一、安装MHA基本环境

1. 安装MHA node

(1) 基本环境说明，本文参考互联网文章学习，搭建MHA与测试如下。

参考文档：http://www.cnblogs.com/xuanzhi201111/p/4231412.html

角色                IP地址            主机名    
=============================================    
Master              192.168.1.121     node1     
Slave               192.168.1.122     node2     
Slave               192.168.1.123     node3     
Monitor host        192.168.1.125     node5 

(2) 在node1,node2,node3,node5操作：

# vi /etc/hosts

192.168.1.121  node1   
192.168.1.122  node2    
192.168.1.123  node3    
192.168.1.125  node5

安装MHA node节点软件包：

# rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm    
# yum install perl-DBD-MySQL perl-CPAN -y    
# tar xf mha4mysql-node-0.56.tar.gz     
# cd mha4mysql-node-0.56    
# perl Makefile.PL        
# make && make install    
 

2. 安装MHA Manager

在node5管理节点上操作：注：MHA Manager主机也是需要安装MHA Node,MHA Manger

# yum install perl-DBD-MySQL perl-CPAN perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager perl-Time-HiRes -y   
# tar xf mha4mysql-manager-0.56.tar.gz    
# cd mha4mysql-manager-0.56    
# perl Makefile.PL    
# make && make install

#说明：安装的脚本程序都在/usr/local/bin/目录下。   
 

3. 节点间配置SSH登录无密码验证（MHA主机之间使用key登录）

在node5（Monitor）：

# ssh-keygen -t rsa   
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node1    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node2    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node3

在node1（Master）：

# ssh-keygen -t rsa   
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node2    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node3    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node5

在node2 (slave)：

# ssh-keygen -t rsa   
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node1    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node3    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node5

在node3 (slave)：

# ssh-keygen -t rsa   
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node1    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node2    
# ssh-copy-id -i /root/.ssh/id_rsa.pub root@node5

二、搭建主从复制环境

1. 主从复制环境配置过程

(1) mysql安装过程略,但是三节点要创建如下链接

node1(主)，node2(主备从）,node3(从)

注意：创建如下链接：   
ln -s /usr/local/mysql/bin/* /usr/local/bin/

node1 my.cnf

server-id              = 1   
binlog-format          = ROW    
log-bin                = master-bin    
log-bin-index          = master-bin.index    
log-slave-updates      = true    
relay_log_purge        = 0

node2 my.cnf

server-id              = 2   
binlog-format          = ROW    
log-bin                = master-bin    
log-bin-index          = master-bin.index    
log-slave-updates      = true    
relay_log_purge        = 0

node3 my.cnf

binlog-format          = ROW   
log-bin                = mysql-bin    
relay-log              = slave-relay-bin    
relay-log-index        = slave-relay-bin.index    
log-slave-updates      = true    
server-id              = 11    
skip-name-resolve    
relay_log_purge        = 0

(2) 在node1 (Master)上备份一份完整的数据：

# mysqldump -uroot -p123456 --master-data=2 --single-transaction -R --triggers -A > all.sql

其中--master-data=2代表备份时刻记录master的Binlog位置和Position。

(3) 在node1 (Master)上创建复制用户:

mysql> grant replication slave on *.* to 'repl'@'192.168.1.%' identified by '123456';    
mysql> flush privileges;

(4) 查看主库备份时的binlog名称和位置，MASTER_LOG_FILE和MASTER_LOG_POS：

# head -n 30 all.sql | grep 'CHANGE MASTER TO'

-- CHANGE MASTER TO MASTER_LOG_FILE='master-bin.000004', MASTER_LOG_POS=120;

(5) 把备份复制到192.168.1.122和192.168.1.123

# scp all.sql 192.168.1.122:/root/   
# scp all.sql 192.168.1.123:/root/

(6) 分别在两台服务器上导入备份，执行复制相关命令

在node2、node3 主机上操作：

# mysql -uroot -p123456 < all.sql

mysql> stop slave;

CHANGE MASTER TO    
MASTER_HOST='192.168.1.121',    
MASTER_USER='repl',     
MASTER_PASSWORD='123456',    
MASTER_LOG_FILE='master-bin.000004',    
MASTER_LOG_POS=120;

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

2. 创建MHA管理用户,在master上创建。

mysql> grant all privileges on *.* to 'root'@'192.168.1.%' identified  by '123456';    
mysql> flush  privileges;

 

三、配置Keepalived VIP

vip配置可以采用两种方式，一种通过keepalived的方式管理虚拟ip的浮动；一人是通过脚本方式，本文通过keepalived方式实现

1. 在node1(Master)与node2（备选主节点）安装keepalived。

# wget http://www.keepalived.org/software/keepalived-1.2.12.tar.gz    
# tar xf keepalived-1.2.12.tar.gz     
# cd keepalived-1.2.12    
# ./configure --prefix=/usr/local/keepalived    
# make &&  make install    
# cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/    
# cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/    
# mkdir /etc/keepalived    
# cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/    
# cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

2. 配置keepalived的配置文件，在node1(master)上配置操作如下:

注：keepalived配置成backup->backup，即IP地址切换后，主起来后IP地址不切换，本文监控脚本由MHA提供，keepalived不提供对mysqld的监控。

# vi /etc/keepalived/keepalived.conf    
! Configuration File for keepalived

global_defs {   
     notification_email {    
     abc@163.com    
   }    
   notification_email_from dba@dbserver.com    
   smtp_server 127.0.0.1    
   smtp_connect_timeout 30    
   router_id MySQL-HA    
}

vrrp_instance VI_1 {   
    state BACKUP    
    interface eth0    
    virtual_router_id 51    
    priority 150    
    advert_int 1    
    nopreempt

    authentication {   
    auth_type PASS    
    auth_pass 1111    
    }

    virtual_ipaddress {   
        192.168.1.130    
    }    
}

3. 配置keepalived的配置文件，在node2(备用节点)上配置操作如下:

# vi /etc/keepalived/keepalived.conf    
! Configuration File for keepalived

global_defs {   
     notification_email {    
     abc@163.com    
   }    
   notification_email_from dba@dbserver.com    
   smtp_server 127.0.0.1    
   smtp_connect_timeout 30    
   router_id MySQL-HA    
}

vrrp_instance VI_1 {   
    state BACKUP    
    interface eth0    
    virtual_router_id 51    
    priority 120    
    advert_int 1    
    nopreempt

    authentication {   
    auth_type PASS    
    auth_pass 1111    
    }

    virtual_ipaddress {   
        192.168.1.130    
    }    
}

4. node1,node2启动keepalived服务

# service keepalived start   
# chkconfig keepalived on

5. node1查看VIP启动情况

[root@node1 ~]# ip a   
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN     
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00    
    inet 127.0.0.1/8 scope host lo    
    inet6 ::1/128 scope host     
       valid_lft forever preferred_lft forever    
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000    
    link/ether 00:0c:29:4e:53:71 brd ff:ff:ff:ff:ff:ff    
    inet 192.168.1.121/24 brd 192.168.1.255 scope global eth0    
    inet 192.168.1.130/32 scope global eth0    
    inet6 fe80::20c:29ff:fe4e:5371/64 scope link     
       valid_lft forever preferred_lft forever

四、配置MHA

1. monitor创建MHA的工作目录，并且创建相关配置文件（在软件包解压后的目录里面有样例配置文件）。

# mkdir -p /etc/masterha   
# mkdir -p /var/log/masterha/app1    
# cp mha4mysql-manager-0.56/samples/conf/app1.cnf /etc/masterha/

修改app1.cnf配置文件，修改后的文件内容如下:

# cat /etc/masterha/app1.cnf

[server default]   
manager_workdir=/var/log/masterha/app1    
manager_log=/var/log/masterha/app1/manager.log    
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=123456     
user=root    
ping_interval=1     
remote_workdir=/tmp     
repl_password=123456    
repl_user=repl    
report_script=/usr/local/bin/send_report    
ssh_user=root  

[server1]   
hostname=192.168.1.121    
port=3306

[server2]   
hostname=192.168.1.122    
port=3306    
candidate_master=1    
check_repl_delay=0

[server3]   
hostname=192.168.1.123    
port=3306

说明:    
master_ip_failover_script= /usr/local/bin/master_ip_failover            #MHA自动切换执行的脚本，需要修改     
master_ip_online_change_script= /usr/local/bin/master_ip_online_change  #手动切换需要执行的脚本，需要修改     
report_script=/usr/local/bin/send_report                               #切换时发送邮件进行报告，需要修改

2. 设置relay log的清除方式（在每个slave节点上）：

(1)在node2,node3 从节点上操作：

将relay_log_purge=0加入my.cnf配置文件，前面已经配置。

(2) 设置定期清理relay脚本（node2,node3上操作）：

# cat purge_relay_log.sh    
#!/bin/bash    
user=root    
passwd=123456    
port=3306    
log_dir='/data/masterha/log'    
work_dir='/data'    
purge='/usr/local/bin/purge_relay_logs'

if [ ! -d $log_dir ]   
then    
   mkdir $log_dir -p    
fi

$purge --user=$user --password=$passwd --disable_relay_log_purge --port=$port --workdir=$work_dir >> $log_dir/purge_relay_logs.log 2>&1

配置定时计划任务

# crontab -e   
0 4 * * * /bin/bash /root/purge_relay_log.sh

 

3. 要想把keepalived服务引入MHA，我们只需要修改切换是触发的脚本文件master_ip_failover即可，在该脚本中添加在master发生宕机时对keepalived的处理。

(1) 编辑脚本/usr/local/bin/master_ip_failover，修改后如下:

# vi /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    
);

my $vip = '192.168.1.130';   
my $ssh_start_vip = "/etc/init.d/keepalived start";    
my $ssh_stop_vip = "/etc/init.d/keepalived stop";

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";    
}

(2) 编辑脚本master_ip_online_change，修改后如下:

#!/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    
#  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;    
use MHA::NodeUtil;    
use Time::HiRes qw( sleep gettimeofday tv_interval );    
use Data::Dumper;

my $_tstart;   
my $_running_interval = 0.1;    
my (    
  $command,              $orig_master_is_new_slave, $orig_master_host,    
  $orig_master_ip,       $orig_master_port,         $orig_master_user,    
  $orig_master_password, $orig_master_ssh_user,     $new_master_host,    
  $new_master_ip,        $new_master_port,          $new_master_user,    
  $new_master_password,  $new_master_ssh_user    
);    
my $vip = '192.168.1.130/24';    
my $key = '1';    
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";    
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";    
my $orig_master_ssh_port = 22;    
my $new_master_ssh_port = 22;    
GetOptions(    
  'command=s'                => \$command,    
  'orig_master_is_new_slave' => \$orig_master_is_new_slave,    
  'orig_master_host=s'       => \$orig_master_host,    
  'orig_master_ip=s'         => \$orig_master_ip,    
  'orig_master_port=i'       => \$orig_master_port,    
  'orig_master_user=s'       => \$orig_master_user,    
  'orig_master_password=s'   => \$orig_master_password,    
  'orig_master_ssh_user=s'   => \$orig_master_ssh_user,    
  '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,    
  'new_master_ssh_user=s'    => \$new_master_ssh_user,    
  'orig_master_ssh_port=i'    => \$orig_master_ssh_port,    
  'new_master_ssh_port=i'    => \$new_master_ssh_port,    
);

exit &main();

sub current_time_us {   
  my ( $sec, $microsec ) = gettimeofday();    
  my $curdate = localtime($sec);    
  return $curdate . " " . sprintf( "%06d", $microsec );    
}

sub sleep_until {   
  my $elapsed = tv_interval($_tstart);    
  if ( $_running_interval > $elapsed ) {    
    sleep( $_running_interval - $elapsed );    
  }    
}

sub get_threads_util {   
  my $dbh                    = shift;    
  my $my_connection_id       = shift;    
  my $running_time_threshold = shift;    
  my $type                   = shift;    
  $running_time_threshold = 0 unless ($running_time_threshold);    
  $type                   = 0 unless ($type);    
  my @threads;

  my $sth = $dbh->prepare("SHOW PROCESSLIST");   
  $sth->execute();

  while ( my $ref = $sth->fetchrow_hashref() ) {   
    my $id         = $ref->{Id};    
    my $user       = $ref->{User};    
    my $host       = $ref->{Host};    
    my $command    = $ref->{Command};    
    my $state      = $ref->{State};    
    my $query_time = $ref->{Time};    
    my $info       = $ref->{Info};    
    $info =~ s/^\s*(.*?)\s*$/$1/ if defined($info);    
    next if ( $my_connection_id == $id );    
    next if ( defined($query_time) && $query_time < $running_time_threshold );    
    next if ( defined($command)    && $command eq "Binlog Dump" );    
    next if ( defined($user)       && $user eq "system user" );    
    next    
      if ( defined($command)    
      && $command eq "Sleep"    
      && defined($query_time)    
      && $query_time >= 1 );

    if ( $type >= 1 ) {   
      next if ( defined($command) && $command eq "Sleep" );    
      next if ( defined($command) && $command eq "Connect" );    
    }

    if ( $type >= 2 ) {   
      next if ( defined($info) && $info =~ m/^select/i );    
      next if ( defined($info) && $info =~ m/^show/i );    
    }

    push @threads, $ref;   
  }    
  return @threads;    
}

sub main {   
  if ( $command eq "stop" ) {    
    ## Gracefully killing connections on the current master    
    # 1. Set read_only= 1 on the new master    
    # 2. DROP USER so that no app user can establish new connections    
    # 3. Set read_only= 1 on the current master    
    # 4. Kill current queries    
    # * Any database access failure will result in script die.    
    my $exit_code = 1;    
    eval {    
      ## Setting read_only=1 on the new master (to avoid accident)    
      my $new_master_handler = new MHA::DBHelper();

      # args: hostname, port, user, password, raise_error(die_on_error)_or_not   
      $new_master_handler->connect( $new_master_ip, $new_master_port,    
        $new_master_user, $new_master_password, 1 );    
      print current_time_us() . " Set read_only on the new master.. ";    
      $new_master_handler->enable_read_only();    
      if ( $new_master_handler->is_read_only() ) {    
        print "ok.\n";    
      }    
      else {    
        die "Failed!\n";    
      }    
      $new_master_handler->disconnect();

      # Connecting to the orig master, die if any database error happens   
      my $orig_master_handler = new MHA::DBHelper();    
      $orig_master_handler->connect( $orig_master_ip, $orig_master_port,    
        $orig_master_user, $orig_master_password, 1 );

      ## Drop application user so that nobody can connect. Disabling per-session binlog beforehand   
      $orig_master_handler->disable_log_bin_local();    
      print current_time_us() . " Drpping app user on the orig master..\n";    
      #FIXME_xxx_drop_app_user($orig_master_handler);

      ## Waiting for N * 100 milliseconds so that current connections can exit   
      my $time_until_read_only = 15;    
      $_tstart = [gettimeofday];    
      my @threads = get_threads_util( $orig_master_handler->{dbh},    
        $orig_master_handler->{connection_id} );    
      while ( $time_until_read_only > 0 && $#threads >= 0 ) {    
        if ( $time_until_read_only % 5 == 0 ) {    
          printf    
"%s Waiting all running %d threads are disconnected.. (max %d milliseconds)\n",    
            current_time_us(), $#threads + 1, $time_until_read_only * 100;    
          if ( $#threads < 5 ) {    
            print Data::Dumper->new( [$_] )->Indent(0)->Terse(1)->Dump . "\n"    
              foreach (@threads);    
          }    
        }    
        sleep_until();    
        $_tstart = [gettimeofday];    
        $time_until_read_only--;    
        @threads = get_threads_util( $orig_master_handler->{dbh},    
          $orig_master_handler->{connection_id} );    
      }

      ## Setting read_only=1 on the current master so that nobody(except SUPER) can write   
      print current_time_us() . " Set read_only=1 on the orig master.. ";    
      $orig_master_handler->enable_read_only();    
      if ( $orig_master_handler->is_read_only() ) {    
        print "ok.\n";    
      }    
      else {    
        die "Failed!\n";    
      }

      ## Waiting for M * 100 milliseconds so that current update queries can complete   
      my $time_until_kill_threads = 5;    
      @threads = get_threads_util( $orig_master_handler->{dbh},    
        $orig_master_handler->{connection_id} );    
      while ( $time_until_kill_threads > 0 && $#threads >= 0 ) {    
        if ( $time_until_kill_threads % 5 == 0 ) {    
          printf    
"%s Waiting all running %d queries are disconnected.. (max %d milliseconds)\n",    
            current_time_us(), $#threads + 1, $time_until_kill_threads * 100;    
          if ( $#threads < 5 ) {    
            print Data::Dumper->new( [$_] )->Indent(0)->Terse(1)->Dump . "\n"    
              foreach (@threads);    
          }    
        }    
        sleep_until();    
        $_tstart = [gettimeofday];    
        $time_until_kill_threads--;    
        @threads = get_threads_util( $orig_master_handler->{dbh},    
          $orig_master_handler->{connection_id} );    
      }

      ## Terminating all threads   
      print current_time_us() . " Killing all application threads..\n";    
      $orig_master_handler->kill_threads(@threads) if ( $#threads >= 0 );    
      print current_time_us() . " done.\n";    
      $orig_master_handler->enable_log_bin_local();    
      $orig_master_handler->disconnect();

      ## After finishing the script, MHA executes FLUSH TABLES WITH READ LOCK   
      eval {    
      `ssh -p$orig_master_ssh_port $orig_master_ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;    
        };    
        if ($@) {    
            warn $@;    
        }    
      $exit_code = 0;    
    };    
    if ($@) {    
      warn "Got Error: $@\n";    
      exit $exit_code;    
    }    
    exit $exit_code;    
  }    
  elsif ( $command eq "start" ) {    
    ## Activating master ip on the new master    
    # 1. Create app user with write privileges    
    # 2. Moving backup script if needed    
    # 3. Register new master's ip to the catalog database

# We don't return error even though activating updatable accounts/ip failed so that we don't interrupt slaves' recovery.   
# If exit code is 0 or 10, MHA does not abort    
    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 current_time_us() . " Set read_only=0 on the new master.\n";    
      $new_master_handler->disable_read_only();

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

      ## Update master ip on the catalog database, etc   
      `ssh -p$new_master_ssh_port $new_master_ssh_user\@$new_master_host \" $ssh_start_vip \"`;    
      $exit_code = 0;    
    };    
    if ($@) {    
      warn "Got Error: $@\n";    
      exit $exit_code;    
    }    
    exit $exit_code;    
  }    
  elsif ( $command eq "status" ) {

    # do nothing   
    exit 0;    
  }    
  else {    
    &usage();    
    exit 1;    
  }    
}

sub usage {   
  print    
"Usage: master_ip_online_change --command=start|stop|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";    
  die;    
}

(3) 编辑脚本send_report，修改后如下:

#!/usr/bin/perl

use strict;   
use warnings FATAL => 'all';    
use Mail::Sender;    
use Getopt::Long;

#new_master_host and new_slave_hosts are set only when recovering master succeeded   
my ( $dead_master_host, $new_master_host, $new_slave_hosts, $subject, $body );    
my $smtp='smtp.163.com';    
my $mail_from='xxxx';    
my $mail_user='xxxxx';    
my $mail_pass='xxxxx';    
my $mail_to=['xxxx','xxxx'];    
GetOptions(    
  'orig_master_host=s' => \$dead_master_host,    
  'new_master_host=s'  => \$new_master_host,    
  'new_slave_hosts=s'  => \$new_slave_hosts,    
  'subject=s'          => \$subject,    
  'body=s'             => \$body,    
);

mailToContacts($smtp,$mail_from,$mail_user,$mail_pass,$mail_to,$subject,$body);

sub mailToContacts {   
    my ( $smtp, $mail_from, $user, $passwd, $mail_to, $subject, $msg ) = @_;    
    open my $DEBUG, "> /tmp/monitormail.log"    
        or die "Can't open the debug      file:$!\n";    
    my $sender = new Mail::Sender {    
        ctype       => 'text/plain; charset=utf-8',    
        encoding    => 'utf-8',    
        smtp        => $smtp,    
        from        => $mail_from,    
        auth        => 'LOGIN',    
        TLS_allowed => '0',    
        authid      => $user,    
        authpwd     => $passwd,    
        to          => $mail_to,    
        subject     => $subject,    
        debug       => $DEBUG    
    };

    $sender->MailMsg(   
        {   msg   => $msg,    
            debug => $DEBUG    
        }    
    ) or print $Mail::Sender::Error;    
    return 1;    
}

# Do whatever you want here

exit 0;

 

五、MHA的日常管理

1. 检查SSH配置(node5 Monitor 监控节点上操作)，如下：

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

Sun May  1 22:05:12 2016 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.   
Sun May  1 22:05:12 2016 - [info] Reading application default configuration from /etc/masterha/app1.cnf..    
Sun May  1 22:05:12 2016 - [info] Reading server configuration from /etc/masterha/app1.cnf..    
Sun May  1 22:05:12 2016 - [info] Starting SSH connection tests..    
Sun May  1 22:05:14 2016 - [debug]     
Sun May  1 22:05:12 2016 - [debug]  Connecting via SSH from root@192.168.1.121(192.168.1.121:22) to root@192.168.1.122(192.168.1.122:22)..    
Sun May  1 22:05:13 2016 - [debug]   ok.    
Sun May  1 22:05:13 2016 - [debug]  Connecting via SSH from root@192.168.1.121(192.168.1.121:22) to root@192.168.1.123(192.168.1.123:22)..    
Sun May  1 22:05:13 2016 - [debug]   ok.    
Sun May  1 22:05:14 2016 - [debug]     
Sun May  1 22:05:13 2016 - [debug]  Connecting via SSH from root@192.168.1.122(192.168.1.122:22) to root@192.168.1.121(192.168.1.121:22)..    
Sun May  1 22:05:13 2016 - [debug]   ok.    
Sun May  1 22:05:13 2016 - [debug]  Connecting via SSH from root@192.168.1.122(192.168.1.122:22) to root@192.168.1.123(192.168.1.123:22)..    
Sun May  1 22:05:14 2016 - [debug]   ok.    
Sun May  1 22:05:14 2016 - [debug]     
Sun May  1 22:05:13 2016 - [debug]  Connecting via SSH from root@192.168.1.123(192.168.1.123:22) to root@192.168.1.121(192.168.1.121:22)..    
Sun May  1 22:05:14 2016 - [debug]   ok.    
Sun May  1 22:05:14 2016 - [debug]  Connecting via SSH from root@192.168.1.123(192.168.1.123:22) to root@192.168.1.122(192.168.1.122:22)..    
Sun May  1 22:05:14 2016 - [debug]   ok.    
Sun May  1 22:05:14 2016 - [info] All SSH connection tests passed successfully.

2. 检查整个复制环境状况(node5 监控节点上操作)，如下：

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

Sun May  1 22:46:44 2016 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.   
Sun May  1 22:46:44 2016 - [info] Reading application default configuration from /etc/masterha/app1.cnf..    
Sun May  1 22:46:44 2016 - [info] Reading server configuration from /etc/masterha/app1.cnf..    
Sun May  1 22:46:44 2016 - [info] MHA::MasterMonitor version 0.56.    
Sun May  1 22:46:45 2016 - [info] GTID failover mode = 0    
Sun May  1 22:46:45 2016 - [info] Dead Servers:    
Sun May  1 22:46:45 2016 - [info] Alive Servers:    
Sun May  1 22:46:45 2016 - [info]   192.168.1.121(192.168.1.121:3306)    
Sun May  1 22:46:45 2016 - [info]   192.168.1.122(192.168.1.122:3306)    
Sun May  1 22:46:45 2016 - [info]   192.168.1.123(192.168.1.123:3306)    
Sun May  1 22:46:45 2016 - [info] Alive Slaves:    
Sun May  1 22:46:45 2016 - [info]   192.168.1.122(192.168.1.122:3306)  Version=5.6.29-log (oldest major version between slaves) log-bin:enabled    
Sun May  1 22:46:45 2016 - [info]     Replicating from 192.168.1.121(192.168.1.121:3306)    
Sun May  1 22:46:45 2016 - [info]     Primary candidate for the new Master (candidate_master is set)    
Sun May  1 22:46:45 2016 - [info]   192.168.1.123(192.168.1.123:3306)  Version=5.6.29-log (oldest major version between slaves) log-bin:enabled    
Sun May  1 22:46:45 2016 - [info]     Replicating from 192.168.1.121(192.168.1.121:3306)    
Sun May  1 22:46:45 2016 - [info] Current Alive Master: 192.168.1.121(192.168.1.121:3306)    
Sun May  1 22:46:45 2016 - [info] Checking slave configurations..    
Sun May  1 22:46:45 2016 - [info]  read_only=1 is not set on slave 192.168.1.122(192.168.1.122:3306).    
Sun May  1 22:46:45 2016 - [warning]  relay_log_purge=0 is not set on slave 192.168.1.122(192.168.1.122:3306).    
Sun May  1 22:46:45 2016 - [info]  read_only=1 is not set on slave 192.168.1.123(192.168.1.123:3306).    
Sun May  1 22:46:45 2016 - [warning]  relay_log_purge=0 is not set on slave 192.168.1.123(192.168.1.123:3306).    
Sun May  1 22:46:45 2016 - [info] Checking replication filtering settings..    
Sun May  1 22:46:45 2016 - [info]  binlog_do_db= , binlog_ignore_db=     
Sun May  1 22:46:45 2016 - [info]  Replication filtering check ok.    
Sun May  1 22:46:45 2016 - [info] GTID (with auto-pos) is not supported    
Sun May  1 22:46:45 2016 - [info] Starting SSH connection tests..    
Sun May  1 22:46:46 2016 - [info] All SSH connection tests passed successfully.    
Sun May  1 22:46:46 2016 - [info] Checking MHA Node version..    
Sun May  1 22:46:47 2016 - [info]  Version check ok.    
Sun May  1 22:46:47 2016 - [info] Checking SSH publickey authentication settings on the current master..    
Sun May  1 22:46:47 2016 - [info] HealthCheck: SSH to 192.168.1.121 is reachable.    
Sun May  1 22:46:47 2016 - [info] Master MHA Node version is 0.56.    
Sun May  1 22:46:47 2016 - [info] Checking recovery script configurations on 192.168.1.121(192.168.1.121:3306)..    
Sun May  1 22:46:47 2016 - [info]   Executing command: save_binary_logs --command=test --start_pos=4 --binlog_dir=/usr/local/mysql/data/ --output_file=/tmp/save_binary_logs_test --manager_version=0.56 --start_file=master-bin.000008     
Sun May  1 22:46:47 2016 - [info]   Connecting to root@192.168.1.121(192.168.1.121:22)..     
  Creating /tmp if not exists..    ok.    
  Checking output directory is accessible or not..    
   ok.    
  Binlog found at /usr/local/mysql/data/, up to master-bin.000008    
Sun May  1 22:46:48 2016 - [info] Binlog setting check done.    
Sun May  1 22:46:48 2016 - [info] Checking SSH publickey authentication and checking recovery script configurations on all alive slave servers..    
Sun May  1 22:46:48 2016 - [info]   Executing command : apply_diff_relay_logs --command=test --slave_user='root' --slave_host=192.168.1.122 --slave_ip=192.168.1.122 --slave_port=3306 --workdir=/tmp --target_version=5.6.29-log --manager_version=0.56 --relay_log_info=/usr/local/mysql/data/relay-log.info  --relay_dir=/usr/local/mysql/data/  --slave_pass=xxx    
Sun May  1 22:46:48 2016 - [info]   Connecting to root@192.168.1.122(192.168.1.122:22)..     
  Checking slave recovery environment settings..    
    Opening /usr/local/mysql/data/relay-log.info ... ok.    
    Relay log found at /usr/local/mysql/data, up to node2-relay-bin.000002    
    Temporary relay log file is /usr/local/mysql/data/node2-relay-bin.000002    
    Testing mysql connection and privileges..Warning: Using a password on the command line interface can be insecure.    
done.    
    Testing mysqlbinlog output.. done.    
    Cleaning up test file(s).. done.    
Sun May  1 22:46:48 2016 - [info]   Executing command : apply_diff_relay_logs --command=test --slave_user='root' --slave_host=192.168.1.123 --slave_ip=192.168.1.123 --slave_port=3306 --workdir=/tmp --target_version=5.6.29-log --manager_version=0.56 --relay_log_info=/usr/local/mysql/data/relay-log.info  --relay_dir=/usr/local/mysql/data/  --slave_pass=xxx    
Sun May  1 22:46:48 2016 - [info]   Connecting to root@192.168.1.123(192.168.1.123:22)..     
  Checking slave recovery environment settings..    
    Opening /usr/local/mysql/data/relay-log.info ... ok.    
    Relay log found at /usr/local/mysql/data, up to slave-relay-bin.000012    
    Temporary relay log file is /usr/local/mysql/data/slave-relay-bin.000012    
    Testing mysql connection and privileges..Warning: Using a password on the command line interface can be insecure.    
done.    
    Testing mysqlbinlog output.. done.    
    Cleaning up test file(s).. done.    
Sun May  1 22:46:48 2016 - [info] Slaves settings check done.    
Sun May  1 22:46:48 2016 - [info]     
192.168.1.121(192.168.1.121:3306) (current master)    
+--192.168.1.122(192.168.1.122:3306)    
+--192.168.1.123(192.168.1.123:3306)

Sun May  1 22:46:48 2016 - [info] Checking replication health on 192.168.1.122..   
Sun May  1 22:46:48 2016 - [info]  ok.    
Sun May  1 22:46:48 2016 - [info] Checking replication health on 192.168.1.123..    
Sun May  1 22:46:48 2016 - [info]  ok.    
Sun May  1 22:46:48 2016 - [info] Checking master_ip_failover_script status:    
Sun May  1 22:46:48 2016 - [info]   /usr/local/bin/master_ip_failover --command=status --ssh_user=root --orig_master_host=192.168.1.121 --orig_master_ip=192.168.1.121 --orig_master_port=3306

IN SCRIPT TEST====/etc/init.d/keepalived stop==/etc/init.d/keepalived start===

Checking the Status of the script.. OK    
Sun May  1 22:46:48 2016 - [info]  OK.    
Sun May  1 22:46:48 2016 - [warning] shutdown_script is not defined.    
Sun May  1 22:46:48 2016 - [info] Got exit code 0 (Not master dead).

MySQL Replication Health is OK.   
[root@node5 masterha]#

3. 开启MHA Manager监控(node5操作)如下：

# mkdir -p  /var/log/masterha/app1/   
# 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 & 

参数说明：   
--remove_dead_master_conf     #该参数代表当发生主从切换后，老的主库的ip将会从配置文件中移除。    
--manger_log                  #日志存放位置    
--ignore_last_failover        #在缺省情况下，如果MHA检测到连续发生宕机，会生成app1.failover.complete文件，会造成MHA管理进程无法启动。

4. 查看MHA Manager监控是否正常：

# masterha_check_status --conf=/etc/masterha/app1.cnf   
app1 (pid:2480) is running(0:PING_OK), master:192.168.1.121

5. 查看启动日志(node5操作)如下：

# tail -n20 /var/log/masterha/app1/manager.log

6. 关闭MHA Manage监控：

(1) 关闭

# masterha_stop --conf=/etc/masterha/app1.cnf

(2) 启动

# 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

六、MHA Failover切换

1. 自动Failover切换

(1) 模拟master mysql关闭   
(2) VIP将会切换到node2    
(3) /etc/masterha/app1.cnf中将原主服务器配置文件清掉。    
(4) masterha_manager监控进程会自动退出关闭，并在/var/log/masterha/app1下生成app1.failover.complete文件，manager.log会记录全过程，从服务器会自动从新的主服务器复制。    
(5) 原主服务器mysqld启动的，需要清掉/var/log/masterha/app1下生成app1.failover.complete文件，添加node1配置文件到/etc/masterha/app1.cnf，通过manager.log中的记录的故障点，重新同步主服务器，成为从节点。

2. 手动Failover切换

(1) 先停MHA Manager进程。   
masterha_stop --conf=/etc/masterha/app1.cnf    
(2) 停掉master mysqld    
(3) 手动切换，在Manager主机上操作如下：    
# masterha_master_switch --master_state=dead --conf=/etc/masterha/app1.cnf --dead_master_host=192.168.1.122 --dead_master_port=3306 --new_master_host=192.168.1.121 --new_master_port=3306 --ignore_last_failover

通过观察日志可以观察切换全过程。   
(4) 如上节方式恢复节点为从服务器。

3.  正常运行情况下切换(Master正在运行)

等补充。

4. 小结

通过对MMM，MHA的环境搭建测试，MHA由于采用复制架构，原理简单，在一些对数据要求比较高的环境，为了保证可靠性，***与半同步结合使用。

本文出自 “koumm的linux技术博客” 博客，请务必保留此出处http://koumm.blog.51cto.com/703525/1769562