DBA成长之路（1）

#MariaDB数据库安装并同步
##具体步骤
1.安装一个数据库(MariaBD)
2.有一个xxx.sql.gz 数据库备份文件
3.导入到新的数据库中
4.让它正常同步

###一、MariaDB的安装和配置

####1、添加yum数据源
建议命名为 MariaDB.repo 类似的名字：
cd /etc/yum.repos.d/
vim /etc/yum.repos.d/MariaDB.repo
然后，写入内容：

# MariaDB 10.0 CentOS repository list - created 2016-03-23 07:50 UTC
# http://mariadb.org/mariadb/repositories/
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.0/centos6-amd64
gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB
gpgcheck=1

该文件的内容是参考官网,并从官网上生成的，设置安装源仓库的 具体的地址为: https://downloads.mariadb.org/mariadb/repositories/
选择好操作系统版本之后既可以查看，其他操作系统的安装源也可以在此处查看并设置。

####2、yum安装MariaDB

yum -y install MariaDB-server MariaDB-client

####3、启动数据库

# 查看mysql状态;关闭数据库  
# service mysql status  
# service mysql stop  
# 启动数据库  
service mysql start  

####4、修改root密码

mysql_secure_installation
使用这个命令来修改密码有很多好处，拒绝远程登录，而且不会出现空密码，可以把空白的用户删除掉，还能指定域是在内网范围的。

MariaDB [mysql]> select user,password,host from user;
+------+-------------------------------------------+-----------------------+
| user | password                                  | host                  |
+------+-------------------------------------------+-----------------------+
| root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | localhost             |
| root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | localhost.localdomain |
| root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | 127.0.0.1             |
| root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | ::1                   |
| rep1 | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | 192.168.42.%          |
| rep  | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | 192.168.42.%          |
+------+-------------------------------------------+-----------------------+

测试，如果使用mysqladmin来修改密码：

mysqladmin -u root password '123456' 
MariaDB [mysql]> select user,password,host from user;
+------+-------------------------------------------+-----------------------+
| user | password                                  | host                  |
+------+-------------------------------------------+-----------------------+
| root | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | localhost             |
| root |                                           | localhost.localdomain |
| root |                                           | 127.0.0.1             |
| root |                                           | ::1                   |
|      |                                           | localhost             |
|      |                                           | localhost.localdomain |
| rep  | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | 192.168.42.%          |
| rep1 | *6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9 | 192.168.42.%          |
+------+-------------------------------------------+-----------------------+

然后这里就出现了很多空密码，甚至还有空用户空密码可以直接登录，安全度不高。
这里由于我是测试数据，所以密码比较简单，如果是重要的服务器，一定要使用复杂密码，切记切记！！
####5、登录数据库
mysql -uroot -p123456
这里是一样的，在重要的服务器上，登录数据库的时候，不能这样暴露密码！

6、插入测试数据

# 创建test_zxh数据库用作后面同步测试
create database test_zxh;
#查看数据库
show databases;
#创建一个测试表
CREATE TABLE Employee(
EpId INT,
EpName nvarchar(20),
EpSex char(2),
EpAdress nvarchar(20),
EpPhone nvarchar(20),
EpEmail nvarchar(20)
);
#插入测试数据
insert into Employee 
value (6366,'laowang','男','菲律宾','18888888888','[email protected]');
#查询测试数据
select * from Employee;

7、slave服务器按照上面安装MariaDB

在slave服务器安装MariaDB，但是不插入数据

二、主从同步

1、环境描述

服务器A(主) 192.168.42.133
　　服务器B(从) 192.168.42.134
　　Mysql版本：10.0.24

2、确认两个服务器上MariaDB版本相同

MariaDB [test_zxh]> status
--------------
mysql  Ver 15.1 Distrib 10.0.24-MariaDB, for Linux (x86_64) using readline 5.1

Connection id:          6
Current database:       test_zxh
Current user:           root@localhost
SSL:                    Not in use
Current pager:          stdout
Using outfile:          ''
Using delimiter:        ;
Server:                 MariaDB
Server version:         10.0.24-MariaDB MariaDB Server
Protocol version:       10
Connection:             Localhost via UNIX socket
Server characterset:    latin1
Db     characterset:    latin1
Client characterset:    utf8
Conn.  characterset:    utf8
UNIX socket:            /var/lib/mysql/mysql.sock
Uptime:                 33 min 57 sec

3、创建同步用户

在主服务器上为从服务器建立一个连接帐户，该帐户必须授予REPLICAITON SLAVE权限。

CREATE USER 'rep1'@'192.168.42.%' IDENTIFIED BY '123456';
grant replication slave on *.* to 'rep1'@'192.168.42.%' identified by '123456';
flush privileges;

4、主从打开binlog

1）主服务器

①.修改MariaDB配置文件

vi /etc/my.cnf
#
# This group is read both both by the client and the server
# use it for options that affect everything
#
[client-server]

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
server-id=1
log-bin=/var/lib/mysql/mysql-bin

[mysqld_safe]
log-error=/var/log/mysqld.log

注意：因为这是在自己的虚拟机里面测试，所以需要配置，一般在服务器中已经开启binlog。
######②.重启服务

[root@localhost mysql]# service mysql restart
Shutting down MySQL... SUCCESS! 
Starting MySQL. SUCCESS!

③.查看master状态

MariaDB [(none)]> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 |      312 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

2）从服务器

①.修改MariaDB配置文件

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
server-id=3
log-bin=/var/lib/mysql/mysql-bin

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

######②.重启服务

[root@localhost scripts]# service mysql restart
 ERROR! MySQL server PID file could not be found!
Starting MySQL.. SUCCESS! 
[root@localhost scripts]# 

5、主库导出sql导入从库

主服务器导出：

#锁表
MariaDB [(none)]> FLUSH TABLES WITH READ LOCK;
#导出test_zxh这个数据库
mysqldump --master-data -uroot -p test_zxh > test_zxh.sql
#查看master状态

MariaDB [(none)]> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000001 |      312 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)
#解除锁表状态
MariaDB [(none)]> UNLOCK TABLES;

（更新之后的方法）
因为mysqldump导出sql的时候自动会去锁表，而且带了–master-data就能把master的position放在sql里面一起执行，所以只需要一步导出就可以，考虑到生产环境中数据大的问题，所以用管道连接压缩，将到出来的sql压缩。

mysqldump --master-data -uroot -p test_zxh | gzip > test_zxh.sql.gz

从服务器导入：

#将导出的sql拷到本地
scp [email protected]:/var/lib/mysql/test_zxh.sql .
#创建test_zxh数据库
MariaDB [(none)]> create database test_zxh;
#导入数据
mysql -uroot -p test_zxh < test_zxh.sql
#查看数据是否导入成功
MariaDB [test_zxh]> select * from Employee;
+------+--------------+-------+----------+-------------+------------------+
| EpId | EpName       | EpSex | EpAdress | EpPhone     | EpEmail          |
+------+--------------+-------+----------+-------------+------------------+
| 6366 | laowang | ?     | 菲律宾     | 18888888888 | [email protected] |
+------+--------------+-------+----------+-------------+------------------+

**（更新后的方法）**直接将压缩的sql边解压边执行，这样能大大增大效率，这里还是使用管道。

#解压并导入数据
cat test_zxh.sql.gz | gunzip | mysql -uroot -p test_zxh
#查看数据插入是否成功
MariaDB [test_zxh]> select * from Employee;
Empty set (0.00 sec)
MariaDB [test_zxh]> select * from Employee;
+------+--------------+-------+----------+-------------+------------------+
| EpId | EpName       | EpSex | EpAdress | EpPhone     | EpEmail          |
+------+--------------+-------+----------+-------------+------------------+
| 6366 | laowang | ?     | 菲律宾     | 18888888888 | [email protected] |
+------+--------------+-------+----------+-------------+------------------+
1 row in set (0.00 sec)

从服务器上开启slave进行同步：

#配置slave信息
CHANGE MASTER TO
MASTER_HOST='192.168.42.133',
MASTER_PORT=3306,
MASTER_USER='rep1',
MASTER_PASSWORD='123456',
MASTER_LOG_FILE='mysql-bin.000001',
MASTER_LOG_POS=312;
#启动slave
MariaDB [(none)]> start slave;
#查看是否同步
MariaDB [(none)]> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.42.133
                  Master_User: rep1
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 979
               Relay_Log_File: localhost-relay-bin.000002
                Relay_Log_Pos: 1202
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           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: 979
              Relay_Log_Space: 1503
              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
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
                   Using_Gtid: No
                  Gtid_IO_Pos: 
1 row in set (0.00 sec)

完成从服务器的同步。