MySQL主从复制

一、简述原理：

原理图

1、master记载二进制日志

2、slave的I/O线程读取master的二进制日志,并将其写入到中继日志中,SQL线程从中继日志中读取时间,并重放其中变乱,更新slave的数据

二、准备工作：

封闭防火墙

#server iptables stop

封闭开机自启

#chkconfig iptables off

封闭selinux

#setenforce 0

在/etc/selinux/config 中,将SELINUX=enforcing改为SELINUX=disabled

同步光阴

#ntpdate 202.120.2.101

=======================================================

三、安装mysql5.6

#cd /usr/local/src

解压mysql包

#tar -zxf MySQL-5.6.23-1.el6.x86_64.rpm-bundle.tar

用yum安装mysql,办理依赖关系

#yum install MySQL-shared-compat-5.6.23-1.el6.x86_64.rpm

#yum install MySQL-server-5.6.23-1.el6.x86_64.rpm

#yum install MySQL-client-5.6.23-1.el6.x86_64.rpm

#yum install MySQL-devel-5.6.23-1.el6.x86_64.rpm

#yum install MySQL-shared-5.6.23-1.el6.x86_64.rpm

创立数据目录

#mkdir -pv /home/mydata/data

#chown -R mysql.mysql /home//mydata

#chmod -R +w /home/mydata

四、改动配置文件

配置文件【主】

#cat /etc/my.cnf

[mysqld]

# Remove leading # and set to the amount of RAM for the most important data

# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.

# innodb_buffer_pool_size = 128M

# Remove leading # to turn on a very important data integrity option: logging

# changes to the binary log between backups.

# log_bin

# These are commonly set, remove the # and set as required.

# basedir = .....

datadir = /home/mydata/data

port = 3306

socket = /var/lib/mysql/mysql.sock

log-bin = master-bin

server_id = 1

skip-external-locking

key_buffer_size = 256M

max_allowed_packet = 1M

table_open_cache = 256

pid-file = /home/mydata/data/mysql.pid

# Remove leading # to set options mainly useful for reporting servers.

# The server defaults are faster for transactions and fast SELECTs.

# Adjust sizes as needed, experiment to find the optimal values.

# join_buffer_size = 128M

sort_buffer_size = 1M

read_buffer_size = 1M

read_rnd_buffer_size = 1M

myisam_sort_buffer_size = 64M

thread_cache_size = 8

query_cache_size= 16M

innodb_file_per_table = on

thread_concurrency = 8

skip_name_resolve = on

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

配置文件【从】

[mysqld]

# Remove leading # and set to the amount of RAM for the most important data

# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.

# innodb_buffer_pool_size = 128M

# Remove leading # to turn on a very important data integrity option: logging

# changes to the binary log between backups.

# log_bin

# These are commonly set, remove the # and set as required.

# basedir = .....

datadir = /home/mydata/data

port = 3306

server_id = 2

pid-file = /home/mydata/data/mysql.pid

relay-log = relay-bin

socket = /var/lib/mysql/mysql.sock

skip-external-locking

key_buffer_size = 256M

max_allowed_packet = 1M

table_open_cache = 256

# Remove leading # to set options mainly useful for reporting servers.

# The server defaults are faster for transactions and fast SELECTs.

# Adjust sizes as needed, experiment to find the optimal values.

# join_buffer_size = 128M

sort_buffer_size = 1M

read_buffer_size = 1M

read_rnd_buffer_size = 1M

myisam_sort_buffer_size = 64M

thread_cache_size = 8

query_cache_size= 16M

innodb_file_per_table = on

thread_concurrency = 8

skip_name_resolve = on

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

初始化MySQL

#/usr/bin/mysql_install_db --datadir=/usr/local/work/mydata --user=mysql

启动服务

#service mysql start

设置root暗码

#mysql>SET PASSWORD FOR 'root'@'localhost' = PASSWORD('123456');

【主节点】授权复制权限账号给从节点

#mysql>grant replication client,replication slave on *.* to 'repuser'@'192.168.%.%' identified by 'reppasswd';

#mysql>flush privileges;

查看状态

#mysql>show master status;

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

【从节点】指定主节点,复制账号

#mysql>change master to master_host='192.168.1.6',master_user='repuser',master_password='reppasswd',master_log_file='master-bin.000001',master_log_pos=120;

查看状态

#mysql>show slave status\G

Slave_IO_Running: Yes

Slave_SQL_Running: Yes

备注：这里只讲到mysql主从复制,但没有讲到如何实现高可用,可以应用keepalived来实现.