本文主要是介绍MHA高可用配置与故障切换，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！
前言：
MHA高可用故障就是单点故障，那么我们如何解决单点故障MHA中Master如何将故障的机器停止，使用备用的Slave服务器一 MHA定义
MHA（MasterHigh Availablity）是一套优秀的Mysql高可用环境下故障切换和主从复制的软件。
解决MySQL 单点的问题。
MySQL故障切换过程中，MHA能做到0-30秒内自动完成故障切换操作。
故障切换的过程中最大程度上保证数据的一致性，以达到真正意义上的高可用。
MHA是建在主从复制的基础上的；0-30秒自动完成故障切换是MHA的特性
1 MHA组成
MHA Manager（管理节点）
MHA Node（数据节点）
MHA Manager 可以单独部署在一台独立的机器上，管理多个 master-slave 集群；也可以部署在一台 slave 节点上。
MHA Manager 会定时探测集群中的 master 节点。当 master 出现故障时，它可以自动将最新数据的 slave 提升为新的 mas然后将所有其他的 slave 重新指向新的 master。整个故障转移过程对应用程序完全透明。Node节点就是探测Mysql数据库是否正常
2 MHA特点
自动故障切换过程中，MHA试图从宕机的主服务器上保存二进制日志，最大程度的保证数据不丢失
使用半同步复制，可以大大降低数据丢失的风险，如果只有一个slave已经收到了最新的二进制日志，MHA可以将最新的二进制日志应用于其他所有的slave服务器上，因此可以保证所有节点的数据一致性
目前MHA支持一主多从架构，最少三台服务，即一主两从
MHA Manger 管理多组主从复制；从服务器要等主服务器宕掉后才能升为主服务器；从服务器中数
据最新最全的才会成为新的主服务器。
3 MHA工作原理（1）
从宕机崩溃的master 保存二进制日志事件（binlog events）；
识别含有最新的更新 slave 日志（可以理解为主从复制数据最新的从服务器）
应用差异的中继日志（relay log）到其他的slave（将数据信息最全最新的从服务器的中继日志给其他的从服务器）
应用从master保存的二进制日志事件
提升一个 salve 为新的master
使其他的slave连接行的master 进行复制。
4 MHA的工作原理（2）
实际就是manager的工作过程
manager会周期性探测master的状态，一旦发现master故障以后，会根据默认，将目前收到最新数
据的从节点指定为新的master，所有的其他从节点指向新的master，同时VIP从原来的主漂移到新
的主。这些对客户端来说都是透明的
有哪些数据库集群高可用方案
有keepalived（单主）、MHA（单主）、MMM（单主）以及MySQL cluster（多主）
所有的高可用都是在主从复制的基础上进行。
keepalived可以完成主备切换，但是不能完成读写分离
5 MMM的工作模式：
支持双主故障切换和双主日常管理，MMM也是用perl语言开发，主要用来监控和管理MySQL的双主复制。虽然叫做双主复制，但是业务上同一时刻只允许对一个主进行写入，另一台备选主上提供部分读服务，以加速在主主切换时备选主的预热，可以说MMM这套脚本程序一方面实现了故障切换的功能，另一方面其内部附加的工具脚本也可以实现多个 Slave 的 read 负载均衡。
二 实验：搭建 MySQL MHA
目的：解决故障切换、尽可能的保存数据，以及所有节点日志的一致性
实验思路：搭建MHA机构---->数据库安装---->一主两从---->MHA搭建
故障模拟：主服务器失效---->主服务器的备胎服务器成为主服务器---->原故障
master:192.168.11.8
slave1:192.168.11.7
slave2:192.168.11.11
MHA manager 节点服务器:192.168.11.14
1 四台服务器同时关闭防火墙防护
systemctl stop firewalldsetenforce 0
2 修改 Master、Slave1、Slave2 节点的 Mysql主配置文件/etc/my.cnf
三台服务器都做此操作
3 在 Master、Slave1、Slave2 节点上都创建两个软链接
ln -s /usr/local/mysql/bin/mysql /usr/sbin/ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/
4 配置 mysql 一主两从
①所有数据库节点进行 mysql 授权
mysql -uroot -p123
grant replication slave on *.* to 'myslave'@'192.168.11.%' identified by '123';
grant all privileges on *.* to 'mha'@'192.168.11.%' identified by 'manager';
grant all privileges on *.* to 'mha'@'master' identified by 'manager';
grant all privileges on *.* to 'mha'@'slave1' identified by 'manager';
grant all privileges on *.* to 'mha'@'slave2' identified by 'manager';
flush privileges;
②在 Master 节点查看二进制文件和同步点
③在 Slave1、Slave2 节点执行同步操作
change master to master_host='192.168.11.8',master_user='myslave',master_password='123',master_log_file='master-bin.000001',master_log_pos=1745; start slave;
④在 Slave1、Slave2 节点查看数据同步结果
show slave status\G
⑤ 两个从库必须设置为只读模式：
set global read_only=1;
⑥在 Master 主库插入条数据，测试是否同步
在主服务器配置
mysql> create database kgc;
Query OK, 1 row affected (0.01 sec)mysql> use kgc;
Database changed
mysql> create table ky35(id int,name varchar(9));
Query OK, 0 rows affected (0.02 sec)mysql> insert into ky35 values(1,'heze');
Query OK, 1 row affected (0.01 sec)
两台从服务器：
mysql> use kgc;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -ADatabase changed
mysql> select * from ky35;
+------+------+
| id | name |
+------+------+
| 1 | heze |
+------+------+
1 row in set (0.01 sec)
5 安装MHA所有组件
①所有服务器上都安装 MHA 依赖的环境，首先安装 epel 源
四台机器同时epel源
yum install epel-release --nogpgcheck -y
四台服务器同时安装环境
yum install -y perl-DBD-MySQL \
perl-Config-Tiny \
perl-Log-Dispatch \
perl-Parallel-ForkManager \
perl-ExtUtils-CBuilder \
perl-ExtUtils-MakeMaker \
perl-CPAN
②安装 MHA 软件包，先在所有服务器上必须先安装 node 组件
对于每个操作系统版本不一样，这里 CentOS7.6选择 0.57 版本。
在所有服务器上必须先安装 node 组件，最后在 MHA-manager 节点上安装 manager 组件，因为 manager 依赖 node 组件。
192.168.11.14 manager
192.168.11.8 master
192.168.11.7 slave2
192.168.11.11 slave3
tar zxvf mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57
perl Makefile.PL
make && make install
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 slavefilter_mysqlbinlog 去除不必要的 ROLLBACK 事件（MHA 已不再使用这个工具）purge_relay_logs 清除中继日志（不会阻塞 SQL 线程）
③在 MHA manager 节点上安装 manager 组件
cd /opt
tar zxvf mha4mysql-manager-0.57.tar.gz
cd mha4mysql-manager-0.57
perl Makefile.PL
make && make install
6 在所有服务器上配置无密码认证
①Manager管理节点免密配置给Master、Slave1和Slave2
ssh-keygen -t rsa #一路按回车键ssh-copy-id 192.168.11.11ssh-copy-id 192.168.11.7ssh-copy-id 192.168.11.8[root@mcb-11-14 .ssh]# ssh-copy-id 192.168.11.11
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.11 (192.168.11.11)' can't be established.
ECDSA key fingerprint is SHA256:O0XjKR3Ec+XTMGJ1HQo6AZq1kqcd8uhO9w53SHlw5As.
ECDSA key fingerprint is MD5:12:10:d5:e0:f6:7d:5c:9f:d8:59:97:cb:85:11:24:b5.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.11's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.11'"
and check to make sure that only the key(s) you wanted were added.[root@mcb-11-14 .ssh]# ssh-copy-id 192.168.11.7
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.7 (192.168.11.7)' can't be established.
ECDSA key fingerprint is SHA256:uQfWnfl20Yj/iVllTVL3GAe3b5oPUj7IkhfWji2tF4Y.
ECDSA key fingerprint is MD5:23:93:1c:28:77:cc:64:8c:b6:fb:4a:c2:90:9c:b5:1a.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.7's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.7'"
and check to make sure that only the key(s) you wanted were added.[root@mcb-11-14 .ssh]# ssh-copy-id 192.168.11.8
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.8 (192.168.11.8)' can't be established.
ECDSA key fingerprint is SHA256:qzO3TB5OcyBmfFhIFfeo2jxnv4c5AIXjwXVOjt4ws/0.
ECDSA key fingerprint is MD5:ee:b0:75:21:4d:0a:13:a4:90:2c:df:1f:1f:fa:85:6b.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.8's password:
②Master主服务器免密配置给Slave1和Slave2
[root@master mha4mysql-node-0.57]#ssh-copy-id 192.168.11.7
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.7 (192.168.11.7)' can't be established.
ECDSA key fingerprint is SHA256:uQfWnfl20Yj/iVllTVL3GAe3b5oPUj7IkhfWji2tF4Y.
ECDSA key fingerprint is MD5:23:93:1c:28:77:cc:64:8c:b6:fb:4a:c2:90:9c:b5:1a.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.7's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.7'"
and check to make sure that only the key(s) you wanted were added.[root@master mha4mysql-node-0.57]#ssh-copy-id 192.168.11.11
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.11 (192.168.11.11)' can't be established.
ECDSA key fingerprint is SHA256:O0XjKR3Ec+XTMGJ1HQo6AZq1kqcd8uhO9w53SHlw5As.
ECDSA key fingerprint is MD5:12:10:d5:e0:f6:7d:5c:9f:d8:59:97:cb:85:11:24:b5.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.11's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.11'"
and check to make sure that only the key(s) you wanted were added.
③Slave2从服务器免密配置给Master和Slave1
[root@slave1 mha4mysql-node-0.57]# ssh-copy-id 192.168.11.8
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.8 (192.168.11.8)' can't be established.
ECDSA key fingerprint is SHA256:qzO3TB5OcyBmfFhIFfeo2jxnv4c5AIXjwXVOjt4ws/0.
ECDSA key fingerprint is MD5:ee:b0:75:21:4d:0a:13:a4:90:2c:df:1f:1f:fa:85:6b.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.8's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.8'"
and check to make sure that only the key(s) you wanted were added.[root@slave1 mha4mysql-node-0.57]# ssh-copy-id 192.168.11.14
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.14 (192.168.11.14)' can't be established.
ECDSA key fingerprint is SHA256:JAQ3v9JIlkv3lauqQxhRmSga7GPl5zIOv0THdDWT1TU.
ECDSA key fingerprint is MD5:d3:64:b1:26:6c:a5:f3:50:38:b2:db:ab:07:67:fe:00.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.14's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.14'"
and check to make sure that only the key(s) you wanted were added.④Slave2从服务器免密配置给Master和Slave1
[root@slave2 ~]# ssh-copy-id 192.168.11.7
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.7 (192.168.11.7)' can't be established.
ECDSA key fingerprint is SHA256:uQfWnfl20Yj/iVllTVL3GAe3b5oPUj7IkhfWji2tF4Y.
ECDSA key fingerprint is MD5:23:93:1c:28:77:cc:64:8c:b6:fb:4a:c2:90:9c:b5:1a.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.7's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.7'"
and check to make sure that only the key(s) you wanted were added.[root@slave2 ~]# ssh-copy-id 192.168.11.8
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.8 (192.168.11.8)' can't be established.
ECDSA key fingerprint is SHA256:qzO3TB5OcyBmfFhIFfeo2jxnv4c5AIXjwXVOjt4ws/0.
ECDSA key fingerprint is MD5:ee:b0:75:21:4d:0a:13:a4:90:2c:df:1f:1f:fa:85:6b.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.8's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.8'"
and check to make sure that only the key(s) you wanted were added.[root@slave2 ~]# ssh-copy-id 192.168.11.14
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"
The authenticity of host '192.168.11.14 (192.168.11.14)' can't be established.
ECDSA key fingerprint is SHA256:JAQ3v9JIlkv3lauqQxhRmSga7GPl5zIOv0THdDWT1TU.
ECDSA key fingerprint is MD5:d3:64:b1:26:6c:a5:f3:50:38:b2:db:ab:07:67:fe:00.
Are you sure you want to continue connecting (yes/no)? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
root@192.168.11.14's password: Number of key(s) added: 1Now try logging into the machine, with: "ssh '192.168.11.14'"
and check to make sure that only the key(s) you wanted were added.
⑤验证免密登录
用一个服务器去登录任意一个服务器，只要能登录就行
ssh 192.168.11.11ssh 192.168.11.8ssh 192.168.11.7ssh 192.168.11.14
7 在 manager 节点上配置 MHA
①在 manager 节点上复制相关脚本到/usr/local/bin 目录
cp -rp /opt/mha4mysql-manager-0.57/samples/scripts /usr/local/binls /usr/local/bin/scriptsll /usr/local/bin/scripts/
②切换 VIP 管理的脚本到 /usr/local/bin 目录，使用master_ip_failover脚本来管理 VIP 和故障切换
cp /usr/local/bin/scripts/master_ip_failover /usr/local/bin 
vim /usr/local/bin/master_ip_failoverEsc :set paste
#进入末行模式 输入set paste 不加#号键
#!/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
);
#############################添加内容部分#########################################
my $vip = '192.168.11.200'; #指定vip的地址（要与自己一致）
my $brdc = '192.168.11.255'; #指定vip的广播地址
my $ifdev = 'ens33'; #指定vip绑定的网卡
my $key = '1'; #指定vip绑定的虚拟网卡序列号
my $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip"; #代表此变量值为ifconfig ens33:1 192.168.10.200
my $ssh_stop_vip = "/sbin/ifconfig ens33:$key down"; #代表此变量值为ifconfig ens33:1 192.168.10.200 down
my $exit_code = 0; #指定退出状态码为0
#my $ssh_start_vip = "/usr/sbin/ip addr add $vip/24 brd $brdc dev $ifdev label $ifdev:$key;/usr/sbin/arping -q -A -c 1 -I $ifdev $vip;iptables -F;";
#my $ssh_stop_vip = "/usr/sbin/ip addr del $vip/24 dev $ifdev label $ifdev:$key";
##################################################################################
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";
}
③创建 MHA 软件目录并拷贝配置文件，使用app1.cnf配置文件来管理 mysql 节点服务器
mkdir /etc/masterha
cp /opt/mha4mysql-manager-0.57/samples/conf/app1.cnf /etc/masterhavim /etc/masterha/app1.cnf
[server default]
manager_log=/var/log/masterha/app1/manager.log
manager_workdir=/var/log/masterha/app1
master_binlog_dir=/usr/local/mysql/data
master_ip_failover_script=/usr/local/bin/master_ip_failover
master_ip_online_change_script=/usr/local/bin/master_ip_online_change
password=manager
ping_interval=1
remote_workdir=/tmp
repl_password=123456
repl_user=myslave
secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.10.14 -s 192.168.10.15
shutdown_script=""
ssh_user=root
user=mha[server1]
hostname=192.168.11.7
port=3306[server2]
candidate_master=1
check_repl_delay=0
hostname=192.168.11.8
port=3306[server3]
hostname=192.168.11.11
port=3306
④在 Master 节点上手动开启虚拟IP
/sbin/ifconfig ens33:1 192.168.11.200/24
一主两从全部注释掉：#default-character-set=utf8
vim /etc/my.cnf检测一下：
sed -n 3p /etc/my.cnf
#default-character-set=utf8#这里主从服务器都需要修改字符集 否则检查repl会报错systemctl restart mysqld.service ④在 manager 节点上测试 ssh 无密码认证，如果正常最后会输出 successfully，
masterha_check_ssh -conf=/etc/masterha/app1.cnf
[root@mcb-11-14 mha4mysql-manager-0.57]# masterha_check_ssh -conf=/etc/masterha/app1.cnf
Sat Mar 30 11:37:01 2024 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sat Mar 30 11:37:01 2024 - [info] Reading application default configuration from /etc/masterha/app1.cnf..
Sat Mar 30 11:37:01 2024 - [info] Reading server configuration from /etc/masterha/app1.cnf..
Sat Mar 30 11:37:01 2024 - [info] Starting SSH connection tests..
Sat Mar 30 11:37:03 2024 - [debug]
Sat Mar 30 11:37:01 2024 - [debug] Connecting via SSH from root@192.168.11.7(192.168.11.7:22) to root@192.168.11.8(192.168.11.8:22)..
Sat Mar 30 11:37:02 2024 - [debug] ok.
Sat Mar 30 11:37:02 2024 - [debug] Connecting via SSH from root@192.168.11.7(192.168.11.7:22) to root@192.168.11.11(192.168.11.11:22)..
Sat Mar 30 11:37:03 2024 - [debug] ok.
Sat Mar 30 11:37:03 2024 - [debug]
Sat Mar 30 11:37:01 2024 - [debug] Connecting via SSH from root@192.168.11.8(192.168.11.8:22) to root@192.168.11.7(192.168.11.7:22)..
Sat Mar 30 11:37:02 2024 - [debug] ok.
Sat Mar 30 11:37:02 2024 - [debug] Connecting via SSH from root@192.168.11.8(192.168.11.8:22) to root@192.168.11.11(192.168.11.11:22)..
Sat Mar 30 11:37:03 2024 - [debug] ok.
Sat Mar 30 11:37:04 2024 - [debug]
Sat Mar 30 11:37:02 2024 - [debug] Connecting via SSH from root@192.168.11.11(192.168.11.11:22) to root@192.168.11.7(192.168.11.7:22)..
Sat Mar 30 11:37:03 2024 - [debug] ok.
Sat Mar 30 11:37:03 2024 - [debug] Connecting via SSH from root@192.168.11.11(192.168.11.11:22) to root@192.168.11.8(192.168.11.8:22)..
Sat Mar 30 11:37:04 2024 - [debug] ok.
Sat Mar 30 11:37:04 2024 - [info] All SSH connection tests passed successfully.
⑤在 manager 节点上测试 mysql 主从连接情况，最后出现 MySQL Replication Health is OK
masterha_check_repl -conf=/etc/masterha/app1.cnf
[root@mcb-11-14 mha4mysql-manager-0.57]# vim /usr/local/bin/master_ip_failover
[root@mcb-11-14 mha4mysql-manager-0.57]# masterha_check_repl -conf=/etc/masterha/app1.cnf
Sat Mar 30 13:04:02 2024 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sat Mar 30 13:04:02 2024 - [info] Reading application default configuration from /etc/masterha/app1.cnf..
Sat Mar 30 13:04:02 2024 - [info] Reading server configuration from /etc/masterha/app1.cnf..
Sat Mar 30 13:04:02 2024 - [info] MHA::MasterMonitor version 0.57.
Sat Mar 30 13:04:03 2024 - [info] GTID failover mode = 0
Sat Mar 30 13:04:03 2024 - [info] Dead Servers:
Sat Mar 30 13:04:03 2024 - [info] Alive Servers:
Sat Mar 30 13:04:03 2024 - [info] 192.168.11.8(192.168.11.8:3306)
Sat Mar 30 13:04:03 2024 - [info] 192.168.11.7(192.168.11.7:3306)
Sat Mar 30 13:04:03 2024 - [info] 192.168.11.11(192.168.11.11:3306)
Sat Mar 30 13:04:03 2024 - [info] Alive Slaves:
Sat Mar 30 13:04:03 2024 - [info] 192.168.11.7(192.168.11.7:3306) Version=5.7.17-log (oldest major version between slaves) log-bin:enabled
Sat Mar 30 13:04:03 2024 - [info] Replicating from 192.168.11.8(192.168.11.8:3306)
Sat Mar 30 13:04:03 2024 - [info] Primary candidate for the new Master (candidate_master is set)
Sat Mar 30 13:04:03 2024 - [info] 192.168.11.11(192.168.11.11:3306) Version=5.7.17 (oldest major version between slaves) log-bin:disabled
Sat Mar 30 13:04:03 2024 - [info] Replicating from 192.168.11.8(192.168.11.8:3306)
Sat Mar 30 13:04:03 2024 - [info] Current Alive Master: 192.168.11.8(192.168.11.8:3306)
Sat Mar 30 13:04:03 2024 - [info] Checking slave configurations..
Sat Mar 30 13:04:03 2024 - [info] read_only=1 is not set on slave 192.168.11.7(192.168.11.7:3306).
Sat Mar 30 13:04:03 2024 - [warning] relay_log_purge=0 is not set on slave 192.168.11.7(192.168.11.7:3306).
Sat Mar 30 13:04:03 2024 - [info] read_only=1 is not set on slave 192.168.11.11(192.168.11.11:3306).
Sat Mar 30 13:04:03 2024 - [warning] relay_log_purge=0 is not set on slave 192.168.11.11(192.168.11.11:3306).
Sat Mar 30 13:04:03 2024 - [warning] log-bin is not set on slave 192.168.11.11(192.168.11.11:3306). This host cannot be a master.
Sat Mar 30 13:04:03 2024 - [info] Checking replication filtering settings..
Sat Mar 30 13:04:03 2024 - [info] binlog_do_db= , binlog_ignore_db=
Sat Mar 30 13:04:03 2024 - [info] Replication filtering check ok.
Sat Mar 30 13:04:03 2024 - [info] GTID (with auto-pos) is not supported
Sat Mar 30 13:04:03 2024 - [info] Starting SSH connection tests..
Sat Mar 30 13:04:06 2024 - [info] All SSH connection tests passed successfully.
Sat Mar 30 13:04:06 2024 - [info] Checking MHA Node version..
Sat Mar 30 13:04:08 2024 - [info] Version check ok.
Sat Mar 30 13:04:08 2024 - [info] Checking SSH publickey authentication settings on the current master..
Sat Mar 30 13:04:08 2024 - [info] HealthCheck: SSH to 192.168.11.8 is reachable.
Sat Mar 30 13:04:09 2024 - [info] Master MHA Node version is 0.57.
Sat Mar 30 13:04:09 2024 - [info] Checking recovery script configurations on 192.168.11.8(192.168.11.8:3306)..
Sat Mar 30 13:04:09 2024 - [info] Executing command: save_binary_logs --command=test --start_pos=4 --binlog_dir=/usr/local/mysql/data --output_file=/tmp/save_binary_logs_test --manager_version=0.57 --start_file=master-bin.000001
Sat Mar 30 13:04:09 2024 - [info] Connecting to root@192.168.11.8(192.168.11.8:22).. Creating /tmp if not exists.. ok.Checking output directory is accessible or not..ok.Binlog found at /usr/local/mysql/data, up to master-bin.000001
Sat Mar 30 13:04:09 2024 - [info] Binlog setting check done.
Sat Mar 30 13:04:09 2024 - [info] Checking SSH publickey authentication and checking recovery script configurations on all alive slave servers..
Sat Mar 30 13:04:09 2024 - [info] Executing command : apply_diff_relay_logs --command=test --slave_user='mha' --slave_host=192.168.11.7 --slave_ip=192.168.11.7 --slave_port=3306 --workdir=/tmp --target_version=5.7.17-log --manager_version=0.57 --relay_log_info=/usr/local/mysql/data/relay-log.info --relay_dir=/usr/local/mysql/data/ --slave_pass=xxx
Sat Mar 30 13:04:09 2024 - [info] Connecting to root@192.168.11.7(192.168.11.7:22).. Checking slave recovery environment settings..Opening /usr/local/mysql/data/relay-log.info ... ok.Relay log found at /usr/local/mysql/data, up to relay-log-bin.000006Temporary relay log file is /usr/local/mysql/data/relay-log-bin.000006Testing 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.
Sat Mar 30 13:04:10 2024 - [info] Executing command : apply_diff_relay_logs --command=test --slave_user='mha' --slave_host=192.168.11.11 --slave_ip=192.168.11.11 --slave_port=3306 --workdir=/tmp --target_version=5.7.17 --manager_version=0.57 --relay_log_info=/usr/local/mysql/data/relay-log.info --relay_dir=/usr/local/mysql/data/ --slave_pass=xxx
Sat Mar 30 13:04:10 2024 - [info] Connecting to root@192.168.11.11(192.168.11.11:22).. Checking slave recovery environment settings..Opening /usr/local/mysql/data/relay-log.info ... ok.Relay log found at /usr/local/mysql/data, up to relay-log-bin.000006Temporary relay log file is /usr/local/mysql/data/relay-log-bin.000006Testing 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.
Sat Mar 30 13:04:10 2024 - [info] Slaves settings check done.
Sat Mar 30 13:04:10 2024 - [info]
192.168.11.8(192.168.11.8:3306) (current master)+--192.168.11.7(192.168.11.7:3306)+--192.168.11.11(192.168.11.11:3306)Sat Mar 30 13:04:10 2024 - [info] Checking replication health on 192.168.11.7..
Sat Mar 30 13:04:10 2024 - [info] ok.
Sat Mar 30 13:04:10 2024 - [info] Checking replication health on 192.168.11.11..
Sat Mar 30 13:04:10 2024 - [info] ok.
Sat Mar 30 13:04:10 2024 - [info] Checking master_ip_failover_script status:
Sat Mar 30 13:04:10 2024 - [info] /usr/local/bin/master_ip_failover --command=status --ssh_user=root --orig_master_host=192.168.11.8 --orig_master_ip=192.168.11.8 --orig_master_port=3306 IN SCRIPT TEST====/sbin/ifconfig ens33:1 down==/sbin/ifconfig ens33:1 192.168.11.200===Checking the Status of the script.. OK
Sat Mar 30 13:04:11 2024 - [info] OK.
Sat Mar 30 13:04:11 2024 - [warning] shutdown_script is not defined.
Sat Mar 30 13:04:11 2024 - [info] Got exit code 0 (Not master dead).MySQL Replication Health is OK.8 在 manager 节点上启动 MHA
[root@mcb-11-14 mha4mysql-manager-0.57]# cd ..
[root@mcb-11-14 opt]# 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 &
[1] 19409
[root@mcb-11-14 opt]# ps -aux|grep manager
root 19409 0.2 0.5 297384 21756 pts/0 S 13:32 0:00 perl /usr/local/bin/masterha_manager --conf=/etc/masterha/app1.cnf --remove_dead_master_conf --ignore_last_failover
root 19631 0.0 0.0 112824 984 pts/0 S+ 13:35 0:00 grep --color=auto manager
[root@mcb-11-14 opt]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 (pid:19409) is running(0:PING_OK), master:192.168.11.8
[root@mcb-11-14 opt]#
三 故障模拟
①在 manager 节点上监控观察日志记录
tail -f /var/log/masterha/app1/manager.log
②将主服务器的Mysql服务停止
systemctl stop mysqld
或
pkill -9 mysql
正常自动切换一次后，MHA 进程会退出。HMA 会自动修改 app1.cnf 文件内容，将宕机的 master 节点删除。查看 slave1 是否接管 VIP
ifconfig
③在 manager 节点上监控再观察日志
----- Failover Report -----app1: MySQL Master failover 192.168.11.8(192.168.11.8:3306) to 192.168.11.7(192.168.11.7:3306) succeededMaster 192.168.11.8(192.168.11.8:3306) is down!Check MHA Manager logs at mcb-11-14:/var/log/masterha/app1/manager.log for details.Started automated(non-interactive) failover.
Invalidated master IP address on 192.168.11.8(192.168.11.8:3306)
The latest slave 192.168.11.7(192.168.11.7:3306) has all relay logs for recovery.
Selected 192.168.11.7(192.168.11.7:3306) as a new master.
192.168.11.7(192.168.11.7:3306): OK: Applying all logs succeeded.
192.168.11.7(192.168.11.7:3306): OK: Activated master IP address.
192.168.11.11(192.168.11.11:3306): This host has the latest relay log events.
Generating relay diff files from the latest slave succeeded.
192.168.11.11(192.168.11.11:3306): OK: Applying all logs succeeded. Slave started, replicating from 192.168.11.7(192.168.11.7:3306)
192.168.11.7(192.168.11.7:3306): Resetting slave info succeeded.
Master failover to 192.168.11.7(192.168.11.7:3306) completed successfully.
可以去manager查看配置文件slave1去除了
vim /etc/masterha/app1.cnf
四 故障修复：
① 模拟修复原 master mysql
systemctl restart mysqld.service②在现主库服务器 mysql2 查看二进制文件和同步点
[root@master opt]#systemctl restart mysqld
[root@master opt]#mysql -uroot -p123
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.17-log Source distributionCopyright (c) 2000, 2016, 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 master status;
+-------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-------------------+----------+--------------+------------------+-------------------+
| master-bin.000002 | 154 | | | |
+-------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)
③ 在原主库服务器 mysql1 执行同步操作
mysql> show master status;
+-------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-------------------+----------+--------------+------------------+-------------------+
| master-bin.000002 | 154 | | | |
+-------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)mysql> change master to master_host='192.168.11.8',master_user='myslave',master_password='123',master_log_file='master-bin.000002',master_log_pos=154;
Query OK, 0 rows affected, 2 warnings (0.02 sec)mysql> start slave;
Query OK, 0 rows affected (0.00 sec)mysql> show slave status\G
④ 在 manager 节点上修改配置文件app1.cnf
[root@mcb-11-14 opt]# vim /etc/masterha/app1.cnf
⑤ 在 manager 节点上启动 MHA
⑥ 在现主库服务器 mysql2 更新数据，在现从服务器 mysql1、mysql3 查看数据
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