MySQL高可用MHA
准备： 在主从复制的基础上面去做一主两从的GTID复制
server1：172.25.40.1（master，mha）
server2：172.25.40.2（slave）
server3：172.25.40.3（slave）
MHA所需安装包：
mha4mysql-manager-0.56-0.el6.noarch.rpm
mha4mysql-node-0.56-0.el6.noarch.rpm
perl-Config-Tiny-2.12-7.1.el6.noarch.rpm
perl-Email-Date-Format-1.002-5.el6.noarch.rpm
perl-Log-Dispatch-2.27-1.el6.noarch.rpm
perl-Mail-Sender-0.8.16-3.el6.noarch.rpm
perl-Mail-Sendmail-0.79-12.el6.noarch.rpm
perl-MIME-Lite-3.027-2.el6.noarch.rpm
perl-MIME-Types-1.28-2.el6.noarch.rpm
perl-Parallel-ForkManager-0.7.9-1.el6.noarch.rpm【server2】【server3】下载安装包
yum install -y mha4mysql-node-0.56-0.el6.noarch.rpm 【server1】
[root@server1 ~]# ssh-keygen ##mha分发公钥和密钥进行免密连接
Enter file in which to save the key (/root/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
[root@server1 ~]# ssh-copy-id 172.25.40.1
[root@server1 ~]# scp -r .ssh/ server2:
[root@server1 ~]# scp -r .ssh/ server3:
[root@server1 ~]# mkdir -p /etc/masterha
[root@server1 ~]# cd /etc/masterha/
[root@server1 masterha]# vim app1.cnf
[server default]
manager_workdir=/etc/masterha //设置manager的工作目录
manager_log=/etc/masterha/app1.log //设置manager的日志
master_binlog_dir=/var/lib/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=Westos.123 //登陆mysql的密码
user=root //设置监控用户root
ping_interval=1 //设置监控主库，发送ping包的时间间隔
remote_workdir=/tmp //设置远端mysql在发生切换时binlog的保存位置
repl_password=Westos.123 //设置复制（slave）用户的密码
repl_user=linux //设置复制环境中的复制用户名
#report_script=/usr/local/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
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=172.25.40.1
port=3306
[server2]
hostname=172.25.40.2
port=3306
candidate_master=1 //设置为候选master，如果设置该参数以后，发生主从切换以后将>会将此从库提升为主库，即使这个主库不是集群中事件最新的slave
check_repl_delay=0 //默认情况下如果一个slave落后master 100M的relay logs的话，MHA将不会选择该slave作为一个新的master，因为对于这个slave的恢复需要花费很长时间，通过设置check_repl_delay=0,MHA触发切换在选择一个新的master的时候将会忽略复制延时，这个参数对于设置了candidate_master=1的主机非常有用，因为这个候选主在切换的过程中一定是新的master
[server3]
hostname=172.25.40.3
port=3306
[root@server1 ~]# masterha_check_ssh --conf=/etc/masterha/app1.cnf #检查MHA Manger到所有MHA Node的SSH连接状态
[root@server1 ~]# mysql -p
mysql> grant all on *.* to root@'172.25.40.%' identified by 'Westos.123'; #在master主机授权root
[root@server1 ~]# masterha_check_repl --conf=/etc/masterha/app1.cnf #查看整个集群的状态
如果出现NOT OK！
报错为：read_only=1
解决：在server2和server3上
mysql> set GLOBAL read_only=1;
手动切换
将server1的master手动切换到server2上
[root@server1 ~]# masterha_master_switch --conf=/etc/masterha/app1.cnf --master_state=alive --new_master_host=172.25.40.2 --new_master_port=3306 --orig_master_is_new_slave
[root@server1 ~]# mysql -p
mysql> show slave status\G;
测试：
【server2】创建数据库表
mysql> create database westos;
mysql> use westos;
mysql> create table userlist(
-> username varchar(15) not null,
-> password varchar(25) not null);
mysql> insert into userlist values ('user1','123');
mysql> insert into userlist values ('user2','123');
mysql> select * from userlist;
【server3】
[root@server3 ~]# mysql -p
mysql> show slave status\G;
mysql> show databases;
mysql> use westos;
mysql> select * from userlist;
可以看到在server2上建立的用户信息也可以同步到server3上。
在每次切换master前在slave主机上执行下面操作：
mysql> set global read_only=1;自动切换
【server1】 slave：
[root@server1 ~]# nohup masterha_manager --conf=/etc/masterha/app1.cnf --ignore_last_failover & #进程打入后台【server2】将master杀死，自动切换到server1，将server1设为master：
[root@server2 ~]# ps ax #可以看到进程
3570 pts/0 S 0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/va
3863 pts/0 Sl 0:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-
[root@server2 ~]# kill -9 3570
[root@server2 ~]# kill -9 3863【server1】现在已经成为master：
[root@server1 ~]# mysql -p
mysql> grant replication slave on *.* to linux@'172.25.40.%' identified by 'Westos.123'; #授权
mysql> show master status;
mysql> use westos;
mysql> insert into westos.userlist values ('user3','333');
mysql> insert into westos.userlist values ('user4','444');
【server3】查看信息：
[root@server2 ~]# mysql -p
mysql> stop slave;
mysql> reset slave;
mysql> reset master;
mysql> start slave;
mysql> show slave status\G;
mysql> use westos;
mysql> select * from userlist;
【server2】查看信息：
[root@server2 ~]# mysql -p
mysql> change master to master_host='172.25.40.1', master_user='linux', master_password='Westos.123', master_auto_position=1; #连接master
mysql> start slave;
mysql> show slave status\G;
mysql> use westos;
mysql> select * from userlist;
[root@server1 ~]# vim /etc/masterha/app1.cnf
5 master_ip_failover_script= /usr/local/bin/master_ip_failover
6 master_ip_online_change_script= /usr/local/bin/master_ip_online_change[root@server1 ~]# vim master_ip_failover
1 #!/usr/bin/env perl
2 use strict;
3 use warnings FATAL => 'all';
4 use Getopt::Long;
5
6 my (
7 $command, $ssh_user, $orig_master_host, $orig_master_ip,
8 $orig_master_port, $new_master_host, $new_master_ip, $new_master_port
9 );
10
11 my $vip = '172.25.40.100/24';
12 my $ssh_start_vip = "/sbin/ip addr add $vip dev eth0";
13 my $ssh_stop_vip = "/sbin/ip addr del $vip dev eth0";
14
15
16 GetOptions(
17 'command=s' => \$command,
18 'ssh_user=s' => \$ssh_user,
19 'orig_master_host=s' => \$orig_master_host,
20 'orig_master_ip=s' => \$orig_master_ip,
21 'orig_master_port=i' => \$orig_master_port,
22 'new_master_host=s' => \$new_master_host,
23 'new_master_ip=s' => \$new_master_ip,
24 'new_master_port=i' => \$new_master_port,
25 );
26
27 exit &main();
28
29 sub main {
30
31 print "\n\nIN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===\n\n";
32
33 if ( $command eq "stop" || $command eq "stopssh" ) {
34
35 my $exit_code = 1;
36 eval {
37 print "Disabling the VIP on old master: $orig_master_host \n";
38 &stop_vip();
39 $exit_code = 0;
40 };
41 if ($@) {
42 warn "Got Error: $@\n";
43 exit $exit_code;
44 }
45 exit $exit_code;
46 }
47 elsif ( $command eq "start" ) {
48
49 my $exit_code = 10;
50 eval {
51 print "Enabling the VIP - $vip on the new master - $new_master_host \n";
52 &start_vip();
53 $exit_code = 0;
54 };
55 if ($@) {
56 warn $@;
57 exit $exit_code;
58 }
59 exit $exit_code;
60 }
61 elsif ( $command eq "status" ) {
62 print "Checking the Status of the script.. OK \n";
63 exit 0;
64 }
65 else {
66 &usage();
67 exit 1;
68 }
69 }
70
71 sub start_vip() {
72 `ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;
73 }
74 sub stop_vip() {
75 return 0 unless ($ssh_user);
76 `ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;
77 }
78
79 sub usage {
80 print
81 "Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --ori g_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_po rt=port\n";
82 }[root@server1 ~]# vim master_ip_online_change
1 #!/usr/bin/env perl
2 use strict;
3 use warnings FATAL =>'all';
4
5 use Getopt::Long;
6
7 my $vip = '172.25.40.100/24';
8 my $ssh_start_vip = "/sbin/ip addr add $vip dev eth0";
9 my $ssh_stop_vip = "/sbin/ip addr del $vip dev eth0";
10 my $exit_code = 0;
11
12 my (
13 $command, $orig_master_is_new_slave, $orig_master_host,
14 $orig_master_ip, $orig_master_port, $orig_master_user,
15 $orig_master_password, $orig_master_ssh_user, $new_master_host,
16 $new_master_ip, $new_master_port, $new_master_user,
17 $new_master_password, $new_master_ssh_user,
18 );
19 GetOptions(
20 'command=s' => \$command,
21 'orig_master_is_new_slave' => \$orig_master_is_new_slave,
22 'orig_master_host=s' => \$orig_master_host,
23 'orig_master_ip=s' => \$orig_master_ip,
24 'orig_master_port=i' => \$orig_master_port,
25 'orig_master_user=s' => \$orig_master_user,
26 'orig_master_password=s' => \$orig_master_password,
27 'orig_master_ssh_user=s' => \$orig_master_ssh_user,
28 'new_master_host=s' => \$new_master_host,
29 'new_master_ip=s' => \$new_master_ip,
30 'new_master_port=i' => \$new_master_port,
31 'new_master_user=s' => \$new_master_user,
32 'new_master_password=s' => \$new_master_password,
33 'new_master_ssh_user=s' => \$new_master_ssh_user,
34 );
35
36
37 exit &main();
38
39 sub main {
40
41 #print "\n\nIN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===\n\n";
42
43 if ( $command eq "stop" || $command eq "stopssh" ) {
44
45 # $orig_master_host, $orig_master_ip, $orig_master_port are passed.
46 # If you manage master ip address at global catalog database,
47 # invalidate orig_master_ip here.
48 my $exit_code = 1;
49 eval {
50 print "\n\n\n***************************************************************\n";
51 print "Disabling the VIP - $vip on old master: $orig_master_host\n";
52 print "***************************************************************\n\n\n\n";
53 &stop_vip();
54 $exit_code = 0;
55 };
56 if ($@) {
57 warn "Got Error: $@\n";
58 exit $exit_code;
59 }
60 exit $exit_code;
61 }
62 elsif ( $command eq "start" ) {
63
64 # all arguments are passed.
65 # If you manage master ip address at global catalog database,
66 # activate new_master_ip here.
67 # You can also grant write access (create user, set read_only=0, etc) here.
68 my $exit_code = 10;
69 eval {
70 print "\n\n\n***************************************************************\n";
71 print "Enabling the VIP - $vip on new master: $new_master_host \n";
72 print "***************************************************************\n\n\n\n";
73 &start_vip();
74 $exit_code = 0;
75 };
76 if ($@) {
77 warn $@;
78 exit $exit_code;
79 }
80 exit $exit_code;
81 }
82 elsif ( $command eq "status" ) {
83 print "Checking the Status of the script.. OK \n";
84 `ssh $orig_master_ssh_user\@$orig_master_host \" $ssh_start_vip \"`;
85 exit 0;
86 }
87 else {
88 &usage();
89 exit 1;
90 }
91 }
92
93 # A simple system call that enable the VIP on the new master
94 sub start_vip() {
95 `ssh $new_master_ssh_user\@$new_master_host \" $ssh_start_vip \"`;
96 }
97 # A simple system call that disable the VIP on the old_master
98 sub stop_vip() {
99 `ssh $orig_master_ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;
100 }
101
102 sub usage {
103 print
104 "Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --orig_ma ster_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=p ort\n";
105 }【server1】此时为master主机：
[root@server1 ~]# ip addr add 172.25.40.100/24 dev eth0 #加入vip
[root@server1 ~]# mv master_ip_* /usr/local/bin
[root@server1 ~]# cd /usr/local/bin
[root@server1 bin]# chmod +x *
[root@server1 ~]# nohup masterha_manager --conf=/etc/masterha/app1.cnf --ignore_last_failover & #将进程打入后台连接vip服务端，进行测试
[kiosk@foundation40 ~]$ ssh root@172.25.40.100
mysql> use westos
mysql> select * from userlist;
mysql> insert into userlist values ('user5','555'); #添加信息在【server2】【server3】上查看建立的信息
mysql> use westos
mysql> select * from userlist;
【server1】结束数据库端，自动跳转其他master端
[root@server1 ~]# ps ax
3553 pts/0 S 0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/m
3846 pts/0 Sl 0:13 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/m
[root@server1 ~]# kill -9 3553
[root@server1 ~]# kill -9 3846【server2】 master切换到server2主机上
查看server1的VIP已经漂移到server2的主机上，表示master已经切换到了server2主机上
【server1】将server1主机连接到master上
[root@server1 ~]# /etc/init.d/mysqld start
[root@server1 ~]# mysql -p
mysql> change master to master_host='172.25.40.2', master_user='linux', master_password='Westos.123', master_auto_position=1;
mysql> use westos;
mysql> select * from userlist;