MySQL数据库主从同步实战过程

   Linux系统MySQL数据库主从同步实战过程

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