mysql5.7双机主主热备
热备这个东西必然消耗资源，对mysql应用的影响暂时还没有研究，对mysql操作频繁的场景下必然会有影响。
数据需要备份的请参考我的博文
mysql数据备份
先下载mysql的rpm安装包。本文档默认是离线环境。
若无特殊说明，操作默认双机都要进行。
首先下载rpm安装包
mysql-5.7.24-1.el7.x86_64.rpm-bundle.tar
解压后安装
rpm -ivh mysql-community-common-5.7.24-1.el7.x86_64.rpm
rpm -ivh mysql-community-libs-5.7.24-1.el7.x86_64.rpm
rpm -ivh mysql-community-client-5.7.24-1.el7.x86_64.rpm
rpm -ivh mysql-community-server-5.7.24-1.el7.x86_64.rpm
rpm -ivh mysql-community-devel-5.7.24-1.el7.x86_64.rpm
启动进程
service mysqld start
查看临时密码
grep 'temporary password' /var/log/mysqld.log
修改密码
/usr/bin/mysql_secure_installation
若想修改密码策略，请参考我的另一篇博文
Mysql修改密码策略
#关防火墙
systemctl stop firewalld
systemctl disable firewalld
我们以10.0.0.1和10.0.0.2来作为两台主机的ip地址
1.修改两台机器的配置文件
10.0.0.1的配置文件为（数据目录一致的话，改下host就能用）
[mysqld]
datadir=/var/lib/mysql
user=mysql
port = 3306
socket= /var/lib/mysql/mysql.sock
log-bin=mysql-bin
gtid-mode=on
enforce-gtid-consistency=true
master-info-repository=TABLE
relay-log-info-repository=TABLE
sync-master-info=1
slave-parallel-workers=2
binlog-checksum=CRC32
master-verify-checksum=1
slave-sql-verify-checksum=1
binlog-rows-query-log_events=1
report-port=3306
report-host=10.0.0.1
#replicate-same-server-id #主要用于同时写的情况
server_id = 1 #从写 server_id = 2
log-slave-updates
slave-skip-errors=all
auto_increment_increment=2
auto_increment_offset=1 #从写 auto_increment_offset = 2
10.0.0.2的配置文件
datadir=/var/lib/mysql
user=mysql
port = 3306
socket= /var/lib/mysql/mysql.sock
log-bin=mysql-bin
gtid-mode=on
enforce-gtid-consistency=true
master-info-repository=TABLE
relay-log-info-repository=TABLE
sync-master-info=1
slave-parallel-workers=2
binlog-checksum=CRC32
master-verify-checksum=1
slave-sql-verify-checksum=1
binlog-rows-query-log_events=1
report-port=3306
report-host=10.0.0.2
#replicate-same-server-id #主要用于同时写的情况
server_id =2
log-slave-updates
slave-skip-errors=all
auto_increment_increment=2
auto_increment_offset=2
2.配置主机
重启mysql服务
service mysqld restart
10.0.0.1上执行命令
grant replication slave on *.* to 'slave'@'10.0.0.2' identified by 'root';
show master status\G;
10.0.0.2上执行命令
grant replication slave on *.* to 'slave'@'10.0.0.1' identified by 'root';
show master status\G;
分别记录两台机器的File和position值。
这里假设10.0.0.1的显示为如下
File: mysql-bin.000001
Position: 891
Binlog_Do_DB:
Binlog_Ignore_DB:
这里假设10.0.0.2的显示为如下
File: mysql-bin.000001
Position: 892
Binlog_Do_DB:
Binlog_Ignore_DB:
10.0.0.1上执行命令
change master to master_host='10.0.0.2',master_user='slave',
master_password='root',master_log_file='mysql-bin.000001',
master_log_pos=892;
start slave;
show slave status\G;
10.0.0.2上执行命令
change master to master_host='10.0.0.1',master_user='slave',
master_password='root',master_log_file='mysql-bin.000001',
master_log_pos=891;
start slave;
show slave status\G;
查看两边的Slave_IO_Running和Slave_SQL_Running的状态值，都为yes则配置完成。
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
再试一下，两边已经是同步的了。
可以通过修改配置文件指定特定的数据库。