MySQL数据库主从同步实战过程详解

本文实例讲述了mysql数据库主从同步实战过程。分享给大家供大家参考，具体如下：

接上一篇：mysql数据库入门之备份数据库

安装环境说明

系统环境：

[root@~]# cat /etc/redhat-release 
centos release 6.5 (final)
[root@~]# uname -r
2.6.32-431.el6.x86_64

数据库：

由于是模拟环境，主从库在同一台服务器上，服务器ip地址192.168.1.7

• 主库使用3306端口
• 从库使用3307端口
• 数据库数据目录/data

安装mysql数据库服务

下载软件包

今天我们是用二进制安装包进行布署mysql数据库服务，其它方式的安装布署方法请参考前面的文章

[root@~]#wget http://mirrors.sohu.com/mysql/mysql-5.5/mysql-5.5.51-linux2.6-x86_64.tar.gz 

创建数据目录、软件安装目录

[root@~]#mkdir /data｛3306，3307｝ -p
[root@~]#mkdri /application

解压软件

[root@~]#tar zxf mysql-5.5.51-linux2.6-x86_64.tar.gz 
[root@~]#mv mysql-5.5.51-linux2.6-x86_64 /application/mysql-5.5.51
[root@~]#ln -s /application/mysql-5.5.51 /application/mysql

创建用户

[root@~]#groupadd mysql
[root@~]#useradd -g mysql -m mysql

初始化数据库

[root@~]#/application/mysql/scripts/mysql_install_db --basedir=/application/mysql --datadir=/data/3306/data --user=mysql

[root@~]#/application/mysql/scripts/mysql_install_db --basedir=/application/mysql --datadir=/data/3307/data --user=mysql

创建配置文件

[root@~]#vi /data/3306/my.cnf
[client]
port   = 3306
socket   = /data/3306/mysql.sock

[mysql]
no-auto-rehash

[mysqld]
user = mysql
port = 3306
socket = /data/3306/mysql.sock
basedir = /application/mysql
datadir = /data/3306/data
open_files_limit = 1024
back_log = 600

max_connections = 800
max_connect_errors = 3000
table_cache = 614
external-locking = false
max_allowed_packet =8m
sort_buffer_size = 1m
join_buffer_size = 1m
thread_cache_size = 100
thread_concurrency = 2
query_cache_size = 2m
query_cache_limit = 1m
query_cache_min_res_unit = 2k
thread_stack = 192k
tmp_table_size = 2m
max_heap_table_size = 2m
long_query_time = 1

pid-file = /data/3306/mysql.pid
log-bin = /data/3306/mysql-bin
#主从同步的关键点，从库上不需要开启
relay-log = /data/3306/relay-bin
relay-log-info-file = /data/3306/relay-log.info
binlog_cache_size = 1m
max_binlog_cache_size = 1m
max_binlog_size = 2m
expire_logs_days = 7
key_buffer_size = 16m
read_buffer_size = 1m
read_rnd_buffer_size = 1m
bulk_insert_buffer_size = 1m
lower_case_table_names = 1
skip-name-resolve
slave-skip-errors = 1032,1062
replicate-ignore-db=mysql
server-id = 1 #主库从库id 不可相同

[mysqldump]
quick
max_allowed_packet = 2m

[mysqld_safe]
log-error=/data/3306/mysql3306.err
pid-file=/data/3306/mysqld.pid

数据库启动脚本：

[root@~]#vi /data/3306/mysql
#!/bin/sh
port=3306
user="root"
pwd="123456"
path="/application/mysql/bin"
sock="/data/${port}/mysql.sock"

start_mysql()
{
 if [ ! -e "$sock" ];then
  printf "starting mysql...\n"
  /bin/sh ${path}/mysqld_safe --defaults-file=/data/${port}/my.cnf 2>&1 > /dev/null &
 else
  printf "mysql is running...\n"
  exit
 fi
}
stop_mysql()
{
 if [ ! -e "$sock" ];then
  printf "mysql is stopped...\n"
  exit
 else
  printf "stoping mysql...\n"
  ${path}/mysqladmin -u ${user} -p${pwd} -s /data/${port}/mysql.sock shutdown
 fi
}
restart_mysql()
{
 printf "restarting mysql...\n"
 stop_mysql
 sleep 2
 start_mysql
}
case $1 in
start)
 start_mysql
;;
stop)
 stop_mysql
;;
restart)
 restart_mysql
;;
*)
 printf "usage: /data/${port}/mysql {start|stop|restart}\n"
esac

备注：主从库配置文件与启动文件一样，只需修改端口与server-id即可完成配置

授权目录并增加启动文件可执行权限

[root@~]#chown -r mysql.mysql /data
[root@~]#find /data -name mysql -exex chmod +x {} \;

启动数据库

[root@~]#/data/3306/mysql start
[root@~]#/data/3307/mysql start

修改默认数据库密码

[root@~]#mysqladmin -uroot password '123456' -s /data/3306/mysql.sock
[root@~]#mysqladmin -uroot password '123456' -s /data/3307/mysql.sock

测试登陆，可以登陆两个数据库即可完成全部安装过程

配置主库

1）备份主库

mkdir /backup

登陆主库创建用步同户并授权

[root@~]#mysql -uroot -p123456 -s /data/3306/mysql.sock

mysql> grant replication slave on *.* to rep@'192.168.1.%' identified by'123456';

query ok, 0 rows affected (0.00 sec)

mysql> flush privileges;

query ok, 0 rows affected (0.00 sec)

执行锁表操作

[root@~]#/application/mysql/bin/mysql -uroot -p123456 -s /data/3306/mysql.sock -e "flush table with read lock;"

备份主库

[root@~]#/application/mysql/bin/mysql -uroot -p123456 -s /data/3306/mysql.sock -e "show master status;" >/backup/mysql.log

[root@~]#/application/mysql/bin/mysqldump -uroot -p123456 -s /data/3306/mysql.sock -a -b |gzip >/backup/mysql.sql.gz

解除锁表状态

[root@~]#/application/mysql/bin/mysql -uroot -p123456 -s /data/3306/mysql.sock -e "unlock tables;" 

备注：以上操作也可以登陆主库进行，但是需要注意的是，执行锁表操作后，需要另开启一个窗口进行数据备份，不可直接退出，防止有数据写入导致备份的数据不完整。最好是使用非交互式操作。

配置从库实现主从同步

将主库的备份文件解压并恢复数据库

[root@backup ]#gzip -d mysql.sql.gz

[root@backup ]#/application/mysql/bin/mysql -uroot -p123456 -s /data/3307/mysql.sock < mysql.sql

查看log日志

[root@backup ]#cat mysql.log
+------------------+----------+--------------+------------------+
| file    | position | binlog_do_db | binlog_ignore_db |
+------------------+----------+--------------+------------------+
| mysql-bin.000002 |  424 |    |     |
+------------------+----------+--------------+------------------+

登陆从库执行下面的操作

mysql> change master to
 -> master_host='192.168.1.7',  #服务器ip
 -> master_port=3306,    #主库端口
 -> master_user='rep',    #同步的用户
 -> master_password='123456',  #同步的用户密码
 -> master_log_file=' mysql-bin.000002', #binlog文件
 -> master_log_pos=424;     #位置点
mysql> start slave;    #开启同步

等待60s后查看同步状态

[root@backup ]# mysql -s /data/3307/mysql.sock -e "show slave status\g"|egrep "seconds_behind_master|_running"
   slave_io_running: yes
   slave_sql_running: yes
   seconds_behind_master: 0

只要出现上述情况说明主从同步成功

测试主从同步

主库创建一个数据库

[root@backup ~]# mysql -s /data/3306/mysql.sock -e "create database tongbuku"

[root@backup ~]# mysql -s /data/3306/mysql.sock -e "show databases"
+-----------------------------+
| database     |
+-----------------------------+
| information_schema   |
| mysql      |
| performance_schema   |
| test      |
| tongbuku     |
+-----------------------------+

查看从库同步情况

[root@backup ~]# mysql -s /data/3307/mysql.sock -e "show databases"
+-----------------------------+
| database     |
+-----------------------------+
| information_schema   |
| mysql      |
| performance_schema   |
| test      |
| tongbuku     |
+-----------------------------+

表明主从同步状态正常，也可以在主库新的数据表中创建表，再插入新的数据来测试主从同步状态