mysql主從複製

一、介紹

       MySQL做爲世界上使用最爲普遍的數據庫之一，免費是其緣由之一。但不可忽略的是它自己的功能的確很強大。隨着技術的發展，在實際的生產環境中，由單臺MySQL數據庫服務器不能知足實際的需求。此時數據庫集羣就很好的解決了這個問題了。採用MySQL分佈式集羣，可以搭建一個高併發、負載均衡的集羣服務器（這篇博客暫時不涉及）。在此以前咱們必需要保證每臺MySQL服務器裏的數據同步。數據同步咱們能夠經過MySQL內部配置就能夠輕鬆完成，主要有主從複製和主主複製。

二、環境

主：192.168.182.155 centos7.2   

從：192.168.182.156 centos7.2   

三、主從複製

3.一、修改配置文件

修改主從服務器的配置文件/etc/my.cnf，在mysqld中添加log-bin=mysql-bin開啓二進制文件

主服務配置：

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

#
# This group is read by the server
#
[mysqld]
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

log-bin=mysql-bin

  server-id=1
  innodb_flush_log_at_trx_commit=1
  sync_binlog=1
  binlog_ignore_db=mysql

#
# include all files from the config directory
#
!includedir /etc/my.cnf.d

 

從服務器配置：

[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

log-bin=mysql-bin

server-id=2

# 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

 

 3.二、開始構建主從複製

在192.168.182.155中建立一個192.168.182.156主機中能夠登陸的MySQL用戶

登錄主數據庫

mysql  -uroot -pwc20080512;

建立鏈接帳號和密碼

MariaDB [(none)]> CREATE USER 'mysql12'@ '192.168.182.156' IDENTIFIED BY 'mysql12';

 

受權

MariaDB [(none)]> GRANT REPLICATION SLAVE ON *.* TO 'mysql12'@192.168.182.156 IDENTIFIED BY 'mysql12';
Query OK, 0 rows affected (0.02 sec)

  MariaDB [(none)]> FLUSH PRIVILEGES;
  Query OK, 0 rows affected (0.02 sec)

 

執行如下命令鎖定數據庫以防止寫入數據

MariaDB [(none)]> FLUSH TABLES WITH READ LOCK;
Query OK, 0 rows affected (0.07 sec)

 

退出mysql命令行，導出數據庫

mysqldump  -uroot -pwc20080512  -B heruiguo  wanghaixue > /opt/mysql.sql;

 

scp 數據文件到從服務器

 scp /opt/mysql.sql  192.168.182.156:/opt

 

登錄從服務器導入數據

[root@localhost ~]# mysql -uroot -pwc20080512</opt/mysql.sql 

 

編輯配置文件my.cnf,在[mysqld]下面加入：

server-id=2

重啓數據庫

systemctl  restart  mariadb.service

 

 

查看192.168.182.155 MySQL服務器二進制文件名與位置

MariaDB [(none)]> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000010 | 327 | wordpress | mysql |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

 

解鎖數據庫

MariaDB [(none)]> UNLOCK TABLES;
Query OK, 0 rows affected (0.00 sec)

 

在從服務器執行

[root@localhost ~]# mysql   -uroot  -pwc20080512

CHANGE MASTER TO
MASTER_HOST='192.168.182.155',
MASTER_USER='mysql12',
MASTER_PASSWORD='mysql12',
MASTER_PORT=3306,
MASTER_LOG_FILE='mysql-bin.000010',
MASTER_LOG_POS=327;

 

 

啓動slave進程。

MariaDB [(none)]> START SLAVE;
Query OK, 0 rows affected, 1 warning (0.00 sec)

 

查看主從複製是否配置成功

MariaDB [(none)]> SHOW SLAVE STATUS\G  
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.182.155
                  Master_User: mysql12
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000010
          Read_Master_Log_Pos: 723
               Relay_Log_File: mariadb-relay-bin.000002
                Relay_Log_Pos: 929
        Relay_Master_Log_File: mysql-bin.000010
             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: 723
              Relay_Log_Space: 1225
              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
1 row in set (0.00 sec)

 

主從配置完成

 

測試

在主服務器上建立數據庫

MariaDB [heruiguo]> create  database  aaa;
Query OK, 1 row affected (0.01 sec)

MariaDB [heruiguo]> SHOW MASTER STATUS;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000012 |      624 |              | mysql            |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

 

在從庫上驗證

MariaDB [heruiguo]> show  databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| aaa                |
| heruiguo           |
| mysql              |
| performance_schema |
| wanghaixue         |
+--------------------+
6 rows in set (0.00 sec)