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MHA 实现故障转移和主从切换
配置MHA
参考博客：https://www.cnblogs.com/xuanzhi201111/p/4231412.html
监控节点 搭建在 3号从服务器上
- 在所有机器都要安装MHA node所需的perl模块（DBD:mysql），可以通过yum安装，如果没epel源,先安装epel源
192.168.2.128 [root ~]$ rpm -ivh http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
Retrieving http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
warning: /var/tmp/rpm-tmp.SAbcKl: Header V3 RSA/SHA256 Signature, key ID 0608b895: NOKEY
Preparing... ########################################### [100%]
1:epel-release ########################################### [100%]
192.168.2.128 [root ~]$ yum install perl-DBD-MySQL -y
- 在所有的节点安装MHA node：（下面以server02为例，记得server03和server04也一样的操作），MHA node和MHA Manager都在要官网下载：
https://code.google.com/archive/p/mysql-master-ha/downloads
192.168.2.128 [root ~]$ tar xf mha4mysql-node-0.56.tar.gz
192.168.2.128 [root ~]$ cd mha4mysql-node-0.56
192.168.2.128 [root mha4mysql-node-0.56]$ perl Makefile.PL
Can't locate ExtUtils/MakeMaker.pm in @INC (@INC contains: inc /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at inc/Module/Install/Makefile.pm line 4.
192.168.2.128 [root mha4mysql-node-0.56]$ yum install -y perl-devel
192.168.2.128 [root mha4mysql-node-0.56]$ perl Makefile.PL
*** Module::AutoInstall version 1.03
*** Checking for Perl dependencies...
Can't locate CPAN.pm in @INC (@INC contains: inc /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at inc/Module/AutoInstall.pm line 279.
192.168.2.128 [root mha4mysql-node-0.56]$ yum install -y perl-CPAN
192.168.2.128 [root mha4mysql-node-0.56]$ perl Makefile.PL
*** Module::AutoInstall version 1.03
*** Checking for Perl dependencies...
[Core Features]
- DBI ...loaded. (1.609)
- DBD::mysql ...loaded. (4.013)
*** Module::AutoInstall configuration finished.
Checking if your kit is complete...
Looks good
Writing Makefile for mha4mysql::node
192.168.2.128 [root mha4mysql-node-0.56]$ make && make install
- master 主机上安装
安装MHA Manager。首先安装MHA Manger依赖的perl模块（我这里使用yum安装）：
mha4mysql-manager-0.54.tar.gz
- MHA-manager 配置
masterha/app1.cnf 文件
[server default]
manager_workdir=/var/log/masterha/app1
manager_log=/var/log/masterha/app1/manager.log
master_binlog_dir=/data/mysql //设置master 保存binlog的位置，以便MHA可以找到master的日志，我这里的也就是mysql的数据目录
#master_ip_failover_script= /usr/local/bin/master_ip_failover //设置自动failover时候的切换脚本
master_ip_online_change_script= /usr/local/bin/master_ip_online_change //设置手动切换时候的切换脚本
password=**** //设置mysql中root用户的密码，这个密码是前文中创建监控用户的那个密码
user=repl
#ping_interval=1 //设置监控主库，发送ping包的时间间隔，默认是3秒，尝试三次没有回应的时候自动进行railover
remote_workdir=/tmp //设置远端mysql在发生切换时binlog的保存位置
repl_password=***** //设置复制用户的密码
repl_user=***** //设置复制环境中的复制用户名
report_script=/usr/local/bin/send_report //设置发生切换后发送的报警的脚本
secondary_check_script= /usr/local/bin/masterha_secondary_check -s server03 -s server02 --user=root --master_host=server02 --master_ip=********* --master_port=3306 //一旦MHA到server02的监控之间出现问题，MHA Manager将会尝试从server03登录到server02
#shutdown_script="" //设置故障发生后关闭故障主机脚本（该脚本的主要作用是关闭主机放在发生脑裂,这里没有使用）
#ssh_user=root //设置ssh的登录用户名
[server1]
hostname=*******
port=3306
[server2]
hostname=******
port=3306
candidate_master=1
check_repl_delay=0
[server3]
hostname=******
port=3306
- 检查SSH配置(server01 192.168.2.131 Monitor 监控节点上操作)，
masterha_check_ssh --conf=/etc/masterha/app1.cnf
- 检查整个复制环境状况(server01 192.168.2.131 Monitor 监控节点上操作)，
masterha_check_repl --conf=/etc/masterha/app1.cnf
- 检查MHA Manager的状态
通过master_check_status脚本查看Manager的状态：
masterha_check_status --conf=/etc/masterha/app1.cnf
- 开启MHA Manager监控
nohup masterha_manager --conf=/etc/masterha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/masterha/app1/manager.log 2>&1 &
MHA 实现VIP切换用到脚本(实现故障转移)
参考博客：https://blog.csdn.net/lichangzai/article/details/50503960
#!/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 = '10.1.5.21/24'; # Virtual IP
my $key = "1";
my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";
my $exit_code = 0;
GetOptions(
'command=s' => \$command,
'ssh_user=s' => \$ssh_user,
'orig_master_host=s' => \$orig_master_host,
'orig_master_ip=s' => \$orig_master_ip,
'orig_master_port=i' => \$orig_master_port,
'new_master_host=s' => \$new_master_host,
'new_master_ip=s' => \$new_master_ip,
'new_master_port=i' => \$new_master_port,
);
exit &main();
sub main {
#print "\n\nIN SCRIPT TEST====$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 you manage 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();
$exit_code = 0;
};
if ($@) {
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 {
print "\n\n\n***************************************************************\n";
print "Enabling the VIP - $vip on new master: $new_master_host \n";
print "***************************************************************\n\n\n\n";
&start_vip();
$exit_code = 0;
};
if ($@) {
warn $@;
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 \"`;
exit 0;
}
else {
&usage();
exit 1;
}
}
# A simple system call that enable the VIP on the new master
sub start_vip() {
`ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
}
# A simple system call that disable the VIP on the old_master
sub stop_vip() {
`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=po
rt –new_master_host=host –new_master_ip=ip –new_master_port=port\n";
}
注意事项：(我躺过的坑)
执行 masterha_check_repl --conf=/etc/masterha/app1.cnf 这个命令报错：
- 删除app1.cnf 中同一行的注释，否则报错
- master_ip_failover 必须放到 /usr/local/bin/ 这个目录下否则报错
- 如果MHA Manager 和 MHA node 安装在同一台机器上，需要让本机也设置免密登录，否则报错
参考：
MYSQL之MHA集群