MHA集群

最新推荐文章于 2024-03-29 16:53:44 发布

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最新推荐文章于 2024-03-29 16:53:44 发布

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MHA Manager（管理节点）

——可以单独部署在一台独立的机器上，管理其他节点

——也可以试部署在一台slave节点上

MHA Node(数据节点)

——运行在每台MySQL服务器上

MHA工作过程

由Manager定时探测集群中的master节点

当master故障时，master自动将拥有最新数据的slave提升为新的master

关键点

从宕机崩溃的master保存二进制日志事件
识别含有最新更新的slave
应用差异的中继日志（relay log）到其他的slave
应用从master保存的二进制日志事件
提升一个slave为新的master
使其他的slave连接新的master进行复制

拓扑图：

一、配置所有数据节点主机之间可以互相以ssh密钥对方式认证登陆

二、配置manager56主机无密码ssh登录所有数据节点主机

三、配置主从同步,要求如下：

51 主库开半同步复制
52 从库（备用主库）开半同步复制
53 从库（备用主库）开半同步复制
54 从库不做备用主库所以不用开半同步复制
55 从库不做备用主库所以不用开半同步复制

不让从库把中继日志删掉，默认会删掉

mysql> set global relay_log_purge=off;
Query OK, 0 rows affected (0.13 sec)

配置数据库服务器：(51~55)
           yum -y install perl-DBD-mysql // 安装依赖包
           rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm
配置管理服务器:(56)
           yum -y install perl-DBD-mysql // 安装依赖包
           rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm //先装Noed在安装Manager
           yum -y install perl-ExtUtils-* perl-CPAN-*
           tar -zxvf mha4mysql-manager-0.56.tar.gz //源码安装Manager
           cd mha4mysql-manager-0.56/
perl Makefile.PL
           make
           make install

[root@mha ~]# mkdir /etc/mha_manager/

[root@mha ~]# cp /opt/mha4mysql-manager-0.56/samples/conf/app1.cnf /etc/mha_manager/

[root@mha ~]# cp /opt/mha4mysql-manager-0.56/samples/conf/master_ip_failover /etc/mha_manager/

[root@mha ~]# vim /etc/mha_manager/app1.cnf //修改MHA配置文件

[server default]
manager_workdir=/etc/mha_manager //定义软件路径
manager_log=/etc/mha_manager/manager.log //指定log日志位置
master_ip_failover_script=/etc/mha_manager/master_ip_failover //自动failover的切换脚本

ssh_user=root //ssh用户名
ssh_port=22
repl_user=replication //主从同步用户名
repl_password=123qqq...A // 主从密码
user=root // 数据库用户名
password=123qqq...A // 数据库密码

[server1] //添加管理主机
hostname=192.168.4.50
candidate_master=1 //设置为候选master

[server2]
hostname=192.168.4.51
candidate_master=1

[server3]
hostname=192.168.4.52
candidate_master=1

[server4]
hostname=192.168.4.53
no_master=1 //不竞选master

[server5]
hostname=192.168.4.54
no_master=1

添加授权用户： //用于MHA检测集群状态

mysql> grant all on *.* to root@"%" identified by "123qqq...A";
Query OK, 0 rows affected (0.10 sec)

添加授权用户： //用于主从授权

grant replication slave on *.* to replication@"%" identified by "123qqq...A";
Query OK, 0 rows affected (0.12 sec)

测试：

SSH测试：

[root@mha ~]# masterha_check_ssh --conf=/etc/mha_manager/app1.cnf

主从配置测试：

[root@mha ~]# masterha_check_repl --conf=/etc/mha_manager/app1.cnf

编辑VIP转换脚本： vim /etc/mha_manager/master_ip_failover

#!/usr/bin/env perl

#  Copyright (C) 2011 DeNA Co.,Ltd.
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by锛�
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#  Foundation, Inc.,
#  51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

## Note: This is a sample script and is not complete. Modify the script based on your environment.

use strict;
use warnings FATAL => 'all';

use Getopt::Long;
use MHA::DBHelper;

my (
  $command,        $ssh_user,         $orig_master_host,
  $orig_master_ip, $orig_master_port, $new_master_host,
  $new_master_ip,  $new_master_port,  $new_master_user,
  $new_master_password
);

my $vip = '192.168.4.100/24';  # Virtual IP 
my $key = "1"; 
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";

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,
  'new_master_user=s'     => \$new_master_user,
  'new_master_password=s' => \$new_master_password,
);

exit &main();

sub main {
  if ( $command eq "stop" || $command eq "stopssh" ) {

    # $orig_master_host, $orig_master_ip, $orig_master_port are passed.
    # If you manage master ip address at global catalog database,
    # invalidate orig_master_ip here.
    my $exit_code = 1;
    eval {

      # updating global catalog, etc
      &stop_vip();
      $exit_code = 0;
    };
    if ($@) {
      warn "Got Error: $@\n";
      exit $exit_code;
    }
    exit $exit_code;
  }
  elsif ( $command eq "start" ) {

    # all arguments are passed.
    # If you manage master ip address at global catalog database,
    # activate new_master_ip here.
    # You can also grant write access (create user, set read_only=0, etc) here.
    my $exit_code = 10;
    eval {
      my $new_master_handler = new MHA::DBHelper();

      # args: hostname, port, user, password, raise_error_or_not
      $new_master_handler->connect( $new_master_ip, $new_master_port,
        $new_master_user, $new_master_password, 1 );

      ## Set read_only=0 on the new master
      $new_master_handler->disable_log_bin_local();
      print "Set read_only=0 on the new master.\n";
      $new_master_handler->disable_read_only();

      ## Creating an app user on the new master
      print "Creating app user on the new master..\n";
      $new_master_handler->enable_log_bin_local();
      $new_master_handler->disconnect();

      ## Update master ip on the catalog database, etc
      &start_vip();
      $exit_code = 0;
    };
    if ($@) {
      warn $@;

      # If you want to continue failover, exit 10.
      exit $exit_code;
    }
    exit $exit_code;
  }
  elsif ( $command eq "status" ) {

    # do nothing
    exit 0;
  }
  else {
    &usage();
    exit 1;
  }
}
sub start_vip() {
    `ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}
sub stop_vip() {
    return 0 unless ($ssh_user);
    `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";
}

启动MHA：

[root@mha ~] # masterha_manager --conf=/etc/mha_manager/app1.cnf --remove_dead_master_conf --ignore_last_failover

--remove_dead_master_conf //当主库坏掉，会自动将这个数据库踢出集群，在配置文件app1.cnf中将主库的配置删除，当你修复好之后需要在配置文件app1.cnf中添加回去

--ignore_last_failover // 默认一台坏掉另外一台顶上去，在8个小时之内又坏了，就不会再切换主机了，所以需要把这个关掉

[root@mha ~] # masterha_check_status --conf=/etc/mha_manager/app1.cnf //查看服务器状态

停止master50，主库会动态迁移

将被删除的50添加到集群

mysql>change master to master_host="192.168.4.51",master_user="replication",master_password="123qqq...A",master_log_file="master51.000003",master_log_pos=154; // 将50设置为现在的主库51的从库

mysql> start slave;
mysql> show slave status\G;

在56中将删除的50信息添加回去
       ]# vim /etc/mha_manager/app1.cnf
               [server1]
               candidate_master=1
               hostname=192.168.4.50