Ubuntu22 mysql8 MHA高可用

mha-manager地址：https://github.com/yoshinorim/mha4mysql-manager

mha-node地址：https://github.com/yoshinorim/mha4mysql-node

mha有mha-manager和mha-node 2个组件

由于主节点有可能会被切换成从节点，而每一个从节点也有可能会被切换成主节点

所以 MHA 对 Mysql 复制环境有特殊要求。

（1）各节点 都要开启 二进制日志 及 中继日志，（master 也要开启中继日志）；

（2）当前各从节 点必须 显式 注明其为 read_only=ON；

（3）关闭各从节点的 relay_log_purge=OFF 中继日志 自动清理功能

（4）各个节点要开启免密互信

各个mysql提前主从，并创建好账号是root 密码是Sykj@2024的用户

一、mha-node

1、下载mha-manager的deb包

https://github.com/yoshinorim/mha4mysql-node/releases/download/v0.58/mha4mysql-node-0.58-0.el7.centos.noarch.rpm

2、安装

apt install -y https://github.com/yoshinorim/mha4mysql-node/releases/download/v0.58/mha4mysql-node-0.58-0.el7.centos.noarch.rpm

二、mha-manager

1、下载mha-manager的deb包

wget https://github.com/yoshinorim/mha4mysql-manager/releases/download/v0.58/mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

2、安装

apt install -y ./mha4mysql-manager_0.58-0_all.deb

3、创建配置文件。

mkdir /etc/mha

vim /etc/mha/app1.cnf

[server default]
user=root       
password=Sykj@2024
ssh_user=root
#master_binlog_dir=/log-bin
ping_interval=3 
repl_user=root
repl_password=Sykj@2024
manager_log=/var/log/mha/app1/manager.log
master_ip_failover_script=/etc/mha/master_ip_failover

[server1]
hostname=192.168.31.30
candidate_master=1  #候选master
check_repl_delay=0
port=3306

[server2]
hostname=192.168.31.31
candidate_master=1  #候选master
check_repl_delay=0
port=3306

[server3]
hostname=192.168.31.31
port=3307
no_master=1

mkdir -p /var/log/mha/app1/

4、编辑故障ip切换脚本

vim  /etc/mha/master_ip_failover

#!/usr/bin/env  perl

#  Copyright (C) 2011 DeNA Co.,Ltd.
#  You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#  Foundation, Inc.,
#  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

## Note: This is a sample script and is not complete. Modify the script based on your environment.

use strict;
use warnings FATAL => 'all';

use Getopt::Long;
use MHA::DBHelper;

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

my $vip = '192.168.31.39/24'; 
my $key = '8';
my $ssh_start_vip = "/usr/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/usr/sbin/ifconfig eth0:$key down";
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,
  'new_master_user=s'     => \$new_master_user,
  'new_master_password=s' => \$new_master_password,
);

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 \" $ssh_start_vip \"`;
}
sub stop_vip() {
     return 0  unless  ($ssh_user);
    `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";
}

5、测试ssh连接

masterha_check_ssh  --conf=/etc/mha/app1.cnf

6、测试主从是否健康

masterha_check_repl --conf=/etc/mha/app1.cnf

7、开启集群

masterha_manager  --conf=/etc/mha/app1.cnf  &

 三、验证故障IP切换

1、在主服务器添加vip

ifconfig eth0:8 192.168.31.39/24

2、关闭主服务器查看从服务器有没有ip切换过来。

## MHA的监控进程，在执行一次切换后，就会结束退出，并留下一个禁止文件 /var/tmp/app1.failover.complete

## 该文件存在的话，不会执行下一次切换

关闭的主库重新加入集群要以从的身份加入