务器的Mysql

[root@node1 ~]# systemctl restart mysql
[root@node2 ~]# systemctl restart mysql

在主服务器上建立账号并授权从服务器（由于Mysql没有设置密码，只需输入mysql登录即可）

[root@node1 ~]#mysql
mysql> GRANT REPLICATION SLAVE ON *.* to 'mysync'@'%' identified by '123456';
一般不用root帐号，“%”表示所有客户端都可能连，只要帐号，密码正确，此处可用具体
客户端IP代替，如192.168.145.226，加强安全。

登录主服务器的mysql，查询master的状态

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 |      760 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

注意 File 和 Position 的值；执行完此步骤后不要再操作主服务器MYSQL，防止主服务器状态值变化

配置从服务器Slave

mysql>change master to master_host='10.0.0.10',master_user='mysync',master_password='123456',
       master_log_file='mysql-bin.000002',master_log_pos=760;   # 注意不要断开，master_log_file 和 master_log_pos 的值在主服务器上面

启动从服务器复制功能

 Mysql>start slave;

检查从服务器复制功能状态

mysql> show slave statusG

   *************************** 1. row ***************************

           Slave_IO_State: Waiting for master to send event
              Master_Host: 10.0.0.10  #主服务器地址
              Master_User: mysync   #授权帐户名，尽量避免使用root
              Master_Port: 3306    #数据库端口，部分版本没有此行
            Connect_Retry: 60
          Master_Log_File: mysql-bin.000002
      Read_Master_Log_Pos: 600    #同步读取二进制日志的位置，大于等于Exec_Master_Log_Pos
           Relay_Log_File: ddte-relay-bin.000002
            Relay_Log_Pos: 760
    Relay_Master_Log_File: mysql-bin.000002
         Slave_IO_Running: Yes    #此状态必须YES
        Slave_SQL_Running: Yes    #此状态必须YES

以上操作过程，主从服务器配置完成

主从服务器测试

主服务器Mysql，建立数据库，并在这个库中建表插入一条数据

 mysql> create database hi_db;
  Query OK, 1 row affected (0.00 sec)

  mysql> use hi_db;
  Database changed

  mysql>  create table hi_tb(id int(3),name char(10));
  Query OK, 0 rows affected (0.00 sec)
 
  mysql> insert into hi_tb values(001,'bobu');
  Query OK, 1 row affected (0.00 sec)

  mysql> show databases;
   +--------------------+
   | Database           |
   +--------------------+
   | information_schema |
   | hi_db                |
   | mysql                |
   | test                 |
   +--------------------+
   4 rows in set (0.00 sec)

从服务器Mysql查询

 mysql> show databases;

   +--------------------+
   | Database               |
   +--------------------+
   | information_schema |
   | hi_db                 |       #看到了吧
   | mysql                 |
   | test          |
   +--------------------+
   4 rows in set (0.00 sec)

   mysql> use hi_db
   Database changed
   mysql> select * from hi_tb;      #查看主服务器上新增的具体数据
   +------+------+
   | id   | name |
   +------+------+
   |    1 | bobu |
   +------+------+
   1 row in set (0.00 sec)
 

完成

 编写一shell脚本，用nagios监控slave的两个yes（Slave_IO及Slave_SQL进程），如发现只有一个或零个yes，就表明主从有问题了，发短信警报

参考文档：

http://blog.51cto.com/369369/790921