【数据库】mysql高可用MHA（以主从复制为基础）

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前言

本博客内容仅为记录博主思路，仅供参考，一切以自己实践结果为准。

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一、MHA高可用

1.2 思路

• 主从复制：先安装数据库–>主服务器授权，刷新授权–>从节点同步配置（需先获得主的文件名及偏移量）
• MHA：搭建相关环境–>所有服务器安装组件包–>主服务器创建VIP地址–>所有服务器进行免交互登陆配置–>配置manger服务器
• manger服务器：复制故障自动切换到系统命令目录–>修改故障自动切换脚本–>修改app1.cnf配置文件（节点服务器管理配置文件）–>启动manger服务
• 主节点故障切换：重启原主节点–>将原主节点设置为从节点–>修改manger服务器app1.cnf配置文件–>重启manger服务

1.1 架构

作用	IP地址	安装服务
主负载均衡器	192.168.13.10	MHA node/mysql5.7
节点服务器1	192.168.13.20	MHA node/mysql5.7
节点服务器2	192.168.13.30	MHA node/mysql5.7
备用负载均衡器	192.168.13.40	MHA node/manager

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1.2 主服务器

• 搭建主从，需安装好mysql数据库，博主已用源码安装

#开启二进制日志，对数据库进行授权（给从/manger）
systemctl disable --now firewalld
setenforce 0
hostnamectl set-hostname Mysql1
su

vim /etc/my.cnf
	server-id = 1
	log_bin = master-bin
	log-slave-updates = true

systemctl restart mysqld.service 
ln -s /usr/local/mysql/bin/mysql /usr/sbin/
ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/

mysql -uroot -pabc123
	grant replication slave on *.* to 'myslave'@'192.168.13.%' identified by '123';
	#为13网段主机进行授权，当用myslave用户，13网段主机地址进行登录时，拥有复制权限
	grant all privileges on *.* to 'mha'@'192.168.13.%' identified by 'manager';
	grant all privileges on *.* to 'mha'@'Mysql1' identified by 'manager';
	grant all privileges on *.* to 'mha'@'Mysql2' identified by 'manager';
	grant all privileges on *.* to 'mha'@'Mysql3' identified by 'manager';
	#为manger主机进行授权，当用mha用户，mysql主机地址进行登录时，拥有一切特权
	flush privileges;
	#刷新权限，使更改生效
	show master status;
	#获得日志文件名及偏移量，每次都不同（本次为：master-bin.000001，1745）

#安装mha所需要的环境
yum install epel-release --nogpgcheck -y

yum install -y perl-DBD-MySQL \
perl-Config-Tiny \
perl-Log-Dispatch \
perl-Parallel-ForkManager \
perl-ExtUtils-CBuilder \
perl-ExtUtils-MakeMaker \
perl-CPAN
#搭建安装node所需要的环境

cd /opt
tar zxvf mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57
perl Makefile.PL
make && make install
ssh-keygen -t rsa
	三次回车到底

ssh-copy-id 192.168.13.20
	输入yes
	输入13.20的root密码，回车实现免交互
ssh-copy-id 192.168.13.30

/sbin/ifconfig ens33:1 192.168.13.200/24
#首次搭建，执行该命令添加VIP地址

ifconfig
#查看VIP地址是否添加成功

1.3 从服务器

• 搭建主从，需安装好mysql数据库，博主已用源码安装
• 另一台从节点操作相同，除了主机名与秒交互需要改为对应

systemctl disable --now firewalld
setenforce 0
hostnamectl set-hostname Mysql2

vim /etc/my.cnf
	server-id = 2
	log_bin = master-bin
	relay-log = relay-log-bin
	relay-log-index = slave-relay-bin.index

systemctl restart mysqld.service 
ln -s /usr/local/mysql/bin/mysql /usr/sbin/
ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/

mysql -uroot -pabc123
	grant replication slave on *.* to 'myslave'@'192.168.13.%' identified by '123';
	grant all privileges on *.* to 'mha'@'192.168.13.%' identified by 'manager';
	grant all privileges on *.* to 'mha'@'Mysql1' identified by 'manager';
	grant all privileges on *.* to 'mha'@'Mysql2' identified by 'manager';
	grant all privileges on *.* to 'mha'@'Mysql3' identified by 'manager';
	flush privileges;
	
	change master to master_host='192.168.13.10',master_user='myslave',master_password='123',master_log_file='master-bin.000001',master_log_pos=1745; 
	start slave;
}

effect_mysql2(){
    
    
yum install epel-release --nogpgcheck -y

yum install -y perl-DBD-MySQL \
perl-Config-Tiny \
perl-Log-Dispatch \
perl-Parallel-ForkManager \
perl-ExtUtils-CBuilder \
perl-ExtUtils-MakeMaker \
perl-CPAN
#搭建安装node所需要的环境

cd /opt
tar zxvf mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57
perl Makefile.PL
make && make install
ssh-keygen -t rsa
	三次回车到底
ssh-copy-id 192.168.13.10
	输入yes
	输入13.20的root密码，回车实现免交互
ssh-copy-id 192.168.13.30

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1.4 manager服务器

systemctl disable --now firewalld
setenforce 0

#安装编译文件所需要的环境
yum install epel-release --nogpgcheck -y
yum install -y perl-DBD-MySQL \
perl-Config-Tiny \
perl-Log-Dispatch \
perl-Parallel-ForkManager \
perl-ExtUtils-CBuilder \
perl-ExtUtils-MakeMaker \
perl-CPAN

cd /opt
tar zxvf mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57
perl Makefile.PL
make && make install

cd /opt
tar zxvf mha4mysql-manager-0.57.tar.gz
cd mha4mysql-manager-0.57
perl Makefile.PL
make && make install

ls /usr/local/bin
#若生成ssh、repl、host、stop等约8个manger控制文件，则表示成功

ssh-keygen -t rsa
	三次回车到底
ssh-copy-id 192.168.13.10
	输入yes
	输入13.20的root密码，回车实现免交互
ssh-copy-id 192.168.13.20
ssh-copy-id 192.168.13.30

cp -rp /opt/mha4mysql-manager-0.57/samples/scripts /usr/local/bin
#此时只是把四个命令的目录复制过去了
cp /usr/local/bin/scripts/master_ip_failover /usr/local/bin
#复制故障自动切换脚本到系统命令目录中，方便自动执行

#修改脚本执行配置（删除原有所有内容，添加如下内容）
vim /usr/local/bin/master_ip_failover
#!/usr/bin/env perl
use strict;
use warnings FATAL => 'all';

use Getopt::Long;

my (
$command, $ssh_user, $orig_master_host, $orig_master_ip,
$orig_master_port, $new_master_host, $new_master_ip, $new_master_port
);

my $vip = '192.168.13.200';
my $brdc = '192.168.13.255';
my $ifdev = 'ens33';
my $key = '1';
my $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig ens33:$key down";
my $exit_code = 0;
#my $ssh_start_vip = "/usr/sbin/ip addr add $vip/24 brd $brdc dev $ifdev label $ifdev:$key;/usr/sbin/arping -q -A -c 1 -I $ifdev $vip;iptables -F;";
#my $ssh_stop_vip = "/usr/sbin/ip addr del $vip/24 dev $ifdev label $ifdev:$key";

GetOptions(
'command=s' => \$command,
'ssh_user=s' => \$ssh_user,
'orig_master_host=s' => \$orig_master_host,
'orig_master_ip=s' => \$orig_master_ip,
'orig_master_port=i' => \$orig_master_port,
'new_master_host=s' => \$new_master_host,
'new_master_ip=s' => \$new_master_ip,
'new_master_port=i' => \$new_master_port,
);

exit &main();

sub main {
    
    

print "\n\nIN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===\n\n";

if ( $command eq "stop" || $command eq "stopssh" ) {
    
    

my $exit_code = 1;
eval {
    
    
print "Disabling the VIP on old master: $orig_master_host \n";
&stop_vip();
$exit_code = 0;
};
if ($@) {
    
    
warn "Got Error: $@\n";
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "start" ) {
    
    

my $exit_code = 10;
eval {
    
    
print "Enabling the VIP - $vip on the new master - $new_master_host \n";
&start_vip();
$exit_code = 0;
};
if ($@) {
    
    
warn $@;
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "status" ) {
    
    
print "Checking the Status of the script.. OK \n";
exit 0;
}
else {
    
    
&usage();
exit 1;
}
}
sub start_vip() {
    
    
`ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}

## A simple system call that disable the VIP on the old_master
sub stop_vip() {
    
    
`ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;
}

sub usage {
    
    
print
"Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --orig_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n";
}
-----脚本内容到此结束-----

mkdir /etc/masterha
cp /opt/mha4mysql-manager-0.57/samples/conf/app1.cnf /etc/masterha
#复制app1.cnf配置文件，管理 mysql所有节点服务器，故障切换后，需到新主服务器再次配置

#修改配置文件（删除原有所有内容，添加如下内容）
vim /etc/masterha/app1.cnf
[server default]
manager_log=/var/log/masterha/app1/manager.log
manager_workdir=/var/log/masterha/app1
master_binlog_dir=/usr/local/mysql/data
master_ip_failover_script=/usr/local/bin/master_ip_failover
master_ip_online_change_script=/usr/local/bin/master_ip_online_change
password=manager
ping_interval=1
remote_workdir=/tmp
repl_password=123
repl_user=myslave
secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.13.20 -s 192.168.13.30
shutdown_script=""
ssh_user=root
user=mha

#这块谁是主服务器,IP就是谁，每次故障之后，该模块会被自动删除，需要手动重新添加
[server1]
hostname=192.168.13.10
port=3306

#从节点模块，备选主服务器
[server2]
candidate_master=1
check_repl_delay=0
hostname=192.168.13.20
port=3306

[server3]
hostname=192.168.13.30
port=3306

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二、导图/结语

• 授权的IP地址一定要细心，命令不要出错，配置文件也不要出错
• 编译安装如果出现问题，那么可能就是编译环境没有搭建好，yum重新安装一遍编译环境即可