一.MHA簡介

MHA（Master High Availability）目前在MySQL高可用方面是一個相對成熟的解決方案诚亚，它由日本DeNA公司的youshimaton（現(xiàn)就職于Facebook公司）開發(fā)跃闹，是一套優(yōu)秀的作為MySQL高可用性環(huán)境下故障切換和主從提升的高可用軟件纪他。在MySQL故障切換過程中，MHA能做到在0~30秒之內(nèi)自動完成數(shù)據(jù)庫的故障切換操作卵迂，并且在進(jìn)行故障切換的過程中苏章，MHA能在最大程度上保證數(shù)據(jù)的一致性，以達(dá)到真正意義上的高可用遏暴。

MHA架構(gòu)圖

image.png

MHA工作原理總結(jié)為以下幾條：

從宕機(jī)崩潰的master保存二進(jìn)制日志事件（binlog events）；
識別含有最新更新的slave指黎；
應(yīng)用差異的中繼日志（relay log）到其他slave朋凉；
應(yīng)用從master保存的二進(jìn)制日志事件（binlog events）；
提升一個slave為新master醋安；
使用其他的slave連接新的master進(jìn)行復(fù)制杂彭。

MHA特點:

故障切換時間 10-30秒
自動監(jiān)控Master以及故障轉(zhuǎn)移
在線切換Master到異機(jī)

二.MHA搭建

2.1 基本環(huán)境

操作系統(tǒng)版本：CentOS Linux release 7.8.2003 (Core)
MySQL版本：5.7.31
VIP ：10.31.1.241

主機(jī)信息:

角色	IP	主機(jī)名	網(wǎng)卡	server_id	功能
Monitor Host	10.31.1.119	hp1	ens192	--	監(jiān)控復(fù)制組
Master	10.31.1.120	hp2	ens192	101	響應(yīng)寫請求
Candidate Master	10.31.1.121	hp3	ens192	102	響應(yīng)讀請求
Slave	10.31.1.122	hp4	ens192	103	響應(yīng)讀請求

2.2 配置主從

配置 hp3墓毒、hp4兩臺同步hp2的主從復(fù)制，參考主從復(fù)制blog亲怠，此處略過

2.3 安裝Perl等依賴模塊

用root用戶在所有四個節(jié)點執(zhí)行下面的操作所计。

# 安裝一個epel源
wget -O /etc/yum.repos.d/epel-7.repo http://mirrors.aliyun.com/repo/epel-7.repo
 
# 用yum安裝依賴包
yum install perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes -y

2.4 配置SSH登錄無密碼驗證

在hdp1 10.31.1.119（Monitor）上用root用戶執(zhí)行：

ssh-keygen -t rsa
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.120
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.121
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.122

在hdp2 10.31.1.120（Master）上用root用戶執(zhí)行：

ssh-keygen -t rsa
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.119
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.121
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.122

在hdp3 10.31.1.121（Candidate Master）上用root用戶執(zhí)行：

ssh-keygen -t rsa
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.119
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.120
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.122

在hdp4 10.31.1.122（Slave）上用root用戶執(zhí)行：

ssh-keygen -t rsa
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.119
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.120
ssh-copy-id -i /root/.ssh/id_rsa.pub root@10.31.1.121

2.5 安裝MHA Node

下載地址：https://github.com/yoshinorim/mha4mysql-manager/wiki/Downloads
在hdp2、hdp3团秽、hdp4上用root用戶執(zhí)行下面的操作主胧。

rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm

安裝完成后，在/usr/bin/目錄下有如下MHA相關(guān)文件：

apply_diff_relay_logs
filter_mysqlbinlog
purge_relay_logs
save_binary_logs

這些腳本工具通常由MHA Manager的腳本觸發(fā)徙垫，無需人為操作。腳本說明：
apply_diff_relay_logs：識別差異的中繼日志事件并將其差異的事件應(yīng)用于其它slave放棒。
filter_mysqlbinlog：去除不必要的ROLLBACK事件（MHA已不再使用這個工具）姻报。
purge_relay_logs：清除中繼日志（不會阻塞SQL線程）。
save_binary_logs：保存和復(fù)制master的二進(jìn)制日志间螟。

2.6 安裝MHA Manager

下載地址：https://github.com/yoshinorim/mha4mysql-manager/wiki/Downloads
在hdp1上用root用戶執(zhí)行下面的操作吴旋。

rpm -ivh mha4mysql-manager-0.56-0.el6.noarch.rpm

安裝報錯

[root@10-31-1-119 src]# rpm -ivh mha4mysql-manager-0.56-0.el6.noarch.rpm 
錯誤：依賴檢測失敗：
        mha4mysql-node >= 0.54 被 mha4mysql-manager-0.56-0.el6.noarch 需要
        perl(MHA::BinlogManager) 被 mha4mysql-manager-0.56-0.el6.noarch 需要
        perl(MHA::NodeConst) 被 mha4mysql-manager-0.56-0.el6.noarch 需要
        perl(MHA::NodeUtil) 被 mha4mysql-manager-0.56-0.el6.noarch 需要
        perl(MHA::SlaveUtil) 被 mha4mysql-manager-0.56-0.el6.noarch 需要
[root@10-31-1-119 src]# 
[root@10-31-1-119 src]# 
[root@10-31-1-119 src]# yum -y install mha4mysql-manager-0.56-0.el6.noarch.rpm
已加載插件：fastestmirror, langpacks
正在檢查 mha4mysql-manager-0.56-0.el6.noarch.rpm: mha4mysql-manager-0.56-0.el6.noarch
mha4mysql-manager-0.56-0.el6.noarch.rpm 將被安裝
正在解決依賴關(guān)系
--> 正在檢查事務(wù)
---> 軟件包 mha4mysql-manager.noarch.0.0.56-0.el6 將被 安裝
--> 正在處理依賴關(guān)系 mha4mysql-node >= 0.54厢破，它被軟件包 mha4mysql-manager-0.56-0.el6.noarch 需要
Loading mirror speeds from cached hostfile
--> 正在處理依賴關(guān)系 perl(MHA::BinlogManager)荣瑟，它被軟件包 mha4mysql-manager-0.56-0.el6.noarch 需要
--> 正在處理依賴關(guān)系 perl(MHA::NodeConst)，它被軟件包 mha4mysql-manager-0.56-0.el6.noarch 需要
--> 正在處理依賴關(guān)系 perl(MHA::NodeUtil)摩泪，它被軟件包 mha4mysql-manager-0.56-0.el6.noarch 需要
--> 正在處理依賴關(guān)系 perl(MHA::SlaveUtil)笆焰，它被軟件包 mha4mysql-manager-0.56-0.el6.noarch 需要
--> 解決依賴關(guān)系完成
錯誤：軟件包：mha4mysql-manager-0.56-0.el6.noarch (/mha4mysql-manager-0.56-0.el6.noarch)
          需要：mha4mysql-node >= 0.54
錯誤：軟件包：mha4mysql-manager-0.56-0.el6.noarch (/mha4mysql-manager-0.56-0.el6.noarch)
          需要：perl(MHA::NodeUtil)
錯誤：軟件包：mha4mysql-manager-0.56-0.el6.noarch (/mha4mysql-manager-0.56-0.el6.noarch)
          需要：perl(MHA::BinlogManager)
錯誤：軟件包：mha4mysql-manager-0.56-0.el6.noarch (/mha4mysql-manager-0.56-0.el6.noarch)
          需要：perl(MHA::NodeConst)
錯誤：軟件包：mha4mysql-manager-0.56-0.el6.noarch (/mha4mysql-manager-0.56-0.el6.noarch)
          需要：perl(MHA::SlaveUtil)
 您可以嘗試添加 --skip-broken 選項來解決該問題
 您可以嘗試執(zhí)行：rpm -Va --nofiles --nodigest
[root@10-31-1-119 src]#

監(jiān)控節(jié)點需要先安裝node再安裝manager

[root@10-31-1-119 src]# rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm
準(zhǔn)備中...                          ################################# [100%]
正在升級/安裝...
   1:mha4mysql-node-0.56-0.el6        ################################# [100%]
[root@10-31-1-119 src]# 
[root@10-31-1-119 src]# rpm -ivh mha4mysql-manager-0.56-0.el6.noarch.rpm
準(zhǔn)備中...                          ################################# [100%]
正在升級/安裝...
   1:mha4mysql-manager-0.56-0.el6     ################################# [100%]
[root@10-31-1-119 src]#

安裝完成后，在/usr/bin/目錄下有如下MHA相關(guān)文件：

masterha_check_repl
masterha_check_ssh
masterha_check_status
masterha_conf_host
masterha_manager
masterha_master_monitor
masterha_master_switch
masterha_secondary_check
masterha_stop
apply_diff_relay_logs
filter_mysqlbinlog
purge_relay_logs
save_binary_logs

2.7 配置MHA

在hdp1上用root用戶執(zhí)行下面（1）见坑、（2）嚷掠、（3）的操作。
（1）建立配置文件目錄

mkdir -p /etc/masterha

（2）創(chuàng)建配置文件/etc/masterha/app1.cnf荞驴，內(nèi)容如下：

[server default]
manager_log=/var/log/masterha/app1/manager.log
manager_workdir=/var/log/masterha/app1.log
master_binlog_dir=/var/lib/mysql
master_ip_failover_script=/usr/bin/master_ip_failover
master_ip_online_change_script=/usr/bin/master_ip_online_change
password=abc123
ping_interval=1
remote_workdir=/tmp
repl_password=abc123
repl_user=repl
secondary_check_script=/usr/bin/masterha_secondary_check -s hp2 -s hp3 --user=root --master_host=hp2 --master_ip=10.31.1.120 --master_port=3306
shutdown_script=""
ssh_user=root
user=root
 
[server1]
hostname=10.31.1.120
port=3306
 
[server2]
candidate_master=1
check_repl_delay=0
hostname=10.31.1.121
port=3306
 
[server3]
hostname=10.31.1.122
port=3306

server default段是manager的一些基本配置參數(shù)不皆，server1、server2熊楼、server3分別對應(yīng)復(fù)制中的master霹娄、第一個slave、第二個slave鲫骗。該文件的語法要求嚴(yán)格犬耻，變量值后不要有多余的空格。主要配置項說明如下执泰。

manager_log：設(shè)置manager的日志文件香追。
manager_workdir：設(shè)置manager的工作目錄。
master_binlog_dir：設(shè)置master保存binlog的位置坦胶，以便MHA可以找到master的日志透典，這里的也就是mysql的數(shù)據(jù)目錄晴楔。
master_ip_failover_script：設(shè)置自動failover時候的切換腳本。
master_ip_online_change_script：設(shè)置手動切換時候的切換腳本峭咒。
password：設(shè)置mysql中root用戶的密碼怎静。
ping_interval：設(shè)置監(jiān)控主庫，發(fā)送ping包的時間間隔卒密，默認(rèn)是3秒忌锯，嘗試三次沒有回應(yīng)的時候自動進(jìn)行railover。
remote_workdir：設(shè)置遠(yuǎn)端mysql在發(fā)生切換時binlog的保存位置漩氨。
repl_password：設(shè)置復(fù)制用戶的密碼西壮。
repl_user：設(shè)置復(fù)制環(huán)境中的復(fù)制用戶名
secondary_check_script：一旦MHA到hdp4的監(jiān)控之間出現(xiàn)問題，MHA Manager將會嘗試從hdp3登錄到hdp4叫惊。
shutdown_script：設(shè)置故障發(fā)生后關(guān)閉故障主機(jī)腳本款青。該腳本的主要作用是關(guān)閉主機(jī)放在發(fā)生腦裂，這里沒有使用霍狰。
ssh_user：設(shè)置ssh的登錄用戶名抡草。
user：設(shè)置監(jiān)控用戶為root。
candidate_master：設(shè)置為候選master蔗坯。設(shè)置該參數(shù)以后康震，發(fā)生主從切換以后將會將此從庫提升為主庫，即使這個主庫不是集群中事件最新的slave宾濒。
check_repl_delay：默認(rèn)情況下如果一個slave落后master 100M的relay logs的話腿短，MHA將不會選擇該slave作為一個新的master，因為對于這個slave的恢復(fù)需要花費很長時間绘梦，通過設(shè)置check_repl_delay=0答姥，MHA觸發(fā)切換在選擇一個新的master的時候?qū)雎詮?fù)制延時，這個參數(shù)對于設(shè)置了candidate_master=1的主機(jī)非常有用谚咬，因為這個候選主在切換的過程中一定是新的master鹦付。

（3）建立軟連接

-- 這一步如果 mysqlbinlog和mysql已經(jīng)可以直接使用就沒問題
ln -s /home/mysql/mysql-5.6.14/bin/mysqlbinlog /usr/bin/mysqlbinlog
ln -s /home/mysql/mysql-5.6.14/bin/mysql /usr/bin/mysql

（4）設(shè)置復(fù)制中Slave的relay_log_purge參數(shù)
在hdp3和hdp4上用mysql用戶執(zhí)行：

mysql -uroot -pabc123 -e "set global relay_log_purge=0"

注意，MHA在發(fā)生切換的過程中择卦，從庫的恢復(fù)過程中依賴于relay log的相關(guān)信息敲长，所以這里要將relay log的自動清除設(shè)置為OFF，采用手動清除relay log的方式秉继。默認(rèn)情況下祈噪，從服務(wù)器上的中繼日志會在SQL線程執(zhí)行完畢后被自動刪除。但是在MHA環(huán)境中尚辑，這些中繼日志在恢復(fù)其他從服務(wù)器時可能會被用到辑鲤，因此需要禁用中繼日志的自動刪除功能。定期清除中繼日志需要考慮到復(fù)制延時的問題杠茬。在ext3的文件系統(tǒng)下月褥，刪除大的文件需要一定的時間弛随，會導(dǎo)致嚴(yán)重的復(fù)制延時。為了避免復(fù)制延時宁赤，需要暫時為中繼日志創(chuàng)建硬鏈接舀透，因為在linux系統(tǒng)中通過硬鏈接刪除大文件速度會很快。（在mysql數(shù)據(jù)庫中决左，刪除大表時愕够，通常也采用建立硬鏈接的方式）

2.8 創(chuàng)建相關(guān)腳本

2.8.1 創(chuàng)建定期清理relay腳本

在hdp3、hdp4兩臺slave上建立/root/purge_relay_log.sh文件佛猛，內(nèi)容如下：

#!/bin/bash
 
. /home/mysql/.bashrc
 
user=root
passwd=abc123
port=3306
log_dir='/data'
work_dir='/data'
purge='/usr/bin/purge_relay_logs'
 
if [ ! -d $log_dir ]
then
   mkdir $log_dir -p
fi
 
$purge --user=$user --password=$passwd --disable_relay_log_purge --port=$port --workdir=$work_dir >> $log_dir/purge_relay_logs.log 2>&1

purge_relay_logs的參數(shù)說明：

user mysql：MySQL用戶名惑芭。
password mysql：MySQL用戶密碼。
port：MySQL端口號继找。
workdir：指定創(chuàng)建relay log的硬鏈接的位置遂跟，默認(rèn)是/var/tmp。由于系統(tǒng)不同分區(qū)創(chuàng)建硬鏈接文件會失敗码荔，故需要執(zhí)行硬鏈接具體位置漩勤，成功執(zhí)行腳本后感挥，硬鏈接的中繼日志文件被刪除缩搅。
disable_relay_log_purge：默認(rèn)情況下，如果relay_log_purge=1触幼，腳本會什么都不清理硼瓣，自動退出。通過設(shè)定這個參數(shù)置谦，當(dāng)relay_log_purge=1的情況下會將relay_log_purge設(shè)置為0堂鲤。清理relay log之后，最后將參數(shù)設(shè)置為OFF媒峡。

改模式為可執(zhí)行：

mkdir -p /data
chmod 755 purge_relay_log.sh

添加到crontab中：

0 4 * * * /bin/bash /root/purge_relay_log.sh

2.8.2 創(chuàng)建自動failover腳本

在hdp1上創(chuàng)建/usr/bin/master_ip_failover文件瘟栖，內(nèi)容如下：

#!/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 = '10.31.1.241';
my $key = '1';
my $ssh_start_vip = "/sbin/ifconfig ens192:$key $vip/24";
my $ssh_stop_vip = "/sbin/ifconfig ens192:$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,
);

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";
}

注意腳本中的vip部分

chmod u+x /usr/bin/master_ip_failover

2.8.3 創(chuàng)建手動failover腳本

在hdp1上創(chuàng)建/usr/bin/master_ip_online_change文件，內(nèi)容如下：

#!/usr/bin/env perl
  
## Note: This is a sample script and is notcomplete. Modify the script based on your environment.
  
use strict;
use warnings FATAL => 'all';
  
use Getopt::Long;
use MHA::DBHelper;
use MHA::NodeUtil;
# use Time::HiRes qw( sleep gettimeofdaytv_interval );
use Time::HiRes qw(sleep gettimeofday tv_interval);
use Data::Dumper;
  
my $_tstart;
my $_running_interval = 0.1;
my (
 $command,         $orig_master_host, $orig_master_ip,
 $orig_master_port, $orig_master_user,
 $new_master_host, $new_master_ip,   $new_master_port,
 $new_master_user, 
);
  
my $vip = '10.31.1.241';  # Virtual IP 
my $key = "1"; 
my $ssh_start_vip = "/sbin/ifconfig ens32:$key $vip/24";
my $ssh_stop_vip = "/sbin/ifconfig ens160:$key down";
my $ssh_user = "root";
my $new_master_password = "123456";
my $orig_master_password = "123456";
  
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,
 'orig_master_user=s'     =>\$orig_master_user,
 #'orig_master_password=s' => \$orig_master_password,
 '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 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) && $command eq "Sleep" );
      nextif ( defined($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 nobodycan connect. Disabling per-session binlog beforehand
     #$orig_master_handler->disable_log_bin_local();
     #print current_time_us() . " Drpping app user on the origmaster..\n";
     #FIXME_xxx_drop_app_user($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 aredisconnected.. (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(exceptSUPER) 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 cancomplete
     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 aredisconnected.. (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 "Disabling the VIPon old master: $orig_master_host \n";
                &stop_vip();    
  
     ## Terminating all threads
     print current_time_us() . " Killing all applicationthreads..\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
  
# We don't return error even thoughactivating updatable accounts/ip failed so that we don't interrupt slaves'recovery.
# If exit code is 0 or 10, MHA does notabort
    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 newmaster.\n";
     $new_master_handler->disable_read_only();
  
     ## Creating an app user on the new master
     #print current_time_us() . " Creating app user on the newmaster..\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 "Enabling 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;
  }
}
  
# A simple system call that enable the VIPon the new master
sub start_vip() {
   `ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}
# A simple system call that disable the VIPon the old_master
sub stop_vip() {
   `ssh $ssh_user\@$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;
}

授權(quán)

chmod u+x /usr/bin/master_ip_online_change

三.檢查MHA配置

3.1 檢查SSH配置

在hdp1上用root用戶操作谅阿。

[root@10-31-1-119 ~]# masterha_check_ssh --conf=/etc/masterha/app1.cnf
Mon Aug 24 17:47:04 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Mon Aug 24 17:47:04 2020 - [info] Reading application default configuration from /etc/masterha/app1.cnf..
Mon Aug 24 17:47:04 2020 - [info] Reading server configuration from /etc/masterha/app1.cnf..
Mon Aug 24 17:47:04 2020 - [info] Starting SSH connection tests..
Mon Aug 24 17:47:06 2020 - [debug] 
Mon Aug 24 17:47:04 2020 - [debug]  Connecting via SSH from root@10.31.1.120(10.31.1.120:22) to root@10.31.1.121(10.31.1.121:22)..
Mon Aug 24 17:47:05 2020 - [debug]   ok.
Mon Aug 24 17:47:05 2020 - [debug]  Connecting via SSH from root@10.31.1.120(10.31.1.120:22) to root@10.31.1.122(10.31.1.122:22)..
Mon Aug 24 17:47:06 2020 - [debug]   ok.
Mon Aug 24 17:47:07 2020 - [debug] 
Mon Aug 24 17:47:05 2020 - [debug]  Connecting via SSH from root@10.31.1.122(10.31.1.122:22) to root@10.31.1.120(10.31.1.120:22)..
Mon Aug 24 17:47:06 2020 - [debug]   ok.
Mon Aug 24 17:47:06 2020 - [debug]  Connecting via SSH from root@10.31.1.122(10.31.1.122:22) to root@10.31.1.121(10.31.1.121:22)..
Mon Aug 24 17:47:07 2020 - [debug]   ok.
Mon Aug 24 17:47:07 2020 - [debug] 
Mon Aug 24 17:47:05 2020 - [debug]  Connecting via SSH from root@10.31.1.121(10.31.1.121:22) to root@10.31.1.120(10.31.1.120:22)..
Mon Aug 24 17:47:06 2020 - [debug]   ok.
Mon Aug 24 17:47:06 2020 - [debug]  Connecting via SSH from root@10.31.1.121(10.31.1.121:22) to root@10.31.1.122(10.31.1.122:22)..
Mon Aug 24 17:47:06 2020 - [debug]   ok.
Mon Aug 24 17:47:07 2020 - [info] All SSH connection tests passed successfully.

3.2 檢查整個復(fù)制環(huán)境狀況

hp2上授權(quán)

create user 'root'@'10.31.1.%' identified by 'abc123';
grant all privileges on *.* to 'root'@'10.31.1.%';
flush privileges;

在hdp1上用root用戶操作半哟。

[root@10-31-1-119 ~]# masterha_check_repl --conf=/etc/masterha/app1.cnf
Mon Aug 24 17:57:22 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Mon Aug 24 17:57:22 2020 - [info] Reading application default configuration from /etc/masterha/app1.cnf..
Mon Aug 24 17:57:22 2020 - [info] Reading server configuration from /etc/masterha/app1.cnf..
Mon Aug 24 17:57:22 2020 - [info] MHA::MasterMonitor version 0.56.
Mon Aug 24 17:57:23 2020 - [info] GTID failover mode = 0
Mon Aug 24 17:57:23 2020 - [info] Dead Servers:
Mon Aug 24 17:57:23 2020 - [info] Alive Servers:
Mon Aug 24 17:57:23 2020 - [info]   10.31.1.120(10.31.1.120:3306)
Mon Aug 24 17:57:23 2020 - [info]   10.31.1.121(10.31.1.121:3306)
Mon Aug 24 17:57:23 2020 - [info]   10.31.1.122(10.31.1.122:3306)
Mon Aug 24 17:57:23 2020 - [info] Alive Slaves:
Mon Aug 24 17:57:23 2020 - [info]   10.31.1.121(10.31.1.121:3306)  Version=5.7.31-log (oldest major version between slaves) log-bin:enabled
Mon Aug 24 17:57:23 2020 - [info]     Replicating from 10.31.1.120(10.31.1.120:3306)
Mon Aug 24 17:57:23 2020 - [info]     Primary candidate for the new Master (candidate_master is set)
Mon Aug 24 17:57:23 2020 - [info]   10.31.1.122(10.31.1.122:3306)  Version=5.7.31-log (oldest major version between slaves) log-bin:enabled
Mon Aug 24 17:57:23 2020 - [info]     Replicating from 10.31.1.120(10.31.1.120:3306)
Mon Aug 24 17:57:23 2020 - [info] Current Alive Master: 10.31.1.120(10.31.1.120:3306)
Mon Aug 24 17:57:23 2020 - [info] Checking slave configurations..
Mon Aug 24 17:57:23 2020 - [info]  read_only=1 is not set on slave 10.31.1.121(10.31.1.121:3306).
Mon Aug 24 17:57:23 2020 - [info]  read_only=1 is not set on slave 10.31.1.122(10.31.1.122:3306).
Mon Aug 24 17:57:23 2020 - [info] Checking replication filtering settings..
Mon Aug 24 17:57:23 2020 - [info]  binlog_do_db= , binlog_ignore_db= 
Mon Aug 24 17:57:23 2020 - [info]  Replication filtering check ok.
Mon Aug 24 17:57:23 2020 - [info] GTID (with auto-pos) is not supported
Mon Aug 24 17:57:23 2020 - [info] Starting SSH connection tests..
Mon Aug 24 17:57:26 2020 - [info] All SSH connection tests passed successfully.
Mon Aug 24 17:57:26 2020 - [info] Checking MHA Node version..
Mon Aug 24 17:57:27 2020 - [info]  Version check ok.
Mon Aug 24 17:57:27 2020 - [info] Checking SSH publickey authentication settings on the current master..
Mon Aug 24 17:57:27 2020 - [info] HealthCheck: SSH to 10.31.1.120 is reachable.
Mon Aug 24 17:57:27 2020 - [info] Master MHA Node version is 0.56.
Mon Aug 24 17:57:27 2020 - [info] Checking recovery script configurations on 10.31.1.120(10.31.1.120:3306)..
Mon Aug 24 17:57:27 2020 - [info]   Executing command: save_binary_logs --command=test --start_pos=4 --binlog_dir=/var/lib/mysql --output_file=/tmp/save_binary_logs_test --manager_version=0.56 --start_file=10-31-1-120-bin.000001 
Mon Aug 24 17:57:27 2020 - [info]   Connecting to root@10.31.1.120(10.31.1.120:22).. 
  Creating /tmp if not exists..    ok.
  Checking output directory is accessible or not..
   ok.
  Binlog found at /var/lib/mysql, up to 10-31-1-120-bin.000001
Mon Aug 24 17:57:28 2020 - [info] Binlog setting check done.
Mon Aug 24 17:57:28 2020 - [info] Checking SSH publickey authentication and checking recovery script configurations on all alive slave servers..
Mon Aug 24 17:57:28 2020 - [info]   Executing command : apply_diff_relay_logs --command=test --slave_user='root' --slave_host=10.31.1.121 --slave_ip=10.31.1.121 --slave_port=3306 --workdir=/tmp --target_version=5.7.31-log --manager_version=0.56 --relay_log_info=/var/lib/mysql/relay-log.info  --relay_dir=/var/lib/mysql/  --slave_pass=xxx
Mon Aug 24 17:57:28 2020 - [info]   Connecting to root@10.31.1.121(10.31.1.121:22).. 
  Checking slave recovery environment settings..
    Opening /var/lib/mysql/relay-log.info ... ok.
    Relay log found at /var/lib/mysql, up to 10-31-1-121-relay-bin.000005
    Temporary relay log file is /var/lib/mysql/10-31-1-121-relay-bin.000005
    Testing mysql connection and privileges..mysql: [Warning] Using a password on the command line interface can be insecure.
 done.
    Testing mysqlbinlog output.. done.
    Cleaning up test file(s).. done.
Mon Aug 24 17:57:28 2020 - [info]   Executing command : apply_diff_relay_logs --command=test --slave_user='root' --slave_host=10.31.1.122 --slave_ip=10.31.1.122 --slave_port=3306 --workdir=/tmp --target_version=5.7.31-log --manager_version=0.56 --relay_log_info=/var/lib/mysql/relay-log.info  --relay_dir=/var/lib/mysql/  --slave_pass=xxx
Mon Aug 24 17:57:28 2020 - [info]   Connecting to root@10.31.1.122(10.31.1.122:22).. 
  Checking slave recovery environment settings..
    Opening /var/lib/mysql/relay-log.info ... ok.
    Relay log found at /var/lib/mysql, up to 10-31-1-122-relay-bin.000005
    Temporary relay log file is /var/lib/mysql/10-31-1-122-relay-bin.000005
    Testing mysql connection and privileges..mysql: [Warning] Using a password on the command line interface can be insecure.
 done.
    Testing mysqlbinlog output.. done.
    Cleaning up test file(s).. done.
Mon Aug 24 17:57:29 2020 - [info] Slaves settings check done.
Mon Aug 24 17:57:29 2020 - [info] 
10.31.1.120(10.31.1.120:3306) (current master)
 +--10.31.1.121(10.31.1.121:3306)
 +--10.31.1.122(10.31.1.122:3306)

Mon Aug 24 17:57:29 2020 - [info] Checking replication health on 10.31.1.121..
Mon Aug 24 17:57:29 2020 - [info]  ok.
Mon Aug 24 17:57:29 2020 - [info] Checking replication health on 10.31.1.122..
Mon Aug 24 17:57:29 2020 - [info]  ok.
Mon Aug 24 17:57:29 2020 - [info] Checking master_ip_failover_script status:
Mon Aug 24 17:57:29 2020 - [info]   /usr/bin/master_ip_failover --command=status --ssh_user=root --orig_master_host=10.31.1.120 --orig_master_ip=10.31.1.120 --orig_master_port=3306 


IN SCRIPT TEST====/sbin/ifconfig ens192:1 down==/sbin/ifconfig ens192:1 10.31.1.241/24===

Checking the Status of the script.. OK 
Mon Aug 24 17:57:29 2020 - [info]  OK.
Mon Aug 24 17:57:29 2020 - [warning] shutdown_script is not defined.
Mon Aug 24 17:57:29 2020 - [info] Got exit code 0 (Not master dead).

MySQL Replication Health is OK.
[root@10-31-1-119 ~]#

3.3 檢查MHA Manager的狀態(tài)

在hdp1上用root用戶操作。

[root@10-31-1-119 ~]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 is stopped(2:NOT_RUNNING).
[root@10-31-1-119 ~]#

顯示"NOT_RUNNING"签餐，這代表MHA監(jiān)控沒有開啟寓涨。執(zhí)行下面的命令后臺啟動MHA。

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

啟動參數(shù)說明：
remove_dead_master_conf：該參數(shù)代表當(dāng)發(fā)生主從切換后氯檐，老的主庫的ip將會從配置文件中移除戒良。
manger_log：日志存放位置。
ignore_last_failover：在缺省情況下冠摄，如果MHA檢測到連續(xù)發(fā)生宕機(jī)糯崎，且兩次宕機(jī)間隔不足8小時的話几缭，則不會進(jìn)行Failover，之所以這樣限制是為了避免ping-pong效應(yīng)拇颅。該參數(shù)代表忽略上次MHA觸發(fā)切換產(chǎn)生的文件奏司，默認(rèn)情況下，MHA發(fā)生切換后會在日志目錄樟插，也就是上面設(shè)置的/data產(chǎn)生app1.failover.complete文件韵洋，下次再次切換的時候如果發(fā)現(xiàn)該目錄下存在該文件將不允許觸發(fā)切換，除非在第一次切換后收到刪除該文件黄锤。為了方便搪缨，這里設(shè)置為--ignore_last_failover。

再次檢查MHA Manager的狀態(tài)：

[root@10-31-1-119 ~]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 monitoring program is now on initialization phase(10:INITIALIZING_MONITOR). Wait for a while and try checking again.
[root@10-31-1-119 ~]#

3.4 查看啟動日志

在hdp1上用root用戶操作鸵熟。

[root@10-31-1-119 ~]# tail -n20 /var/log/masterha/app1/manager.log
    Cleaning up test file(s).. done.
Mon Aug 24 18:06:00 2020 - [info] Slaves settings check done.
Mon Aug 24 18:06:00 2020 - [info] 
10.31.1.120(10.31.1.120:3306) (current master)
 +--10.31.1.121(10.31.1.121:3306)
 +--10.31.1.122(10.31.1.122:3306)

Mon Aug 24 18:06:00 2020 - [info] Checking master_ip_failover_script status:
Mon Aug 24 18:06:00 2020 - [info]   /usr/bin/master_ip_failover --command=status --ssh_user=root --orig_master_host=10.31.1.120 --orig_master_ip=10.31.1.120 --orig_master_port=3306 


IN SCRIPT TEST====/sbin/ifconfig eth1:1 down==/sbin/ifconfig eth1:1 10.31.1.241/24===

Checking the Status of the script.. OK 
Mon Aug 24 18:06:00 2020 - [info]  OK.
Mon Aug 24 18:06:00 2020 - [warning] shutdown_script is not defined.
Mon Aug 24 18:06:00 2020 - [info] Set master ping interval 1 seconds.
Mon Aug 24 18:06:00 2020 - [info] Set secondary check script: /usr/bin/masterha_secondary_check -s hdp2 -s hdp3 --user=root --master_host=hdp2 --master_ip=10.31.1.120 --master_port=3306
Mon Aug 24 18:06:00 2020 - [info] Starting ping health check on 10.31.1.120(10.31.1.120:3306)..
Mon Aug 24 18:06:00 2020 - [info] Ping(SELECT) succeeded, waiting until MySQL doesn't respond..

四.功能測試

4.1 初始綁定VIP

在hdp2 10.31.1.112（master）上用root用戶執(zhí)行：

/sbin/ifconfig ens192:1 10.31.1.241/24

執(zhí)行記錄

[root@10-31-1-120 src]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:54:f4:e5 brd ff:ff:ff:ff:ff:ff
    inet 10.31.1.120/24 brd 10.31.1.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::b3f8:a2f7:5ba0:b68d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
[root@10-31-1-120 src]# 
[root@10-31-1-120 src]# 
[root@10-31-1-120 src]# /sbin/ifconfig ens192:1 10.31.1.241/24
[root@10-31-1-120 src]# 
[root@10-31-1-120 src]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:54:f4:e5 brd ff:ff:ff:ff:ff:ff
    inet 10.31.1.120/24 brd 10.31.1.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet 10.31.1.241/24 brd 10.31.1.255 scope global secondary ens192:1
       valid_lft forever preferred_lft forever
    inet6 fe80::b3f8:a2f7:5ba0:b68d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
[root@10-31-1-120 src]#

也可以手工解除綁定

[root@10-31-1-120 keepalived-2.0.15]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:54:f4:e5 brd ff:ff:ff:ff:ff:ff
    inet 10.31.1.120/24 brd 10.31.1.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet 10.31.1.241/24 brd 10.31.1.255 scope global secondary ens192:1
       valid_lft forever preferred_lft forever
    inet6 fe80::b3f8:a2f7:5ba0:b68d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
[root@10-31-1-120 keepalived-2.0.15]# 
[root@10-31-1-120 keepalived-2.0.15]# 
[root@10-31-1-120 keepalived-2.0.15]# ifconfig ens192:10.31.1.241/24 down
SIOCSIFFLAGS: 無法指定被請求的地址
[root@10-31-1-120 keepalived-2.0.15]# 
[root@10-31-1-120 keepalived-2.0.15]# 
[root@10-31-1-120 keepalived-2.0.15]# ifconfig ens192:1 down             
[root@10-31-1-120 keepalived-2.0.15]# 
[root@10-31-1-120 keepalived-2.0.15]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:54:f4:e5 brd ff:ff:ff:ff:ff:ff
    inet 10.31.1.120/24 brd 10.31.1.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::b3f8:a2f7:5ba0:b68d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
[root@10-31-1-120 keepalived-2.0.15]#

4.2 測試自動切換

4.2.1 通過vip登陸mysql

[root@uattest ~]# mysql -uroot -p -h10.31.1.241
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 27
Server version: 5.7.31-log MySQL Community Server (GPL)

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>

4.2.2 停止主庫hp1的mysql服務(wù)器

service mysqld stop
ip addr

[root@10-31-1-120 src]# service mysqld stop
Redirecting to /bin/systemctl stop mysqld.service
[root@10-31-1-120 src]# 
[root@10-31-1-120 src]# 
[root@10-31-1-120 src]# 
-- 可以看到  10.31.1.241的vip已經(jīng)不再hp1(master)上了
[root@10-31-1-120 src]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:54:f4:e5 brd ff:ff:ff:ff:ff:ff
    inet 10.31.1.120/24 brd 10.31.1.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet6 fe80::b3f8:a2f7:5ba0:b68d/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff

4.2.3 hp2和hp3查看

hp2

-- 可以看到 10.31.1.241這個vip飄到hp2上了
[root@10-31-1-121 src]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens192: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
    link/ether 00:0c:29:e1:fe:b4 brd ff:ff:ff:ff:ff:ff
    inet 10.31.1.121/24 brd 10.31.1.255 scope global noprefixroute ens192
       valid_lft forever preferred_lft forever
    inet 10.31.1.241/24 brd 10.255.255.255 scope global ens192:1
       valid_lft forever preferred_lft forever
    inet6 fe80::9470:f61e:6e0e:48e4/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::1aa1:d23e:e28a:fb62/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
    inet6 fe80::f974:3f03:d1f0:1672/64 scope link noprefixroute 
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:c4:b9:a5 brd ff:ff:ff:ff:ff:ff

-- hp2已經(jīng)由從庫變?yōu)橹鲙炝?[root@10-31-1-121 src]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 53
Server version: 5.7.31-log MySQL Community Server (GPL)

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> 
mysql> show slave status\G
Empty set (0.00 sec)

mysql> show master status\G
*************************** 1. row ***************************
             File: 10-31-1-121-bin.000001
         Position: 507
     Binlog_Do_DB: 
 Binlog_Ignore_DB: 
Executed_Gtid_Set: 
1 row in set (0.00 sec)

hp3

hp3變?yōu)榱薶p2的從庫
[root@10-31-1-122 bin]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 48
Server version: 5.7.31-log MySQL Community Server (GPL)

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.31.1.121
                  Master_User: repl
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: 10-31-1-121-bin.000001
          Read_Master_Log_Pos: 507
               Relay_Log_File: 10-31-1-122-relay-bin.000002
                Relay_Log_Pos: 679
        Relay_Master_Log_File: 10-31-1-121-bin.000001
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
              Replicate_Do_DB: 
          Replicate_Ignore_DB: 
           Replicate_Do_Table: 
       Replicate_Ignore_Table: 
      Replicate_Wild_Do_Table: 
  Replicate_Wild_Ignore_Table: 
                   Last_Errno: 0
                   Last_Error: 
                 Skip_Counter: 0
          Exec_Master_Log_Pos: 507
              Relay_Log_Space: 892
              Until_Condition: None
               Until_Log_File: 
                Until_Log_Pos: 0
           Master_SSL_Allowed: No
           Master_SSL_CA_File: 
           Master_SSL_CA_Path: 
              Master_SSL_Cert: 
            Master_SSL_Cipher: 
               Master_SSL_Key: 
        Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
                Last_IO_Errno: 0
                Last_IO_Error: 
               Last_SQL_Errno: 0
               Last_SQL_Error: 
  Replicate_Ignore_Server_Ids: 
             Master_Server_Id: 102
                  Master_UUID: 5ad1f5aa-e2cb-11ea-ba89-000c29e1feb4
             Master_Info_File: /var/lib/mysql/master.info
                    SQL_Delay: 0
          SQL_Remaining_Delay: NULL
      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates
           Master_Retry_Count: 86400
                  Master_Bind: 
      Last_IO_Error_Timestamp: 
     Last_SQL_Error_Timestamp: 
               Master_SSL_Crl: 
           Master_SSL_Crlpath: 
           Retrieved_Gtid_Set: 
            Executed_Gtid_Set: 
                Auto_Position: 0
         Replicate_Rewrite_DB: 
                 Channel_Name: 
           Master_TLS_Version: 
1 row in set (0.00 sec)

4.3 還原環(huán)境

還原數(shù)據(jù)庫復(fù)制：

-- 在hdp2副编、hdp3、hdp4上重置master流强、slave
stop slave;
reset master;
reset slave all;
 
-- 在hdp3痹届、hdp4上重新指向hdp2為master
change master to
master_host='10.31.1.120',
master_port=3306,
master_user='repl',
master_password='abc123',
master_log_file='10-31-1-120-bin.000001',
master_log_pos=154;
 
start slave;
show slave status\G

還原VIP綁定：

# 在hdp3上用root用戶執(zhí)行
/sbin/ifconfig ens192:1 down
 
# 在hdp2上用root用戶執(zhí)行
/sbin/ifconfig ens192:1 10.31.1.241/24

還原配置文件：
編輯在hdp1上/etc/masterha/app1.cnf，將[server1]段添加回去打月。

啟動MHA Manage：

# 在hdp1上用root用戶執(zhí)行
nohup masterha_manager --conf=/etc/masterha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/masterha/app1/manager.log 2>&1 &

至此環(huán)境還原完畢队腐。

4.4 測試手工切換

4.4.1 停止MHA Manage

在hp1用root用戶操作

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

4.4.2 關(guān)閉master

在hdp2上用root用戶操作。

service mysqld stop

4.4.3 執(zhí)行手工切換

在hdp1上用root用戶操作奏篙。

masterha_master_switch --master_state=dead --conf=/etc/masterha/app1.cnf --dead_master_host=10.31.1.120 --dead_master_port=3306 --new_master_host=10.31.1.121 --new_master_port=3306 --ignore_last_failover