Mysql_MHA高可用架构搭建
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环境及兼容包
系统环境：centos6.5
Mysql： mysql-5.5.6 数据库用源码安装，这里就不介绍了
主机分配：
Master ： 192.168.0.101 node1 （主库）
Slave1 ： 192.168.0.102 node2 （备用主库）
Slave2 ： 192.168.0.103 node3 （从库+MHA控制节点）
MHA兼容包见附件
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添加免密码登录，互为认证
++++++++++以下操作在三台节点上都的执行#+++++++++++++
##添加hosts,并修改各自主机名
192.168.0.101node1
192.168.0.102node2
192.168.0.103node3
##添加秘钥
ssh-keygen -t rsa
cat/root/.ssh/id_rsa.pub >/root/.ssh/authorized_keys
##将三个节点的秘钥都添加到 authorized_keys，包括自己的秘钥
##在三个节点上依次执行下列命令用以检查 ssh
ssh node1 date
ssh node2 date
ssh node3 date
##只有互为认证登录成功才能继续后续操作
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安装MHA node 包
++++++++++以下操作在三台节点上都的执行#+++++++++++++
##更新yum为阿里源
mv/etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.old
wget -O/etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
yum clean all
yum makecache
yum update
##安装环境包
yum installperl-DBD-MySQL perl perl-devel cpan
rpm -ivhmha4mysql-node-0.56-0.el6.noarch.rpm
##mha node 安装完成后会在/usr/bin 下面生成以下四个脚本：（这些工具通常由mha manger的脚本触发，无需人工操作）
/usr/bin/save_binary_logs ##保存和复制master的二进制日志
/usr/bin/apply_diff_relay_logs ##识别差异的中继日志事件并将其差异的事件应用于其他slave
/usr/bin/filter_mysqlbinlog ##去除不必要的ROLLBACK事件（MHA已经不再使用这个工具）
/usr/bin/purge_relay_logs ##清除中继日志（不会阻塞SQL线程）
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安装MHA manager节点包
[node3]#tar xf mha.tar.gz
[node3]# cd mha
##登陆node3尝试安装mha4mysql-manager-0.56-0.el6.noarch，果然报错缺少perl模块的包
##按安装顺序整理如下：
compat-db43-4.3.29-15.el6
perl-Mail-Sender-0.8.16-3.el6
perl-Mail-Sendmail-0.79-12.el6
perl-Config-Tiny-2.12-7.1.el6
perl-Parallel-ForkManager-0.7.9-1.el6
perl-Log-Dispatch-2.27-1.el6
#在安装perl-Log-Dispatch-2.27-1.el6包时还会遇到有模块的包需要安装，按安装顺序整理如下：
perl-TimeDate-1.16-11.1.el6
perl-MIME-Types-1.28-2.el6
perl-MailTools-2.04-4.el6
perl-Email-Date-Format-1.002-5.el6
perl-Params-Validate-0.92-3.el6
perl-MIME-Lite-3.027-2.el6
之后便可以正常安装mha4mysql-manager-0.56-0.el6.noarch
rpm -ivh mha4mysql-manager-0.56-0.el6.noarch.rpm
##mha manager 安装完成后会在/usr/bin 下面生成一些脚本：
/usr/bin/masterha_check_repl ##检查mysql复制状况
/usr/bin/masterha_check_ssh ##检查MHA的ssh配置状况
/usr/bin/masterha_check_status ##检测当前MHA运行状态
/usr/bin/masterha_conf_host ##添加或删除配置的server信息
/usr/bin/masterha_manager ##启动MHA
/usr/bin/masterha_master_monitor ##监测master是否宕机
/usr/bin/masterha_master_switch ##控制故障转移（自动或手动）
/usr/bin/masterha_secondary_check ##也是监测master是否宕机的脚本
/usr/bin/masterha_stop ##关闭MHA
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修改数据库为主从
##将三个数据库文件 my.cf 中 server-id = 的值依次修改为 1、2、3
[node1]#mysql-uroot
mysql> show master status;
//查看 master_log_file和 Position 值
##在三个库中都添加repl和monitor用户
mysql> GRANT REPLICATION SLAVE ON *.* TO‘repl‘@‘192.168.0.%‘ IDENTIFIED BY ‘123456‘;
mysql> grant all privileges on *.* to‘monitor‘@‘192.168.0.%‘ identified by ‘123456‘;
mysql> flush privileges;
##在node1 上执行下列语句
mysql> install plugin rpl_semi_sync_master soname‘semisync_master.so‘;
//主库安装semisync_master插件
mysql> set global rpl_semi_sync_master_enabled=1;
mysql> set globalrpl_semi_sync_master_timeout=30000;
//表示主库在某次事务中，如果等待时间超过30000毫秒，那么则降级为普通模式，不再等待备库。如果主库再次探测到，备库恢复了，则会自动再次回到Semi-sync状态。
##node2和node3上操作：
mysql> CHANGE MASTER TO
MASTER_HOST=‘192.168.0.101‘,
MASTER_PORT=3306,
MASTER_USER=‘repl‘,
MASTER_PASSWORD=‘123456‘,
MASTER_LOG_FILE=‘mysql-bin.000004‘,
MASTER_LOG_POS=0;
//MASTER_LOG_FILE= 和 MASTER_LOG_POS= 参数的值填写刚刚showmaster status查询的值
mysql> install plugin rpl_semi_sync_slave soname‘semisync_slave.so‘;
mysql> set global rpl_semi_sync_slave_enabled=1;
mysql> flush privileges;
mysql> start slave;
####从mysql5.5之后，mysql为了保证主从库数据一致性，引进了semi-sync功能，
semi-sync意思是MASTER只需要接收到其中一台SLAVE的返回信息，就会commit；否则需等待直至切换成异步再提交。
优点：
当事务返回客户端成功后，则日志一定在至少两台主机上存在。
MySQL的Semi-sync适合小事务，且两台主机的延迟又较小，则Semi-sync可以实现在性能很小损失的情况下的零数据丢失。
缺点：
完成单个事务增加了额外的等待延迟，延迟的大小取决于网络的好坏。
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Manager节点配置
[node3]#
[node3]# mkdir -p/etc/masterha /masterha/app1 /masterha/scripts
[node3]# cd/etc/masterha/
[node3]# vimapp1.cnf
//app1.cnf 文件文末提供，在这里先把这两项参数值留空，到添加VIP 地址的时候在改成文 app1.cnf 文件中的值
master_ip_failover_script=""
master_ip_online_change_script=""
###检测配置
##检测ssh配置
[node3]# exportPERL5LIB=$PERL5LIB:/usr/lib/perl5/vendor_perl/
[node3]#masterha_check_ssh --conf=/etc/masterha/app1.cnf
##检测mysql配置
[node3]#masterha_check_repl --conf=/etc/masterha/app1.cnf
##检查MHA 的运行状态
[node3]#masterha_check_status --conf=/etc/masterha/app1.cnf
###运行MHA
[node3]# nohupmasterha_manager --conf=/etc/masterha/app1.cnf < /dev/null >/masterha/app1/manager.log 2>&1 &
[node3]# tail -f/masterha/app1/manager.log
[node3]#masterha_check_status --conf=/etc/masterha/app1.cnf
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验证
##先在master库上查看slave信息
mysql> show slave hosts;
+-----------+------+------+-----------+
| Server_id | Host | Port | Master_id |
+-----------+------+------+-----------+
| 3 | | 3306 | 1 |
| 2 | | 3306 | 1 |
+-----------+------+------+-----------+
##关闭 node1 上面的 master 库，然后在node2的slave库上查看是否切为主库
mysql> show slave hosts;
+-----------+------+------+-----------+
| Server_id | Host | Port | Master_id |
+-----------+------+------+-----------+
| 3 | | 3306 | 2 |
+-----------+------+------+-----------+
##恢复高可用架构
##failover成功之后，MHA就会停了，这时候是slave1 到slave2的主从复制，假设192.168.0.101 数据库恢复了，那我们需要恢复高可用架构，让MHA启动。
##这是时候需要做的是，启动192.168.0.101数据库，在manager上面执行以下命令，找到CHANGEMASTER 执行即可。
[node1]# grep -i"All other slaves should start replication from here"/masterha/app1/manager.log
Fri Aug 2512:11:40 2017 - [info] All other slavesshould start replication from here. Statement should
be: CHANGE MASTERTO MASTER_HOST=‘192.168.0.102‘, MASTER_PORT=3306,MASTER_LOG_FILE=‘mysql-bin.000012‘,
MASTER_LOG_POS=328, MASTER_USER=‘repl‘, MASTER_PASSWORD=‘123456‘;
//注意 MASTER_HOST= MASTER_LOG_FILE= MASTER_LOG_POS= 三个的值
[node1]# mysql-uroot
mysql> CHANGEMASTER TO MASTER_HOST=‘192.168.0.102‘, MASTER_LOG_FILE=‘mysql-bin.000012‘,MASTER_LOG_POS=328, MASTER_USER=‘repl‘, MASTER_PASSWORD=‘123456‘;
mysql> slavestart;
[node2]#mysql-uroot
mysql> showslave hosts;
+-----------+------+------+-----------+
| Server_id | Host | Port | Master_id |
+-----------+------+------+-----------+
| 3 | | 3306 | 2 |
| 1 | | 3306 | 2 |
+-----------+------+------+-----------+
###在开启MHA 服务，然后关闭node2 上面的mysql模拟宕机
[node3]# nohupmasterha_manager --conf=/etc/masterha/app1.cnf < /dev/null >/masterha/app1/manager.log 2>&1 &
##还需删除app1.failover.complete文件，否则会报错
[node3]# rm -f/masterha/app1/app1.failover.complete
[node2]# servicemysql3306 stop
[node1]# mysql-uroot
mysql> showslave hosts;
+-----------+------+------+-----------+
| Server_id | Host | Port | Master_id |
+-----------+------+------+-----------+
| 3 | | 3306 | 1 |
+-----------+------+------+-----------+
##在执行上面（恢复高可用架构） 操作，将slave1 加入到集群里来
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VIP地址漂移
####注意必须所有的主机网卡信息都为 eth0
##先在 node1 上添加虚拟地址
[node1]#/sbin/ifconfig eth0:1 192.168.0.100/24
##修改app1.cnf 配置文件中
master_ip_failover_script=/etc/masterha/master_ip_failover #master failover时执行
master_ip_online_change_script=/etc/masterha/master_ip_online_change #master switchover时执行
##编辑master_ip_failover和 master_ip_online_change文件
[node3]# cd/etc/masterha/
[node3]# vimmaster_ip_failover
[node3]# vimmaster_ip_online_change
//配置文件内容在文档末尾
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app1.cnf 配置文件
[server default]
user=monitor
password=123456
ping_interval=10
#repl_workdir=/masterha/app1
repl_user=repl
repl_password=123456
ssh_user=root
master_ip_failover_script=/etc/masterha/master_ip_failover
master_ip_online_change_script=/etc/masterha/master_ip_online_change
#report_script= /etc/masterha/send_report
shutdown_script=""
secondary_check_script=/usr/bin/masterha_secondary_check-s node2 -s node1
manager_workdir=/masterha/app1
manager_log=/masterha/app1/manager.log
#remote_workdir=/masterha/app1
[server1]
hostname=192.168.0.101
port=3306
master_binlog_dir=/data/mysql/data3306
candidate_master=1
#check_repl_delay=0
[server2]
hostname=192.168.0.102
port=3306
master_binlog_dir=/data/mysql/data3306
candidate_master=1
#check_repl_delay=0
[server3]
hostname=192.168.0.103
#port=3306
#master_binlog_dir=/data/mysql/data3306
no_master=1
#node3不参与竞选，只作从库和manager使用
read_only=1
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配置文件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 = ‘192.168.0.100/24‘;
my $key = "1";
my $ssh_start_vip = "/sbin/ifconfig eth0:$key$vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$keydown";
my $exit_code = 0;
GetOptions(
‘command=s‘ => \$command,
‘ssh_user=s‘ => \$ssh_user,
‘orig_master_host=s‘ => \$orig_master_host,
‘orig_master_ip=s‘ => \$orig_master_ip,
‘orig_master_port=i‘ => \$orig_master_port,
‘new_master_host=s‘ => \$new_master_host,
‘new_master_ip=s‘ => \$new_master_ip,
‘new_master_port=i‘ => \$new_master_port,
);
exit &main();
sub main {
#print "\n\nIN SCRIPTTEST====$ssh_stop_vip==$ssh_start_vip===\n\n";
if ( $command eq "stop" || $command eq"stopssh" ) {
#$orig_master_host, $orig_master_ip, $orig_master_port are passed.
# If youmanage master ip address at global catalog database,
#invalidate orig_master_ip here.
my$exit_code = 1;
eval {
print"\n\n\n***************************************************************\n";
print"Disabling the VIP - $vip on old master: $orig_master_host\n";
print"***************************************************************\n\n\n\n";
&stop_vip();
$exit_code = 0;
};
if ([email protected]){
warn"Got Error: [email protected]\n";
exit$exit_code;
}
exit$exit_code;
}
elsif ( $command eq "start" ) {
# allarguments are passed.
# If youmanage master ip address at global catalog database,
# activatenew_master_ip here.
# You canalso grant write access (create user, set read_only=0, etc) here.
my $exit_code = 10;
eval {
print"\n\n\n***************************************************************\n";
print"Enabling the VIP - $vip on new master: $new_master_host \n";
print"***************************************************************\n\n\n\n";
&start_vip();
$exit_code = 0;
};
if ([email protected]){
[email protected];
exit $exit_code;
}
exit$exit_code;
}
elsif ( $command eq "status" ) {
print"Checking the Status of the script.. OK \n";
`ssh$ssh_user\@$orig_master_host \" $ssh_start_vip \"`;
exit0;
}
else {
&usage();
exit1;
}
}
# A simple system call that enable the VIP on the newmaster
sub start_vip() {
`ssh $ssh_user\@$new_master_host \" $ssh_start_vip\"`;
}
# A simple system call that disable the VIP on theold_master
sub stop_vip() {
`ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip\"`;
}
sub usage {
"Usage: master_ip_failover–command=start|stop|stopssh|status –orig_master_host=host –orig_master_ip=ip–orig_master_port=po
rt –new_master_host=host –new_master_ip=ip–new_master_port=port\n";
}
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配置文件master_ip_online_change
#!/usr/bin/env perl
use strict;
use warnings FATAL =>‘all‘;
use Getopt::Long;
my $vip = ‘192.168.0.100/24‘;
my $key = "1";
my $ssh_start_vip = "/sbin/ifconfig eth0:$key$vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$keydown";
my $exit_code = 0;
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, $new_master_ssh_user,
);
GetOptions(
‘command=s‘ => \$command,
‘orig_master_is_new_slave‘ => \$orig_master_is_new_slave,
‘orig_master_host=s‘ =>\$orig_master_host,
‘orig_master_ip=s‘ =>\$orig_master_ip,
‘orig_master_port=i‘ =>\$orig_master_port,
‘orig_master_user=s‘ =>\$orig_master_user,
‘orig_master_password=s‘ =>\$orig_master_password,
‘orig_master_ssh_user=s‘ =>\$orig_master_ssh_user,
‘new_master_host=s‘ =>\$new_master_host,
‘new_master_ip=s‘ =>\$new_master_ip,
‘new_master_port=i‘ =>\$new_master_port,
‘new_master_user=s‘ =>\$new_master_user,
‘new_master_password=s‘ => \$new_master_password,
‘new_master_ssh_user=s‘ =>\$new_master_ssh_user,
);
exit &main();
sub main {
#print "\n\nIN SCRIPTTEST====$ssh_stop_vip==$ssh_start_vip===\n\n";
if ( $command eq "stop" || $command eq"stopssh" ) {
#$orig_master_host, $orig_master_ip, $orig_master_port are passed.
# If youmanage master ip address at global catalog database,
#invalidate orig_master_ip here.
my $exit_code = 1;
eval {
print"\n\n\n***************************************************************\n";
print"Disabling the VIP - $vip on old master: $orig_master_host\n";
print"***************************************************************\n\n\n\n";
&stop_vip();
$exit_code = 0;
};
if ([email protected]){
warn"Got Error: [email protected]\n";
exit$exit_code;
}
exit$exit_code;
}
elsif ( $command eq "start" ) {
# allarguments are passed.
# If youmanage master ip address at global catalog database,
# activatenew_master_ip here.
# You canalso grant write access (create user, set read_only=0, etc) here.
my $exit_code = 10;
eval {
print"\n\n\n***************************************************************\n";
print"Enabling the VIP - $vip on new master: $new_master_host \n";
print"***************************************************************\n\n\n\n";
&start_vip();
$exit_code = 0;
};
if ([email protected]){
[email protected];
exit$exit_code;
}
exit$exit_code;
}
elsif ( $command eq "status" ) {
print"Checking the Status of the script.. OK \n";
`ssh$orig_master_ssh_user\@$orig_master_host \" $ssh_start_vip \"`;
exit0;
}
else {
&usage();
exit1;
}
}
# A simple system call that enable the VIP on the newmaster
sub start_vip() {
`ssh $new_master_ssh_user\@$new_master_host \"$ssh_start_vip \"`;
}
# A simple system call that disable the VIP on theold_master
sub stop_vip() {
`ssh $orig_master_ssh_user\@$orig_master_host \"$ssh_stop_vip \"`;
}
sub usage {
"Usage: master_ip_failover–command=start|stop|stopssh|status –orig_master_host=host –orig_master_ip=ip–orig_master_port=po
rt –new_master_host=host –new_master_ip=ip–new_master_port=port\n";
}