目录
一.MHA的简介
- MHA(Master High Availability)目前在MySQL高可用方面是一个相对成熟的解决方案,MHA是由日本人开发,是一套优秀的MySQL故障切换和主从复制的高可用软件
- 在MySQL故障切换的过程中,MHA能做到0~30秒之内自动完成数据库的故障切换操作,并且在进行故障切换的过程中,MHA能够最大程度上保证数据库的一致性,以达到真正意义上的高可用
- MHA由perl语言编写,该工具仅仅使用于MySQLReplication环境,目的在于维持Master主库的高可用性
- MHA是基于标准的MySQL复制(异步/半同步)
- MHA由两部分组成管理节点(MHA manager)和数据节点(MHA Node)两部分组成
- MHA manager 可以单独部署在一台服务器上,可以部署在一台slave上面
- 主从复制架构:主从复制(一主多从);MHA架构(多主多从);MMM架构(双主多从)
- MHA架构,图解
二.MHA的搭建方案
- 实验环境
主机名 | IP地址 | 系统 | 软件包 |
mysql1(master) | 192.168.43.101(虚拟:192.168.43.200) | centos7 | mysql-5.6.36.tar.gz cmake-2.8.6.tar.gz mha4mysql-node-0.57.tar.gz |
mysql2(slave1) | 192.168.43.102 | centos7 | |
mysql3(slave2) | 192.168.43.103 | centos7 | |
manager | 192.168.43.104 | centos7 | mha4mysql-node-0.57.tar.gz mha4mysql-manager-0.57.tar.gz |
- 操作步骤脚本
##MHA
##一主两从
##故障模拟(主库失效、备选主库成为主库、从库2将备选主库指向为主库)
#服务器 MHA manager,先安装node组件,在安装manager管理节点
#MySQL-master,安装node组件
#MySQL-slave-master,安装node组件
#MySQL-slave,安装node组件
#由于是CentOS7版本,所以下载MHA0.57版本
##实现(安装MySQL数据库、配置MySQL一主两从、安装MHA软件、配置无密码认证、配置MySQL MHA高可用、模拟master故障切换)
-------------------安装MySQL------------------------
#安装编译环境
yum install ncurses-devel gcc-c++ perl-Module-Install -y
#安装gmake编译软件
tar zxvf cmake-2.8.6.tar.gz
cd cmake-2.8.6
./configure
gmake && gmake install
##安装MySQL数据库
tar zxvf mysql-5.6.36.tar.gz
cd mysql-5.6.36
cmake -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \
-DDEFAULT_CHARSET=utf8 \
-DDEFAULT_COLLATION=utf8_general_ci \
-DWITII_EXTRA_CHARSETS=all \
-DSYSCONFDTR=/etc
make && make install
#覆盖原有的数据库文件
[root@mysql2 mysql-5.6.36]# cp support-files/my-default.cnf /etc/my.cnf
#添加执行脚本
[root@mysql2 mysql-5.6.36]# cp support-files/mysql.server /etc/rc.d/init.d/mysqld
[root@mysql2 mysql-5.6.36]# cd
chmod +x /etc/rc.d/init.d/mysqld
chkconfig --add mysqld
echo "PATH=$PATH:/usr/local/mysql/bin" >> /etc/profile
source /etc/profile
groupadd mysql
useradd -M -s /sbin/nologin mysql -g mysql
chown -R mysql.mysql /usr/local/mysql
#初始化数据库
/usr/local/mysql/scripts/mysql_install_db \
--basedir=/usr/local/mysql \
--datadir=/usr/local/mysql/data \
--user=mysql
###修改master 的主配置文件/etc/my.cnf,三台服务器的server-id不能一样
vim /etc/my.cnf
#在mysqld下
server-id = 1
log_bin = master-bin
log-slave-updates = true
###配置从服务器,msyql2、mysql3
vim /etc/my.cnf
#在mysqld下
server-id = 2
log_bin = master-bin
relay-log = relay-log-bin
relay-log-index = slave-relay-bin.index
##给master 、slave1、slave2分别做两个软链接,mysqlbinlog是二进制日志文件
ln -s /usr/local/mysql/bin/mysql /usr/sbin/
ln -s /usr/local/mysql/bin/mysqlbinlog /usr/sbin/
##master 、 slave1 、slave2 启动MySQL
/usr/local/mysql/bin/mysqld_safe --user=mysql &
systemctl stop firewalld
setenforce 0
netstat -natp | grep mysqld
----------------------配置所有MySQL服务器主从复制----------------------------------
##在所有数据库上授权两个用户,一个是从数据库同步用户myslave,另一个是manager(监控者)使用
mysql -uroot -p #直接回车进入数据库#
grant replication slave on *.* to 'myslave'@'192.168.43.%' identified by '123';
grant all privileges on *.* to 'mha'@'192.168.43.%' identified by 'manager';
flush privileges;
##下面三条授权按理论是不用添加的,但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
##mha 、mysql1 、mysql2、mysql3为主机名
grant all privileges on *.* to 'mha'@'mysql1' identified by 'manager';
grant all privileges on *.* to 'mha'@'mysql2' identified by 'manager';
grant all privileges on *.* to 'mha'@'mysql3' identified by 'manager';
flush privileges;
##在master(mysql1)上查看二进制文件和同步点
show master status;
+-------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-------------------+----------+--------------+------------------+-------------------+
| master-bin.000001 | 1292 | | | |
+-------------------+----------+--------------+------------------+-------------------+
##接下来在mysql的从服务器上执行主从同步
change master to master_host='192.168.43.101',
master_user='myslave',
master_password='123',
master_log_file='master-bin.000004',
master_log_pos=411;
#开启服务
start slave;
show slave status\G
##必须设置两个从数据库为只读模式,
set global read_only=1;
##设置完全直接验证主从复制功能!!!
-----错误------
Slave_IO_Running: Connecting
1.网络不通
2.账户密码错误
3.防火墙
4.mysql配置文件问题
5.连接服务器时语法
6.主服务器mysql权限
----------------------------安装MHA软件------------------------------------------
##所有服务器安装MHA依赖的环境,安装epel源
yum install epel-release --nogpgcheck -y
#安装perl环境包,针对MySQL数据库
yum install -y perl-DBD-MySQL \
perl-Config-Tiny \
perl-Log-Dispatch \
perl-Parallel-ForkManager \
perl-ExtUtils-CBuilder \
perl-ExtUtils-MakeMaker \
perl-CPAN
##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
#安装node组件
#解压Node组件
tar xzvf mha4mysql-node-0.57.tar.gz
cd mha4mysql-node-0.57
#用perl编译、安装
perl Makefile.PL
make
make install
----------------------在manger上面配置---------------------------
#安装manager组件(必须先装node组件)
#解压
tar xzvf mha4MHA-manager-0.57.tar.gz
[root@manager ~]# cd mha4mysql-manager-0.57/
#用perl编译,安装
perl Makefile.PL
make
make install
##生成的执行脚本
##,manager安装后在/usr/local/bin下面会生成一下几个工具,包括以下几个:
masterha_check_ssh 检查MHA的SSH配置状况
masterha_check_repl 检查MySQL复制状态
masterha_manager 启动manager的脚本
masterha_check_status 检测当前MHA运行状态
masterha_master_monitor 检测master是否宕机
masterha_master_switch 添加或故障转移(自动或者手动)
masterha_conf_host 添加或删除配置的server信息
masterha_stop 关闭manager
##node安装后也会在/usr/local/bin 下面会生成几个脚本(这些工具通常由MHAManager的脚本触发,无需人为操作)
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 清楚中继日志(不会阻塞SQL线程)
-----------------------------配置无密码认证------------------------------------
##open-ssh,身份验证,无密钥验证
#在manager上配置到所有数据库节点的无密码认证
ssh-keygen -t rsa //一直回车
ssh-copy-id 192.168.43.101
ssh-copy-id 192.168.43.102
ssh-copy-id 192.168.43.103
#在master上配置到数据库节点slave1和slave2的无密码认证
ssh-keygen -t rsa
ssh-copy-id 192.168.43.102
ssh-copy-id 192.168.43.103
#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 192.168.43.101
ssh-copy-id 192.168.43.103
#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 192.168.43.101
ssh-copy-id 192.168.43.102
----------------在manager上------------------
###配置MHA
#在manager节点上复制脚本到/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,分别为
master_ip_failover //自动切换时,VIP管理的脚本,即故障转移
master_ip_online_change //在线切换时VIP的管理
power_manager //故障发生时,关闭主机的脚本
send_report //因故障切换后发送报警的脚本
##复制上述的自动切换VIP管理脚本到/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
vim /usr/local/bin/scripts/master_ip_failover(删除原有内容,直接复制)
#!/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 = '192.168.43.200';
my $brdc = '192.168.43.255';
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";
}
-------------------------------创建MHA软件目录并且拷贝配置文件,在manager上-------------------
##创建目录,方便编辑
mkdir /etc/masterha
cp /root/mha4MHA-manager-0.57/samples/conf/appl.cnf /etc/masterha
##配置管理节点
vim /etc/masterha/app1.cnf
[server default]
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binlog的相同
master_binlog_dir=/usr/local/mysql/data //设置数据存放
master_ip_failover_script=/usr/local/bin/scripts/master_ip_failover //故障切换
master_ip_online_change_script=/usr/local/bin/scripts/master_ip_online_change
user=mha //监控用户和密码
password=manager
ping_interval=1
remote_workdir=/tmp
repl_password=123 //复制用户和密码
repl_user=myslave
#report_script=/usr/local/send_report //报警脚本
secondary_check_script=/usr/local/bin/masterha_secondary_check -s 192.168.43.102 -s 192.168.43.103
shutdown_script=""
ssh_user=root
//指定三台管理节点
[server1]
hostname=192.168.43.101
port=3306
[server2]
candidate_master=1
hostname=192.168.43.102
check_repl_delay=0
port=3306
[server3]
hostname=192.168.43.103
port=3306
###在manager上测试ssh 无密码认证 ,正常是successfuly
masterha_check_ssh --conf=/etc/masterha/app1.cnf
#出现
All SSH connection tests passed successfully.
###检查复制,即健康状态
masterha_check_repl -conf=/etc/masterha/app1.cnf
#出现
MySQL Replication Health is OK.
##第一次配置需要去master上手动开启虚拟IP,浮动IP,不需要重启网卡
/sbin/ifconfig ens33:1 192.168.43.200/24
###启动MHA,在manager上
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] 61687
##查看MHA状态,可以当前的master是MySQL节点
[root@manager ~]# masterha_check_status --conf=/etc/masterha/app1.cnf
app1 (pid:61687) is running(0:PING_OK), master:192.168.43.101
##查看MHA日志,也可以当前master是192.168.43.101
cat /var/log/masterha/app1/manager.log
#生效192.168.43.200
IN SCRIPT TEST====/sbin/ifconfig ens33:1 down==/sbin/ifconfig ens33:1 192.168.43.200===
##在master上,查看MySQL的VIP地址(192.168.43.200)
ifconfig
--------------------------------验证-----------------------------------------
##在manager上启用监控观察日志记录
tailf /var/log/masterha/app1/manager.log
#出现
Started automated(non-interactive) failover.
Invalidated master IP address on 192.168.43.101(192.168.43.101:3306)
The latest slave 192.168.43.102(192.168.43.102:3306) has all relay logs for recovery.
Selected 192.168.43.102(192.168.43.102:3306) as a new master.
192.168.43.102(192.168.43.102:3306): OK: Applying all logs succeeded.
192.168.43.102(192.168.43.102:3306): OK: Activated master IP address.
192.168.43.103(192.168.43.103:3306): This host has the latest relay log events.
Generating relay diff files from the latest slave succeeded.
192.168.43.103(192.168.43.103:3306): OK: Applying all logs succeeded. Slave started, replicating from 192.168.43.102(192.168.43.102:3306)
192.168.43.102(192.168.43.102:3306): Resetting slave info succeeded.
Master failover to 192.168.43.102(192.168.43.102:3306) completed successfully.
##在master上,关闭mysql服务, 查看master变化
pkill -9 mysql
##在备份mysql上,ifconfig,查看浮动路由
#出现
ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.43.200 netmask 255.255.255.0 broadcast 192.168.43.255
ether 00:0c:29:0b:69:b8 txqueuelen 1000 (Ethernet)
#####另外开启测试机
yum insatll -y mariadb
mysql -h 192.168.43.200 -u root -p //先给权限
##在备份MySQL上,授予权限
grant all on *.* 'root'@'%' identified by 'abc123'
##测试机上,创建新库,查看主从同步
三.MHA操作实例
1.配置三台mysql(master,slave1,slave2),查看主从同步,在master上创建school库
- 配置无密钥验证
- 在manager上进行ssh无密码检查
- 在manager上进行健康检查
- 验证配置