MySQL数据库---MHA高可用群集架构

MHA概述
日本DeNA公司youshimaton (现就职于Facebook公司) 开发
一套优秀的作为MySQL高可用性环境下故障切换和主从提升的高可用软件

MHA的组成

MHA Manager (管理节点)
MHA Node (数据节点)

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的不丢失
使用MySQL 5.5的半同步复制,可以大大降低数据丢失的风险

实验思路

1、MHA架构

(1)数据库安装
(2)一主两从
(3)MHA搭建

2、故障模拟

(1)主库失效
(2)备选主库成为主库
(3)从库2将备选主库指向为主库

部署环境

1、实验环境
服务器角色IP地址服务软件包
master192.168.142.130mha4mysql-node
slave1192.168.142.131mha4mysql-node
slave2192.168.142.132mha4mysql-node
manager192.168.142.133mha4mysql-manager、 mha4mysql-node

2、实验要求

本案例要求通过MHA监控MySQL 数据库在故障时进行自动切换,不影响业务。

3、实现思路

(1)安装MySQL数据库
(2)配置MySQL一主两从
(3)安装MHA软件
(4)配置无密码认证
(5)配置MySQL MHA高可用
(6)模拟master 故障切换

第一步:在三台MySQL节点上分别安装数据库

(MySOL版本请使用5.6.36, cmake版本请使用2.8.6)

1、安装编译依赖的环境

yum install -y install ncurses-devel gcc gcc-c++ perl-Module-Install

2、远程挂载

mkdir /abc
mount.cifs //192.168.1421/mha /abc/

3、安装gmake编译软件

cd /abc/mha/
tar zxvf cmake-2.8.6.tar.gz -C /opt/

cd /opt/cmake-2.8.6/
./configure
gmake && gmake install

4、安装MySQL数据库

cd /abc/mha/
tar zxvf mysql-5.6.36.tar.gz -C /opt/

cd /opt/mysql-5.6.36/
cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql -DDEFAULT_CHARSET=utf8 -DDEFAULT_COLLATION=utf8_general_ci -DWITH_EXTRA_CHARSETS=all -DSYSCONFDIR=/etc

make && make install

cp support-files/my-default.cnf /etc/my.cnf
cp support-files/mysql.server /etc/rc.d/init.d/mysqld

chmod +x /etc/rc.d/init.d/mysqld
chkconfig --add mysqld
echo "PATH=$PATH:/usr/local/mysql/bin" >> /etc/profile
source /etc/profile

useradd -M -s /sbin/nologin mysql
chown -R mysql.mysql /usr/local/mysql

/usr/local/mysql/scripts/mysql_install_db --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --user=mysql

5、修改master的主配置文件/etc/my.cnf文件,三台服务器的server-id不能一样

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

第二步:配置从服务器1

修改 mysql 的主配置文件

#在/etc/my.cnf中修改或者增加下面内容。
[mysqld]
server-id = 2
log_bin = master-bin
relay-log = relay-log-bin
relay-log-index = slave-relay-bin.index

第三步:配置从服务器2

1.修改 mysql 的主配置文件:/etc/my.cnf

vim /etc/my.cnf
[mysql]
server-id = 3
log_bin = master-bin
relay-log = relay-log-bin
relay-log-index = slave-relay-bin.index

2.在master、slave1、slave2上分别做两个软连接

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

3.master、slave1、slave2上启动mysql,并查看开启状况

#启动mysql
/usr/local/mysql/bin/mysqld_safe --user=mysql &

#查看服务端口状态
netstat -ntap | grep 3306

#关闭防火墙和安全功能
systemctl stop firewalld.service 
setenforce 0

第四步:配置MySQL一主两从

1.mysq主从配置相对比较简单需要注意的是授权,在所有数据库节点上授权两个用户,一个是从库同步使用用户myslave,另一个是manager使用监控用户mha

grant replication slave on *.* to ‘myslave‘@‘192.168.142.%‘ identified by ‘123‘;
grant all privileges on *.* to ‘mha‘@‘192.168.142.%‘ identified by ‘manager‘;
flush privileges;

2.下面三条授权按理论是不用添加的,但是做案例实验环境时候通过MHA检查mysql主从有报错,
报两个从库通过主机名连接不上主库,所以所有数据库加上下面的授权

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‘;

#刷新数据库
flush privileges;

3.在master主机上查看二进制文件和同步点

mysql> show master status;
+-------------------+----------+--------------+------------------+-------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-------------------+----------+--------------+------------------+-------------------+
| master-bin.000001 |     1292 |              |                  |                   |
+-------------------+----------+--------------+------------------+-------------------+

4.在slave1、slave2上分别执行同步

change master to master_host=‘192.168.142.130‘,master_user=‘myslave‘,master_password=‘123‘,master_log_file=‘masterbin.000001‘,master_log_pos=1292;
start slave;
#开启slave

5.查看IO和SQL线程都是yes代表代表同步正常

show slave status\G;

             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
#必须设置两个从库为只读模式

#设置两个从库为只读模式
set global read_only=1;

#刷新数据库
flush privileges;

第五步:安装MHA软件(所有服务器上都安装MHA依赖的环境,首先安装epel源)


#关闭防火墙和安全功能
systemctl stop firewalld.service 
setenforce 0

#安装MHA依赖的环境
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

#安装node(在所有服务器上安装node)
tar zxvf /abc/rpm/MHA/mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57/
perl Makefile.PL
make && make install

第六步:在MHA-manager上安装manager组件(注意:先安装node组件才能安装manager组件)

tar zxvf /abc/rpm/MHA/mha4mysql-manager-0.57.tar.gz
cd mha4mysql-manager-0.57/
perl Makefile.PL 
make
make install

manager安装后会在/usr/local/bin下面生成几个工具:

masterha_conf_host           
#添加或删除配置的server信息

masterha_stop                   
#关闭manager

masterha_manager            
#启动manager脚本

masterha_check_repl         
#检查mysql复制情况

masterha_master_monitor 
#检查master是否宕机

masterha_check_ssh          
#检查MHA的SSH配置状况

masterha_master_switch    
#控制故障转移(自动或者手动)

masterha_check_status      
#检测当前MHA运行状态

node安装后也会在/usr/local/bin下面生成几个脚本(这些工具通常由MHA Manager的脚本出发,无需人为陈操作)

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与其他的slave

filter_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)

save_binary_logs            
#保存和复制master的二进制日志

第七步:配置无密码验证

(1)在manager上配置到所有数据库节点的无密码认证

#因为是无密码验证,所以一路按回车键
ssh-keygen -t rsa         
ssh-copy-id 192.168.142.130
ssh-copy-id 192.168.142.131
ssh-copy-id 192.168.142.132

(2)在master上配置到数据库节点slave1和slave2的无密码验证

ssh-keygen -t rsa
ssh-copy-id 192.168.142.131
ssh-copy-id 192.168.142.132

(3)在slave1上配置到数据库节点master和slave2的无密码认证

ssh-keygen -t rsa
ssh-copy-id 192.168.142.130
ssh-copy-id 192.168.142.132

(4)在slave2上配置到数据库节点master和slave1的无密码认证

ssh-keygen -t rsa
ssh-copy-id 192.168.142.130
ssh-copy-id 192.168.142.131

第八步:配置MHA

1.在manager节点上复制相关脚本到/usr/local/bin目录

cp -ra /root/mha4mysql-manager-0.57/samples/scripts /usr/local/bin
#拷贝后会有四个执行文件

#查看目录权限
ll /usr/local/bin/scripts/

-rwxr-xr-x. 1 1001 1001  3648 May 31  2015 master_ip_failover            #自动切换时VIP管理的脚本
-rwxr-xr-x. 1 1001 1001  9870 May 31  2015 master_ip_online_change      #在线切换时VIP的管理
-rwxr-xr-x. 1 1001 1001 11867 May 31  2015 power_manager           #故障发生后关闭主机的脚本
-rwxr-xr-x. 1 1001 1001  1360 May 31  2015 send_report             #因故障切换后发送警报的脚本

2.复制上述的自动切换时VIP管理的脚本到/usr/local/bin目录,这里使用脚本管理VIP

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

3.重新编写 master_ip_failover 脚本:(删除原有内容,直接写入下述内容)

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
);

#添加内容部分
my $vip = ‘192.168.142.200‘;
my $brdc = ‘192.168.142.255‘;
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;
#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";
}

4.创建MHA软件目录并拷贝配置文件

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

[server default]
#manager配置文件
manager_log=/var/log/masterha/app1/manager.log     

#manager日志
manager_workdir=/var/log/masterha/app1

#master保存binlog的位置,这里的路径要与master里配置的bilog的相同
master_binlog_dir=/usr/local/mysql/data

#设置自动failover时候的切换脚本。也就是上边的那个脚本
master_ip_failover_script=/usr/local/bin/master_ip_failover

#设置手动切换时候的切换脚本
master_ip_online_change_script=/usr/local/bin/master_ip_online_change

#这个密码是前文中创建监控用户的那个密码
password=manager
remote_workdir=/tmp

#设置复制用户密码
repl_password=123

#设置复制用户的用户
repl_user=myslave

#设置发生切换后发生报警的脚本
reporl_script=/usr/local/send_report
secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.45.130 -s 192.168.45.134

#设置故障发生关闭故障脚本主机
shutdown_script=""

#设置ssh的登录用户名
ssh_user=root

#设置监控用户
user=mha

[server1]
hostname=192.168.142.
port=3306

[server2]
candidate_master=1
check_repl_delay=0
hostname=192.168.142.
port=3306

[server3]
hostname=192.168.142.
port=3306

5.测试ssh无密码认证

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

#注意:第一次配置需要去master上手动开启虚拟IP
/sbin/ifconfig ens33:1 192.168.142.200/24

6.启动MHA

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 &

7.查看MHA状态,可以看到当前的master是mysql1节点

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

8.查看MHA日志,也可以看到当前的master是192.168.142.130

cat /var/log/masterha/app1/manager.log

第九步:故障模拟

1、启动监控观察日志记录

tailf /var/log/masterha/app1/manager.log

2、查看地址变化

pkill -9 mysql        
#宕掉mysql服务      

VIP地址不会因为manager节点停止MHA服务而消失,VIP地址会转移到slave1上

#从服务器查看vip地址转移
ifconfig

ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.142.131  netmask 255.255.255.0  broadcast 192.168.142.255
        inet6 fe80::b81a:9df:a960:45ac  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:97:8e:66  txqueuelen 1000  (Ethernet)
        RX packets 1687418  bytes 1157627305 (1.0 GiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1376468  bytes 170996461 (163.0 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.142.200  netmask 255.255.255.0  broadcast 192.168.142.255
        ether 00:0c:29:97:8e:66  txqueuelen 1000  (Ethernet)

3、在mha-manager上开启另外一个新的终端,直接yum安装一个mysql

yum install mysql -y

#在slave1上赋予权限,要不然mha-manager这边是进不到数据库的:
grant all on *.* to ‘root‘@‘%‘ identified by ‘abc123‘;

#在mh-manager上进行登录:
 mysql -h 192.168.142.200 -uroot -p
Enter password:             
#输入密码

(1)创建个数据库school,并创建个表info,写一下简单的内容

MySQL [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.00 sec)

MySQL [(none)]> create database school;
Query OK, 1 row affected (0.00 sec)

MySQL [(none)]> use school;
Database changed
MySQL [school]> create table info (id int);
Query OK, 0 rows affected (0.01 sec)

(2)创建好以后再slave1上的数据库中查看,会同步数据

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| school             |
| test               |
+--------------------+

(3)因为slave1和slave2之间是相互同步的,所以在slave2上数据也应该同步

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| school             |
| test               |
+--------------------+

谢谢阅读!!!

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