mysql中MHA如何搭建

2024-04-02 19:55

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这篇文章主要为大家展示了“mysql中MHA如何搭建”，内容简而易懂，条理清晰，希望能够帮助大家解决疑惑，下面让小编带领大家一起研究并学习一下“mysql中MHA如何搭建”这篇文章吧。

操作系统：
debian5.0.2

数据库版本：
mysql5.0.51a

结构：
manager : 192.168.1.136(M1)

master : 192.168.1.20:3306(N1)
slave1 : 192.168.1.20:3307(N2)
slave2 : 192.168.1.20:3308(N3)
slave3 : 192.168.1.20:3309(N4)

软件包准备：
mha4mysql-manager_0.55-1_all.deb(还有对应的二进制包，源码包)
mha4mysql-node_0.54-1_all.deb

准备就绪：
①安装依赖包
apt-get install libdbd-mysql-perl
apt-get install libconfig-tiny-perl
apt-get install liblog-dispatch-perl
apt-get install libparallel-forkmanager-perl
centos版(yum install perl-DBD-MySQL perl-Config-Tiny perl-Log-Dispatch perl-Parallel-ForkManager)

②安装mha manager包和node包
M1：dpkg -i mha4mysql-manager_0.55-1_all.deb
N1：dpkg -i mha4mysql-node_0.54-1_all.deb
N2：dpkg -i mha4mysql-node_0.54-1_all.deb
N3：dpkg -i mha4mysql-node_0.54-1_all.deb
N4：dpkg -i mha4mysql-node_0.54-1_all.deb

③主机信任(由于公司环境的原因，这里使用的是mysql用户)
M1:
#su mysql
#ssh-keygen -t rsa
#cat ~/.ssh/id_rsa.pub
将公钥内容添加到N1,N2,N3,N4的对应用户(这里是mysql用户)下的./ssh/authorized_keys下即可实现M1到N1,N2,N3,N4的免密登录。
另外，这里踩了个坑，就是免密登录的server端(N1,N2,N3,N4)即/etc/ssh/sshd_config文件必须开启公钥登录
mysql中MHA如何搭建
免密登录的client端(M1)即/etc/ssh/ssh_config文件不能关闭公钥登录(这个参数设置之后在公司环境下貌似还是不能免密登录，最后用了默认配置就可以了)

N1,N2,N3,N4节点之间也互相信任

2016-12-4 22:44:12 ADD
ssh客户端得注释以下参数才能免密登录
PreferredAuthentications password

③新建mysql mha管理账户，mysql repl复制用户
mysql中MHA如何搭建

④新建mha工作目录
M1 ：mkdir -p /opt/mha_manager/log chown -R mysql /opt/mha_manager
N1~N4：mkdir -p /opt/mha_node chown -R mysql /opt/mha_node

⑤配置manager
M1:
#mkdir -p /etc/mha
#cat /etc/mha/app1.conf

manager_workdir=/opt/mha_manager_work
manager_log=/opt/mha_manager_work/log/app1.log
remote_workdir=/opt/mha_node
对以上的配置文件更改属主为ssh信任账户(这里是mysql)

另外(源码安装的mysql注意)：

mha远程登录操作mysql的时候默认用不到/usr/local/mysql/bin下面的mysql 以及 mysqlbinlog会报相应的错误信息，

这个时候我们需要做如下操作

#ln -s /usr/local/mysql/bin/mysqlbinlog /usr/bin/mysqlbinlog

#ln -s /usr/local/mysql/bin/mysql /usr/bin/mysql

④开启manager

这里要注意的是，不要后台启动，即不要以 masterha_manager --conf=/etc/mha/app1.conf & 形式启动，不然会报错退出。我们前台启动，然后ctrl+z , bg放入后台。

至此，整个搭建过程完毕。

注意事项：

①slave最好设置 read_only=1 relay_log_purge=0,利用定时任务删除relay_log;

②mha进行failover之后会在app1.log中记录相应的chang master to master_xxx等信息，因此我们可以通过这条信息手动将
所宕master
连接到新主;

③可以使用(masterha_master_switch --master_state=alive --conf=/etc/mha/app1.cnf)进行手动切换主，然后将新主手动添加作为老主的从(步骤2)，注意mha manager必须处于关闭状态(masterha_check_status --conf=xxx);

④我们可以在app1.conf配置主库宕机后vip的飘逸脚本(
master_ip_failover_script=/usr/bin/masterha_ip_failover
)，但是第一次必须得自己手动在master添加vip.

附 masterha_ip_failover脚本

点击(此处)折叠或打开

#!/usr/bin/env perl
#
# 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;
my (
$command, $ssh_user, $orig_master_host, $orig_master_ip,
$orig_master_port, $new_master_host, $new_master_ip, $new_master_port
);
my $vip = '192.168.1.111/24';
my $key = '0';
my $ssh_start_vip = "sudo /sbin/ifconfig eth2:$key $vip";
my $ssh_stop_vip = "sudo /sbin/ifconfig eth2:$key down";
#my $ssh_Bcast_arp = "/usr/bin/arping -c 3 -A 10.1.99.233"; #ARP回复模式，更新邻居。要是不加则服务器会自动等到vip缓存失效，期间VIP会有一定时间的不可用。
GetOptions(
'command=s' => \$command,
'ssh_user=s' => \$ssh_user,
'orig_master_host=s' => \$orig_master_host,
'orig_master_ip=s' => \$orig_master_ip,
'orig_master_port=i' => \$orig_master_port,
'new_master_host=s' => \$new_master_host,
'new_master_ip=s' => \$new_master_ip,
'new_master_port=i' => \$new_master_port,
);
exit &main();
sub main {
print "\n\nIN SCRIPT TEST====$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();
# &start_arp();
$exit_code = 0;
};
if ($@) {
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 -p56000 $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}
#sub start_arp() {
# `ssh $ssh_user\@$new_master_host \" $ssh_Bcast_arp \"`;
#}
sub stop_vip() {
`ssh -p56000 $ssh_user\@$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";
}