6、MHA

MHA含义

什么MHA,master high availability

建立在主从复制基础之上的故障切换的软件系统。

主从复制的单点问题：

当主从复制当中，主服务器发生故障，会自动切换到一台从服务器，然后把从服务器升格为主，继续主从的架构。

主从复制+读写分离+MHA，mysql初始化进行的操作。

relay_log_recovery=1

启用之后，从库崩溃或者重启时，会自动尝试从日志当中恢复。

安装MHA的组件：

NODE MANAGER

node表示：监控每台机器上mysql的状态，传回给manager。

manager:管理节点，控制MHA的状态

操作过程

mysql1 主 31

同步日期

vim /etc/my.cnf

#从数据库同步使用
CREATE USER 'myslave'@'192.168.32.%' IDENTIFIED WITH mysql_native_password BY '123456';

GRANT REPLICATION SLAVE ON *.* TO 'myslave'@'192.168.32.%';

#manager 使用
CREATE USER 'mha'@'192.168.32.%' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'192.168.32.%' WITH GRANT OPTION;

#防止从库通过主机名连接不上主库
CREATE USER 'mha'@'master' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'master';

CREATE USER 'mha'@'slave1' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'slave1';

CREATE USER 'mha'@'slave2' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'slave2';

flush privileges;

添加MHA安装包

apt install -y libdbd-mysql-perl \
libconfig-tiny-perl \
liblog-dispatch-perl \
libparallel-forkmanager-perl \
libextutils-cbuilder-perl \
libmodule-install-perl \
make

cd 进去

perl Makefile.PL

make && make install

mysql2 从1----主备 32

#从数据库同步使用
CREATE USER 'myslave'@'192.168.233.%' IDENTIFIED WITH mysql_native_password BY '123456';

GRANT REPLICATION SLAVE ON *.* TO 'myslave'@'192.168.233.%';

#manager 使用
CREATE USER 'mha'@'192.168.233.%' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'192.168.233.%' WITH GRANT OPTION;

#防止从库通过主机名连接不上主库
CREATE USER 'mha'@'master' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'master';

CREATE USER 'mha'@'slave1' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'slave1';

CREATE USER 'mha'@'slave2' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'slave2';

flush privileges;

添加MHA安装包

apt install -y libdbd-mysql-perl \
libconfig-tiny-perl \
liblog-dispatch-perl \
libparallel-forkmanager-perl \
libextutils-cbuilder-perl \
libmodule-install-perl \
make

cd 进去

perl Makefile.PL

make && make install

mysql3 从2 32

#从数据库同步使用
CREATE USER 'myslave'@'192.168.233.%' IDENTIFIED WITH mysql_native_password BY '123456';

#防止从库通过主机名连接不上主库
CREATE USER 'mha'@'master' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'master';

CREATE USER 'mha'@'slave1' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'slave1';

CREATE USER 'mha'@'slave2' IDENTIFIED WITH mysql_native_password BY 'manager';
GRANT ALL PRIVILEGES ON *.* TO 'mha'@'slave2';

flush privileges;

添加MHA安装包

apt install -y libdbd-mysql-perl \
libconfig-tiny-perl \
liblog-dispatch-perl \
libparallel-forkmanager-perl \
libextutils-cbuilder-perl \
libmodule-install-perl \
make

cd 进去

perl Makefile.PL

make && make install

nginx MHA的组件 20

添加MHA安装包

apt install -y libdbd-mysql-perl \
libconfig-tiny-perl \
liblog-dispatch-perl \
libparallel-forkmanager-perl \
libextutils-cbuilder-perl \
libmodule-install-perl \
make

cd 进去

perl Makefile.PL

make && make install

添加manager安装包

配置所有节点之间的MHA的ssh通信

免密登入彼此之间的服务器

nginx1 -------mysql 1 2 3

mysql1 -----------mysql 2 3

mysql2-------------mysql 1 3

mysql3 ------------- mysql 1 2

cp -rp /opt/mha4mysql-manager-0.57/samples/scripts /usr/local/bin

清空内容复制脚本

#!/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 = '192.168.233.100';
my $brdc = '192.168.233.255';
my $ifdev = 'ens33';
my $key = '1';
my $ssh_start_vip = "/sbin/ifconfig ens33:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig ens33:$key down";
my $exit_code = 0;
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";
}

清空数据复制脚本

[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 192.168.32.32 -s 192.168.32.33
#从对主监听
shutdown_script=""
ssh_user=root
user=mha

[server1]
hostname=192.168.32.31
#主服务器
port=3306

[server2]
candidate_master=1
check_repl_delay=0
hostname=192.168.32.32
#备用主服务器
port=3306

[server3]
hostname=192.168.32.33
#从服务器2
port=3306

mysql1 2 3

nginx1

$str =~ /(\d+)\.(\d+)/;
my $strmajor = "$1.$2";
my $result = sprintf( '%03d%03d', $1, $2 ) if $str =~ m/(\d+)\.(\d+)/;

检查ssh通信状态

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

启动

nginx1

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 &

nohup：执行记录，把执行记录保存

检查master节点

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

test1