Detailed deployment steps for MySQL MHA high availability configuration and failover

MHA manager node server: CentOS7.4 (64 bit) manager/192.168.126.10, install MHA node and manager components Master node server: CentOS7.4 (64 bit) mysql1/192.168.126.20, install mysql5.7, MHA node components Slave1 node server: CentOS7.4 (64 bit) mysql2/192.168.126.30, install mysql5.7, MHA node components Slave2 node server: CentOS7.4 (64 bit) mysql3/192.168.126.40, install mysql5.7, MHA node components

systemctl stop firewalld
systemctl disable firewalld
setenforce 0

hostnamectl set-hostname Mysql1
hostnamectl set-hostname Mysql2
hostnamectl set-hostname Mysql3

vim /etc/my.cnf
[mysqld]
server-id = 1
log_bin = master-bin
log-slave-updates = true

systemctl restart mysqld

vim /etc/my.cnf
server-id = 2 #The server-ids of the three servers cannot be the same log_bin = master-bin
relay-log = relay-log-bin
relay-log-index = slave-relay-bin.index

systemctl restart mysqld

ln -s /usr/local/mysql/bin/mysql /usr/sbin/
ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/

mysql -uroot -p
grant replication slave on *.* to 'myslave'@'192.168.126.%' identified by '123'; #Slave database synchronization use grant all privileges on *.* to 'mha'@'192.168.126.%' identified by 'manager'; #manager use grant all privileges on *.* to 'mha'@'Mysql1' identified by 'manager'; #Prevent the slave library from connecting to the master library through the host name grant all privileges on *.* to 'mha'@'Mysql2' identified by 'manager';
grant all privileges on *.* to 'mha'@'Mysql3' identified by 'manager';
flush privileges;

change master to master_host='192.168.126.20',master_user='myslave',master_password='123',master_log_file='master-bin.000001',master_log_pos=1747; 

start slave;

show slave status\G		
// Make sure both IO and SQL threads are Yes, indicating that the synchronization is normal.
Slave_IO_Running: Yes
Slave_SQL_Running: Yes

set global read_only=1; 

yum install epel-release --nogpgcheck -y

yum install -y perl-DBD-MySQL \
perl-Config-Tiny \
perl-Log-Dispatch \
perl-Parallel-ForkManager \
perl-ExtUtils-CBuilder \
perl-ExtUtils-MakeMaker \
perl - CPAN

cd /opt
tar zxvf mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57
perl Makefile.PL
make && make install

cd /opt
tar zxvf mha4mysql-manager-0.57.tar.gz
cd mha4mysql-manager-0.57
perl Makefile.PL
make && make install

ssh-keygen -t rsa #Press Enter all the way ssh-copy-id 192.168.126.20
ssh-copy-id 192.168.126.30
ssh-copy-id 192.168.126.40 

ssh-keygen -t rsa
ssh-copy-id 192.168.126.30
ssh-copy-id 192.168.126.40

ssh-keygen -t rsa
ssh-copy-id 192.168.126.20
ssh-copy-id 192.168.126.40

ssh-keygen -t rsa
ssh-copy-id 192.168.126.20
ssh-copy-id 192.168.126.30

cp -rp /opt/mha4mysql-manager-0.57/samples/scripts /usr/local/bin
//After copying, there will be four executable files ll /usr/local/bin/scripts/

master_ip_failover #Script for VIP management during automatic switching master_ip_online_change #Vip management during online switching power_manager #Script for shutting down the host after a failure occurs send_report #Script for sending an alarm after a failure switch 

cp /usr/local/bin/scripts/master_ip_failover /usr/local/bin

vim /usr/local/bin/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
);
###############################Add content section#########################################
my $vip = '192.168.126.200'; #Specify the address of vipmy $brdc = '192.168.126.255'; #Specify the broadcast address of vipmy $ifdev = 'ens33'; #Specify the network card bound to vipmy $key = '1'; #Specify the serial number of the virtual network card bound to vipmy $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip"; #Represents that the value of this variable is ifconfig ens33:1 192.168.126.200
my $ssh_stop_vip = "/sbin/ifconfig ens33:$key down"; #This variable value represents ifconfig ens33:1 192.168.126.200 down
my $exit_code = 0; #Specify the exit status code as 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 disables 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";
}

mkdir /etc/masterha
cp /opt/mha4mysql-manager-0.57/samples/conf/app1.cnf /etc/masterha

vim /etc/masterha/app1.cnf #Delete the original content, directly copy and modify the IP address of the node server [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=123
repl_user=myslave
secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.126.30 -s 192.168.126.40
shutdown_script=""
ssh_user=root
user=mha

[server1]
hostname=192.168.126.20
port=3306

[server2]
candidate_master=1
check_repl_delay=0
hostname=192.168.126.30
port=3306

[server3]
hostname=192.168.126.40
port=3306

[server default]
manager_log=/var/log/masterha/app1/manager.log #manager log manager_workdir=/var/log/masterha/app1.log #manager working directory master_binlog_dir=/usr/local/mysql/data/ #The location where master saves binlog. The path here must be consistent with the path of binlog configured in master so that MHA can find it master_ip_failover_script=/usr/local/bin/master_ip_failover #Set the switching script for automatic failover, which is the script above master_ip_online_change_script=/usr/local/bin/master_ip_online_change #Set the switching script for manual switching password=manager #Set the password of the root user in mysql. This password is the password for creating the monitoring user in the previous article ping_interval=1 #Set the time interval for monitoring the main database and sending ping packets. The default is 3 seconds. Automatically failover after three attempts without response
remote_workdir=/tmp #Set the location where the remote MySQL binlog is saved when switching occurs repl_password=123 #Set the password of the replication user repl_user=myslave #Set the user of the replication user report_script=/usr/local/send_report #Set the script for sending alarms after switching secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.126.30 -s 192.168.126.40 #Specify the IP address of the slave server to be checked shutdown_script="" #Set the script to shut down the faulty host after a failure occurs (the main function of this script is to shut down the host to prevent brain split, which is not used here)
ssh_user=root #Set the ssh login username user=mha #Set monitoring user root

[server1]
hostname=192.168.126.20
port=3306

[server2]
hostname=192.168.126.30
port=3306
candidate_master=1
#Set to candidate master. After setting this parameter, the slave database will be promoted to the master database after the master-slave switch occurs, even if the master database is not the latest slave in the cluster

check_repl_delay=0
#By default, if a slave lags behind the master by more than 100M relay logs, MHA will not select the slave as a new master, because it takes a long time to recover the slave; by setting check_repl_delay=0, MHA triggers the switch to ignore the replication delay when selecting a new master. This parameter is very useful for hosts with candidate_master=1, because the candidate master must be the new master during the switch.

[server3]
hostname=192.168.126.40
port=3306

/sbin/ifconfig ens33:1 192.168.126.200/24 

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

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

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 &

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

cat /var/log/masterha/app1/manager.log | grep "current master" 

ifconfig

//To shut down the manager service, you can use the following command.
masterha_stop --conf=/etc/masterha/app1.cnf
Or you can directly kill the process ID to shut it down.

tail -f /var/log/masterha/app1/manager.log 

systemctl stop mysqld
or pkill -9 mysql 

systemctl restart mysqld

#View the binary files and synchronization points on the current master server Mysql2 show master status;

#Execute synchronization operation on the original master server mysql1 change master to master_host='192.168.126.30',master_user='myslave',master_password='123',master_log_file='master-bin.000001',master_log_pos=1747;

start slave;

show slave status\G

vim /etc/masterha/app1.cnf
......
secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.126.20 -s 192.168.126.40
......
[server1]
hostname=192.168.126.30
port=3306

[server2]
candidate_master=1
check_repl_delay=0
hostname=192.168.126.20
port=3306

[server3]
hostname=192.168.126.40
port=3306

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 &

#Solve the problem of Chinese and English characters being incompatible and reporting errors dos2unix /usr/local/bin/master_ip_failover