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花了小一天的时间，终于实现了centos7 mariadb主从复制配置搭建，下面记录一下过程
环境:
虚拟机:vm8; centos7 版本：7.2.1511; mariadb 版本：centos7.2内置的
主库服务器： 10.69.5.200，CentOS 7，MariaDB 10已安装，有数据。
从库服务器1： 10.69.5.201，CentOS 7，MariaDB 10已安装，无应用数据。
主服务器配置
以下操作在主服务器192.168.71.151的/etc/my.cnf上进行。
1.修改配置文件，命令：vim /etc/my.cnf，输入下列代码：
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | [root@localhost ~] # cat /etc/my.cnf [mysqld] datadir= /var/lib/mysql socket= /var/lib/mysql/mysql .sock ` # 新添加的部分 # 配置主从时需要添加以下信息 start innodb_file_per_table=NO log-bin= /var/lib/mysql/master-bin #log-bin没指定存储目录，则是默认datadir指向的目录 binlog_format=mixed server- id =200 #每个服务器都需要添加server_id配置，各个服务器的server_id需要保证唯一性，实践中通常设置为服务器IP地址的最后一位 #配置主从时需要添加以下信息 end ` # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 # Settings user and group are ignored when systemd is used. # If you need to run mysqld under a different user or group, # customize your systemd unit file for mariadb according to the # instructions in http://fedoraproject.org/wiki/Systemd [mysqld_safe] log-error= /var/log/mariadb/mariadb .log pid- file = /var/run/mariadb/mariadb .pid # # include all files from the config directory # !includedir /etc/my .cnf.d |
最后，:wq!保存退出
2.重启mariadb服务，输入命令
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| 1 | [root@localhost ~] # systemctl restart mariadb.service |
3.登录mariadb
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| 1 | [root@localhost ~] # mysql -u root -padmin |
注：-p后是密码，中间没有空格
4.创建帐号并赋予replication的权限
从库,从主库复制数据时需要使用这个帐号进行
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| 1 2 | MariaDB [(none)]> GRANT REPLICATION SLAVE ON *.* TO 'root' @ '10.69.5.%' IDENTIFIED BY 'admin' ; Query OK, 0 rows affected (0.00 sec) |
5.备份数据库数据，用于导入到从数据库中
加锁
实际工作中，备份的时候是不让往库中写数据的，所以数据库要加锁，只能读
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| 1 2 | MariaDB [(none)]> FLUSH TABLES WITH READ LOCK; Query OK, 0 rows affected (0.00 sec) |
记录主库log文件及其当前位置
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| 1 2 3 4 5 6 | MariaDB [(none)]> SHOW MASTER STATUS; + ------------------+----------+--------------+------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | + ------------------+----------+--------------+------------------+ | mysql-bin.000001 | 694 | | | + ------------------+----------+--------------+------------------+ |
记住File和Position的部分，从服务器会用到
备份数据，输入命令：
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| 1 | [root@localhost ~] # mysqldump -uroot -p --all-databases > /root/db.sql |
解锁 主库
数据备份完成后，就可以释放主库上的锁：
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| 1 2 | MariaDB [(none)]> UNLOCK TABLES; Query OK, 0 rows affected (0.00 sec) |
从服务器配置
以下在从服务器上的操作
1.导入主库的数据
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| 1 | [root@localhost ~] # mysql -uroot -p < db.sql |
2.从服务器/etc/my.cnf配置,设置relay-log
my.cnf文件中添加一行relay_log=relay-bin
如果不设置，默认是按主机名 + “-relay-bin”生成relay log。
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | [root@localhost ~] # cat /etc/my.cnf [mysqld] datadir= /var/lib/mysql socket= /var/lib/mysql/mysql .sock # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 ` #配置主从时需要添加以下信息 start innodb_file_per_table=NO server- id =201 #一般与服务器ip的最后数字一致 relay-log= /var/lib/mysql/relay-bin #配置主从时需要添加以下信息 end ` # Settings user and group are ignored when systemd is used. # If you need to run mysqld under a different user or group, # customize your systemd unit file for mariadb according to the # instructions in http://fedoraproject.org/wiki/Systemd [mysqld_safe] log-error= /var/log/mariadb/mariadb .log pid- file = /var/run/mariadb/mariadb .pid # # include all files from the config directory # !includedir /etc/my .cnf.d |
3.重启服务
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| 1 | [root@localhost ~] # systemctl restart mariadb.service |
4.登录mariadb
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| 1 | [root@localhost ~] # mysql -u root -padmin |
5.设置主从复制
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| 1 2 | MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST= '10.69.5.200' ,MASTER_USER= 'root' , MASTER_PASSWORD= 'admin' , MASTER_LOG_FILE= 'master-bin.000001' , MASTER_LOG_POS= 694; Query OK, 0 rows affected (0.02 sec) |
这个命令完成以下几个任务：
a.设置当前服务器为主服务器(10.69.5.200)的从库
b.提供当前数据库(从库)从主库复制数据时所需的用户名和密码，即上面的GRANT REPLICATION SLAVE ON *.* TO ‘root’@’10.69.5.%’ IDENTIFIED BY ‘admin’;设置的
c.指定从库开始复制主库时需要使用的日志文件和文件位置，即上面主库执行SHOW MASTER STATUS;显示结果中的File和Position
6.开启主从复制
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| 1 2 | MariaDB [(none)]> START SLAVE; Query OK, 0 rows affected (0.00 sec) |
7.查看从库状态
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | MariaDB [(none)]> show slave status\G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 10.69.5.200 Master_User: root Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000001 Read_Master_Log_Pos: 694 Relay_Log_File: relay-bin.000003 Relay_Log_Pos: 530 Relay_Master_Log_File: master-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: 694 Relay_Log_Space: 818 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: 200 1 row in set (0.00 sec) |
注意：结果中Slave_IO_Running和Slave_SQL_Running必须为Yes，如果不是，需要根据提示的错误修改。
验证
主服务器：
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | MariaDB [(none)]> show databases; + --------------------+ | Database | + --------------------+ | information_schema | | mysql | | mytest | | performance_schema | | test | + --------------------+ 5 rows in set (0.04 sec) MariaDB [(none)]> use mytest; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed MariaDB [mytest]> select * from user ; + ----+------+ | id | name | + ----+------+ | 1 | t | | 2 | t2 | | 3 | t3 | + ----+------+ 3 rows in set (0.00 sec) MariaDB [mytest]> insert into user ( name ) values ( 't4' ); Query OK, 1 row affected (0.01 sec) MariaDB [mytest]> select * from user ; + ----+------+ | id | name | + ----+------+ | 1 | t | | 2 | t2 | | 3 | t3 | | 4 | t4 | + ----+------+ 4 rows in set (0.00 sec) |
查看从服务器数据是否变化：
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | MariaDB [(none)]> use mytest; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed MariaDB [mytest]> select * from user ; + ----+------+ | id | name | + ----+------+ | 1 | t | | 2 | t2 | + ----+------+ 2 rows in set (0.00 sec) MariaDB [mytest]> select * from user ; + ----+------+ | id | name | + ----+------+ | 1 | t | | 2 | t2 | | 4 | t4 | + ----+------+ 3 rows in set (0.00 sec) |
可以看到，从服务器更新了数据
搭建过程中遇到的问题及解决方法
问题1：从服务器设置主从复制出现错误:
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| 1 2 | MariaDB [mytest]> start slave; ERROR 1201 (HY000): Could not initialize master info structure; more error messages can be found in the MariaDB error log |
发现
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| 1 2 | Slave_IO_Running: No Slave_SQL_Running: No |
进一步发现我输入的是：CHANGE MASTER TO MASTER_HOST=’192.168.71.151′,MASTER_USER=’slave_user’, MASTER_PASSWORD=’bigs3cret’, MASTER_LOG_FILE=’mysql-bin.000001′, MASTER_LOG_POS= 469;
重新输入：MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST=’10.69.5.200′,MASTER_USER=’root’, MASTER_PASSWORD=’admin’, MASTER_LOG_FILE=’mysql-bin.000001′, MASTER_LOG_POS= 469;
报错：ERROR 1201 (HY000): Could not initialize master info structure; more error messages can be found in the MariaDB error log
于是看错误日志：/var/log/mariadb/mariadb.log
错误日志的位置在/etc/my.cnf中配置：log-error=/
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| 1 2 3 | [root@localhost ~] # cat /var/log/mariadb/mariadb.log 160915 12:52:02 [ERROR] Failed to open the relay log './mariadb-relay-bin.000001' (relay_log_pos 4) 160915 12:52:02 [ERROR] Could not find target log during relay log initialization |
通过查找答案： 删除/var/lib/mysql/路径下the ‘master.info’ ‘mysqld-relay-bin.*’ ‘relay-log.info’ ‘relay-log-index.*’
运行命令：rm -rf master.info,rm -rf *relay*
重启服务：[root@localhost mysql]# systemctl restart mariadb.service
进入mariadb:
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| 1 2 3 4 5 6 7 | [root@localhost mysql] # mysql -u root -padmin MariaDB [(none)]> flush logs; Query OK, 0 rows affected (0.00 sec) MariaDB [(none)]> reset slave; Query OK, 0 rows affected (0.00 sec) |
重新设置主从复制关系：
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| 1 2 | MariaDB [(none)]> CHANGE MASTER TO MASTER_HOST= '10.69.5.200' ,MASTER_USER= 'root' , MASTER_PASSWORD= 'admin' , MASTER_LOG_FILE= 'master-bin.000001' , MASTER_LOG_POS= 694; Query OK, 0 rows affected (0.02 sec) |
这次成功了。
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| 1 2 | MariaDB [(none)]> start slave; Query OK, 0 rows affected (0.01 sec) |
查看从库状态：
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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | MariaDB [(none)]> show slave status\G *************************** 1. row *************************** Slave_IO_State: Connecting to master Master_Host: 10.69.5.200 Master_User: root Master_Port: 3306 Connect_Retry: 60 Master_Log_File: master-bin.000001 Read_Master_Log_Pos: 694 Relay_Log_File: relay-bin.000001 Relay_Log_Pos: 4 Relay_Master_Log_File: master-bin.000001 Slave_IO_Running: Connecting Slave_SQL_Running: Yes ··· ··· ··· Replicate_Ignore_Server_Ids: Master_Server_Id: 0 1 row in set (0.00 sec) |
发现问题2.Slave_IO_Running: Connecting
问题2.Slave_IO_Running: Connecting
查看错误日志
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| 1 2 3 4 | [root@localhost ~] # cat /var/log/mariadb/mariadb.log ··· 160915 13:17:56 [Note] Slave SQL thread initialized, starting replication in log 'master-bin.000001' at position 694, relay log '/var/lib/mysql/relay-bin.000001' position: 4 160915 13:17:56 [ERROR] Slave I /O : error connecting to master 'root@10.69.5.200:3306' - retry- time : 60 retries: 86400 message: Can 't connect to MySQL server on ' 10.69.5.200' (113), Error_code: 2003 |
这时运行telnet命令
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| 1 | [root@localhost ~] # telnet 10.69.5.200 3306 |
-bash: telnet: 未找到命令
安装telnet
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| 1 | [root@localhost ~] # yum -y install telnet-server.x86_64 |
安装成功后重启telnet服务
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| 1 2 3 | [root@localhost ~] # systemctl start telnet.socket [root@localhost ~] # systemctl enable telnet.socket [root@localhost ~] # telnet 10.69.5.200 3306 |
-bash: telnet: 未找到命令
还是不行
这回我reboot重启虚拟机，运行命令
注意：这回不是”yum -y install telnet-server.x86_64″了，这回没有telnet-server了
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| 1 | [root@localhost ~] # yum install telnet.x86_64 |
运行成功了
接着
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| 1 2 3 4 5 6 | [root@localhost ~] # systemctl enable telnet.socket [root@localhost ~] # systemctl start telnet.socket [root@localhost ~] # firewall-cmd --add-service=telnet --permanent success [root@localhost ~] # telnet telnet> |
telnet终于安装成功了
从最新版本的centos7系统开始，默认的是 Mariadb而不是mysql！
使用系统自带的repos安装很简单：
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| 1 | yum install mariadb mariadb-server |
- systemctl start mariadb ==> 启动mariadb
- systemctl enable mariadb ==> 开机自启动
- mysql_secure_installation ==> 设置 root密码等相关
- mysql -u root -p 123456 ==> 测试登录！
