MHA + proxysql 高可用以及读写分离

环境

vip     192.168.1.101

slave   192.168.1.16  5.7.17 3306

master  192.168.1.135 5.7.17 3306

proxysql 192.168.1.16（为方便proxysql放在了16节点上)

一 MHA的搭建

1.安装MHA软件，首先安装epel源。（2台机器）

rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

2.安装perl相关组件（2台机器）

yum install perl-DBD-MySQL

yum install perl-Config-Tiny

yum install perl-Log-Dispatch

yum install perl-Parallel-ForkManager

3.安装MHA软件 (两台机器建议都安装,切换方便)（2台机器）

rpm -ivh mha4mysql-node-0.56-.el6.noarch.rpm

rpm -ivh mha4mysql-manager-0.56-.el6.noarch.rpm

4.建立SSH信任关系

5.授权

GRANT ALL PRIVILEGES ON *.* TO 'zhuch'@'%' IDENTIFIED BY  "zhuch"

GRANT REPLICATION SLAVE ON *.* TO 'slave'@'%' IDENTIFIED BY  "oracle"

6.创建应用目录

mkdir /etc/masterha

拷贝如下文件到 /etc/masterha

[root@mysql3 masterha]# ls -l

total 32

-rw-r--r--. 1 root root   509 Feb 10 02:29 app1.conf

-rw-r--r--. 1 root root    55 Feb 10 03:15 drop_vip.sh

-rw-r--r--. 1 root root    57 Feb 10 03:15 init_vip.sh

-rw-r--r--. 1 root root   354 Feb 10 02:25 masterha_default.conf

-rwxr-xr-x. 1 root root  3978 Feb 10 03:16 master_ip_failover

-rwxr-xr-x. 1 root root 10390 Feb 10 03:17 master_ip_online_change

app1.conf MHA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,只不过这里我们直接创建一个重新编辑）

[root@mysql3 masterha]# cat app1.conf
[server default]

#mha manager工作目录
manager_workdir = /var/log/masterha/app1
manager_log = /var/log/masterha/app1/app1.log
remote_workdir = /var/log/masterha/app1

[server1]
hostname=192.168.1.16
master_binlog_dir = /data/mysql/mysql3306/logs
candidate_master = 1
check_repl_delay = 0 #用防止master故障时，切换时slave有延迟，卡在那里切不过来。

[server3]
hostname=192.168.1.135
master_binlog_dir=/data/mysql/mysql3306/logs
candidate_master = 1
check_repl_delay = 0

drop_vip.sh 解除绑定vip

[root@mysql3 masterha]# cat drop_vip.sh

vip="192.168.1.101/24"

/sbin/ip addr del $vip dev eth0

init._vip.sh 绑定vip

[root@mysql3 masterha]# cat init_vip.sh

vip="192.168.1.101/24"

/sbin/ip addr add $vip dev eth0

masterha_default.conf 全局级配置文件

[root@mysql3 masterha]# cat masterha_default.conf
[server default]
#MySQL的用户和密码
user=zhuch
password=zhuch

#系统ssh用户
ssh_user=root

#复制用户
repl_user=slave
repl_password=oracle

#监控
ping_interval=1
#shutdown_script=""

#切换调用的脚本
master_ip_failover_script= /etc/masterha/master_ip_failover
master_ip_online_change_script= /etc/masterha/master_ip_online_change

master_ip_failover 自动failover脚本

[root@mysql3 masterha]# cat 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

#  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;

#自定义该组机器的vip

my $vip = "192.168.1.101";

my $if = "eth0";

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

);

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,

);

sub add_vip {

        my $output1 = `ssh -o ConnectTimeout=  -o ConnectionAttempts= $orig_master_host /sbin/ip addr del $vip/ dev $if`;

        my $output2 = `ssh -o ConnectTimeout=  -o ConnectionAttempts= $new_master_host /sbin/ip addr add $vip/ dev $if`;

}

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 = ;

    eval {

      # updating global catalog, etc

      $exit_code = ;

    };

    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 = ;

    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,  );

      ## 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";

      #FIXME_xxx_create_user( $new_master_handler->{dbh} );

      $new_master_handler->enable_log_bin_local();

      $new_master_handler->disconnect();

      ## Update master ip on the catalog database, etc

      &add_vip();

      $exit_code = ;

    };

    if ($@) {

      warn $@;

      # If you want to continue failover, exit 10.

      exit $exit_code;

    }

    exit $exit_code;

  }

  elsif ( $command eq "status" ) {

    # do nothing

    exit ;

  }

  else {

    &usage();

    exit ;

  }

}

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";

}

master_ip_online_change 手动failover脚本

[root@mysql3 masterha]# cat master_ip_online_change

#!/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;

#添加vip定义

my $vip = "192.168.1.101";

my $if = "eth0";

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,

);

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,

);

exit &main();

sub drop_vip {

        my $output = `ssh -o ConnectTimeout=  -o ConnectionAttempts= $orig_master_host /sbin/ip addr del $vip/ dev $if`;

        #mysql里的连接全部干掉

        #FIXME

}

sub add_vip {

        my $output = `ssh -o ConnectTimeout=  -o ConnectionAttempts= $new_master_host /sbin/ip addr add $vip/ dev $if`;

}

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;

  $running_time_threshold =  unless ($running_time_threshold);

  $type                   =  unless ($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};

    $info =~ s/^\s*(.*?)\s*$/$/ if defined($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 >=  );

    if ( $type >=  ) {

      next if ( defined($command) && $command eq "Sleep" );

      next if ( defined($command) && $command eq "Connect" );

    }

    if ( $type >=  ) {

      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 = ;

    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,  );

      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,  );

      ## 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";

      print current_time_us() . " drop vip $vip..\n";

      #drop_app_user($orig_master_handler);

     &drop_vip();

      ## Waiting for N * 100 milliseconds so that current connections can exit

      my $time_until_read_only = ;

      $_tstart = [gettimeofday];

      my @threads = get_threads_util( $orig_master_handler->{dbh},

        $orig_master_handler->{connection_id} );

      while ( $time_until_read_only >  && $#threads >= 0 ) {

        if ( $time_until_read_only %  ==  ) {

          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()->Terse()->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 = ;

      @threads = get_threads_util( $orig_master_handler->{dbh},

        $orig_master_handler->{connection_id} );

      while ( $time_until_kill_threads >  && $#threads >= 0 ) {

        if ( $time_until_kill_threads %  ==  ) {

          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()->Terse()->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

      $exit_code = ;

    };

    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 = ;

    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,  );

      ## 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";

      print current_time_us() . "Add vip $vip on $if..\n";

     # create_app_user($new_master_handler);

      &add_vip();

      $new_master_handler->enable_log_bin_local();

      $new_master_handler->disconnect();

      ## Update master ip on the catalog database, etc

      $exit_code = ;

    };

    if ($@) {

      warn "Got Error: $@\n";

      exit $exit_code;

    }

    exit $exit_code;

  }

  elsif ( $command eq "status" ) {

    # do nothing

    exit ;

  }

  else {

    &usage();

    exit ;

  }

}

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;

}

7.在主库绑定vip(执行脚本)

sh init._vip.sh

8.检测SSH 是否ok

[root@mysql2 opt]# masterha_check_ssh --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf

Sat Feb  ::  - [info] Reading default configuration from /etc/masterha/masterha_default.conf..

Sat Feb  ::  - [info] Reading application default configuration from /etc/masterha/app1.conf..

Sat Feb  ::  - [info] Reading server configuration from /etc/masterha/app1.conf..

Sat Feb  ::  - [info] Starting SSH connection tests..

Sat Feb  ::  - [debug]

Sat Feb  ::  - [debug]  Connecting via SSH from root@192.168.1.135(192.168.1.135:) to root@192.168.1.16(192.168.1.16:)..

Sat Feb  ::  - [debug]   ok.

Sat Feb  ::  - [debug]

Sat Feb  ::  - [debug]  Connecting via SSH from root@192.168.1.16(192.168.1.16:) to root@192.168.1.135(192.168.1.135:)..

Sat Feb  ::  - [debug]   ok.

Sat Feb  ::  - [info] All SSH connection tests passed successfully.

9.检测主从复制情况是否ok

[root@mysql2 opt]# masterha_check_ssh --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf

Sat Feb  ::  - [info] Reading default configuration from /etc/masterha/masterha_default.conf..

Sat Feb  ::  - [info] Reading application default configuration from /etc/masterha/app1.conf..

Sat Feb  ::  - [info] Reading server configuration from /etc/masterha/app1.conf..

Sat Feb  ::  - [info] Starting SSH connection tests..

Sat Feb  ::  - [debug]

Sat Feb  ::  - [debug]  Connecting via SSH from root@192.168.1.135(192.168.1.135:) to root@192.168.1.16(192.168.1.16:)..

Sat Feb  ::  - [debug]   ok.

Sat Feb  ::  - [debug]

Sat Feb  ::  - [debug]  Connecting via SSH from root@192.168.1.16(192.168.1.16:) to root@192.168.1.135(192.168.1.135:)..

Sat Feb  ::  - [debug]   ok.

Sat Feb  ::  - [info] All SSH connection tests passed successfully.

[root@mysql2 opt]#

[root@mysql2 opt]#

[root@mysql2 opt]# masterha_check_repl --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf

Sat Feb  ::  - [info] Reading default configuration from /etc/masterha/masterha_default.conf..

Sat Feb  ::  - [info] Reading application default configuration from /etc/masterha/app1.conf..

Sat Feb  ::  - [info] Reading server configuration from /etc/masterha/app1.conf..

Sat Feb  ::  - [info] MHA::MasterMonitor version 0.56.

Sat Feb  ::  - [info] GTID failover mode =

Sat Feb  ::  - [info] Dead Servers:

Sat Feb  ::  - [info] Alive Servers:

Sat Feb  ::  - [info]   192.168.1.16(192.168.1.16:)

Sat Feb  ::  - [info]   192.168.1.135(192.168.1.135:)

Sat Feb  ::  - [info] Alive Slaves:

Sat Feb  ::  - [info]   192.168.1.16(192.168.1.16:)  Version=5.7.-log (oldest major version between slaves) log-bin:enabled

Sat Feb  ::  - [info]     GTID ON

Sat Feb  ::  - [info]     Replicating from 192.168.1.135(192.168.1.135:)

Sat Feb  ::  - [info]     Primary candidate for the new Master (candidate_master is set)

Sat Feb  ::  - [info] Current Alive Master: 192.168.1.135(192.168.1.135:)

Sat Feb  ::  - [info] Checking slave configurations..

Sat Feb  ::  - [info]  read_only= is not set on slave 192.168.1.16(192.168.1.16:).

Sat Feb  ::  - [info] Checking replication filtering settings..

Sat Feb  ::  - [info]  binlog_do_db= , binlog_ignore_db=

Sat Feb  ::  - [info]  Replication filtering check ok.

Sat Feb  ::  - [info] GTID (with auto-pos) is supported. Skipping all SSH and Node package checking.

Sat Feb  ::  - [info] Checking SSH publickey authentication settings on the current master..

Sat Feb  ::  - [info] HealthCheck: SSH to 192.168.1.135 is reachable.

Sat Feb  ::  - [info]

192.168.1.135(192.168.1.135:) (current master)

 +--192.168.1.16(192.168.1.16:)

Sat Feb  ::  - [info] Checking replication health on 192.168.1.16..

Sat Feb  ::  - [info]  ok.

Sat Feb  ::  - [info] Checking master_ip_failover_script status:

Sat Feb  ::  - [info]   /etc/masterha/master_ip_failover --command=status --ssh_user=root --orig_master_host=192.168.1.135 --orig_master_ip=192.168.1.135 --orig_master_port=

Sat Feb  ::  - [info]  OK.

Sat Feb  ::  - [warning] shutdown_script is not defined.

Sat Feb  ::  - [info] Got exit code  (Not master dead).

MySQL Replication Health is OK.

10.设置从库上的 relay_log_purge=0 以及 read_only=1 (只读)

'set global relay_log_purge=0'

'set global read_only=1'

应用差异的中继日志到其他从库的时候也许会用到 ,但是我们这里一主一从其实不必配置,如果设置了 relay_log_purge=0 的话,又怕从库的relay log产生过多,这时候我们可以使用purge_relay_logs 命令定时删除,这个是MHA自带的

可以写成一个脚本定时删除如下:

#!/bin/bash

user=zhuch

passwd=zhuch

port=

log_dir='/etc/masterha/log'

work_dir='/etc/masterha/relay_log_node'

purge='/usr/bin/purge_relay_logs'

if [ ! -d $log_dir ]

then

    mkdir $log_dir -p

fi

if [ ! -d $work_dir ]

then

    mkdir $work_dir -p

fi

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

基本上MHA 就已经搭建完了 ,主库挂掉后会切换到从库并且vip 也会漂移到从库

二安装配置proxysql

1.安装

下载地址 https://www.percona.com/downloads/proxysql/

rpm -ivh proxysql-1.4.--centos67.x86_64.rpm

2.配置登入proxysql 把MySQL主从信息添加进去,将主库master放入写节点中,也加就是hostgroup_id 为100中,slave节点做读放到1000中

mysql -uadmin -padmin -P6032 -h127.0.0.1

但是注意:这里我直接将写节点的设置为 VIP 192.168.1.101

insert into mysql_servers(hostgroup_id,hostname,port,weight,max_connections,max_replication_lag,comment) values(,'192.168.1.101',,,,,'vip');

insert into mysql_servers(hostgroup_id,hostname,port,weight,max_connections,max_replication_lag,comment) values(1000,'192.168.1.16',3306,1,1000,10,'slave'

admin@ 23:16:  [(none)]> select * from mysql_servers;

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------------+

| hostgroup_id | hostname      | port | status | weight | compression | max_connections | max_replication_lag | use_ssl | max_latency_ms | comment       |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------------+

| 100          | 192.168.1.101 | 3306 | ONLINE | 1      | 0           | 1000            | 10                  | 0       | 0              | test proxysql |

| 1000         | 192.168.1.16  | 3306 | ONLINE | 1      | 0           | 1000            | 10                  | 0       | 0              | test proxysql |

+--------------+---------------+------+--------+--------+-------------+-----------------+---------------------+---------+----------------+---------------+

3. 配置后端使用的MySQL用户,需要先在后端MySQL(135,16) 里真实存在,一个是监控账号,一个是程序账号:

GRANT ALL PRIVILEGES ON *.* TO 'proxysql'@'192.168.1.16'  identified by 'proxysql'
GRANT ALL PRIVILEGES ON *.* TO 'sbuser'@'%' identified by 'sbuser'

在后端MySQL里添加完之后再配置proxysql: 这里需要注意,default_hostgroup需要和上面的对应

insert into mysql_users(username,password,active,default_hostgroup,transaction_persistent) values('sbuser','sbuser',1,100,1);

admin@ 23:37:  [(none)]> select * from mysql_users;

+----------+-------------------------------------------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+

| username | password                                  | active | use_ssl | default_hostgroup | default_schema | schema_locked | transaction_persistent | fast_forward | backend | frontend | max_connections |

+----------+-------------------------------------------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+

| sbuser   | sbuser　　　　　　　　　　　　　　　　　　　　　 | 1      | 0       | 100               |                | 0             | 1                      | 0            | 1       | 1        | 10000           |

+----------+-------------------------------------------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+

4.设置健康的监测账号

admin@ 23:37:  [(none)]>set mysql-monitor_username='proxysql';

admin@ 23:37:  [(none)]>set mysql-monitor_password='proxysql';

-- 应用到线上

load mysql servers to runtime;

load mysql users to runtime;

load mysql variables to runtime;

-- 持久化

save mysql servers to disk;

save mysql users to disk;

save mysql variables to disk;

要是是用明文密码设置mysql_users，在这里可以用save命令来转换成了hash值的密码：

save mysql users to mem;

admin@ 23:39:  [(none)]> select * from mysql_users;

+----------+-------------------------------------------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+

| username | password                                  | active | use_ssl | default_hostgroup | default_schema | schema_locked | transaction_persistent | fast_forward | backend | frontend | max_connections |

+----------+-------------------------------------------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+

| sbuser   | *CA96E56547F43610DDE9EB7B12B4EF4C51CDDFFC | 1      | 0       | 100               |                | 0             | 1                      | 0            | 1       | 1        | 10000           |

+----------+-------------------------------------------+--------+---------+-------------------+----------------+---------------+------------------------+--------------+---------+----------+-----------------+

5.配置路由

-- 发送到M

admin@127.0.0.1 : (none) 04:58:11>INSERT INTO mysql_query_rules(active,match_pattern,destination_hostgroup,apply) VALUES(1,'^SELECT.*FOR UPDATE$',100,1);

Query OK, 1 row affected (0.00 sec)

-- 发送到S

admin@127.0.0.1 : (none) 05:08:17>INSERT INTO mysql_query_rules(active,match_pattern,destination_hostgroup,apply) VALUES(1,'^SELECT',1000,1);

Query OK, 1 row affected (0.00 sec)

admin@127.0.0.1 : (none) 05:09:37>load mysql query rules to runtime;

Query OK, 0 rows affected (0.00 sec)

admin@127.0.0.1 : (none) 05:09:57>save mysql query rules to disk;

Query OK, 0 rows affected (0.00 sec)

6.连接数据库6033 测试读写分离

[root@mysql2 sysbench]# mysql -usbuser -psbuser -P6033 -h192.168.1.

sbuser@ 23:59:  [(none)]> show databases;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| mysql              |

| performance_schema |

| sys                |

| z1_email           |

| z1_exchange        |

| z1_relation        |

+--------------------+

7 rows in set (0.03 sec)

sbuser@ 00:02:  [(none)]>

sbuser@ 00:02:  [(none)]>

sbuser@ 00:02:  [(none)]> use z1_email;

Database changed, 2 warnings

sbuser@ 00:02:  [z1_email]>

sbuser@ 00:02:  [z1_email]> insert into a1 values(134);

Query OK, 1 row affected (0.01 sec)

sbuser@ 00:03:  [z1_email]> insert into a1 values(146);

Query OK, 1 row affected (0.01 sec)

sbuser@ 00:03:  [z1_email]> insert into a1 values(157);

Query OK, 1 row affected (0.02 sec)

sbuser@ 00:03:  [z1_email]>

sbuser@ 00:03:  [z1_email]> selet * from a1;

ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'selet * from a1' at line 1

sbuser@ 00:03:  [z1_email]>

sbuser@ 00:03:  [z1_email]>

sbuser@ 00:03:  [z1_email]>

sbuser@ 00:03:  [z1_email]>

sbuser@ 00:03:  [z1_email]> select * from a1;

+------+

| id   |

+------+

|    1 |

|    2 |

|   12 |

|   13 |

|   14 |

|  111 |

|  222 |

|  333 |

|  250 |

|    5 |

|    6 |

|    7 |

|    8 |

|    9 |

|   10 |

|   11 |

|   12 |

|   13 |

|   14 |

|   15 |

|   15 |

|   15 |

|   16 |

|  123 |

|  124 |

|   17 |

| 1000 |

| 1001 |

| 1002 |

| 1003 |

| 1003 |

| 1004 |

| 1004 |

|  134 |

|  146 |

|  157 |

+------+

36 rows in set (0.00 sec)

进入管理账户6032端口查看,可以看到的确有读写分离已经完成了

admin@ 00:10:  [(none)]> select * from stats_mysql_query_digest;

+-----------+--------------------+----------+--------------------+--------------------------+------------+------------+------------+----------+----------+----------+

| hostgroup | schemaname         | username | digest             | digest_text              | count_star | first_seen | last_seen  | sum_time | min_time | max_time |

+-----------+--------------------+----------+--------------------+--------------------------+------------+------------+------------+----------+----------+----------+

| 1000      | z1_email           | sbuser   | 0xB17CC7AAA7E39A4A | select * from a1         | 1          | 1518278606 | 1518278606 | 2123     | 2123     | 2123     |

| 100       | z1_email           | sbuser   | 0x496C8B86BBC0D398 | insert into a1 values(?) | 3          | 1518278580 | 1518278588 | 30478    | 6373     | 16671    |

| 1000      | information_schema | sbuser   | 0x620B328FE9D6D71A | SELECT DATABASE()        | 1          | 1518278568 | 1518278568 | 508      | 508      | 508      |

| 100       | information_schema | sbuser   | 0x02033E45904D3DF0 | show databases           | 1          | 1518278563 | 1518278563 | 30233    | 30233    | 30233    |

+-----------+--------------------+----------+--------------------+--------------------------+------------+------------+------------+----------+----------+----------+

4 rows in set (0.00 sec)

三测试

1. 模拟主库宕机的情况

分析:主库挂掉后proxysql的写入情况

主库故障,使用MHA 手动failover 将 vip 切换到从库 192.168.1.16上 ,此时 192.168.1.16 上的 vip是192.168.1.101

admin@ 00:17:  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+--------+--------+

| hostgroup_id | hostname      | port | status | weight |

+--------------+---------------+------+--------+--------+

| 100          | 192.168.1.101 | 3306 | ONLINE | 1      |

| 1000         | 192.168.1.16  | 3306 | ONLINE | 1      |

+--------------+---------------+------+--------+--------+

2 rows in set (0.00 sec)

从上面可以看出来 mysql_servers 中的 hostname 的写是192.168.1.101 读是192.168.1.16,这样一来是不是主库挂了后手动切换后就可以直接写了呢? 测试一下

在主节点上模拟主库挂掉的情况
[root@mysql3 masterha]# ps -ef |grep mysql

mysql         Feb10 pts/    :: mysqld --defaults-file=/etc/my.cnf

root          : pts/    :: grep mysql

[root@mysql3 masterha]#

[root@mysql3 masterha]#

[root@mysql3 masterha]# kill -

然后去6033 程序端口查看是否可以写发现报错了,超时

sbuser@ ::  [z1_email]> insert into a1 values();

ERROR  (HY000): Max connect timeout reached while reaching hostgroup  after 10001ms

然后去6033 程序端口查看是否可以读发现也报错了,超时 (这里很奇怪按理说可以读才对)

sbuser@ ::  [z1_email]> select * from a1;

ERROR  (HY000): Max connect timeout reached while reaching hostgroup  after 10000ms

现在进行手动切换

masterha_master_switch --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf --dead_master_host=192.168.1.135 --master_state=dead --new_master_host=192.168.1.16 --ignore_last_failover

现在已经切换完毕了并且vip已经切换到了 192.168.1.16上

[root@mysql2 masterha]# ip addr show

: lo: <LOOPBACK,UP,LOWER_UP> mtu  qdisc noqueue state UNKNOWN

    link/loopback ::::: brd :::::

    inet 127.0.0.1/ scope host lo

    inet6 ::/ scope host

       valid_lft forever preferred_lft forever

: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc pfifo_fast state UNKNOWN qlen

    link/ether :0c:::bf:e3 brd ff:ff:ff:ff:ff:ff

    inet 192.168.1.16/ brd 192.168.1.255 scope global eth0

    inet 192.168.1.101/ scope global secondary eth0

    inet6 fe80::20c:29ff:fe92:bfe3/ scope link

       valid_lft forever preferred_lft forever

这时候再去程序端口 6033 进行插入和读取的操作,发现可以进行读写了

sbuser@ 19:08:  [z1_email]> select * from a1;

+------+

| id   |

+------+

|    1 |

|    2 |

|   12 |

|   13 |

|   14 |

|  111 |

|  222 |

|  333 |

|  250 |

|    5 |

|    6 |

|    7 |

|    8 |

|    9 |

|   10 |

|   11 |

|   12 |

|   13 |

|   14 |

|   15 |

|   15 |

|   15 |

|   16 |

|  123 |

|  124 |

|   17 |

| 1000 |

| 1001 |

| 1002 |

| 1003 |

| 1003 |

| 1004 |

| 1004 |

|  134 |

|  146 |

|  157 |

+------+

36 rows in set (0.00 sec)

sbuser@ 19:08:  [z1_email]>

sbuser@ 19:08:  [z1_email]> insert into a1 values(1590);

Query OK, 1 row affected (0.00 sec)

此时主库恢复后 change 到新的主库

root@ 19:21:  [(none)]> change master to master_host='192.168.1.16',

    -> master_user='slave',

    -> master_password='oracle',

    -> master_auto_position=1;

查看主从同步状态是OK的

root@ 19:51:  [(none)]> show slave status\G;

*************************** 1. row ***************************

               Slave_IO_State: Waiting for master to send event

                  Master_Host: 192.168.1.16

                  Master_User: slave

                  Master_Port: 3306

                Connect_Retry: 60

              Master_Log_File: mysql-bin.000018

          Read_Master_Log_Pos: 2231

               Relay_Log_File: mysql3-relay-bin.000002

                Relay_Log_Pos: 675

        Relay_Master_Log_File: mysql-bin.000018

             Slave_IO_Running: Yes

            Slave_SQL_Running: Yes

              Replicate_Do_DB:

          Replicate_Ignore_DB:

           Replicate_Do_Table:

       Replicate_Ignore_Table:

      Replicate_Wild_Do_Table:

  Replicate_Wild_Ignore_Table:

                   Last_Errno: 0

                   Last_Error:

                 Skip_Counter: 0

          Exec_Master_Log_Pos: 2231

              Relay_Log_Space: 883

              Until_Condition: None

               Until_Log_File:

                Until_Log_Pos: 0

           Master_SSL_Allowed: No

           Master_SSL_CA_File:

           Master_SSL_CA_Path:

              Master_SSL_Cert:

            Master_SSL_Cipher:

               Master_SSL_Key:

        Seconds_Behind_Master: 0

Master_SSL_Verify_Server_Cert: No

                Last_IO_Errno: 0

                Last_IO_Error:

               Last_SQL_Errno: 0

               Last_SQL_Error:

  Replicate_Ignore_Server_Ids:

             Master_Server_Id: 330616

                  Master_UUID: 25aa2017-083b-11e8-b78a-000c2992bfe3

             Master_Info_File: mysql.slave_master_info

                    SQL_Delay: 0

          SQL_Remaining_Delay: NULL

      Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates

           Master_Retry_Count: 86400

                  Master_Bind:

      Last_IO_Error_Timestamp:

     Last_SQL_Error_Timestamp:

               Master_SSL_Crl:

           Master_SSL_Crlpath:

           Retrieved_Gtid_Set: 25aa2017-083b-11e8-b78a-000c2992bfe3:59554

            Executed_Gtid_Set: 25aa2017-083b-11e8-b78a-000c2992bfe3:1-59554,

7af79590-0840-11e8-ac17-000c29459399:1-10

                Auto_Position: 1

         Replicate_Rewrite_DB:

                 Channel_Name:

           Master_TLS_Version:

1 row in set (0.00 sec)

此时我们再去管理端口查看一下,发现其实管理端口只有192.168.1.16 和 vip 192.168.1.101 并且vip 已经漂移到了 192.168.1.16这台机器上

[root@mysql2 opt]# mysql -uadmin -padmin -P6032 -h127.0.0.

mysql: [Warning] Using a password on the command line interface can be insecure.

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is

Server version: 5.5. (ProxySQL Admin Module)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

admin@ ::  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+--------+--------+

| hostgroup_id | hostname      | port | status | weight |

+--------------+---------------+------+--------+--------+

|           | 192.168.1.101 |  | ONLINE |       |

|          | 192.168.1.16  |  | ONLINE | 1      |

+--------------+---------------+------+--------+--------+

 rows in set (0.00 sec)

然后我们加入192.168.1.135 并且我这里分配的权重是9

insert into mysql_servers(hostgroup_id,hostname,port,weight,max_connections,max_replication_lag,comment) values(1000,'192.168.1.135',3306,9,1000,10,'test proxysql');

admin@ 19:59: [(none)]> load mysql servers to runtime;
Query OK, 0 rows affected (0.01 sec)

admin@ 19:59: [(none)]> save mysql servers to disk;
Query OK, 0 rows affected (0.05 sec)

查看runtime_mysql_servers ,有十分之九的概率的读操作会分配到 192.168.1.135 十分之一的读会在 192.168.1.16 并且全部的写操作都在 192.168.1.16(因为VIP 192.168.1.101在16上)

admin@ 19:59:  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+--------+--------+

| hostgroup_id | hostname      | port | status | weight |

+--------------+---------------+------+--------+--------+

| 100          | 192.168.1.101 | 3306 | ONLINE | 1      |

| 1000         | 192.168.1.135 | 3306 | ONLINE | 9      |

| 1000         | 192.168.1.16  | 3306 | ONLINE | 1      |

+--------------+---------------+------+--------+--------+

现在主库为192.168.1.16 如果此时主库挂了怎么办? 是否还会影响在proxysql中的读写操作呢?

我们再次模拟主库挂掉的情况此时主库是 192.168.1.16

[root@mysql2 opt]# ps -ef |grep mysql

root      2976 21612  0 19:50 pts/4    00:00:00 mysql -uroot -px xxxx

root      2983  6583  0 19:53 pts/3    00:00:00 mysql -uadmin -px xxx -P6032 -h127.0.0.1

root      3369 15620  0 22:09 pts/1    00:00:00 grep mysql

mysql    28714 15620  0 Feb10 pts/1    00:01:51 mysqld --defaults-file=/etc/my.cnf

root     31851 21524  0 Feb10 pts/0    00:00:00 mysql -usbuser -px xxxx -P6033 -h192.168.1.16

[root@mysql2 opt]#

[root@mysql2 opt]#

[root@mysql2 opt]# kill -9 28714

此时再去 proxysql的程序端口6033中做读操作超时不可读

sbuser@ 20:35:  [z1_email]> select * from a1;

ERROR 9001 (HY000): Max connect timeout reached while reaching hostgroup 1000 after 10000ms

此时再去 proxysql的程序端口6033中做写操作超时不可写

sbuser@ 22:17:  [z1_email]> insert into a1 values(1591);

ERROR 9001 (HY000): Max connect timeout reached while reaching hostgroup 100 after 10001ms

这时候我们做基于MHA 的手动failover操作

masterha_master_switch --global_conf=/etc/masterha/masterha_default.conf --conf=/etc/masterha/app1.conf --dead_master_host=192.168.1.16 --master_state=dead --new_master_host=192.168.1.135 --ignore_last_failover

此时vip 已经漂移到192.168.1.135 上了 ,并且我们进proxysql管理端口 6032 看看

admin@ 20:35:  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+---------+--------+

| hostgroup_id | hostname      | port | status  | weight |

+--------------+---------------+------+---------+--------+

| 100          | 192.168.1.101 | 3306 | SHUNNED | 1      |

| 1000         | 192.168.1.135 | 3306 | ONLINE  | 9      |

| 1000         | 192.168.1.16  | 3306 | SHUNNED | 1      |

+--------------+---------------+------+---------+--------+

我们再进入 proxysql的 6033 端口看看是否可以做读操作因为此时 192.168.1.135 的状态还是online的

sbuser@ 22:22:  [z1_email]> select * from a1;

+------+

| id   |

+------+

|    1 |

|    2 |

|   12 |

|   13 |

|   14 |

|  111 |

|  222 |

|  333 |

|  250 |

|    5 |

|    6 |

|    7 |

|    8 |

|    9 |

|   10 |

|   11 |

|   12 |

|   13 |

|   14 |

|   15 |

|   15 |

|   15 |

|   16 |

|  123 |

|  124 |

|   17 |

| 1000 |

| 1001 |

| 1002 |

| 1003 |

| 1003 |

| 1004 |

| 1004 |

|  134 |

|  146 |

|  157 |

| 1590 |

+------+

37 rows in set (0.00 sec)

可见是可以读的,那么我们vip 已经漂移到了192.168.1.135上了啊是否可以写呢?

sbuser@ 22:23:  [z1_email]> insert into a1 values(1591);

Query OK, 1 row affected (0.14 sec)

发现可以写的,我们再回到管理端口6302 去看看居然发现 vip 192.168.1.101 的状态又变回了ONLINE (emmmm.....)

admin@ 22:21:  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+---------+--------+

| hostgroup_id | hostname      | port | status  | weight |

+--------------+---------------+------+---------+--------+

| 100          | 192.168.1.101 | 3306 | ONLINE  | 1      |

| 1000         | 192.168.1.135 | 3306 | ONLINE  | 9      |

| 1000         | 192.168.1.16  | 3306 | SHUNNED | 1      |

+--------------+---------------+------+---------+--------+

3 rows in set (0.01 sec)

所以这里我觉得应该是proxysql 没有立刻获取 vip 已经漂移的状态,显示的是 SHUNNED ,但是并不影响使用只是显示有问题

最后我们再把 192.168.1.16 恢复起来 change 到新的master 192.168.1.135上

[root@mysql2 masterha]# mysqld --defaults-file=/etc/my.cnf &

[] 3490

[root@mysql2 masterha]# mysql -uroot -poracle

mysql: [Warning] Using a password on the command line interface can be insecure.

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 3

Server version: 5.7.17-log MySQL Community Server (GPL)

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

root@ 22:28:  [(none)]> change master to master_host='192.168.1.135',

    -> master_user='slave',

    -> master_password='oracle',

    -> master_auto_position=1;

Query OK, 0 rows affected, 2 warnings (0.07 sec)

root@ 22:35:  [(none)]> start slave;

Query OK, 0 rows affected (0.02 sec)

root@ 22:36:  [(none)]> show slave status\G;

*************************** 1. row ***************************

               Slave_IO_State: Waiting for master to send event

                  Master_Host: 192.168.1.135

                  Master_User: slave

                  Master_Port: 3306

                Connect_Retry: 60

              Master_Log_File: mysql-bin.000016

          Read_Master_Log_Pos: 743

               Relay_Log_File: mysql2-relay-bin.000002

                Relay_Log_Pos: 675

        Relay_Master_Log_File: mysql-bin.000016

             Slave_IO_Running: Yes

            Slave_SQL_Running: Yes
　　　　　　　 ........

再查看一下 proxysql的管理端口 6032,发现192.168.1.16显示状态还是

admin@ 22:24:  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+---------+--------+

| hostgroup_id | hostname      | port | status  | weight |

+--------------+---------------+------+---------+--------+

| 100          | 192.168.1.101 | 3306 | ONLINE  | 1      |

| 1000         | 192.168.1.135 | 3306 | ONLINE  | 9      |

| 1000         | 192.168.1.16  | 3306 | SHUNNED | 1      |

+--------------+---------------+------+---------+--------+

3 rows in set (0.01 sec)

我们去proxysql的程序端口6033 进行查询一次

sbuser@ 22:23:  [z1_email]> select * from a1;

+------+

| id   |

+------+

|    1 |

|    2 |

|   12 |

|   13 |

|   14 |

|  111 |

|  222 |

|  333 |

|  250 |

|    5 |

|    6 |

|    7 |

|    8 |

|    9 |

|   10 |

|   11 |

|   12 |

|   13 |

|   14 |

|   15 |

|   15 |

|   15 |

|   16 |

|  123 |

|  124 |

|   17 |

| 1000 |

| 1001 |

| 1002 |

| 1003 |

| 1003 |

| 1004 |

| 1004 |

|  134 |

|  146 |

|  157 |

| 1590 |

| 1591 |

+------+

38 rows in set (0.00 sec)

再查看一下 proxysql的管理端口 6032看看可见都显示ONLINE 了

admin@ 22:37:  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+--------+--------+

| hostgroup_id | hostname      | port | status | weight |

+--------------+---------------+------+--------+--------+

| 100          | 192.168.1.101 | 3306 | ONLINE | 1      |

| 1000         | 192.168.1.135 | 3306 | ONLINE | 9      |

| 1000         | 192.168.1.16  | 3306 | ONLINE | 1      |

+--------------+---------------+------+--------+--------+

3 rows in set (0.01 sec)

最后做一个总结:

MHA + proxysql 可以做到高可用和读写分离,在主库挂掉后切换到从库,通过主库的vip漂移的特性将proxysql中的写节点配置成vip,

并且总是主库在做写操作的,因为vip在哪台机器哪台机器就是主库。

而且如果我们做了如下结构的proxysql策略,则无论是哪台机器挂掉 ,只要进行切换就不会影响读和写

admin@ 22:37:  [(none)]> select hostgroup_id,hostname,port,status,weight from runtime_mysql_servers;

+--------------+---------------+------+--------+--------+

| hostgroup_id | hostname      | port | status | weight |

+--------------+---------------+------+--------+--------+

| 100          | 192.168.1.101 | 3306 | ONLINE | 1      |

| 1000         | 192.168.1.135 | 3306 | ONLINE | 9      |

| 1000         | 192.168.1.16  | 3306 | ONLINE | 1      |

+--------------+---------------+------+--------+--------+

3 rows in set (0.01 sec)