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... "
/bin/sh ${Path}/mysqld_safe --defaults-file=/data/${port}/my.cnf 2>&1 > /dev/null &
else
printf "MySQL is running... "
exit
fi
}
stop_mysql()
{
if [ ! -e "$sock" ];then
printf "MySQL is stopped... "
exit
else
printf "Stoping MySQL... "
${Path}/mysqladmin -u ${user} -p${pwd} -S /data/${port}/mysql.sock shutdown
fi
}
restart_mysql()
{
printf "Restarting MySQL... "
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} "
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 statusG"|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