MySQL MHA部署与测试-MySQL 8.0.20-mha4mysql-0.58版本

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mysql MHA部署与测试-上篇

1、介绍

1.1 简介

MHA（Master High Availability）目前在MySQL高可用方面是一个相对成熟的解决方案，它由日本DeNA公司的youshimaton（现就职于Facebook公司）开发，是一套优秀的作为MySQL高可用性环境下故障切换和主从提升的高可用软件

1.2 主要特性

MHA的主要特征：

  • 从master的监控到故障转移全部都能自动完成，故障转移也可以手动执行
  • 可在秒级单位内实现故障转移
  • 可将任意slave提升到master
  • 具备在多个点上调用外部脚本（扩展）的技能，可以用在电源OFF或者IP地址的故障转移上
  • 安装和卸载不用停止当前的mysql进程
  • MHA自身不会增加服务器负担，不会降低性能，不用追加服务器
  • 不依赖Storage Engine
  • 不依赖二进制文件的格式（不论是statement模式还是Row模式）
  • 针对OS挂掉的故障转移，检测系统是否挂掉需要10秒，故障转移仅需4秒

1.3 组成结构

manager 组件
masterha_manger             # 启动MHA 
masterha_check_ssh      	  # 检查MHA的SSH配置状况 
masterha_check_repl         # 检查MySQL复制状况，配置信息
masterha_master_monitor     # 检测master是否宕机 
masterha_check_status       # 检测当前MHA运行状态 
masterha_master_switch     	# 控制故障转移（自动或者手动）
masterha_conf_host      	  # 添加或删除配置的server信息

node 组件
save_binary_logs            # 保存和复制master的二进制日志 
apply_diff_relay_logs       # 识别差异的中继日志事件并将其差异的事件应用于其他的
purge_relay_logs            # 清除中继日志（不会阻塞SQL线程）

2、MHA部署

2.1 环境准备

2.1.1 拓扑

image

2.1.2 环境准备

需准备Linux环境Mysql1主2从环境，本次部署具体使用软件版本情况如下
操作系统：Linux CentOS 7.6
数据库：MySQL 8.0.20
MHA：mha4mysql-0.58

2.2 环境部署

2.2.1 安装操作系统

操作系统版本：Linux CentOS 7.6

主机名及ip：

db1：192.168.10.51，db2：192.168.10.52，db3：192.168.10.53

2.2.2 安装数据库

分别在三台服务器安装MySQL 8.0.20数据库
配置文件如下：

[mysqld]
user=mysql
basedir=/usr/local/mysql
datadir=/data/3306/data
socket=/tmp/mysql.sock

gtid-mode=on                        # gtid开关
enforce-gtid-consistency=true       # 强制GTID一致
log-slave-updates=1                 # 从库强制更新binlog日志

log_bin = mysql-bin
binlog_format = mixed
expire_logs_days = 15
log-error=/data/3306/data/mysql_error.log
server-id = 51     # server-id 三台不同 ，db2为52，db3为53
default_authentication_plugin=mysql_native_password   #修改密码加密方式

[mysql]
socket=/tmp/mysql.sock

2.2.3 搭建主从环境

搭建主从环境，确认1主2从运行正常

2.3 MHA部署

2.3.1 节点互信

db01
rm -rf /root/.ssh 
ssh-keygen
ssh-copy-id 192.168.10.51
ssh-copy-id 192.168.10.52
ssh-copy-id 192.168.10.53
db02
ssh-keygen
ssh-copy-id 192.168.10.51
ssh-copy-id 192.168.10.52
ssh-copy-id 192.168.10.53
db03
ssh-keygen
ssh-copy-id 192.168.10.51
ssh-copy-id 192.168.10.52
ssh-copy-id 192.168.10.53

2.3.2 下载软件

mkdir -p /data/tools/ && cd /data/tools
wget https://qiniu.wsfnk.com/mha4mysql-node-0.58-0.el7.centos.noarch.rpm --no-check-certificate
wget https://qiniu.wsfnk.com/mha4mysql-manager-0.58-0.el7.centos.noarch.rpm --no-check-certificate

2.3.3 创建软连接

ln -s /usr/local/mysql/bin/mysqlbinlog  /usr/bin/mysqlbinlog
ln -s /usr/local/mysql/bin/mysql          /usr/bin/mysql

2.3.4 安装软件

安装node软件（mha的manager软件是依赖于node软件运行的，所以需要先安装node端）
db1-db3

yum install perl-DBD-MySQL -y
rpm -ivh mha4mysql-node-0.58-0.el7.centos.noarch.rpm

安装manager
db3

yum install -y perl-Config-Tiny epel-release perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes
yum install -y mha4mysql-manager-0.58-0.el7.centos.noarch.rpm

2.3.5 创建用户

在db1主库中创建mha用户，此用户用于mha用来确认各节点存活状态、binlog_server拉去binlog日志。
(mysql 8.0之后版本需要单独创建用户后授权。注意密码加密方式)

create user mha@\'192.168.10.%\' identified by \'mha\';
grant all privileges on *.* to mha@\'192.168.10.%\';

2.3.6 创建相关目录

db3

#创建配置文件目录
 mkdir -p /etc/mha
#创建日志目录
 mkdir -p /var/log/mha/app1

2.3.7 manager配置文件

db3

cat > /etc/mha/app1.cnf <<eof [server="" default]="" manager_log="/var/log/mha/app1/manager" #="" mha的工作日志设置="" manager_workdir="/var/log/mha/app1" mha工作目录="" master_binlog_dir="/data/3306/data" 主库的binlog目录="" user="mha" 监控用户="" password="mha" 监控密码="" ping_interval="2" 心跳检测的间隔时间="" repl_password="123" 复制用户="" repl_user="rep" 复制密码="" ssh_user="root" ssh互信的用户="" [server1]="" 节点信息....="" hostname="192.16.10.51" port="3306" [server2]="" candidate_master="1" 被选主="" [server3]="" no_master="1" 不参与选主="" eof="" ```="" ####="" 2.3.8="" 检查状态="" db3="" ```shell="" 检查ssl互通情况="" [root@db3="" ~]#="" vim="" etc="" mha="" app1.cnf="" masterha_check_ssh="" --conf="/etc/mha/app1.cnf" ...="" tue="" jun="" 1="" 17:01:47="" 2021="" -="" [info]="" all="" ssh="" connection="" tests="" passed="" successfully.="" 检查="" mha配置文件="" masterha_check_repl="" mysql="" replication="" health="" is="" not="" ok!="" 2.3.9="" 启动manager服务="" db03="" nohup="" masterha_manager="" --remove_dead_master_conf="" --ignore_last_failover="" <="" dev="" null=""> /var/log/mha/app1/manager.log 2>&1 &
[1] 4406

--conf=/etc/mha/app1.cnf    # 指定配置文件
--remove_dead_master_conf   # 剔除已经死亡的节点
--ignore_last_failover      # 默认不能短时间(8小时)多次切换，此参数跳过检查

2.3.10 查看mha运行状态

[root@db3 ~]# masterha_check_status --conf=/etc/mha/app1.cnf
app1 (pid:4406) is running(0:PING_OK), master:192.168.10.51

3、vip、故障提醒、binlog_server

master_ip_failover  # vip故障转移脚本
send_report         # 故障提醒脚本

3.1 vip 功能部署

vip（eth0:1）网卡日常绑定在主库的网卡上，如主库出现错误导致mha重新选主，也会跟随移动到新主库的网卡上。所以要求各mha节点网卡名称一致
vip网段要求与各节点均在同一网段内
vip实现脚本是根据源码perl脚本重新编写master_ip_failover

3.1.1 准备脚本

#!/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 = \'192.168.10.49/24\';
my $key = \'1\';
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";
my $ssh_Bcast_arp= "/sbin/arping -I eth0 -c 3 -A 192.168.10.49";

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

3.1.2 修改脚本

脚本中以下部分按照要求修改

vim  /usr/local/bin/master_ip_failover

my $vip = \'192.168.10.49/24\';      # vip网段，与各节点服务器网段一致。
my $key = \'1\';                     # 虚拟网卡eth0:1 的 1
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";  # 网卡按照实际网卡名称填写
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";   # 网卡按照实际网卡名称填写
my $ssh_Bcast_arp= "/sbin/arping -I eth0 -c 3 -A 192.168.10.49"; # 重新声明mac地址，arp

3.1.3 上传脚本并授权

\\cp -a * /usr/local/bin    # 上传脚本文件到/usr/local/bin 
chmod +x /usr/local/bin/*  # 给脚本增加执行权限 
dos2unix /usr/local/bin/*  # 处理脚本中的中文字符

3.1.4 修改manager配置文件

在配置文件中增加vip故障转移部分

vim /etc/mha/app1.cnf 
master_ip_failover_script=/usr/local/bin/master_ip_failover

3.1.5 重启mha

masterha_stop  --conf=/etc/mha/app1.cnf 
nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover  < /dev/null> /var/log/mha/app1/manager.log 2>&1 &

3.1.6 在主库db1增加vip

ifconfig eth0:1 192.168.10.49/24

3.2 故障提醒功能部署

3.2.1 准备脚本

#!/usr/bin/perl

use strict;
use warnings FATAL => \'all\';
use Mail::Sender;
use Getopt::Long;
 
#new_master_host and new_slave_hosts are set only when recovering master succeeded
my ( $dead_master_host, $new_master_host, $new_slave_hosts, $subject, $body );
my $smtp=\'smtp.qq.com\';
my $mail_from=\'xxxxxx@qq.com\';
my $mail_user=\'xxxxx\';
my $mail_pass=\'xxxxxx\';
#my $mail_to=[\'to1@qq.com\',\'to2@qq.com\'];
my $mail_to=\'xxxxxx@qq.com\';
 
GetOptions(
  \'orig_master_host=s\' => \\$dead_master_host,
  \'new_master_host=s\'  => \\$new_master_host,
  \'new_slave_hosts=s\'  => \\$new_slave_hosts,
  \'subject=s\'          => \\$subject,
  \'body=s\'             => \\$body,
);
 
# Do whatever you want here
mailToContacts($smtp,$mail_from,$mail_user,$mail_pass,$mail_to,$subject,$body);
 
sub mailToContacts {
	my ($smtp, $mail_from, $mail_user, $mail_pass, $mail_to, $subject, $msg ) = @_;
	open my $DEBUG, ">/tmp/mail.log"
		or die "Can\'t open the debug	file:$!\\n";
	my $sender = new Mail::Sender {
		ctype		=> \'text/plain;charset=utf-8\',
		encoding	=> \'utf-8\',
		smtp		=> $smtp,
		from		=> $mail_from,
		auth		=> \'LOGIN\',
		TLS_allowed	=> \'0\',
		authid		=> $mail_user,
		authpwd		=> $mail_pass,
		to		=> $mail_to,
		subject		=> $subject,
		debug		=> $DEBUG
	};
	$sender->MailMsg(
		{
			msg => $msg,
			debug => $DEBUG
		}
	) or print $Mail::Sender::Error;
	return 1;
}
 
exit 0;

修改以下部分为个人邮箱内容

#new_master_host and new_slave_hosts are set only when recovering master succeeded
my ( $dead_master_host, $new_master_host, $new_slave_hosts, $subject, $body );
my $smtp=\'smtp.qq.com\';                   # 发件服务器
my $mail_from=\'xxxxxx@qq.com\';            # 发件地址
my $mail_user=\'xxxxx\';                    # 发件用户名
my $mail_pass=\'xxxxxx\';                   # 发件邮箱密码
my $mail_to=\'xxxxxx@qq.com\';              # 收件地址

#my $mail_to=[\'to1@qq.com\',\'to2@qq.com\']; # 可设置收件邮箱群组

3.2.2 修改manager配置文件

vim /etc/mha/app1.cnf 
# 添加一行： 
report_script=/usr/local/bin/send_report

3.2.3 重启mha

masterha_stop  --conf=/etc/mha/app1.cnf 
nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover  < /dev/null> /var/log/mha/app1/manager.log 2>&1 &

3.3 binlog_server搭建

binlog_server功能主要是实时拉去主库binlog进行存储，如果主库出现宕机，mha切换主从时，通过binlog_server服务器拿取bin_log日志对新主库进行数据补偿，实现日志补偿冗余

3.3.1 创建相关目录

mkdir -p /data/binlog_server/   # binlog_server存储目录
chown -R mysql.mysql /data/*    # 授权

3.3.2 开启binlog_server服务

cd  /data/binlog_server/     # 进入binlog_server存储目录
mysql -e "show slave status \\G"|grep "Master_Log"  # 确认当前slave的io进程拉取的日志量

## 启动binlog日志拉取守护进程
mysqlbinlog  -R --host=192.168.10.51 --user=mha --password=mha --raw  --stop-never mysql-bin.000004 &      # 注意：拉取日志的起点,需要按照目前从库的已经获取到的二进制日志点为起点

3.3.3 修改manager配置文件

增加以下内容

vim /etc/mha/app1.cnf 
[binlog1]
no_master=1
hostname=192.168.10.53
master_binlog_dir=/data/binlog_server/

3.3.4 重启mha

masterha_stop  --conf=/etc/mha/app1.cnf 
nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover  < /dev/null> /var/log/mha/app1/manager.log 2>&1 &

4、MHA工作原理介绍

4.1 主要工作流程介绍

  • 1、启动MHA-manager
nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover  < /dev/null> /var/log/mha/app1/manager.log 2>&1 &
  • 2、监控
/usr/bin/masterha_master_monitor # 每隔ping_interval秒探测1次，连续4次还没有，说明主库宕机。
  • 3、选主
    根据各项参数选择新主
  • 4、数据补偿
    对新主的数据差异进行补偿。
  • 5、切换
    所有从库解除主从身份。stop slave ; reset slave;
    重构新的主从关系。change master to
  • 6、迁移vip
    将vip网卡（eth0:1）绑定至新主服务器。
  • 7、故障提醒
    发送故障提醒邮件
  • 8、额外数据补偿
    根据binlog_server 服务器进行额外数据补偿
  • 9、剔除故障节点
    将故障的主服务器剔除mha环境（配置文件删除）
  • 10、manager程序“自杀

4.2 mha选主策略

4.2.1 选主依据

1、日志量latest

选取获取binlog最多的slave节点，为latest节点

[root@db3 ~]# mysql -uroot -p123456 -e "show slave status\\G" |grep Master_Log
          Master_Log_File: mysql-bin.000005
          Read_Master_Log_Pos: 196
          Relay_Master_Log_File: mysql-bin.000005
          Exec_Master_Log_Pos: 196

2、备选主pref
manager配置文件中指定了candidate_master=1参数

[server2]            
hostname=192.168.10.52
port=3306
candidate_master=1     # 备选主

3、不被选主
配置文件中设置no_master=1

[server3]
no_master=1    # 不被选
hostname=192.168.10.53
port=3306

二进制日志没开log_bin
如果从库落后主库100M的日志量（可以关闭） check_slave_delay

4.2.2 节点数组

alive 存活
latest 日志最新
perf 被选
bad 不选

4.2.3 选主判断

从上至下按条件依次筛选，上条不符合才会选择下一条
1、没有pref和bad，就选latest第一个（根据配置文件server1-2-3）
2、即是latest又是perf，又不是bad
3、perf和latest，都不是bad，选perf
4、第3条也可能选latest，如perf差100M以上binlog
5、如果以上条件都不满足，且只有一个salve可选，则选择此slave
6、没有符合的slave，则选主失败，failover失败

4.3 数据补偿

4.3.1 原主库ssh可连接

各个从节点调用： save_binary_logs脚本，立即保存缺失部分的binlog到各自节点/var/tmp目录

4.3.2 原主库ssh不能连接

从节点调用apply_diff_relay_logs，进行relay-log日志差异补偿

4.3.3 额外数据补偿(主库日志冗余机制)

binlog_server实现数据补偿

MySQL MHA部署与测试-下篇

1、故障测试

1.1 操作流程

# 追踪mha-manager日志
[root@db03 ~]# tail -f  /var/log/mha/app1/manager 
# 关闭主库
[root@db01 ~]# /etc/init.d/mysqld stop

1.2 日志查看

# 确认主库宕机部分
Wed Jun  2 16:55:42 2021 - [warning] Got error on MySQL select ping: 1053 (Server shutdown in progress)
Wed Jun  2 16:55:42 2021 - [info] Executing SSH check script: exit 0
Wed Jun  2 16:55:42 2021 - [info] HealthCheck: SSH to 192.168.10.51 is reachable.
Wed Jun  2 16:55:44 2021 - [warning] Got error on MySQL connect: 2003 (Can\'t connect to MySQL server on \'192.168.10.51\' (111))
Wed Jun  2 16:55:44 2021 - [warning] Connection failed 2 time(s)..
Wed Jun  2 16:55:46 2021 - [warning] Got error on MySQL connect: 2003 (Can\'t connect to MySQL server on \'192.168.10.51\' (111))
Wed Jun  2 16:55:46 2021 - [warning] Connection failed 3 time(s)..
Wed Jun  2 16:55:48 2021 - [warning] Got error on MySQL connect: 2003 (Can\'t connect to MySQL server on \'192.168.10.51\' (111))
Wed Jun  2 16:55:48 2021 - [warning] Connection failed 4 time(s)..
Wed Jun  2 16:55:48 2021 - [warning] Master is not reachable from health checker!
Wed Jun  2 16:55:48 2021 - [warning] Master 192.168.10.51(192.168.10.51:3306) is not reachable!



# 确认各节点状态
Wed Jun  2 16:55:48 2021 - [warning] SSH is reachable.
Wed Jun  2 16:55:48 2021 - [info] Connecting to a master server failed. Reading configuration file /etc/masterha_default.cnf and /etc/mha/app1.cnf again, and trying to connect to all servers to check server status..
Wed Jun  2 16:55:48 2021 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Wed Jun  2 16:55:48 2021 - [info] Reading application default configuration from /etc/mha/app1.cnf..
Wed Jun  2 16:55:48 2021 - [info] Reading server configuration from /etc/mha/app1.cnf..
Wed Jun  2 16:55:49 2021 - [info] GTID failover mode = 1
Wed Jun  2 16:55:49 2021 - [info] Dead Servers:
Wed Jun  2 16:55:49 2021 - [info]   192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:49 2021 - [info] Alive Servers:
Wed Jun  2 16:55:49 2021 - [info]   192.168.10.52(192.168.10.52:3306)
Wed Jun  2 16:55:49 2021 - [info]   192.168.10.53(192.168.10.53:3306)
Wed Jun  2 16:55:49 2021 - [info] Alive Slaves:
Wed Jun  2 16:55:49 2021 - [info]   192.168.10.52(192.168.10.52:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:49 2021 - [info]     GTID ON
Wed Jun  2 16:55:49 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:49 2021 - [info]     Primary candidate for the new Master (candidate_master is set)
Wed Jun  2 16:55:49 2021 - [info]   192.168.10.53(192.168.10.53:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:49 2021 - [info]     GTID ON
Wed Jun  2 16:55:49 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:49 2021 - [info]     Not candidate for the new Master (no_master is set)
Wed Jun  2 16:55:49 2021 - [info] Checking slave configurations..
Wed Jun  2 16:55:49 2021 - [info]  read_only=1 is not set on slave 192.168.10.52(192.168.10.52:3306).
Wed Jun  2 16:55:49 2021 - [info]  read_only=1 is not set on slave 192.168.10.53(192.168.10.53:3306).
Wed Jun  2 16:55:49 2021 - [info] Checking replication filtering settings..
Wed Jun  2 16:55:49 2021 - [info]  Replication filtering check ok.
Wed Jun  2 16:55:49 2021 - [info] Master is down!
Wed Jun  2 16:55:49 2021 - [info] Terminating monitoring script.
Wed Jun  2 16:55:49 2021 - [info] Got exit code 20 (Master dead).
Wed Jun  2 16:55:49 2021 - [info] MHA::MasterFailover version 0.58.
Wed Jun  2 16:55:49 2021 - [info] Starting master failover.
Wed Jun  2 16:55:49 2021 - [info] 
Wed Jun  2 16:55:49 2021 - [info] * Phase 1: Configuration Check Phase..
Wed Jun  2 16:55:49 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] GTID failover mode = 1
Wed Jun  2 16:55:51 2021 - [info] Dead Servers:
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info] Checking master reachability via MySQL(double check)...
Wed Jun  2 16:55:51 2021 - [info]  ok.
Wed Jun  2 16:55:51 2021 - [info] Alive Servers:
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.52(192.168.10.52:3306)
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.53(192.168.10.53:3306)
Wed Jun  2 16:55:51 2021 - [info] Alive Slaves:
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.52(192.168.10.52:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Primary candidate for the new Master (candidate_master is set)
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.53(192.168.10.53:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Not candidate for the new Master (no_master is set)
Wed Jun  2 16:55:51 2021 - [info] Starting GTID based failover.
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] ** Phase 1: Configuration Check Phase completed.
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] * Phase 2: Dead Master Shutdown Phase..
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] Forcing shutdown so that applications never connect to the current master..
Wed Jun  2 16:55:51 2021 - [info] Executing master IP deactivation script:
Wed Jun  2 16:55:51 2021 - [info]   /usr/local/bin/master_ip_failover --orig_master_host=192.168.10.51 --orig_master_ip=192.168.10.51 --orig_master_port=3306 --command=stopssh --ssh_user=root  

# VIP状态检查，日志补偿（此部分未发现日志缺失）
IN SCRIPT TEST====/sbin/ifconfig eth0:1 down==/sbin/ifconfig eth0:1 192.168.10.49/24===

Disabling the VIP on old master: 192.168.10.51 
SIOCSIFFLAGS: Cannot assign requested address
Wed Jun  2 16:55:51 2021 - [info]  done.
Wed Jun  2 16:55:51 2021 - [warning] shutdown_script is not set. Skipping explicit shutting down of the dead master.
Wed Jun  2 16:55:51 2021 - [info] * Phase 2: Dead Master Shutdown Phase completed.
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] * Phase 3: Master Recovery Phase..
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] * Phase 3.1: Getting Latest Slaves Phase..
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] The latest binary log file/position on all slaves is mysql-bin.000005:196
Wed Jun  2 16:55:51 2021 - [info] Latest slaves (Slaves that received relay log files to the latest):
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.52(192.168.10.52:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Primary candidate for the new Master (candidate_master is set)
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.53(192.168.10.53:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Not candidate for the new Master (no_master is set)
Wed Jun  2 16:55:51 2021 - [info] The oldest binary log file/position on all slaves is mysql-bin.000005:196
Wed Jun  2 16:55:51 2021 - [info] Oldest slaves:
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.52(192.168.10.52:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Primary candidate for the new Master (candidate_master is set)
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.53(192.168.10.53:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Not candidate for the new Master (no_master is set)
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] * Phase 3.3: Determining New Master Phase..
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] Searching new master from slaves..
Wed Jun  2 16:55:51 2021 - [info]  Candidate masters from the configuration file:
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.52(192.168.10.52:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Primary candidate for the new Master (candidate_master is set)
Wed Jun  2 16:55:51 2021 - [info]  Non-candidate masters:
Wed Jun  2 16:55:51 2021 - [info]   192.168.10.53(192.168.10.53:3306)  Version=8.0.20 (oldest major version between slaves) log-bin:enabled
Wed Jun  2 16:55:51 2021 - [info]     GTID ON
Wed Jun  2 16:55:51 2021 - [info]     Replicating from 192.168.10.51(192.168.10.51:3306)
Wed Jun  2 16:55:51 2021 - [info]     Not candidate for the new Master (no_master is set)
Wed Jun  2 16:55:51 2021 - [info]  Searching from candidate_master slaves which have received the latest relay log events..

# 选主结束，开始切换
Wed Jun  2 16:55:51 2021 - [info] New master is 192.168.10.52(192.168.10.52:3306)
Wed Jun  2 16:55:51 2021 - [info] Starting master failover..
Wed Jun  2 16:55:51 2021 - [info] 
From:
192.168.10.51(192.168.10.51:3306) (current master)
 +--192.168.10.52(192.168.10.52:3306)
 +--192.168.10.53(192.168.10.53:3306)

To:
192.168.10.52(192.168.10.52:3306) (new master)
 +--192.168.10.53(192.168.10.53:3306)
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] * Phase 3.3: New Master Recovery Phase..
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info]  Waiting all logs to be applied.. 
Wed Jun  2 16:55:51 2021 - [info]   done.
Wed Jun  2 16:55:51 2021 - [info] Getting new master\'s binlog name and position..
Wed Jun  2 16:55:51 2021 - [info]  mysql-bin.000005:196
Wed Jun  2 16:55:51 2021 - [info]  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST=\'192.168.10.52\', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER=\'rep\', MASTER_PASSWORD=\'xxx\';
Wed Jun  2 16:55:51 2021 - [info] Master Recovery succeeded. File:Pos:Exec_Gtid_Set: mysql-bin.000005, 196, f4682075-c1b9-11eb-86b2-000c2934cc5a:1-21
Wed Jun  2 16:55:51 2021 - [info] Executing master IP activate script:
Wed Jun  2 16:55:51 2021 - [info]   /usr/local/bin/master_ip_failover --command=start --ssh_user=root --orig_master_host=192.168.10.51 --orig_master_ip=192.168.10.51 --orig_master_port=3306 --new_master_host=192.168.10.52 --new_master_ip=192.168.10.52 --new_master_port=3306 --new_master_user=\'mha\'   --new_master_password=xxx
Unknown option: new_master_user
Unknown option: new_master_password

# 切换vip，处理manager配置文件（将db1踢出mha环境）
IN SCRIPT TEST====/sbin/ifconfig eth0:1 down==/sbin/ifconfig eth0:1 192.168.10.49/24===

Enabling the VIP - 192.168.10.49/24 on the new master - 192.168.10.52 
Wed Jun  2 16:55:51 2021 - [info]  OK.
Wed Jun  2 16:55:51 2021 - [info] ** Finished master recovery successfully.
Wed Jun  2 16:55:51 2021 - [info] * Phase 3: Master Recovery Phase completed.
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] * Phase 4: Slaves Recovery Phase..
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] * Phase 4.1: Starting Slaves in parallel..
Wed Jun  2 16:55:51 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info] -- Slave recovery on host 192.168.10.53(192.168.10.53:3306) started, pid: 48882. Check tmp log /var/log/mha/app1/192.168.10.53_3306_20210602165549.log if it takes time..
Wed Jun  2 16:55:53 2021 - [info] 
Wed Jun  2 16:55:53 2021 - [info] Log messages from 192.168.10.53 ...
Wed Jun  2 16:55:53 2021 - [info] 
Wed Jun  2 16:55:51 2021 - [info]  Resetting slave 192.168.10.53(192.168.10.53:3306) and starting replication from the new master 192.168.10.52(192.168.10.52:3306)..
Wed Jun  2 16:55:51 2021 - [info]  Executed CHANGE MASTER.
Wed Jun  2 16:55:52 2021 - [info]  Slave started.
Wed Jun  2 16:55:52 2021 - [info]  gtid_wait(f4682075-c1b9-11eb-86b2-000c2934cc5a:1-21) completed on 192.168.10.53(192.168.10.53:3306). Executed 0 events.
Wed Jun  2 16:55:53 2021 - [info] End of log messages from 192.168.10.53.
Wed Jun  2 16:55:53 2021 - [info] -- Slave on host 192.168.10.53(192.168.10.53:3306) started.
Wed Jun  2 16:55:53 2021 - [info] All new slave servers recovered successfully.
Wed Jun  2 16:55:53 2021 - [info] 
Wed Jun  2 16:55:53 2021 - [info] * Phase 5: New master cleanup phase..
Wed Jun  2 16:55:53 2021 - [info] 
Wed Jun  2 16:55:53 2021 - [info] Resetting slave info on the new master..
Wed Jun  2 16:55:53 2021 - [info]  192.168.10.52: Resetting slave info succeeded.
Wed Jun  2 16:55:53 2021 - [info] Master failover to 192.168.10.52(192.168.10.52:3306) completed successfully.
Wed Jun  2 16:55:53 2021 - [info] Deleted server1 entry from /etc/mha/app1.cnf .
Wed Jun  2 16:55:53 2021 - [info] 

# 切换完成
----- Failover Report -----

app1: MySQL Master failover 192.168.10.51(192.168.10.51:3306) to 192.168.10.52(192.168.10.52:3306) succeeded

Master 192.168.10.51(192.168.10.51:3306) is down!

Check MHA Manager logs at db3:/var/log/mha/app1/manager for details.

Started automated(non-interactive) failover.
Invalidated master IP address on 192.168.10.51(192.168.10.51:3306)
Selected 192.168.10.52(192.168.10.52:3306) as a new master.
192.168.10.52(192.168.10.52:3306): OK: Applying all logs succeeded.
192.168.10.52(192.168.10.52:3306): OK: Activated master IP address.
192.168.10.53(192.168.10.53:3306): OK: Slave started, replicating from 192.168.10.52(192.168.10.52:3306)
192.168.10.52(192.168.10.52:3306): Resetting slave info succeeded.
Master failover to 192.168.10.52(192.168.10.52:3306) completed successfully.

2、主动切换

故障后进行主动切换，查看主从状态和vip环境确认

主库已切换至db2

[root@db3 ~ ]# mysql -uroot -p123456 -e "show slave status\\G;" |grep Master_Host
mysql: [Warning] Using a password on the command line interface can be insecure.
                  Master_Host: 192.168.10.52   # 主库已变更
vip`已切换至`db2
[root@db2 ~]# ip a |grep eth0
2: eth0: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    inet 192.168.10.52/24 brd 192.168.10.255 scope global noprefixroute eth0
    inet 192.168.10.49/24 brd 192.168.10.255 scope global secondary eth0:1

3、在线切换

3.1 只切换角色

3.1.1 切换命令

masterha_master_switch  --conf=/etc/mha/app1.cnf --master_state=alive --new_master_host=192.168.10.51 --orig_master_is_new_slave --running_updates_limit=10000

master_ip_online_change_script is not defined. If you do not disable writes on the current master manually, applications keep writing on the current master. Is it ok to proceed? (yes/NO): yes

# 命令解析
--conf=/etc/mha/app1.cnf  # 指定配置文件
--master_state=alive      # 主库在线的情况下进行切换
--new_master_host=192.168.10.51   # 指定新主ip
--orig_master_is_new_slave  # 原主库改为从库
running_updates_limit=10000  # 网络延时(ping值)超过1w毫秒不进行切换

3.1.2 注意内容

此命令一般不会在生产环境使用，只用于测试
1、需要关闭mha-manager，不然切换无法执行成功。报错如下：

Tue Jun  8 10:03:54 2021 - [error][/usr/share/perl5/vendor_perl/MHA/MasterRotate.pm, ln143] Getting advisory lock failed on the current master. MHA Monitor runs on the current master. Stop MHA Manager/Monitor and try again.
Tue Jun  8 10:03:54 2021 - [error][/usr/share/perl5/vendor_perl/MHA/ManagerUtil.pm, ln177] Got ERROR:  at /usr/bin/masterha_master_switch line 53.

2、需要将原主库锁住Flush table with read lock，使其只读。因为在切换完主从后，vip尚未切换，此段时间数据还会写入到原主库，导致数据不一致。警告如下：

It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 192.168.10.52(192.168.10.52:3306)? (YES/no): yes

3、需要手工切换vip

4、需要重新拉取主库binlog（binlog-server）

3.2 脚本功能实现

功能: 在线切换时，自动锁原主库，VIP自动切换

3.2.1 准备脚本

vim /usr/local/bin/master_ip_online_change
#!/usr/bin/env perl

use strict;
use warnings FATAL => \'all\';
use Getopt::Long;
use MHA::DBHelper;
use MHA::NodeUtil;
use Time::HiRes qw( sleep gettimeofday tv_interval );
use Data::Dumper;
my $_tstart;
my $_running_interval = 0.1;
my (
  $command,              $orig_master_is_new_slave, $orig_master_host,
  $orig_master_ip,       $orig_master_port,         $orig_master_user,
  $orig_master_password, $orig_master_ssh_user,     $new_master_host,
  $new_master_ip,        $new_master_port,          $new_master_user,
  $new_master_password,  $new_master_ssh_user,
);
 
###########################################################################
my $vip = "10.0.0.55";
my $key = "1";
my $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig ens33:$key $vip down";
my $ssh_Bcast_arp= "/sbin/arping -I ens33 -c 3 -A 10.0.0.55";
###########################################################################
 
GetOptions(
  \'command=s\'                => \\$command,
  \'orig_master_is_new_slave\' => \\$orig_master_is_new_slave,
  \'orig_master_host=s\'       => \\$orig_master_host,
  \'orig_master_ip=s\'         => \\$orig_master_ip,
  \'orig_master_port=i\'       => \\$orig_master_port,
  \'orig_master_user=s\'       => \\$orig_master_user,
  \'orig_master_password=s\'   => \\$orig_master_password,
  \'orig_master_ssh_user=s\'   => \\$orig_master_ssh_user,
  \'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,
  \'new_master_ssh_user=s\'    => \\$new_master_ssh_user,
);
exit &main();
sub current_time_us {
  my ( $sec, $microsec ) = gettimeofday();
  my $curdate = localtime($sec);
  return $curdate . " " . sprintf( "%06d", $microsec );
}
sub sleep_until {
  my $elapsed = tv_interval($_tstart);
  if ( $_running_interval > $elapsed ) {
    sleep( $_running_interval - $elapsed );
  }
}
sub get_threads_util {
  my $dbh                    = shift;
  my $my_connection_id       = shift;
  my $running_time_threshold = shift;
  my $type                   = shift;
  $running_time_threshold = 0 unless ($running_time_threshold);
  $type                   = 0 unless ($type);
  my @threads;
  my $sth = $dbh->prepare("SHOW PROCESSLIST");
  $sth->execute();
  while ( my $ref = $sth->fetchrow_hashref() ) {
    my $id         = $ref->{Id};
    my $user       = $ref->{User};
    my $host       = $ref->{Host};
    my $command    = $ref->{Command};
    my $state      = $ref->{State};
    my $query_time = $ref->{Time};
    my $info       = $ref->{Info};
    $info =~ s/^\\s*(.*?)\\s*$/$1/ if defined($info);
    next if ( $my_connection_id == $id );
    next if ( defined($query_time) && $query_time < $running_time_threshold );
    next if ( defined($command)    && $command eq "Binlog Dump" );
    next if ( defined($user)       && $user eq "system user" );
    next
      if ( defined($command)
      && $command eq "Sleep"
      && defined($query_time)
      && $query_time >= 1 );
    if ( $type >= 1 ) {
      next if ( defined($command) && $command eq "Sleep" );
      next if ( defined($command) && $command eq "Connect" );
    }
    if ( $type >= 2 ) {
      next if ( defined($info) && $info =~ m/^select/i );
      next if ( defined($info) && $info =~ m/^show/i );
    }
    push @threads, $ref;
  }
  return @threads;
}
sub main {
  if ( $command eq "stop" ) {
    ## Gracefully killing connections on the current master
    # 1. Set read_only= 1 on the new master
    # 2. DROP USER so that no app user can establish new connections
    # 3. Set read_only= 1 on the current master
    # 4. Kill current queries
    # * Any database access failure will result in script die.
    my $exit_code = 1;
    eval {
      ## Setting read_only=1 on the new master (to avoid accident)
      my $new_master_handler = new MHA::DBHelper();
      # args: hostname, port, user, password, raise_error(die_on_error)_or_not
      $new_master_handler->connect( $new_master_ip, $new_master_port,
        $new_master_user, $new_master_password, 1 );
      print current_time_us() . " Set read_only on the new master.. ";
      $new_master_handler->enable_read_only();
      if ( $new_master_handler->is_read_only() ) {
        print "ok.\\n";
      }
      else {
        die "Failed!\\n";
      }
      $new_master_handler->disconnect();
      # Connecting to the orig master, die if any database error happens
      my $orig_master_handler = new MHA::DBHelper();
      $orig_master_handler->connect( $orig_master_ip, $orig_master_port,
        $orig_master_user, $orig_master_password, 1 );
      ## Drop application user so that nobody can connect. Disabling per-session binlog beforehand
      $orig_master_handler->disable_log_bin_local();
      print current_time_us() . " Drpping app user on the orig master..\\n";
###########################################################################
      #FIXME_xxx_drop_app_user($orig_master_handler);
###########################################################################
      ## Waiting for N * 100 milliseconds so that current connections can exit
      my $time_until_read_only = 15;
      $_tstart = [gettimeofday];
      my @threads = get_threads_util( $orig_master_handler->{dbh},
        $orig_master_handler->{connection_id} );
      while ( $time_until_read_only > 0 && $#threads >= 0 ) {
        if ( $time_until_read_only % 5 == 0 ) {
          printf
"%s Waiting all running %d threads are disconnected.. (max %d milliseconds)\\n",
            current_time_us(), $#threads + 1, $time_until_read_only * 100;
          if ( $#threads < 5 ) {
            print Data::Dumper->new( [$_] )->Indent(0)->Terse(1)->Dump . "\\n"
              foreach (@threads);
          }
        }
        sleep_until();
        $_tstart = [gettimeofday];
        $time_until_read_only--;
        @threads = get_threads_util( $orig_master_handler->{dbh},
          $orig_master_handler->{connection_id} );
      }
      ## Setting read_only=1 on the current master so that nobody(except SUPER) can write
      print current_time_us() . " Set read_only=1 on the orig master.. ";
      $orig_master_handler->enable_read_only();
      if ( $orig_master_handler->is_read_only() ) {
        print "ok.\\n";
      }
      else {
        die "Failed!\\n";
      }
      ## Waiting for M * 100 milliseconds so that current update queries can complete
      my $time_until_kill_threads = 5;
      @threads = get_threads_util( $orig_master_handler->{dbh},
        $orig_master_handler->{connection_id} );
      while ( $time_until_kill_threads > 0 && $#threads >= 0 ) {
        if ( $time_until_kill_threads % 5 == 0 ) {
          printf
"%s Waiting all running %d queries are disconnected.. (max %d milliseconds)\\n",
            current_time_us(), $#threads + 1, $time_until_kill_threads * 100;
          if ( $#threads < 5 ) {
            print Data::Dumper->new( [$_] )->Indent(0)->Terse(1)->Dump . "\\n"
              foreach (@threads);
          }
        }
        sleep_until();
        $_tstart = [gettimeofday];
        $time_until_kill_threads--;
        @threads = get_threads_util( $orig_master_handler->{dbh},
          $orig_master_handler->{connection_id} );
      }
###########################################################################
      print "disable the VIP on old master: $orig_master_host \\n";
      &stop_vip();
###########################################################################
      ## Terminating all threads
      print current_time_us() . " Killing all application threads..\\n";
      $orig_master_handler->kill_threads(@threads) if ( $#threads >= 0 );
      print current_time_us() . " done.\\n";
      $orig_master_handler->enable_log_bin_local();
      $orig_master_handler->disconnect();
      ## After finishing the script, MHA executes FLUSH TABLES WITH READ LOCK
      $exit_code = 0;
    };
    if ($@) {
      warn "Got Error: $@\\n";
      exit $exit_code;
    }
    exit $exit_code;
  }
  elsif ( $command eq "start" ) {
    ## Activating master ip on the new master
    # 1. Create app user with write privileges
    # 2. Moving backup script if needed
    # 3. Register new master\'s ip to the catalog database
    my $exit_code = 10;
    eval {
      my $new_master_handler = new MHA::DBHelper();
      # args: hostname, port, user, password, raise_error_or_not
      $new_master_handler->connect( $new_master_ip, $new_master_port,
        $new_master_user, $new_master_password, 1 );
      ## Set read_only=0 on the new master
      $new_master_handler->disable_log_bin_local();
      print current_time_us() . " Set read_only=0 on the new master.\\n";
      $new_master_handler->disable_read_only();
      ## Creating an app user on the new master
      print current_time_us() . " Creating app user on the new master..\\n";
###########################################################################
      #FIXME_xxx_create_app_user($new_master_handler);
###########################################################################
      $new_master_handler->enable_log_bin_local();
      $new_master_handler->disconnect();
      ## Update master ip on the catalog database, etc
###############################################################################
      print "enable the VIP: $vip on the new master: $new_master_host \\n ";
      &start_vip();
###############################################################################
      $exit_code = 0;
    };
    if ($@) {
      warn "Got Error: $@\\n";
      exit $exit_code;
    }
    exit $exit_code;
  }
  elsif ( $command eq "status" ) {
    # do nothing
    exit 0;
  }
  else {
    &usage();
    exit 1;
  }
}
###########################################################################
sub start_vip() {
	`ssh $new_master_ssh_user\\@$new_master_host \\" $ssh_start_vip \\"`;
}
sub stop_vip() {
	`ssh $orig_master_ssh_user\\@$orig_master_host \\" $ssh_stop_vip \\"`;
}
###########################################################################
sub usage {
  print
"Usage: master_ip_online_change --command=start|stop|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";
  die;
}

根据自身环境修改以下内容（与vip脚本设置一致）

my $vip = \'192.168.10.49/24\';      # vip网段，与各节点服务器网段一致。
my $key = \'1\';                     # 虚拟网卡eth0:1 的 1
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";  # 网卡按照实际网卡名称填写
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";   # 网卡按照实际网卡名称填写
my $ssh_Bcast_arp= "/sbin/arping -I eth0 -c 3 -A 192.168.10.49"; # 重新声明mac地址，arp

3.2.2 mha配置文件

修改mha-manager配置文件，增加一下内容

vim /etc/mha/app1.cnf
master_ip_online_change_script=/usr/local/bin/master_ip_online_change

3.2.3 关停mha服务

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

3.2.4 检查repl

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

3.2.5 在线切换

masterha_master_switch  --conf=/etc/mha/app1.cnf --master_state=alive --new_master_host=192.168.10.51 --orig_master_is_new_slave --running_updates_limit=10000

From:
192.168.10.52(192.168.10.52:3306) (current master)
 +--192.168.10.51(192.168.10.51:3306)
 +--192.168.10.53(192.168.10.53:3306)

To:
192.168.10.51(192.168.10.51:3306) (new master)
 +--192.168.10.53(192.168.10.53:3306)
 +--192.168.10.52(192.168.10.52:3306)
 
Tue Jun  8 10:44:10 2021 - [info] Switching master to 192.168.10.51(192.168.10.51:3306) completed successfully.  # 切换成功

3.2.6 确认vip

[root@db1 ~]# ip a |grep eth0
2: eth0: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    inet 192.168.10.51/24 brd 192.168.10.255 scope global noprefixroute eth0
    inet 192.168.10.49/24 brd 192.168.10.255 scope global secondary eth0:1

3.2.7 重构binlog-server

1、查询当前salve当前拿取的binlog日志

[root@db3 ~]# mysql -uroot -p123456 -e "show slave status \\G"|grep "Master_Log" 
              Master_Log_File: mysql-bin.000006
          Read_Master_Log_Pos: 196
        Relay_Master_Log_File: mysql-bin.000006
          Exec_Master_Log_Pos: 196

2、关停当前binlog-server服务，清除binlog-server目录里拉取的日志文件

[root@db03 bin]# ps -ef |grep mysqlbinlog
root      28144  16272  0 17:50 pts/1    00:00:00 mysqlbinlog -R --host=192.168.10.52 --user=mha --password=x x --raw --stop-never mysql-bin.000005
root      28529  16272  0 18:03 pts/1    00:00:00 grep --color=auto mysqlbinlog
[root@db03 bin]# kill -9 28144
[root@db03 bin]# cd /data/binlog_server/
[root@db03 binlog_server]# ll
total 4
-rw-r----- 1 root root 194 Apr  1 17:50 mysql-bin.000005
[root@db03 binlog_server]# rm -rf *
[1] 28534

3、进入日志目录，重新启动binlog-server守护进程

[root@db03 bin]# cd /data/binlog_server/
[root@db03 binlog_server]# mysqlbinlog  -R --host=192.168.10.51 --user=mha --password=mha --raw  --stop-never mysql-bin.000009 &

3.2.8 重新启动mha

[root@db03 bin]# nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover  < /dev/null> /var/log/mha/app1/manager.log 2>&1 &

[root@db03 binlog_server]# masterha_check_status   --conf=/etc/mha/app1.cnf 
app1 (pid:28535) is running(0:PING_OK), master:192.168.10.51

mysql

</broadcast,multicast,up,lower_up></broadcast,multicast,up,lower_up>

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