MySQL集群搭建(5)-MHA高可用架构
来源：SegmentFault
时间：2023-02-22 18:20:07 462浏览 收藏
怎么入门数据库编程？需要学习哪些知识点？这是新手们刚接触编程时常见的问题；下面golang学习网就来给大家整理分享一些知识点，希望能够给初学者一些帮助。本篇文章就来介绍《MySQL集群搭建(5)-MHA高可用架构》，涉及到MySQL、数据库、高可用、MHA、DBA，有需要的可以收藏一下
前面的文章介绍了怎么从单点开始搭建
M(RW)
|
+-------+-------+
S1(R) S2(R) S3(R)
这种复制方式非常常见，当
M(RW)----M2(R, candidate_master=1)
|
+-------+-------+
S1(R) S2(R)
双主结构也是常见的复制模式，如果当前
# 安装依赖 yum install perl perl-devel perl-DBD-MySQL # 安装 node 工具 rpm -ivh mha4mysql-node-0.56-0.el6.noarch.rpm
Manager安装
在 Manager 主机上执行
# 进入 mysql 用户 su - mysql # 生成密钥对, 执行命令，然后按回车 ssh-keygen -t rsa # 复制公钥到相应主机 ssh-copy-id mysql@10.0.0.247 ssh-copy-id mysql@10.0.0.248 ssh-copy-id mysql@10.0.0.249 ssh-copy-id mysql@10.0.1.24
3.6 配置 Manager
新建
sudo /sbin/ifconfig eth0:1 10.0.0.237 netmask 255.255.255.255
down VIP
sudo /sbin/ifconfig eth0:1 down
配置切换脚本
masterha_check_ssh 检查 MHA 的 SSH 配置状况 masterha_check_repl 检查 MySQL 复制状况 masterha_manger 启动 MHA masterha_stop 停止 MHA 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 手动故障转移 masterha_conf_host 添加或删除配置的 server 信息
Node
save_binary_logs 保存 master 的二进制日志 apply_diff_relay_logs 对比识别中继日志的差异部分 purge_relay_logs 清除中继日志(MHA中继日志需要使用这个命令清除)
命令的使用方法可以通过执行 日志中显示 可以看到 查看 注意: MHA在切换完成后会结束 Manager 进程 切换后 切换成功，查看 注意：手动切换的时候先把 MHA Manager 停了 停止 [mysql@chengqm ~]$ tail -18 /etc/masterha/manager.log
Fri Dec 21 13:56:39 2018 - [info]
10.0.0.247(10.0.0.247:3306) (current master)
+--10.0.0.248(10.0.0.248:3306)
+--10.0.0.249(10.0.0.249:3306)
Fri Dec 21 13:56:39 2018 - [info] Checking master_ip_failover_script status:
Fri Dec 21 13:56:39 2018 - [info] /etc/masterha/script/master_ip_failover --command=status --ssh_user=mysql --orig_master_host=10.0.0.247 --orig_master_ip=10.0.0.247 --orig_master_port=3306
VIP Command: start=sudo /sbin/ifconfig eth0:1 10.0.0.237 netmask 255.255.255.255 stop=sudo /sbin/ifconfig eth0:1 down
Check script.. OK
Fri Dec 21 13:56:39 2018 - [info] OK.
Fri Dec 21 13:56:39 2018 - [warning] shutdown_script is not defined.
Fri Dec 21 13:56:39 2018 - [info] Set master ping interval 1 seconds.
Fri Dec 21 13:56:39 2018 - [info] Set secondary check script: /usr/bin/masterha_secondary_check -s 10.0.0.247 -s 10.0.0.248
Fri Dec 21 13:56:39 2018 - [info] Starting ping health check on 10.0.0.247(10.0.0.247:3306)..
Fri Dec 21 13:56:39 2018 - [info] Ping(SELECT) succeeded, waiting until MySQL doesn't respond..
[mysql@cluster02 ~]$ ifconfig
eth0 Link encap:Ethernet HWaddr FA:16:3E:66:7E:E8
inet addr:10.0.0.248 Bcast:10.0.255.255 Mask:255.255.0.0
inet6 addr: fe80::f816:3eff:fe66:7ee8/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:40197173 errors:0 dropped:0 overruns:0 frame:0
TX packets:10470689 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4063358126 (3.7 GiB) TX bytes:2269241789 (2.1 GiB)
eth0:1 Link encap:Ethernet HWaddr FA:16:3E:66:7E:E8
inet addr:10.0.0.237 Bcast:10.0.0.237 Mask:255.255.255.255
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
...
2018-12-21T14:04:41.782336+08:00 5525 Query SHOW SLAVE STATUS
2018-12-21T14:04:41.788318+08:00 5525 Query STOP SLAVE IO_THREAD
2018-12-21T14:04:41.900734+08:00 5525 Query SHOW SLAVE STATUS
2018-12-21T14:04:42.044801+08:00 5525 Query SHOW SLAVE STATUS
2018-12-21T14:04:42.668581+08:00 5525 Query SHOW SLAVE STATUS
2018-12-21T14:04:42.670336+08:00 5525 Query STOP SLAVE SQL_THREAD
...
2018-12-21T14:04:42.863904+08:00 5526 Query SET GLOBAL read_only=0
...
2018-12-21T14:04:43.950986+08:00 5527 Query SET @rpl_semi_sync_slave= 1
...
2018-12-21T14:04:04.835218+08:00 90 Query STOP SLAVE IO_THREAD
2018-12-21T14:04:04.955706+08:00 90 Query SHOW SLAVE STATUS
2018-12-21T14:04:05.092123+08:00 90 Query SHOW SLAVE STATUS
2018-12-21T14:04:06.018838+08:00 90 Query SHOW SLAVE STATUS
2018-12-21T14:04:06.034225+08:00 90 Query SHOW SLAVE STATUS
2018-12-21T14:04:06.036613+08:00 90 Query SHOW SLAVE STATUS
2018-12-21T14:04:06.038475+08:00 90 Query STOP SLAVE SQL_THREAD
2018-12-21T14:04:06.160142+08:00 90 Query SHOW SLAVE STATUS
2018-12-21T14:04:06.162224+08:00 90 Query STOP SLAVE
2018-12-21T14:04:06.163171+08:00 90 Query SHOW SLAVE STATUS
2018-12-21T14:04:06.164554+08:00 90 Query RESET SLAVE
2018-12-21T14:04:06.825564+08:00 90 Query CHANGE MASTER TO MASTER_HOST = '10.0.0.248' MASTER_USER = 'repl' MASTER_PASSWORD = <secret> MASTER_PORT = 3306 MASTER_LOG_FILE = 'mysql-bin.000005' MASTER_LOG_POS = 154
2018-12-21T14:04:06.981718+08:00 90 Query SET GLOBAL relay_log_purge=0
2018-12-21T14:04:06.982802+08:00 90 Query START SLAVE</secret>
4.3 手动切换
[mysql@chengqm ~]$ masterha_master_switch --conf=/etc/masterha/app2.cnf --master_state=alive --new_master_host=10.0.0.247 --new_master_port=3306 --orig_master_is_new_slave
......
It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 10.0.0.248(10.0.0.248:3306)? (YES/no): yes
......
Sun Dec 23 16:50:48 2018 - [info]
From:
10.0.0.248(10.0.0.248:3306) (current master)
+--10.0.0.247(10.0.0.247:3306)
+--10.0.0.249(10.0.0.249:3306)
To:
10.0.0.247(10.0.0.247:3306) (new master)
+--10.0.0.249(10.0.0.249:3306)
+--10.0.0.248(10.0.0.248:3306)
Starting master switch from 10.0.0.248(10.0.0.248:3306) to 10.0.0.247(10.0.0.247:3306)? (yes/NO): yes
......
Sun Dec 23 16:51:36 2018 - [info] 10.0.0.247: Resetting slave info succeeded.
Sun Dec 23 16:51:36 2018 - [info] Switching master to 10.0.0.247(10.0.0.247:3306) completed successfully.
[mysql@cluster01 ~]$ ifconfig
eth0 Link encap:Ethernet HWaddr FA:16:3E:DE:80:33
inet addr:10.0.0.247 Bcast:10.0.255.255 Mask:255.255.0.0
inet6 addr: fe80::f816:3eff:fede:8033/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:20585872 errors:0 dropped:0 overruns:0 frame:0
TX packets:5519122 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1785787985 (1.6 GiB) TX bytes:1068115408 (1018.6 MiB)
eth0:1 Link encap:Ethernet HWaddr FA:16:3E:DE:80:33
inet addr:10.0.0.237 Bcast:10.0.0.237 Mask:255.255.255.255
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
4.4 停止 MHA
MHA
的命令如下，就不演示了
masterha_stop --conf=配置文件
5 总结
总的来说，
MHA是一套非常优秀而且使用比较广的高可用程序，它可以自动补齐日志使得一致性有保证，部署的时候不需要改变原有架构就可以使用。但是使用起来还是有一点复杂的，因为
MHA不接管
VIP，所以要自己写脚本实现，而且只保证
Master高可用，没有
Slave高可用，还有就是中继日志要自己设定时任务来清理。
不管怎么说，在没有更好的方案下，
MHA还是值得使用的。
附
master_ip_failover 脚本
#!/usr/bin/env perl
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 = '10.0.0.237';
my $key = '1';
my $ssh_start_vip = "sudo /sbin/ifconfig eth0:$key $vip netmask 255.255.255.255";
my $ssh_stop_vip = "sudo /sbin/ifconfig eth0:$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 {
print "\n\n VIP Command: start=$ssh_start_vip stop=$ssh_stop_vip\n\n";
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 {
print "Disabling the VIP on old master: $orig_master_host \n";
&stop_vip();
# updating global catalog, etc
$exit_code = 0;
};
if ($@) {
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();
$new_master_handler->disconnect();
print "Enabling the VIP - $vip on the new master - $new_master_host \n";
&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" ) {
print "Check script.. OK \n";
# 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";
}
master_ip_online_change 脚本
#!/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
);
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,
);
my $vip = '10.0.0.237';
my $key = '1';
my $ssh_start_vip = "sudo /sbin/ifconfig eth0:$key $vip netmask 255.255.255.255";
my $ssh_stop_vip = "sudo /sbin/ifconfig eth0:$key down";
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 = 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 );
$orig_master_handler->disable_log_bin_local();
## 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 ( $#threads new( [$_] )->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 ( $#threads new( [$_] )->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();
print "Disabling the VIP on old master: $orig_master_host \n";
&stop_vip();
## After finishing the script, MHA executes FLUSH TABLES WITH READ LOCK
$exit_code = 0;
};
if ($@) {
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();
$new_master_handler->enable_log_bin_local();
$new_master_handler->disconnect();
print "Enabling the VIP - $vip on the new master - $new_master_host \n";
&start_vip();
## Update master ip on the catalog database, etc
$exit_code = 0;
};
if ($@) {
warn "Got Error: $@\n";
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "status" ) {
# do nothing
exit 0;
}
else {
&usage();
exit 1;
}
}
sub start_vip() {
return 0 unless ($new_master_ssh_user);
`ssh $new_master_ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}
sub stop_vip() {
return 0 unless ($orig_master_ssh_user);
`ssh $orig_master_ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;
}
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;
}
send_report 脚本
#!/usr/bin/perl
use strict;
use warnings FATAL => 'all';
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, $title, $content);
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,
);
# 调用外部脚本
$title="[mha switch]";
$content="`date +'%Y-%m-%d %H:%M'` old_master=".$dead_master_host." new_master=".$new_master_host;
system("sh /etc/masterha/script/send_report.sh $title $content");
exit 0;
清理中继日志定时任务
下面是我的定时任务，参数自行替换,
workdir需要和中继日志在同一个盘
# 每小时清理一次 0 * * * * (/usr/bin/purge_relay_logs --user=mha_manager --password=mha_manager --disable_relay_log_purge --port=3306 --workdir=/tmp/relaylogtmp >> /var/log/purge_relay_logs.log 2>&1)
MHA Wiki: https://github.com/yoshinorim...
文中关于mysql的知识介绍，希望对你的学习有所帮助！若是受益匪浅，那就动动鼠标收藏这篇《MySQL集群搭建(5)-MHA高可用架构》文章吧，也可关注golang学习网公众号了解相关技术文章。
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