MHA高可用架构
- 用一个管理节点监控后端数据库主库可用性
- 提供VIP漂移接口，不提供具体方法
- 提供补全从库日志的脚本
MHA
- 监控主库，提供自动主从切换；
- 提供VIP漂移接口
- 提供补全从库日志的脚本
MHA的安装步骤
- 规划
- 配置服务器间域名和ssh互信访问
- 在manager节点安装MHA node 和manager组件及依赖包
- 在数据库服务器安装MHA node组件及依赖包
- 配置VIP管理脚本master_ip_failover和master_ip_online_change
- 配置MHA配置文件mha_manager.cnf
- 数据库配置主从，添加mha连接用户 ...etc
- 启动MHA开始监控数据库主从集群
演示
演示MHA部署-环境介绍
环境请自行提取下载
http://pan.baidu.com/s/1qXDOeba
操作步骤
操作步骤：
- .确保主从复制配置完成
- 此列中主从复制账号repl
-
- ##
-
- 虚拟ip已经，部署在主库
- 主库，为mha提供mha账户
-
-
-
-
- .确保hosts和hostname配置正确
- ##
-
- root@debtest1:~/.ssh# cat /etc/hosts
- 127.0.0.1 localhost
- 192.168.0.113 debtest1.sam.test debtest1
- 192.168.0.114 debtest2.sam.test debtest2
- 192.168.0.115 debtest3.sam.test debtest3
-
- # The following lines are desirable for IPv6 capable hosts
- :: localhost ip6-localhost ip6-loopback
- ff02:: ip6-allnodes
- ff02:: ip6-allrouters
- root@debtest1:~/.ssh# cat /etc/hostname
- debtest1
-
- ###############################################################################
-
- .使用ssh-keygen工具生成统一公私钥对,并同步到所有三台机器.测试公私钥验证访问
- ##
-
- ssh-keygen -t rsa
-
- cd ~/.ssh
- cat id_rsa.pub authorized_keys
-
-
- scp ./* root@debtest2:/root/.ssh/
- scp ./* root@debtest3:/root/.ssh/
-
-
- ssh debtest1
- ssh debtest2
- ssh debtest3
-
-
- ###############################################################################
-
- 3.规划节点用户和ip配置
- ##
-
-
- 192.168.0.113 debtest1 --> master
- 192.168.0.114 debtest2 --> mysql1(master)
- 192.168.0.115 debtest3 --> mysql2(slave)
- 192.168.0.119 vip
-
- 定好虚拟ip后别忘了在当前的主库上添加虚拟ip
- ##
- ip addr add 192.168.0.119/32 dev eth1
-
- #删除虚拟ip的命令
- ##ip addr del 192.168.0.119/32 dev eth1
-
- ###############################################################################
-
- 4.在全部节点上安装mha node包和其依赖包
- ##
-
-
- debtest1,debtest1,debtest1
-
- apt-get install libdbd-mysql-perl
-
- dpkg -i mha4mysql-node_0.53_all.deb
-
- ###############################################################################
-
- 5.仅需要在manager节点上安装mha manager包及其依赖包
- ##
-
- debtest1
-
- apt-get install libdbd-mysql-perl
- apt-get install libconfig-tiny-perl
- apt-get install liblog-dispatch-perl
- apt-get install libparallel-forkmanager-perl
-
- dpkg -i mha4mysql-manager_0.53_all.deb
-
-
- ###############################################################################
-
-
- 6.建立配置文件目录,编辑mha必要的三个文件,一个配置文件,2个虚拟ip管理脚本且内容可以一致
- ##
-
- master_ip_online_change
- master_ip_failover
- mha_manager.cnf
-
-
- ###############################################################################
-
- 7.可以尝试验证一下配置是否成功
- ##
-
- masterha_check_ssh --conf=./mha_manager.cnf
- masterha_check_repl --conf=./mha_manager.cnf
-
- ###############################################################################
-
- 8.在manager节点启动mha服务,然后观察日志,并尝试关闭当前主库,注意观察日志,主要看失效发现,日志检测,ip漂移和角色切换过程
- ##
-
- nohup /usr/bin/masterha_manager --conf=/root/mha_base/mha_manager.cnf --ignore_last_failover < /dev/null > /root/mha_base/manager.log 2>&1 &
MHA配置文件
MHA配置文件 [server default]
manager_workdir=/root/mha_base
manager_log=/root/mha_base/manager.log
remote_workdir=/root/mha_base ssh_user=root
ssh_port=
user=mha
password=mha
repl_user=repl
repl_password=repl
multi_tier_slave=
ping_interval=
ping_type=CONNECT
master_ip_failover_script=/root/mha_base/master_ip_failover
master_ip_online_change_script=/root/mha_base/master_ip_online_change
secondary_check_script=/usr/bin/masterha_secondary_check -s 192.168.0.113 -s 192.168.0.115 --user=root --port= --master_host=debtest2 --master_ip=192.168.0.114 --master_port= [server1]
candidate_master=
ignore_fail=
check_repl_delay =
hostname=debtest2
ip=192.168.0.114
port=
ssh_port=
master_binlog_dir=/var/log/mysql/ [server2]
candidate_master=
ignore_fail=
check_repl_delay =
hostname=debtest3
ip=192.168.0.115
port=
ssh_port=
master_binlog_dir=/var/log/mysql/
VIP漂移脚本
#!/usr/bin/env perl ## Note: This is a sample script and is not complete. Modify the script based on your environment. use strict;
use warnings FATAL => 'all'; use Getopt::Long;
use MHA::DBHelper; my (
$command, $ssh_user, $orig_master_host,
$orig_master_ip, $orig_master_port, $new_master_host,
$new_master_ip, $new_master_port
); my $vip = '192.168.0.119/24'; #virtual ip
my $ssh_start_vip = "ip addr add $vip dev eth1";
my $ssh_stop_vip = "ip addr del $vip dev eth1"; 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 {
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 {
print "Disabling the VIP on old master: $orig_master_host \n";
&stop_vip();
$exit_code = ;
# updating global catalog, etc };
if ($@) {
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=, etc) here.
my $exit_code = ;
eval {
print "Enabling the VIP - $vip on old master: $new_master_host \n";
&start_vip();
$exit_code = ;
};
if ($@) {
warn $@; # If you want to continue failover, exit .
exit $exit_code;
}
exit $exit_code;
}
elsif ( $command eq "status" ) { # do nothing
exit ;
}
else {
&usage();
exit ;
}
} # Enable the VIP on the new_master
sub start_vip() {
`ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
} # Disable the VIP on the old_master sub stop_vip() {
my $ssh_user = "root";
`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=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n";
}