目录

• 一、恢复MHA
• 二、MHA切换
• 三、配置VIP漂移

一、恢复MHA

#1.修复旧主库 
[root@db01 ~]# /etc/init.d/mysqld start 
#2.在mha日志中找到change master语句 
#GTID模式下：
[root@db04 ~]# grep -i 'change master to' /etc/mha/manager.log
Tue Nov 19 20:49:31 2019 - [info] All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='slave', MASTER_PASSWORD='123'; 

#普通模式下：
[root@db03 ~]# grep -i 'change master to' /etc/mha/manager.log 
Tue Nov 19 19:22:22 2019 - [info]  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3306, MASTER_LOG_FILE='mysql-bin.000003', MASTER_LOG_POS=120, MASTER_USER='slave', MASTER_PASSWORD='xxx';

#3.在旧主库中执行change master语句 
CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3306, MASTER_AUTO_POSITION=1, MASTER_USER='slave', MASTER_PASSWORD='123'; 

#4.将mha配置文件修复 
[server1]
hostname=10.0.0.51 
port=3306 

#5.启动mha 
[root@db04 ~]# nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf -- ignore_last_failover < /dev/null > /etc/mha/manager.log 2>&1 &
##### MHA启动命令 详解
nohup masterha_manager --conf=/etc/mha/app1.cnf 
#从配置文件中移除旧主库 
--remove_dead_master_conf 
#忽略上一次切换 
--ignore_last_failover 
## mha工作机制：在mha一次切换后，会在mha的工作目录下生成一个lock，锁文件

执行脚本恢复

[root@db01 ~]# cat mysql_vip.sh 
#!/bin/bash
/etc/init.d/mysqld start
mha=10.0.0.53
change=`ssh $mha "grep -i 'change master to' /etc/mha/manager.log"|awk -F : '{print $4}'|sed 's#xxx#123#g'`
mysql -e "$change;start slave;"
ssh $mha \cp /etc/mha/app1.cnf.ori /etc/mha/app1.cnf

二、MHA切换

如果在数据量相同的情况下，根据配置文件中的server标签，越小优先级越高。

[server4]
hostname=10.0.0.53
port=3306

[server2]
hostname=10.0.0.53
port=3306

[server1]
hostname=10.0.0.54
port=3306

[server3]
hostname=10.0.0.53
port=3306

注意：如果10.0.0.53宕机，会自动切换到10.0.0.54当主库

三、配置VIP漂移

VIP漂移的两种方式
1）通过keepalived的方式，管理虚拟IP的漂移
2）通过MHA自带脚本方式，管理虚拟IP的漂移

修改配置文件

#编辑配置文件
[root@mysql-db03 ~]# vim /etc/mha/app1.cnf
#在[server default]标签下添加
[server default]
#使用MHA自带脚本
master_ip_failover_script=/usr/local/bin/master_ip_failover

编辑脚本

[root@db03 ~]# cat /etc/mha/master_ip_failover 
#!/usr/bin/env perl

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

use Getopt::Long;

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

my $vip = '10.0.0.55/24';
my $key = '0';
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$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,
);

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";
}

#根据配置文件中脚本路径编辑
[root@mysql-db03 ~]# vim /etc/mha/master_ip_failover
#修改以下几行内容
my $vip = '10.0.0.55/24';
my $key = '0';
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down"; 

注意：

1.脚本权限问题

2.语法问题

3.格式问题

[root@db04 mha]# chmod +x master_ip_failover 
[root@db04 mha]# dos2unix master_ip_failover 
dos2unix: converting file master_ip_failover to Unix format ... 

手动绑定VIP

#绑定vip
[root@mysql-db01 ~]# ifconfig eth0:0 10.0.0.55/24
#查看vip
[root@mysql-db01 ~]# ip a |grep eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
   inet 10.0.0.51/24 brd 10.0.0.255 scope global eth0
   inet 10.0.0.55/24 brd 10.0.0.255 scope global secondary eth0:0

测试ip漂移

#登录db02
[root@mysql-db02 ~]# mysql -uroot -p123
#查看slave信息
mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.51
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000007
          Read_Master_Log_Pos: 191
               Relay_Log_File: mysql-db02-relay-bin.000002
                Relay_Log_Pos: 361
        Relay_Master_Log_File: mysql-bin.000007
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
#停掉主库
[root@mysql-db01 ~]# /etc/init.d/mysqld stop
Shutting down MySQL..... SUCCESS!
#在db01上查看vip信息
[root@mysql-db01 ~]# ip a |grep eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
inet 10.0.0.51/24 brd 10.0.0.255 scope global eth0

[root@db01 ~]# mysql
mysql> show master status;
+------------------+----------+--------------+------------------+------------------------------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set                        |
+------------------+----------+--------------+------------------+------------------------------------------+
| mysql-bin.000005 |      120 |              |                  | 6e607afa-0a67-11ea-ac08-000c29f3321a:1-2 |
+------------------+----------+--------------+------------------+------------------------------------------+
1 row in set (0.00 sec)


#在db02上查看vip信息
[root@mysql-db02 ~]# ip a |grep eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    inet 10.0.0.52/24 brd 10.0.0.255 scope global eth0
    inet 10.0.0.55/24 brd 10.0.0.255 scope global secondary eth0:0
    
#在db03上查看从库slave信息

mysql> show slave status\G
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 10.0.0.52
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000006
          Read_Master_Log_Pos: 191
               Relay_Log_File: mysql-db03-relay-bin.000002
                Relay_Log_Pos: 361
        Relay_Master_Log_File: mysql-bin.000006
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes

写脚本启动mha,检测主库，并绑定主库虚拟vip

[root@db03 ~]# vim mha_check.sh
#1.在manager节点上检查MHA复制状态
mha=10.0.0.53
# 启动mha
\cp /etc/mha/app1.cnf.ori /etc/mha/app1.cnf
ssh $mha 'nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_cnf --ignore_last_failover < /dev/null > /etc/mha/manager.log 2>&1 &'
echo "mha 正在启动，请稍后..."
sleep 20
#定义主库
master_ip=`ssh $mha "masterha_check_status --conf=/etc/mha/app1.cnf"|awk -F : '{print $4}'`

if [[ $? = 0 ]];then
   echo "mha 启动成功，master_ip: $master_ip "
else
        echo "$(date +%F-%T) MHA没有启动" > /etc/mha/app1.log
fi

#2.主库先绑定虚拟vip
ssh $master_ip 'ifconfig eth0:0 10.0.0.55/24'
#宕掉主库会自己恢复
#ssh $master  '/etc/init.d/mysqld stop'

配置文件

[root@db03 ~]# vim /etc/mha/app1.cnf.ori 
[server default]
manager_log=/etc/mha/manager.log
manager_workdir=/etc/mha/app1
master_binlog_dir=/application/mysql/data
master_ip_failover_script=/etc/mha/master_ip_failover
password=123
ping_interval=2
repl_password=123
repl_user=db
ssh_user=root
user=mha
[server1]
hostname=10.0.0.51
port=3306

[server3]
hostname=10.0.0.53
port=3306

[server4]
hostname=10.0.0.54
port=3306

[server2]
hostname=10.0.0.52
port=3306

[binlog1]
no_master=1
hostname=10.0.0.53
master_binlog_dir=/data/mysql/binlog/

执行结果

[root@db03 ~]# sh mha_check.sh 
mha 正在启动，请稍后...
mha 启动成功，master_ip: 10.0.0.54 

把自动恢复宕机主库的脚本写进perl里，宕机自动恢复变成从库

[root@db03 ~]# cat mysql_vip.sh 
#!/bin/bash
/etc/init.d/mysqld start
mha=10.0.0.53
change=`ssh $mha "grep -i 'change master to' /etc/mha/manager.log"|awk -F : '{print $4}'|sed 's#xxx#123#g'`
mysql -e "$change;start slave;"

[root@db03 mha]# cat master_ip_failover
#!/usr/bin/env perl
...
sub start_vip() {
    `ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
    `ssh $ssh_user\@$orig_master_host \" sh /root/mysql_vip.sh \"`;
...

perl脚本参考

[root@db03 mha]# pwd
/etc/mha
[root@db03 mha]# cat master_ip_failover 
#!/usr/bin/env perl

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

use Getopt::Long;

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

my $vip = '10.0.0.55/24';
my $key = '0';
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$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,
);

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 \"`;
    `ssh $ssh_user\@$orig_master_host \" sh /root/mysql_vip.sh \"`;

}
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";
}