MySQL高可用MHA

环境：

一、环境部署

①更改主机名，添加hosts文件
[root@192 ~]# hostnamectl set-hostname master1
[root@192 ~]# hostnamectl set-hostname master2
[root@192 ~]# hostnamectl set-hostname slave
[root@192 ~]# hostnamectl set-hostname manager
[root@master1 ~]# cat /etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.1.12 master1
192.168.1.13 master2
192.168.1.14 slave
192.168.1.7 manager

[root@master1 ~]# for i in master2 slave manager ; do scp /etc/hosts $i:/etc/hosts;done
分发给其他主机

②配置密钥ssh(所有主机各配置相同操作)
例如master1：
[root@master1 ~]# ssh-keygen -t rsa
在所有主机都必须拷贝密钥于其他主机
[root@master1 ~]# for i in master1 master2 slave manager ; do ssh-copy-id $i ; done
拷贝密钥
[root@master1 ~]# for i in master1 master2 slave manager ; do ssh $i hostname ; done
测试登录

③关闭防火墙以及selinx

④集群主机时间同步

⑤安装环境插件
[root@192 ~]# yum -y install epel-release
[root@192 ~]# yum -y install perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Config-IniFiles ncftp perl-Params-Validate perl-CPAN perl-Test-Mock-LWP.noarch perl-LWP-Authen-Negotiate.noarch perl-devel perl-ExtUtils-CBuilder perl-ExtUtils-MakeMaker

二、配置DB主从

步骤：

①检查mysql状态
mysql半同步是由谷歌提供，master是semisync_master.so，slave是semisync_slave.so，如不清楚路径可以先进行查询

mysql> show variables like ‘%plugin_dir%’;

再进行检查是否支持动态载入
mysql> show variables like ‘%have_dynamic_loading%’;

②安装mysql半同步插件(在所有的mysql主机)
mysql> install plugin rpl_semi_sync_master soname ‘semisync_master.so’;
mysql> install plugin rpl_semi_sync_slave soname ‘semisync_slave.so’;
检查是否正确安装
mysql> show plugins;

查看半同步相关信息
mysql> show variables like ‘rpl_semi_sync%’;

③配置mysql半同步复制
master1:
[root@master1 ~]# cat /etc/my.cnf

[mysqld]
basedir = /usr/local/mysql
datadir = /usr/local/mysql/data
port = 3306
server_id = 1
socket = /usr/local/mysql/mysql.sock
log-error=/usr/local/mysql/data/mysqld.err
log-bin = mysql-bin
log-bin-index = mysql-bin.index
rpl_semi_sync_master_enabled = 1
rpl_semi_sync_master_timeout = 1000
rpl_semi_sync_slave_enabled = 1
relay_log_purge = 0
relay-log = relay-bin
relay-log-index = slave-relay-bin.index
[client]
host = 127.0.0.1
user = root
password = 123.com

master2:
[root@master2 ~]# cat /etc/my.cnf

[mysqld]
basedir = /usr/local/mysql
datadir = /usr/local/mysql/data
port = 3306
server_id = 2
socket = /usr/local/mysql/mysql.sock
log-error=/usr/local/mysql/data/mysqld.err
log-bin = mysql-bin
log-bin-index = mysql-bin.index
rpl_semi_sync_master_enabled = 1
rpl_semi_sync_master_timeout = 1000
rpl_semi_sync_slave_enabled = 1
relay_log_purge = 0
relay-log = relay-bin
relay-log-index = slave-relay-bin.index
[client]
host = 127.0.0.1
user = root
password = 123.com

slave:
[root@slave ~]# cat /etc/my.cnf

[mysqld]
basedir = /usr/local/mysql
datadir = /usr/local/mysql/data
port = 3306
server_id = 3
socket = /usr/local/mysql/mysql.sock
log-error=/usr/local/mysql/data/mysqld.err
log-bin = mysql-bin
log-bin-index = mysql-bin.index
rpl_semi_sync_slave_enabled = 1
relay-log = relay-bin
relay-log-index = slave-relay-bin.index
read_only = 1
[client]
host = 127.0.0.1
user = root
password = 123.com

全部重启服务
[root@master1 ~]# systemctl restart mysqld

mysql> show variables like ‘%rpl_semi_sync%’;

这是主从master的半同步状态
mysql> show variables like ‘%rpl_semi_sync%’;

这是slave的半同步状态，发现主插件是关闭的

④权限与change
master1:

mysql> grant replication slave on *.* to rep@'%' identified by '123.com';
mysql> show master status;

+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |      436 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+

master2:

mysql> grant replication slave on *.* to rep@'%' identified by '123.com';
mysql> change master to master_host='192.168.1.12',master_user='rep',master_password='123.com',master_log_file='mysql-bin.000001',master_log_pos=436;
mysql> start slave;

slave:

mysql> change master to master_host='192.168.1.12',master_user='rep',master_password='123.com',master_log_file='mysql-bin.000001',master_log_pos=436;
mysql> start slave;

回到master1:

mysql> grant all privileges on *.* to manager@'%' identified by '123.com';
mysql> show status like '%rpl_semi_sync%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 2     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
+--------------------------------------------+-------+

因为已经配置主从复制，在master1上创建manager用户同步到其他主机授权manager监控节点工作

三、配置MHA

步骤：

①安装MHA(manager节点两个包都需要安装，三台DB只需要安装node包)
例如master1:
[root@master1 ~]# tar zxf mha4mysql-node-0.56.tar.gz
[root@master1 ~]# cd mha4mysql-node-0.56/
[root@master1 mha4mysql-node-0.56]# perl Makefile.PL
[root@master1 mha4mysql-node-0.56]# make && make install

manager:
[root@manager ~]# tar zxf mha4mysql-node-0.56.tar.gz
[root@manager ~]# cd mha4mysql-node-0.56/
[root@manager mha4mysql-node-0.56]# perl Makefile.PL
[root@manager mha4mysql-node-0.56]# make && make install

[root@manager mha4mysql-node-0.56]# cd ..
[root@manager ~]# tar zxf mha4mysql-manager-0.56.tar.gz
[root@manager ~]# cd mha4mysql-manager-0.56/
[root@manager mha4mysql-manager-0.56]# perl Makefile.PL
[root@manager mha4mysql-manager-0.56]# make && make install

创建一些可用目录
[root@manager ~]# cd /
[root@manager /]# mkdir etc/masterha
[root@manager /]# mkdir -p masterha/app1
[root@manager /]# mkdir scripts
[root@manager /]# cd ~/mha4mysql-manager-0.56/
[root@manager mha4mysql-manager-0.56]# cp samples/conf/* /etc/masterha/
[root@manager mha4mysql-manager-0.56]# cp samples/scripts/* /scripts/
[root@manager mha4mysql-manager-0.56]#

②配置MHA
[root@manager ~]# vim /etc/masterha/app1.cnf

[server default]
manager_workdir=//masterha/app1
manager_log=/masterha/app1/manager.log
user=manager
password=123.com
ssh_user=root
repl_user=rep
repl_password=123.com
ping_interval=1

[server1]
hostname=192.168.1.12
port=3306
master_binlog_dir=/usr/local/mysql/data
candidate_master=1

[server2]
hostname=192.168.1.13
port=3306
master_binlog_dir=/usr/local/mysql/data
candidate_master=1
         
[server3] 
hostname=192.168.1.14
port=3306
master_binlog_dir=/usr/local/mysql/data
no_master=1

③ssh有效性验证
[root@manager ~]# masterha_check_ssh –global_conf=/etc/masterha/masterha_default.cnf –conf=/etc/masterha/app1.cnf

.......
Tue Apr 24 16:46:58 2018 - [debug]   ok.
Tue Apr 24 16:46:58 2018 - [debug]  Connecting via SSH from root@192.168.1.14(192.168.1.14:22) to root@192.168.1.13(192.168.1.13:22)..
Tue Apr 24 16:46:58 2018 - [debug]   ok.
Tue Apr 24 16:46:58 2018 - 
 All SSH connection tests passed successfully.

如有报错，务必检查无密ssh连接情况，确保其他主机已经分享公钥

④集群复制有效性验证
[root@manager ~]# masterha_check_ssh –global_conf=/etc/masterha/masterha_default.cnf –conf=/etc/masterha/app1.cnf

..........
Tue Apr 24 16:50:24 2018 - 
   Connecting to root@192.168.1.13(192.168.1.13:22).. 
Can't exec "mysqlbinlog": No such file or directory at /usr/local/share/perl5/MHA/BinlogManager.pm line 106.
mysqlbinlog version command failed with rc 1:0, please verify PATH, LD_LIBRARY_PATH, and client options
 at /usr/local/bin/apply_diff_relay_logs line 492.
Tue Apr 24 16:50:25 2018 - [error][/usr/local/share/perl5/MHA/MasterMonitor.pm, ln201] Slaves settings check failed!
Tue Apr 24 16:50:25 2018 - [error][/usr/local/share/perl5/MHA/MasterMonitor.pm, ln390] Slave configuration failed.
Tue Apr 24 16:50:25 2018 - [error][/usr/local/share/perl5/MHA/MasterMonitor.pm, ln401] Error happend on checking configurations.  at /usr/local/bin/masterha_check_repl line 48.
Tue Apr 24 16:50:25 2018 - [error][/usr/local/share/perl5/MHA/MasterMonitor.pm, ln500] Error happened on monitoring servers.
Tue Apr 24 16:50:25 2018 - 
 Got exit code 1 (Not master dead).

MySQL Replication Health is NOT OK!

发现报错Can’t exec “mysqlbinlog”: No such file or directory at /usr/local/share/perl5/MHA/BinlogManager.pm line 106.

解决方法在所有DB服务器进行软连接执行文件操作
[root@master1 ~]# ln -s /usr/local/mysql/bin/* /usr/local/bin

⑤启动manager
[root@manager ~]# nohup masterha_manager –conf=/etc/masterha/app1.cnf &> /tmp/mha_manager.log &
[1] 8126
[root@manager ~]# masterha_check_status –conf=/etc/masterha/app1.cnf

app1 (pid:8126) is running(0:PING_OK), master:192.168.1.12

四、MHA高可用验证

步骤：

①将master1中mysql服务宕掉
[root@master1 ~]# systemctl stop mysqld

②在manager查看MHA日志
[root@manager ~]# cat /masterha/app1/manager.log

.......
Started automated(non-interactive) failover.
The latest slave 192.168.1.13(192.168.1.13:3306) has all relay logs for recovery.
Selected 192.168.1.13 as a new master.
192.168.1.13: OK: Applying all logs succeeded.
192.168.1.14: This host has the latest relay log events.
Generating relay diff files from the latest slave succeeded.
192.168.1.14: OK: Applying all logs succeeded. Slave started, replicating from 192.168.1.13.
192.168.1.13: Resetting slave info succeeded.
Master failover to 192.168.1.13(192.168.1.13:3306) completed successfully

发现master failover已经成功

③查看slave复制状态
mysql> show slave status\G

*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.13
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 436
......

发现master IP已经转为192.168.1.13，io线程与sql线程正常运行，MHA搭建成功

④MHA manager端日常操作
1)发生主从切换后，manager服务会自动停掉，却在manager_workdir(/masterha/app1)目录生成文件app1.failover.complate，若要启动MHA，必须确保此文件已经删除
[root@manager ~]# cd /masterha/
[root@manager masterha]# ls
app1
[root@manager masterha]# cd app1/
[root@manager app1]# ls
app1.failover.complete manager.log
[root@manager app1]# mv app1.failover.complete /tmp

2)重新定义master1位置，需要把master1设置为master2的slave服务器
mysql> change master to master_host=’192.168.1.13′,master_user=’rep’,master_password=’123.com’,master_log_file=’mysql-bin.000001′,master_log_pos=436;
mysql> start slave;

3)停止MHA
[root@manager app1]# masterha_stop –conf=/etc/masterha/app1.cnf

4)启动MHA
[root@manager app1]# nohup masterha_manager –conf=/etc/masterha/app1.cnf &> /tmp/mha_manager.log &
[1] 8613
[root@manager app1]# masterha_check_status –conf=/etc/masterha/app1.cnf
app1 (pid:8613) is running(0:PING_OK), master:192.168.1.13

5)主从切换后续工作
重构计划，切换后的master2成为主库，想要master1重夺主库，重新执行以上五步，包括停止master2库。原主库数据文件完整情况可以通过以下方式得到change master命令
[root@manager app1]# grep -i ‘change master to master’ /masterha/app1/manager.log | tail -1

Tue Apr 24 17:16:59 2018 - 
  All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='192.168.1.12', MASTER_PORT=3306, MASTER_LOG_FILE='mysql-bin.000002', MASTER_LOG_POS=154, MASTER_USER='rep', MASTER_PASSWORD='xxx';

mysql> CHANGE MASTER TO MASTER_HOST=’192.168.1.12′, MASTER_PORT=3306, MASTER_LOG_FILE=’mysql-bin.000002′, MASTER_LOG_POS=154, MASTER_USER=’rep’, MASTER_PASSWORD=’123.com’;
mysql> start slave;
mysql> show slave status \G

*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.12
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000002
          Read_Master_Log_Pos: 154

[root@manager ~]# cd /masterha/app1/
[root@manager app1]# ls
app1.failover.complete manager.log
[root@manager app1]# mv app1.failover.complete /tmp
mv: overwrite ‘/tmp/app1.failover.complete’? y

[root@manager app1]# nohup masterha_manager –conf=/etc/masterha/app1.cnf &> /tmp/mha_manager.log &
[1] 9015
[root@manager app1]# masterha_check_status –conf=/etc/masterha/app1.cnf
app1 (pid:9015) is running(0:PING_OK), master:192.168.1.12

6)定期删除中继日志
在配置主从复制中，slave设置了参数relay_log_purge=0，所以slave节点需要定期删除中继日志，建议每个slave节点删除中继日志时间错开
[root@slave ~]# crontab -e

0 5 * * * /usr/local/bin/purge_relay_logs --user=root --password=123.com --port=3306 --disable_relay_log_purge >> /var/log/purge_
relay.log 2>&

五、配置VIP

vip配置可以采用两种方式，一种通过keepalived方式管理虚拟ip浮动；另一种通过脚本启动虚拟ip方式(就是不需要任何第三方应用程序)

1.keepalived方式管理虚拟ip

步骤：

①在两台master安装keepalived
[root@master1 ~]# wget http://www.keepalived.org/sof…
[root@master1 ~]# yum -y install openssl openssl-devel
[root@master1 ~]# cd keepalived-1.4.3/
[root@master1 keepalived-1.4.3]# ./configure –prefix=/ && make && make install
[root@master1 keepalived-1.4.3]# whereis keepalived
keepalived: /usr/sbin/keepalived /etc/keepalived

检查cent7启动脚本中执行程序位置
[root@master1 ~]# vim /usr/lib/systemd/system/keepalived.service

[Unit]
Description=LVS and VRRP High Availability Monitor
After= network-online.target syslog.target
Wants=network-online.target

[Service]
Type=forking
PIDFile=/var/run/keepalived.pid
KillMode=process
EnvironmentFile=-//etc/sysconfig/keepalived
ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS
ExecReload=/bin/kill -HUP $MAINPID

[Install]
WantedBy=multi-user.target

②配置keepalived
master1：
[root@master1 ~]# cat /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id mysql-ha1
}

vrrp_instance VI_1 {
    state BACKUP
    interface eno16777736
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.100
    }
}

master2：
[root@master2 ~]# cat /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id mysql-ha2
}

vrrp_instance VI_1 {
    state BACKUP
    interface eno16777736
    virtual_router_id 51
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.1.100
    }
}

③启动keepalived
[root@master1 ~]# systemctl start keepalived
[root@master2 ~]# systemctl start keepalived
查看master1虚拟ip状态
[root@master1 ~]# ip a

......
2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:db:f7:b8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.12/24 brd 192.168.1.255 scope global dynamic eno16777736
       valid_lft 77805sec preferred_lft 77805sec
    inet 192.168.1.100/32 scope global eno16777736
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fedb:f7b8/64 scope link 
       valid_lft forever preferred_lft forever

④MHA引入keepalived
mysql服务进程挂掉后通过MHA停止keepalived，想要引入MHA，我们只需要修改触发脚本文件，添加master发生宕机后对keepalived的处理
[root@manager /]# vim /scripts/master_ip_failover

#!/usr/bin/env perl

#  Copyright (C) 2011 DeNA Co.,Ltd.
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#  Foundation, Inc.,
#  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

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

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

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

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

my $vip = '192.168.1.100';
my $ssh_start_vip = "/usr/bin/systemctl start keepalived";
my $ssh_stop_vip = "/usr/bin/systemctl stop keepalived";

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

exit &main();

sub main {

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

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

    # $orig_master_host, $orig_master_ip, $orig_master_port are passed.
    # If you manage master ip address at global catalog database,
    # invalidate orig_master_ip here.
    my $exit_code = 1;
    eval {
      print "Disabling the VIP on old master:$orig_master_host \n";
      &stop_vip();
      # updating global catalog, etc
      $exit_code = 0;
    };
    if ($@) {
      warn "Got Error: $@\n";
      exit $exit_code;
    }
    exit $exit_code;
  }
  elsif ( $command eq "start" ) {

    # all arguments are passed.
    # If you manage master ip address at global catalog database,
    # activate new_master_ip here.
    # You can also grant write access (create user, set read_only=0, etc) here.
    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
      #$new_master_handler->disable_log_bin_local();
      #print "Set read_only=0 on the new master.\n";
      #$new_master_handler->disable_read_only();

      ## Creating an app user on the new master
      #print "Creating app user on the new master..\n";
      #FIXME_xxx_create_user( $new_master_handler->{dbh} );
      #$new_master_handler->enable_log_bin_local();
      #$new_master_handler->disconnect();

      ## Update master ip on the catalog database, etc
      #FIXME_xxx;
      print"Enabling the VIP - $vip on the new master - $new_master_host \n";
      &start_vip();
      $exit_code = 0;
    };
    if ($@) {
      warn $@;

      # If you want to continue failover, exit 10.
      exit $exit_code;
    }
    exit $exit_code;
  }
  elsif ( $command eq "status" ) {
    print "Checking the status of the script..OK \n";
    #`ssh $ssh_user\@cluster1\"$ssh_start_vip\"`;

    # do nothing
    exit 0;
  }
  else {
    &usage();
    exit 1;
  }
}

sub start_vip(){
    `ssh $ssh_user\@$new_master_host\"$ssh_start_vip\"`;
}

sub stop_vip(){
    return 0 unless ($ssh_user);
    `ssh $ssh_user\@$orig_master_host\"$ssh_stop_vip\"`;
}

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

⑤停止MHA
[root@manager ~]# masterha_stop –conf=/etc/masterha/app1.cnf

⑥添加参数
[root@manager ~]# vim /etc/masterha/app1.cnf

[server default]
master_ip_failover_script=/scripts/master_ip_failover
manager_workdir=//masterha/app1
manager_log=/masterha/app1/manager.log
........

⑦启动MHA，并且查看状态
[root@manager ~]# nohup masterha_manager –conf=/etc/masterha/app1.cnf &> /tmp/mha_manager.log &
[1] 10520
[root@manager ~]# masterha_check_status –conf=/etc/masterha/app1.cnf
app1 (pid:10520) is running(0:PING_OK), master:192.168.1.12

再次查看集群状态是否会报错
[root@manager ~]# masterha_check_repl –conf=/etc/masterha/app1.cnf

.......
Checking the status of the script..OK 
Tue Apr 24 18:39:12 2018 - 
  OK.
Tue Apr 24 18:39:12 2018 - 
 shutdown_script is not defined.
Tue Apr 24 18:39:12 2018 - 
 Got exit code 0 (Not master dead).

MySQL Replication Health is OK.

可以看到没有报错
master_ip_failover内容意思当主库放生故障，会触发MHA切换，manager会停掉主库上的keepalived服务，触发vip飘逸到从库

⑧测试
宕掉master1中mysql服务
[root@master1 ~]# systemctl stop mysqld

查看master1中网卡绑定情况
[root@master1 init.d]# ip a

.......
2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:db:f7:b8 brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.12/24 brd 192.168.1.255 scope global dynamic eno16777736
       valid_lft 74322sec preferred_lft 74322sec
    inet 192.168.1.100/32 scope global eno16777736
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fedb:f7b8/64 scope link 
       valid_lft forever preferred_lft forever

发现vip地址并没飘逸

回到manager查看manager.log文件，发现并没有报错，排查到为master_ip_failover脚本并有杀死keepalived进程
解决方法将两台主机中拷贝keepalived脚本执行文件，在keepalived的tar包解压后keepalived/etc/init.d/keepalived拷贝到/etc/init.d/下，修改master_ip_failover脚本文件参数项

......
my $ssh_start_vip = "/etc/init.d/keepalived start";
my $ssh_stop_vip = "/etc/init.d/keepalived stop";
......

删除app1.failover.complete，重新定义master，启动mha，再一次宕掉master1服务进行验证
[root@master1 ~]# ps -ef | grep keep
root 26079 3646 0 19:47 pts/1 00:00:00 grep –color=auto keep
发现keepalived已经被关闭

再去观察master2的vip地址
[root@master2 ~]# ip a

......
2: eno16777736: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:4b:6a:1e brd ff:ff:ff:ff:ff:ff
    inet 192.168.1.13/24 brd 192.168.1.255 scope global dynamic eno16777736
       valid_lft 70169sec preferred_lft 70169sec
    inet 192.168.1.100/32 scope global eno16777736
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe4b:6a1e/64 scope link 
       valid_lft forever preferred_lft forever

vip已经转移验证成功，注意后续重构mysql服务器

2.通过脚本实现虚拟IP切换

步骤：

①手动绑定vip
[root@master1 ~]# ifconfig eno16777736:0 192.168.1.100/24
[root@master1 ~]# ifconfig

eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.12  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::20c:29ff:fedb:f7b8  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:db:f7:b8  txqueuelen 1000  (Ethernet)
        RX packets 31589  bytes 8780116 (8.3 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 25911  bytes 5726902 (5.4 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eno16777736:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.100  netmask 255.255.255.0  broadcast 192.168.1.255
        ether 00:0c:29:db:f7:b8  txqueuelen 1000  (Ethernet)

②修改app1.cnf文件和master_ip_failover文件
在[server default]下添加master_ip_failover_script=/scripts/master_ip_failover

在之上keepalived的master_ip_failover脚本中修改并添加四项参数

......
my $vip = '192.168.1.100';
my $key = '0';
my $ssh_start_vip = "/usr/sbin/ifconfig eno16777736:$key $vip";
my $ssh_stop_vip = "/usr/sbin/ifconfig eno16777736:$key down";
......

③重新启动MHA
[root@manager ~]# masterha_stop –conf=/etc/masterha/app1.cnf
[root@manager ~]# nohup masterha_manager –conf=/etc/masterha/app1.cnf &> /tmp/mha_manager.log &

④测试
宕掉master1
[root@master1 ~]# systemctl stop mysqld

查看slave复制状态
mysql> show slave status\G

*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 192.168.1.13
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000005
          Read_Master_Log_Pos: 154

查看master2 vip状态
[root@master2 ~]# ifconfig

eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.13  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::20c:29ff:fedb:f7b8  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:db:f7:b8  txqueuelen 1000  (Ethernet)
        RX packets 32959  bytes 8939121 (8.5 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 26418  bytes 5872252 (5.6 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eno16777736:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.100  netmask 255.255.255.0  broadcast 192.168.1.255
        ether 00:0c:29:db:f7:b8  txqueuelen 1000  (Ethernet)

vip已经被master2接管，验证成功

六、总结

MHA软件由两部分组成，manager工具包和node工具包

Manager工具包工具：

masterha_check_ssh            检查MHA的SSH配置状况
masterha_check_repl            检查MySQL复制状况
masterha_manager                启动MHA
masterha_master_monitor        检测master是否宕机
masterha_master_switch        控制故障转移
masterha_conf_host            添加或删除配置的server信息

Node工具包工具：

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slave
filter_mysqlbinlog                去除不必要的ROLLBACK事件
purge_relay_logs                清除中继日志