一、MySQL主從復制原理圖

MySQL主從復制原理：實現主從復制原理是三個線程完成的，主的I/O線程，備的I/O線程與SQL線程

1、首先主庫db01需要開啟binlog、授權一個replication client賬號，鎖表進行一次數據全備

2、從庫db02、db03導入主庫全備數據從而實現主從數據一致性，從庫執行change master to將主機、端口、用戶名、密碼、binlog文件名、binlog位置點存入master.info中

3、從庫start slave，首先由從庫的I/O線程攜帶master.info的信息去詢問主庫，驗證rep賬號，根據binlog文件和位置點，將新增的binlog文件發回去，同時攜帶著發送到的文件和位置點，從庫收到存到master.info中，收到的binlog日誌存放在reply-bin文件中，由從庫的SQL執行，先解析binlog文件再先入數據庫，執行到的信息存入repay.info中。從庫會一直詢問主庫是否有新的數據，主庫有新的數據會返回給從庫。

二、MySQL主從復制部署

1、部署環境

[root@db01 tools]# cat /etc/redhat-release 
CentOS release 6.9 (Final)
[root@db01 tools]# uname -r
2.6.32-696.el6.x86_64
[root@db01 tools]# ll /application/
total 4
lrwxrwxrwx  1 root  root    26 2017-10-24 11:33 mysql -> /application/mysql-5.6.34/
drwxr-xr-x 13 mysql mysql 4096 2017-10-24
 
 11:33 mysql-5.6.34

2、服務器規劃

3、安裝部署

useradd -s /sbin/nologin -M mysql
cd /server/tools
tar xf mysql-5.6.34-linux-glibc2.5
 
-x86_64.tar.gz
mkdir -p /application/
mv /server/tools/mysql-5.6.34-*-x86_64 /application/mysql-5.6.34
ln -s /application/mysql-5.6.34/ /application/mysql
chown -R mysql.mysql /application/mysql/
/application/mysql/scripts/mysql_install_db --basedir=/application/mysql --datadir=/application/mysql/data --user=mysql
\cp /application/mysql/support-files/mysql.server /etc/init.d/mysqld
chmod +x /etc/init.d/mysqld
sed -i ‘s#/usr/local/mysql#/application/mysql#g‘ /application/mysql/bin/mysqld_safe /etc/init.d/mysqld
\cp /application/mysql/support-files/my-default.cnf /etc/my.cnf
/etc/init.d/mysqld start
lsof -i:3306
echo ‘export PATH=/application/mysql/bin:$PATH‘ >>/etc/profile
source /etc/profile
chkconfig --add mysqld 
chkconfig mysqld on
/application/mysql/bin/mysqladmin -u root password ‘123456‘

4、修改db01、db02、db03數據庫配置文件/etc/my.conf

[root@db01 ~]# egrep "log_bin|server_id" /etc/my.cnf
log_bin = mysql-bin  #主庫開啟log_bin 
server_id = 1        #server_id一定不能相同

[root@db02 ~]# grep server_id /etc/my.cnf 
server_id = 2

[root@db03 ~]# grep server_id /etc/my.cnf 
server_id = 3

5、主庫db01操作

mysql -uroot -p123456#登錄數據庫
grant replication slave on *.* to ‘rep‘@‘172.16.1.%‘ identified by ‘123456‘;#授權從庫用戶
flush table with read lock;#鎖表
show master status; #查看主庫binlog和位置點+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |      326 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
mysqldump -uroot -p123456 -A -B --master-data=2|gzip >/tmp/mysql_$(date +%F).sql.gz #全備主庫數據
[root@db01 ~]# scp -rp /tmp/mysql_2017-10-24.sql.gz 172.16.1.52:/tmp/ #分發主庫全備數據到從庫
[root@db01 ~]# scp -rp /tmp/mysql_2017-10-24.sql.gz 172.16.1.53:/tmp/
mysql> unlock table;#解鎖表

linux運維、架構之路-MySQL主從復制