##################MHA部署####################
1.服务器
192.168.56.21 mydb1 #Master
192.168.56.22 mydb2 #Slave
192.168.56.23 mydb3 #MHA manager

2. 所有机器修改vim /etc/hosts
192.168.56.21 mydb1
192.168.56.22 mydb2
192.168.56.23 mydb3

3.设置SSH公钥免密码登录
#root用户操作(/root),pwd

mkdir ~/.ssh
chmod 700 ~/.ssh
cd ~/.ssh
ssh-keygen -t rsa #一直回车
ls -al
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
ls -al
chmod 600 ~/.ssh/authorized_keys
cd ..
scp -r .ssh 192.168.56.22:/root/
scp -r .ssh 192.168.56.23:/root/

ssh mydb1
ssh mydb2
ssh mydb3

4.下载mha4mysql-manager和mha4mysql-node
https://github.com/yoshinorim/mha4mysql-manager
https://github.com/yoshinorim/mha4mysql-node

5.在三个节点（node 和 manager）安装perl-DBD-MySQL，用光盘作yum源，#包括了3个包：Perl-DBD-MySQL,mysql-libs,perl-DBI
yum install perl-DBD-MySQL
yum install perl-DBI
yum install mysql-libs

6.在三个节点安装node（包括管理节点）
yum -y install perl-CPAN 下载perl需要的依赖包库
perl -MCPAN -e "install inc::Module::Install 在依赖包库中，查找和安装Makefile.PL需要的包，具体程序是 use inc::Module::Install;
参考https://perlmaven.com/cant-locate-inc-module-install-in-inc
上面实际下载的是Module-Install-1.18.tar.gz 这个包
//perl -MCPAN -e shell
//perl -MCPAN -e "install Module::Depends"
参考 http://cache.baiducontent.com/c?m=9f65cb4a8c8507ed4fece7631046893b4c4380147d8c8c4668d4e419ce3b4c413037bfa6663f405a8e906b6075ab4f5bbdf06270670123b598c8d40895ac925f75ce786a6459db0144dc42f39a5125b07fcd0caef14ef0ba8169cfef9480810a44cb23127af7e78a2a424bdd6f814f6df4a6e85f135d07bb9d6b39ae&p=8b2a971cc89401ff57ee967c525285&newp=80769a478a8702c308e2977c0f43cc231610db2151d7d0106b82c825d7331b001c3bbfb423241a05d8ce7c6d04aa4b5feaf4357534072ba3dda5c91d9fb4c57479d463771c&user=baidu&fm=sc&query=inc/Module/Install%2Epm+in+%40INC&qid=e9eec041000013a8&p1=10

tar xzvf mha4mysql-node-0.56.tar.gz
cd mha4mysql-node-0.56
perl Makefile.PL
注意 在安装perl install模块后，这里终于可以正常执行了，在执行PL后，系统会验证哪些包missing，这时就可以根据他的提示安装少的包了

make && make install

7.在管理节点安装manager

//可以先查看本机已安的包名

rpm -qa perl-Config-Tiny perl-Params-Validate perl-MIME-Types perl-Email-Date-Format perl-Mail-Sender perl-Mail-Sendmail perl-TimeDate perl-MailTools perl-MIME-Lite perl-Log-Dispatch perl-Parallel-ForkManager
共11个包
rpm -qa perl-Config-Tiny perl-Params-Validate perl-MIME-Types perl-Email-Date-Format perl-Mail-Sender perl-Mail-Sendmail perl-TimeDate perl-MailTools perl-MIME-Lite perl-Log-Dispatch perl-Parallel-ForkManager | xargs rpm -ivh
上面命令直接安装

rpm -ivh perl-Config-Tiny-2.12-1.el5.rf.noarch.rpm
rpm -ivh perl-Params-Validate-0.95-1.el5.rf.i386.rpm
rpm -ivh perl-MIME-Types-1.28-2.el6.noarch.rpm
rpm -ivh perl-Email-Date-Format-1.002-5.el6.noarch.rpm
rpm -ivh perl-Mail-Sender-0.8.16-3.el6.noarch.rpm
rpm -ivh perl-Mail-Sendmail-0.79-12.el6.noarch.rpm
rpm -ivh perl-TimeDate-1.16-11.1.el6.noarch.rpm
rpm -ivh perl-MailTools-2.04-4.el6.noarch.rpm
rpm -ivh perl-MIME-Lite-3.027-2.el6.noarch.rpm
rpm -ivh perl-Log-Dispatch-2.26-1.el5.rf.noarch.rpm
rpm -ivh perl-Parallel-ForkManager-0.7.5-2.2.el5.rf.noarch.rpm
如果上面包都没有，直接从yum源下载并安装
yum install perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes -y
yum install perl-Time-HiRes #光盘yum源

tar xzvf mha4mysql-manager-0.56.tar.gz
cd mha4mysql-manager-0.56
perl Makefile.PL
make && make install

8 配置主从同步GTID方式
这里用的是init.sh脚本，能自动搭建主从GTID服务器，且在一台机器上。当机器上没有mysql用户时，此脚本有些问题，在脚本初始化后要
做的修改是
show grants for 'rpl_user@127.0.0.1';
主库上建立repl用户
grant replication slave on *.* to rpl_user@% identified by '1234';
从库上去掉多余的rpl_user,注意要先去掉权限才能删除这个用户
revoke replication slave on *.* from rpl_user@127.0.0.1
revoke replication slave on *.* from 'rpl_user'@'%';
drop user 'rpl_user'@'%';

9修改root用户默认密码
安装mysql开始 root用户没有密码，怕影响mha，所以建立root用户密码
use mysql;
mysql> (老版本)update user set password=password("123456") where user="root";
（5.7.11）update user set authentication_string=password("123456") where user="root";
flush privileges;

ln -s /usr/local/mysql_5.7/bin/mysql /usr/bin //软链接调用mysql命令

####################常用命令###############
/usr/local/bin/masterha_check_ssh --conf=/u01/mha/etc/app.cnf
/usr/local/bin/masterha_check_repl --conf=/u01/mha/etc/app.cnf
/usr/local/bin/masterha_manager --conf=/u01/mha/etc/app.cnf &
/u01/mha/etc/masterha_check_status --conf=/u01/mha/etc/app.cnf
/usr/local/bin/masterha_stop --conf=/u01/mha/etc/app.cnf

masterha_check_ssh --conf=/u01/mha/etc/app.cnf //监控ssh是否正常
masterha_check_repl --conf=/u01/mha/etc/app.cnf //监控主从复制是否正常
MHA masterha_check_repl 检测过程
###################切换######################
一、failover故障切换

1.模拟主库宕机
[root@mydb3~]# ssh mydb1 "killall -r mysqld"

2.查看管理节点日志，可以看到VIP已经漂移
[root@mydb3 ~]# cat /u01/mha/log/manager.log |grep -i vip

3. 验证VIP是否位于节点mydb2
[root@mydb3 ~]# ssh mydb2 "ifconfig |grep 56.201 -B1"

4. 查看管理节点MHA切换日志
[root@mydb3 ~]# tail /u01/mha/log/manager.log

5. new master(old slave)
show master status\G

6. new slave(old:master)
(1)打开MySQL
mysqld_safe --defaults-file=/u01/my3306/my.cnf &

(2)检查数据库
show master status\G
show slave status\G

(3)在管理节点日志中查主库的日志文件和位置
cat /u01/mha/etc/app/manager.log |grep -i change

(4)在slave连接master
CHANGE MASTER TO
MASTER_HOST='192.168.56.21',
MASTER_PORT=3306,
MASTER_LOG_FILE='mysql-bin.000005',
MASTER_LOG_POS=120,
MASTER_USER='rep',
MASTER_PASSWORD='rep123';

7.启动管理节点
/usr/local/bin/masterha_manager --conf=/u01/mha/etc/app.cnf &
/usr/local/bin/masterha_manager --conf=/u01/mha/etc/app.cnf --ignore_last_failover &

二、switchover线上切换

1.master：关闭event_scheduler（即192.168.56.21）
set global event_scheduler=off;

2.manager：关闭管理进程 （即192.168.56.23）
/usr/local/bin/masterha_stop --conf=/u01/mha/etc/app.cnf

3.manager：检查配置文件
/u01/mha/etc/app.cnf 有没有被修改破坏。如果破坏需要重新编辑正确配置文件：/u01/mha/etc/app.cnf
cp /u01/mha/etc/app.cnf.bak /u01/mha/etc/app.cnf

4.开始切换：
/u01/mha/etc/masterha_master_switch --master_state=alive --conf=/u01/mha/etc/app.cnf

5.new master(old slave)
mysql> show master status\G
*************************** 1. row ***************************
File: binlog.000021
Position: 299
Binlog_Do_DB:
Binlog_Ignore_DB:
Executed_Gtid_Set:
1 row in set (0.00 sec)

6.new slave(old master)
CHANGE MASTER TO
MASTER_HOST='192.168.56.22',
MASTER_PORT=3306,
MASTER_LOG_FILE='binlog.000021',
MASTER_LOG_POS=299,
MASTER_USER='rep',
MASTER_PASSWORD='rep123';

mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

mysql> show slave status\G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 192.168.56.12
Master_User: repl
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: binlog.000017
Read_Master_Log_Pos: 299
Relay_Log_File: relaylog.000002
Relay_Log_Pos: 280
Relay_Master_Log_File: binlog.000017
Slave_IO_Running: Yes
Slave_SQL_Running: Yes

7.启动管理节点
/u01/mha/etc/masterha_manager --conf=/u01/mha/etc/app.cnf &
/u01/mha/etc/masterha_manager --conf=/u01/mha/etc/app.cnf --remove_dead_master_conf --ignore_last_failover

https://www.cnblogs.com/zhoujinyi/p/3808673.html

#################配置文件###################
vim /u01/mha/etc/app.cnf

[server default]
user = root
password = 123456
ssh_user = root
repl_user = rpl_user
repl_password = rpl_pass
ping_interval = 1
ping_type = SELECT

manager_workdir=/u01/mha/etc/app
manager_log=/u01/mha/log/manager.log
remote_workdir=/u01/mha/etc/app
master_binlog_dir="/u01/mysql_5.7/s1/log/binlog"

#master_ip_failover_script="/u01/mha/etc/master_ip_failover"
#master_ip_online_change_script="/u01/mha/etc/master_ip_failover"

shutdown_script=""

report_script=""

#check_repl_delay=0

[server1]
hostname=iZ2zehy7gff0kpg1swp1czZ
port=33091
master_binlog_dir="/apps/dbdat/mysql5_data33091/log"
candidate_master=1
ignore_fail=1

[server2]
hostname=iZ2zehy7gff0kpg1swp1czZ
port=33092
master_binlog_dir="/u01/mysql_5.7/s2/log/binlog"
candidate_master=1
ignore_fail=1

---------------------------------------------------------------------------------
vim /u01/mha/etc/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 = '192.168.56.201/24'; # Virtual IP
my $key = "1";
my $int = "eth0";
my $ssh_start_vip = "/sbin/ifconfig $int:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig $int:$key down";
my $arp_effect = "/sbin/arping -Uq -s192.168.56.201 -I $int 192.168.56.1 -c 3"; # Virtual IP and gat
eway
#my $test = "echo successfull >/tmp/test.txt";
$ssh_user = "root";
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" ) {

# $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();
$exit_code = 0;
};
if ($@) {
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 {
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";
#`ssh $ssh_user\@cluster1 \" $ssh_start_vip \"`;
&status();
exit 0;
}
else {
&usage();
exit 1;
}
}

# A simple system call that enable the VIP on the new master
sub start_vip() {
`ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
`ssh $ssh_user\@$new_master_host \" $arp_effect \"`;
# `ssh $ssh_user\@$new_master_host \" $test \"`;
}
# 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 status() {
print `ssh $ssh_user\@$orig_master_host \" ip add show $int \"`;
}

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