MySQL一主两从

服务器说明:

　　MySQL-Master:192.168.1.

　　MySQL-Slave1:192.168.1.

　　MySQL-Slave2:192.168.1.

关闭防火墙，关闭selinux

统一采用源码安装MySQL-5.6.16.tar.gz。具体的包可以百度或者官网下载(https://www.mysql.com/)

首先，在三台服务器上统一安装MySQL。具体过程如下

yum -y install make gcc-c++ cmake bison-devel  ncurses-devel
tar -zvxf mysql-5.6..tar.gz
cd mysql-5.6.

进行cmake编译
cmake \
-DCMAKE_INSTALL_PREFIX=/usr/local/mysql \
-DMYSQL_DATADIR=/usr/local/mysql/data \
-DSYSCONFDIR=/etc \
-DWITH_MYISAM_STORAGE_ENGINE= \
-DWITH_INNOBASE_STORAGE_ENGINE= \
-DWITH_MEMORY_STORAGE_ENGINE= \
-DWITH_READLINE= \
-DMYSQL_UNIX_ADDR=/usr/local/mysql/mysql.sock \
-DMYSQL_TCP_PORT= \
-DENABLED_LOCAL_INFILE= \
-DWITH_PARTITION_STORAGE_ENGINE= \
-DEXTRA_CHARSETS=all \
-DDEFAULT_CHARSET=utf8 \
-DDEFAULT_COLLATION=utf8_general_ci

安装
make && make install

使用下面的命令查看是否有mysql用户及用户组

cat /etc/passwd      #查看用户列表
cat /etc/group       #查看用户组列表

如果没有就创建

groupadd mysql
useradd -g mysql mysql

修改/usr/local/mysql权限

chown -R mysql:mysql /usr/local/mysql

初始化MySQL

cd /usr/local/mysql        #进入MySQL目录

scripts/mysql_install_db --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --user=mysql    

###################################################################################################

注：在启动MySQL服务时，会按照一定次序搜索my.cnf，先在/etc目录下找，找不到则会搜索"$basedir/my.cnf"，在本例中就是 /usr/local/mysql/my.cnf，这是新版MySQL的配置文件的默认位置！

注意：在CentOS 6.4版操作系统的最小安装完成后，在/etc目录下会存在一个my.cnf，需要将此文件更名为其他的名字，如：/etc/my.cnf.bak，否则，该文件会干扰源码安装的MySQL的正确配置，造成无法启动 

在使用"yum update"更新系统后，需要检查下/etc目录下是否会多出一个my.cnf，如果多出，将它重命名成别的。否则，MySQL将使用这个配置文件启动，可能造成无法正常启动等问题

##################################################################################################

#注意：
    初始化时可能会遇到报错，报错原因如下
    scripts/mysql_install_db  -bash: scripts/mysql_install_db: /usr/bin/perl: 坏的解释器: 没有那个文件或目录

解决办法：
    yum install -y perl-Module-Install.noarch
    重新执行初始化

cp support-files/mysql.server /etc/init.d/mysql         #拷贝启动脚本
chkconfig mysql on                                     #添加开机自启
service mysql start  --启动MySQL                        #启动MySQL

再启动过程中，发现启动失败一直报这个错误

Starting MySQL. ERROR! The server quit without updating PID file (/var/lib/mysql/xxxxxxxx.pid).

解决办法还是看我上面红框中的最后一句话，由于我的/etc/下有一个my.cnf 没有重命名，启动MySQL的时候会首先查看/etc，那么就会照成冲突，所以将/etc/my.cnf 备份为 my.cnf.bak。重新启动MySQL ok

MySQL启动成功后，root默认没有密码，我们需要设置root密码。

设置之前，我们需要先设置PATH，要不不能直接调用mysql

修改/etc/profile文件，在文件末尾添加

PATH=/usr/local/mysql/bin:$PATH
export PATH
退出后执行source /etc/profile

#登录mysql并修改密码
mysql
mysql> SET PASSWORD = PASSWORD('new password');

到这里MySQL就算是搭建完成了，接下来配置主从同步

首先创建授权账户

mysql> GRANT REPLICATION SLAVE ON *.* TO 'slave1'@'192.168.1.136' IDENTIFIED BY 'slave1';

mysql> GRANT REPLICATION SLAVE ON *.* TO 'slave2'@'192.168.1.140' IDENTIFIED BY 'slave2';

Master数据库退出MySQL，编辑/usr/local/mysql/my.cnf

[mysqld]              #在mysqld下面添加如下两行

server-id = 2
log-bin=mysql-bin
binlog-ignore-db=mysql　　#忽略的数据库
binlog-ignore-db=information-schema

重启Master数据库

查看状态

mysql> show master status;
+------------------+----------+--------------+--------------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB         | Executed_Gtid_Set |
+------------------+----------+--------------+--------------------------+-------------------+
| mysql-bin.000003 |      120 |              | information_schema,mysql |                   |
+------------------+----------+--------------+--------------------------+-------------------+
1 row in set (0.00 sec)

同样将两台slave服务器也进行如下修改

编辑/usr/local/mysql/my.cnf文件

#slave1
[mysqld]
log-bin=mysql-bin
server-id=136
replicate_ignore_db=mysql       #被忽略的数据库
replicate-ignore-db=information-schema
slave-skip-errors=all           #跳过所有错误

#slave2
[mysqld]
log-bin=mysql-bin
server-id=140
replicate_ignore_db=mysql       #被忽略的数据库
replicate-ignore-db=information-schema
slave-skip-errors=all           #跳过所有错误

参数说明

replicate_do_db=db_name            #只复制db_name数据库
replicate_ignore_db=db_name        #不复制db_name数据库
replicate_do_table=tb_name         #复制tb_name表
replicate_ignore_table=tb_name     #不复制tb_name表
replicate_wild_do_table=test%      #复制以test为开头并且后面跟上任意
read-only=1                        #只读

重新启动两台从库

分别在两台机器上操作stop slave；

然后在分别在两台机器上做如下操作

在slave1上操作

change master to master_host='192.168.1.142',
master_user='slave1',　　　　　　#注意用户名
master_password='slave1',　　　　#注意密码
master_log_file='mysql-bin.000003',
master_log_pos=120;

在slave2上操作

change master to master_host='192.168.1.142',
master_user='slave2',          #注意用户名
master_password='slave2',    #注意面
master_log_file='mysql-bin.000003',
master_log_pos=120;    

分别在两台机器上操作start slave;

最后分别查看从库状态

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.142
                  Master_User: slave1
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 120
               Relay_Log_File: elk-node2-relay-bin.000002
                Relay_Log_Pos: 283
        Relay_Master_Log_File: mysql-bin.000003
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB: mysql,information-schema
           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: 120
              Relay_Log_Space: 460
              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
                  Master_UUID: 780d388c-7040-11e7-b42a-000c29199d74
             Master_Info_File: /usr/local/mysql/data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position: 0
1 row in set (0.00 sec)

slave1

mysql> show slave status\G;
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.142
                  Master_User: slave2
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000003
          Read_Master_Log_Pos: 120
               Relay_Log_File: controller01-relay-bin.000002
                Relay_Log_Pos: 283
        Relay_Master_Log_File: mysql-bin.000003
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB:
          Replicate_Ignore_DB: mysql,information-schema
           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: 120
              Relay_Log_Space: 463
              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
                  Master_UUID: 780d388c-7040-11e7-b42a-000c29199d74
             Master_Info_File: /usr/local/mysql/data/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it
           Master_Retry_Count: 86400
                  Master_Bind:
      Last_IO_Error_Timestamp:
     Last_SQL_Error_Timestamp:
               Master_SSL_Crl:
           Master_SSL_Crlpath:
           Retrieved_Gtid_Set:
            Executed_Gtid_Set:
                Auto_Position: 0
1 row in set (0.00 sec)

slave2

通过主库查看从库状态

mysql> show slave hosts;
+-----------+------+------+-----------+--------------------------------------+
| Server_id | Host | Port | Master_id | Slave_UUID                           |
+-----------+------+------+-----------+--------------------------------------+
|       136 |      | 3306 |         2 | 8346c426-7040-11e7-b42a-000c29dcd50c |
|       140 |      | 3306 |         2 | 8d82f208-7040-11e7-b42a-000c29e2e25f |
+-----------+------+------+-----------+--------------------------------------+
2 rows in set (0.00 sec)

ps:可能执行show slave status;时发现 Slave_IO_Running: Connecting。解决方法，首先查看用户名密码是否正确，各主机之间是否能ping同，防火墙是否关闭，博主在做实验的时候就没有关闭防火墙导致一直连接不上。

测试

在Master数据库创建一个测试库与测试表

/*创建库*/
mysql> CREATE database test_mysql;
/*创建表*/
mysql> create table python_one(
    -> id int(11)
    -> name varchar(255)
    -> );

/*插入两条数据*/
INSERT INTO python_one(id,name,) value(1,'字典');
INSERT INTO python_one(id,name,) value(2,'函数');

/*查看数据*/
mysql> SELECT * FROM python_one;
+------+--------+
| id   | name   |
+------+--------+
|    1 | 字典   |
|    2 | 函数   |
+------+--------+
2 rows in set (0.01 sec)

分别在两个从库上面查看数据

Slave1

mysql> SELECT * FROM test_mysql.python_one;
+------+--------+
| id   | name   |
+------+--------+
|    1 | 字典   |
|    2 | 函数   |
+------+--------+
2 rows in set (0.00 sec)

Slave2

mysql> SELECT * FROM test_mysql.python_one;
+------+--------+
| id   | name   |
+------+--------+
|    1 | 字典   |
|    2 | 函数   |
+------+--------+
2 rows in set (0.00 sec)

测试结果没有问题，一主多从就搭建完成了