第十四周作业

1、 MariaDB主从复制原理

答：

• 主MySQL服务器上的数据操作会被记录到二进制日志中
• 主MySQL服务器上的dump thread会将二进制日志中的数据发送给从MySQL服务器
• 从MySQL服务器通过IO thread接收主MySQL服务器的二进制日志中的数据，并将这些数据写入自己的中继日志中
• 从MySQL服务器最后使用sql thread将中继日志中的数据写入到服务器中，做到同步数据

 

2 、MariaDB一主一从架构构建

准备两台纯新的CentOS7.6服务器，其中主机称为node1的服务器地址为192.168.130.132，主机称为node2的服务器地址为192.168.130.133

答： 

主mysql服务器：node1

 

• 在配置文件中添加如下几行

 

[root@node1 ~]#vim /etc/my.cnf
[mysqld]
server-id=132
log_bin=/data/mysql_log/binlog
binlog_format=row

• 创建二进制日志所在目录，并启动服务

[root@node1 ~]#mkdir /data/mysql_log
[root@node1 ~]#chown mysql.mysql /data/mysql_log
[root@node1 ~]#systemctl restart mariadb

• 创建用于同步的用户，并查看二进制日志的位置

MariaDB [(none)]> GRANT replication slave ON *.* TO 'repluser'@'192.168.130.%' IDENTIFIED BY 'magedu';
Query OK, 0 rows affected (0.00 sec)
MariaDB [(none)]> show master logs;
+---------------+-----------+
| Log_name      | File_size |
+---------------+-----------+
| binlog.000001 |       245 |
+---------------+-----------+
1 row in set (0.00 sec)

 

从MySQL服务器：node2

• 在配置文件中添加如下一行，并启动服务

[root@node2 ~]#vim /etc/my.cnf
[mysqld]
server-id=133

[root@node2 ~]#systemctl start mariadb

• 在mysql中执行如下语句

MariaDB [(none)]> CHANGE MASTER TO
    -> MASTER_HOST='192.168.130.132',
    -> MASTER_USER='repluser',
    -> MASTER_PASSWORD='magedu',
    -> MASTER_PORT=3306,
    -> MASTER_LOG_FILE='binlog.000001',
    -> MASTER_LOG_POS=245;
Query OK, 0 rows affected (0.00 sec)

• 开启从服务器上的2个线程

MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show slave statusG
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.0.0.7
Master_User: repluser
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: binlog.000001
Read_Master_Log_Pos: 398
Relay_Log_File: mariadb-relay-bin.000002
Relay_Log_Pos: 679
Relay_Master_Log_File: binlog.000001
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB:
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 398
Relay_Log_Space: 975
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
Replicate_Ignore_Server_Ids:
Master_Server_Id: 132
1 row in set (0.00 sec)

 

测试：

• 在主MySQL服务器上导入数据库

[root@node1 ~]#mysql < hellodb_innodb.sql 

• 在从MySQL服务器上查看

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hellodb            |
| mysql              |
| performance_schema |
| test               |
+--------------------+
5 rows in set (0.00 sec)

 

3 、MariaDB级联复制

上一节中我们完成了一主一从的MariaDB的主从复制架构，但是有的时候，我们期望有一个后备的MariaDB的节点，只备份存储数据，不需要对外提供服务。为了实现该功能，我们可以在之前的一主一从架构上进行调整，即将从节点的二进制文件打开，然后给他配置一个远程同步数据用户，接着使用一台新的服务器做为从服务器的从属，同步从服务器数据，下面我们在原来的架构上添加一台新的CentOS7.6，作为节点3，IP地址为192.168.130.134

答：

 中间MySQL服务器：node2

• 在中间MySQL服务器的配置文件中开启二进制日志，并重启服务

[root@node2 ~]#vim /etc/my.cnf

[mysqld]
server-id=133
log_bin
log_slave_updates
binlog_format=row

[root@node2 ~]#systemctl restart mariadb

• 对中间MySQL服务器做完全备份，并发送给node3

[root@node2 ~]#mysqldump -uroot -A -F --single-transaction --master-data=1 > /backup/all.sql
[root@node2 ~]#scp /backup/all.sql 192.168.130.134:/backup

 

节点3：node3

• 修改刚刚收到的all.sql文件

CHANGE MASTER TO 
MASTER_HOST='10.0.0.17',
MASTER_USER='repluser',
MASTER_PASSWORD='magedu',
MASTER_PORT=3306,
MASTER_LOG_FILE='mariadb-bin.000002', MASTER_LOG_POS=245;

• 在node3配置文件中加入server-id并还原备份，由于之前已经在备份文件中指定了二进制文件的位置，所以还原后节点3自然而然就知道了以后的同步位置

[root@node3 ~]#vim /etc/my.cnf
[mysqld]
server-id=134

[root@node3 ~]#systemctl start mariadb
[root@node3 ~]#mysql < /backup/all.sql

• 开启2个线程

MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.00 sec)


#可以看到之前node1上有的数据库和表已经还原到node3上

[root@node3 ~]#mysql
Welcome to the MariaDB monitor. Commands end with ; or g.
Your MariaDB connection id is 3
Server version: 5.5.65-MariaDB MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> use hellodb
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MariaDB [hellodb]> show tables;
+-------------------+
| Tables_in_hellodb |
+-------------------+
| classes |
| coc |
| courses |
| scores |
| students |
| teachers |
| toc |
+-------------------+
7 rows in set (0.00 sec)

 

测试

• 在node1上调用过程生产testlog表

[root@node1 ~]#mysql hellodb < testlog.sql 
[root@node1 ~]#mysql hellodb
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MariaDB connection id is 9
Server version: 5.5.65-MariaDB MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB [hellodb]> call sp_testlog;

• 在node3上查看是否同步

MariaDB [hellodb]> select count(*) from testlog
    -> ;
+----------+
| count(*) |
+----------+
|   100000 |
+----------+
1 row in set (0.02 sec)

 

 4 、MariaDB半同步复制

答：

环境

• 3台centos8主机
• 主服务器：10.0.0.8
• 从服务器：10.0.0.18
• 从服务器：10.0.0.28

 主MySQL服务器

• 修改配置文件，添加如下几行

[mysqld]
server-id=8
log-bin=/data/mysql-log/bin-log
plugin-load-add=semisync_master
rpl-semi-sync-master-enabled
rpl-semi-sync-master-timeout=3000

• 创建复制数据的用户，并查看二进制日志位置

MariaDB [(none)]> GRANT REPLICATION SLAVE ON *.* TO 'rpluser'@'10.0.0.%' IDENTIFIED BY 'magedu';
Query OK, 0 rows affected (3.001 sec)

MariaDB [(none)]> show master logs;
+----------------+-----------+
| Log_name       | File_size |
+----------------+-----------+
| bin-log.000001 |       349 |
| bin-log.000002 |       524 |
+----------------+-----------+
2 rows in set (0.000 sec)

• 查看主节点的半同步状态

MariaDB [(none)]> SHOW VARIABLES LIKE '%semi%';
+---------------------------------------+--------------+
| Variable_name                         | Value        |
+---------------------------------------+--------------+
| rpl_semi_sync_master_enabled          | ON           |
| rpl_semi_sync_master_timeout          | 3000         |
| rpl_semi_sync_master_trace_level      | 32           |
| rpl_semi_sync_master_wait_no_slave    | ON           |
| rpl_semi_sync_master_wait_point       | AFTER_COMMIT |
| rpl_semi_sync_slave_delay_master      | OFF          |
| rpl_semi_sync_slave_enabled           | OFF          |
| rpl_semi_sync_slave_kill_conn_timeout | 5            |
| rpl_semi_sync_slave_trace_level       | 32           |
+---------------------------------------+--------------+
9 rows in set (0.001 sec)

MariaDB [(none)]> SHOW STATUS LIKE '%semi%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 1     |
| Rpl_semi_sync_master_get_ack               | 1     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
| Rpl_semi_sync_master_net_wait_time         | 0     |
| Rpl_semi_sync_master_net_waits             | 1     |
| Rpl_semi_sync_master_no_times              | 1     |
| Rpl_semi_sync_master_no_tx                 | 1     |
| Rpl_semi_sync_master_request_ack           | 1     |
| Rpl_semi_sync_master_status                | ON    |
| Rpl_semi_sync_master_timefunc_failures     | 0     |
| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |
| Rpl_semi_sync_master_tx_wait_time          | 0     |
| Rpl_semi_sync_master_tx_waits              | 0     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 0     |
| Rpl_semi_sync_slave_send_ack               | 0     |
| Rpl_semi_sync_slave_status                 | OFF   |
+--------------------------------------------+-------+
18 rows in set (0.001 sec)

 

所有从MySQL服务器

• 修改配置文件，添加如下几行

[mysqld]
server-id=18
plugin-load-add=semisync_slave
rpl-semi-sync-slave-enabled

• 重启服务，并添加主节点，开启从节点线程

MariaDB [(none)]> CHANGE MASTER TO
    -> MASTER_HOST='10.0.0.8',
    -> MASTER_USER='rpluser',
    -> MASTER_PASSWORD='magedu',
    -> MASTER_PORT=3306,
    -> MASTER_LOG_FILE='bin-log.000001',
    -> MASTER_LOG_POS=349;
Query OK, 0 rows affected (0.027 sec)

 MariaDB [(none)]> start slave;
 Query OK, 0 rows affected (0.002 sec)

• 查看从节点的半同步状态

MariaDB [(none)]> SHOW VARIABLES LIKE '%semi%';
+---------------------------------------+--------------+
| Variable_name                         | Value        |
+---------------------------------------+--------------+
| rpl_semi_sync_master_enabled          | OFF          |
| rpl_semi_sync_master_timeout          | 10000        |
| rpl_semi_sync_master_trace_level      | 32           |
| rpl_semi_sync_master_wait_no_slave    | ON           |
| rpl_semi_sync_master_wait_point       | AFTER_COMMIT |
| rpl_semi_sync_slave_delay_master      | OFF          |
| rpl_semi_sync_slave_enabled           | ON           |
| rpl_semi_sync_slave_kill_conn_timeout | 5            |
| rpl_semi_sync_slave_trace_level       | 32           |
+---------------------------------------+--------------+
9 rows in set (0.001 sec)

MariaDB [(none)]> SHOW STATUS LIKE '%semi%';
+--------------------------------------------+-------+
| Variable_name                              | Value |
+--------------------------------------------+-------+
| Rpl_semi_sync_master_clients               | 0     |
| Rpl_semi_sync_master_get_ack               | 0     |
| Rpl_semi_sync_master_net_avg_wait_time     | 0     |
| Rpl_semi_sync_master_net_wait_time         | 0     |
| Rpl_semi_sync_master_net_waits             | 0     |
| Rpl_semi_sync_master_no_times              | 0     |
| Rpl_semi_sync_master_no_tx                 | 0     |
| Rpl_semi_sync_master_request_ack           | 0     |
| Rpl_semi_sync_master_status                | OFF   |
| Rpl_semi_sync_master_timefunc_failures     | 0     |
| Rpl_semi_sync_master_tx_avg_wait_time      | 0     |
| Rpl_semi_sync_master_tx_wait_time          | 0     |
| Rpl_semi_sync_master_tx_waits              | 0     |
| Rpl_semi_sync_master_wait_pos_backtraverse | 0     |
| Rpl_semi_sync_master_wait_sessions         | 0     |
| Rpl_semi_sync_master_yes_tx                | 0     |
| Rpl_semi_sync_slave_send_ack               | 1     |
| Rpl_semi_sync_slave_status                 | ON    |
+--------------------------------------------+-------+
18 rows in set (0.001 sec)

 

测试

停止所有从节点，在主节点新增数据库，3秒后才创建成功

#未关闭从节点的情况下，在主节点上创建数据库，立即生效
MariaDB [(none)]> create database db1;
Query OK, 1 row affected (0.001 sec)

#所有从节点上实现
MariaDB [(none)]> stop slave;
Query OK, 0 rows affected (0.004 sec)

#主节点上实现，等待了3秒才显示成功
MariaDB [(none)]> create database db2;
Query OK, 1 row affected (3.001 sec)

 

5、 MariaDB高可用方案MHA

答：

环境：

• 10.0.0.7：centos7，MHA管理端
• 10.0.0.8：centos8，Master
• 10.0.0.18：centos18，Slave
• 10.0.0.28：centos28，Slave

配置MHA管理端

• 安装mha4mysql-manager和mha4mysql-node软件包，都为0.56版本

[root@mha ~]#ls mha4mysql-*
mha4mysql-manager-0.56-0.el6.noarch.rpm  mha4mysql-node-0.56-0.el6.noarch.rpm
[root@mha ~]#yum install -y mha4mysql-*.rpm

• 在各个节点之间实现SSH KEY验证

[root@mha ~]#ssh-keygen
[root@mha ~]#ssh-copy-id 10.0.0.7
[root@mha ~]#rsync -av .ssh 10.0.0.8:/root
[root@mha ~]#rsync -av .ssh 10.0.0.18:/root
[root@mha ~]#rsync -av .ssh 10.0.0.28:/root

• 在MHA管理节点实现MHA配置文件

[root@mha ~]#mkdir /etc/mastermha
[root@mha ~]#cd /etc/mastermha
[root@mha mastermha]#vim app1.cnf 
[server default]
user=mhauser
password=magedu
manager_workdir=/data/mastermha/app1/
manager_log=/data/mastermha/app1/manager.log
remote_workdir=/data/mastermha/app1/
ssh_user=root
repl_user=rpluser
repl_password=magedu
ping_interval=1
master_ip_failover_script=/usr/local/bin/master_ip_failover
report_script=/usr/local/bin/sendmail.sh
check_repl_delay=0
[server1]
hostname=10.0.0.8
[server2]
hostname=10.0.0.18
[server3]
hostname=10.0.0.28
candidate_master=1

• 配置”切换主节点脚本"和“节点切换后，发送邮件脚本”

#当主节点故障后 ，执行切换节点的脚本
[root@mha mastermha]#vim /usr/local/bin/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 = '10.0.0.100';#设置Virtual IP
my $gateway = '10.0.0.254';#网关Gateway IP
my $interface = 'eth0';
my $key = "1";
my $ssh_start_vip = "/sbin/ifconfig $interface:$key $vip;/sbin/arping -I $interface -c 3 -s $vip $gateway >/dev/null 2>&1";
my $ssh_stop_vip = "/sbin/ifconfig $interface:$key down";
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 "

IN SCRIPT TEST====$ssh_stop_vip==$ssh_start_vip===

";
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 "Disabling the VIP on old master: $orig_master_host 
";
&stop_vip();
$exit_code = 0;
};
if ($@) {
warn "Got Error: $@
";
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 "Enabling the VIP - $vip on the new master - $new_master_host 
";
&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 
";
`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=port --new_master_host=host --new_master_ip=ip --new_master_port=port
";
}

[root@mha mastermha]#chmod +x /usr/local/bin/master_ip_failover 

#设置切换节点后，发送邮件通知
[root@mha ~]#vim .mailrc
set from=465454572@qq.com
set smtp=smtp.qq.com
set smtp_auth_user=465454572@qq.com
set smtp_auth_password=QQ邮箱授权码

[root@mha ~]#vim /usr/local/bin/sendmail.sh 
echo "MySQL is down" | mail -s "MHA Warning" 465454572@qq.com

[root@mha mastermha]#chmod +x /usr/local/bin/sendmail.sh

配置主从节点，并启动半同步复制

• 在所有主从节点上安装mha4mysql-node-0.56-0.el6.noarch.rpm

[root@master ~]#yum install -y mha4mysql-node-0.56-0.el6.noarch.rpm
[root@slave1 ~]#yum install -y mha4mysql-node-0.56-0.el6.noarch.rpm
[root@slave2 ~]#yum install -y mha4mysql-node-0.56-0.el6.noarch.rpm

• Master主节点配置文件中添加如下几行

[root@master ~]#vim /etc/my.cnf.d/mariadb-server.cnf 
[mysqld]
server-id=8
log-bin
skip-name-resolve
general-log    #通用日志可选择性开启
plugin-load-add=semisync_master    #加载半同步复制的主节点插件
rpl-semi-sync-master-enabled    #以主节点身份开启半同步复制
rpl-semi-sync-master-timeout=3000    #设置半同步复制的超时时长

• 启动Master，并且创建主从复制用户和MHA连接所有节点的用户

[root@master ~]#systemctl start mariadb
[root@master ~]#mysql
MariaDB [(none)]> GRANT replication slave ON *.* TO rpluser@'10.0.0.%' IDENTIFIED BY 'magedu';
Query OK, 0 rows affected (3.001 sec)

MariaDB [(none)]> GRANT all ON *.* TO mhauser@'10.0.0.%' IDENTIFIED BY 'magedu';
Query OK, 0 rows affected (0.000 sec)

  MariaDB [(none)]> SHOW MASTER LOGS;
  +--------------------+-----------+
  | Log_name | File_size |
  +--------------------+-----------+
  | mariadb-bin.000001 | 28198 |
  | mariadb-bin.000002 | 722 |
  +--------------------+-----------+
  2 rows in set (0.000 sec)

• 在主节点上配置和MHA连接的虚拟ip地址（VIP）

#主从节点都必须安装ifconfig命令，因为之后切换主节点是，虚拟地址飘到新的主节点上时，脚本中使用的就是ifconfig命令，若无ifconfig命令，该虚拟地址就飘不到新的主节点上了
[root@master ~]#yum install -y net-tools

[root@master ~]#ifconfig eth0:1 10.0.0.100
[root@master ~]#ifconfig eth0:1
eth0:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.0.100  netmask 255.0.0.0  broadcast 10.255.255.255
        ether 00:0c:29:a8:d1:eb  txqueuelen 1000  (Ethernet)

• 配置slave1和slave2，并启动同步

#修改配置文件，并设置同步
#slave1
[root@slave1 ~]#vim /etc/my.cnf.d/mariadb-server.cnf 
[mysqld]
server-id=18
log-bin
read-only
skip-name-resolve
relay-log-purge=0
plugin-load-add=semisync_slave
rpl-semi-sync-slave-enabled

[root@slave1 ~]#systemctl restart mariadb
[root@slave1 ~]#mysql
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MariaDB connection id is 9
Server version: 10.3.17-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB [(none)]> CHANGE MASTER TO
    -> MASTER_HOST='10.0.0.8',
    -> MASTER_USER='rpluser',
    -> MASTER_PASSWORD='magedu',
    -> MASTER_PORT=3306,
    -> MASTER_LOG_FILE='mariadb-bin.000001',
    -> MASTER_LOG_POS=28198;
Query OK, 0 rows affected (0.025 sec)
[root@slave2 ~]#mysql
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MariaDB connection id is 9
Server version: 10.3.17-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB [(none)]> CHANGE MASTER TO
    -> MASTER_HOST='10.0.0.8',
    -> MASTER_USER='rpluser',
    -> MASTER_PASSWORD='magedu',
    -> MASTER_PORT=3306,
    -> MASTER_LOG_FILE='mariadb-bin.000001',
    -> MASTER_LOG_POS=28198;
Query OK, 0 rows affected (0.004 sec)

MariaDB [(none)]> START SLAVE;
Query OK, 0 rows affected (0.002 sec)


#slave2
[root@slave2 ~]#vim /etc/my.cnf.d/mariadb-server.cnf
[mysqld]
server-id=28
log-bin
read-only
skip-name-resolve
relay-log-purge=0
plugin-load-add=semisync_slave
rpl-semi-sync-slave-enabled

[root@slave2 ~]#mysql
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MariaDB connection id is 9
Server version: 10.3.17-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB [(none)]> CHANGE MASTER TO
    -> MASTER_HOST='10.0.0.8',
    -> MASTER_USER='rpluser',
    -> MASTER_PASSWORD='magedu',
    -> MASTER_PORT=3306,
    -> MASTER_LOG_FILE='mariadb-bin.000001',
    -> MASTER_LOG_POS=28198;
Query OK, 0 rows affected (0.004 sec)

MariaDB [(none)]> START SLAVE;
Query OK, 0 rows affected (0.002 sec)

#安装ifconfig命令
[root@slave1 ~]#yum install -y net-tools

  [root@slave2 ~]#yum install -y net-tools

检查MHA相关环境

• 检查各节点的ssh连接

[root@mha ~]#masterha_check_ssh --conf=/etc/mastermha/app1.cnf 
Sun Sep 27 13:14:52 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sun Sep 27 13:14:52 2020 - [info] Reading application default configuration from /etc/mastermha/app1.cnf..
Sun Sep 27 13:14:52 2020 - [info] Reading server configuration from /etc/mastermha/app1.cnf..
Sun Sep 27 13:14:52 2020 - [info] Starting SSH connection tests..
Sun Sep 27 13:14:54 2020 - [debug] 
Sun Sep 27 13:14:52 2020 - [debug]  Connecting via SSH from root@10.0.0.18(10.0.0.18:22) to root@10.0.0.8(10.0.0.8:22)..
Sun Sep 27 13:14:53 2020 - [debug]   ok.
Sun Sep 27 13:14:53 2020 - [debug]  Connecting via SSH from root@10.0.0.18(10.0.0.18:22) to root@10.0.0.28(10.0.0.28:22)..
Warning: Permanently added '10.0.0.28' (ECDSA) to the list of known hosts.
Sun Sep 27 13:14:53 2020 - [debug]   ok.
Sun Sep 27 13:14:54 2020 - [debug] 
Sun Sep 27 13:14:53 2020 - [debug]  Connecting via SSH from root@10.0.0.28(10.0.0.28:22) to root@10.0.0.8(10.0.0.8:22)..
Sun Sep 27 13:14:53 2020 - [debug]   ok.
Sun Sep 27 13:14:53 2020 - [debug]  Connecting via SSH from root@10.0.0.28(10.0.0.28:22) to root@10.0.0.18(10.0.0.18:22)..
Sun Sep 27 13:14:54 2020 - [debug]   ok.
Sun Sep 27 13:14:54 2020 - [debug] 
Sun Sep 27 13:14:52 2020 - [debug]  Connecting via SSH from root@10.0.0.8(10.0.0.8:22) to root@10.0.0.18(10.0.0.18:22)..
Warning: Permanently added '10.0.0.18' (ECDSA) to the list of known hosts.
Sun Sep 27 13:14:53 2020 - [debug]   ok.
Sun Sep 27 13:14:53 2020 - [debug]  Connecting via SSH from root@10.0.0.8(10.0.0.8:22) to root@10.0.0.28(10.0.0.28:22)..
Warning: Permanently added '10.0.0.28' (ECDSA) to the list of known hosts.
Sun Sep 27 13:14:54 2020 - [debug]   ok.
Sun Sep 27 13:14:54 2020 - [info] All SSH connection tests passed successfully.

• 检查主从复制

[root@mha ~]#masterha_check_repl --conf=/etc/mastermha/app1.cnf 
MySQL Replication Health is OK.

开启MHA

[root@mha ~]#masterha_manager --conf=/etc/mastermha/app1.cnf 
Sun Sep 27 13:36:56 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sun Sep 27 13:36:56 2020 - [info] Reading application default configuration from /etc/mastermha/app1.cnf..
Sun Sep 27 13:36:56 2020 - [info] Reading server configuration from /etc/mastermha/app1.cnf..

[root@mha ~]#masterha_check_status --conf=/etc/mastermha/app1.cnf
app1 (pid:36419) is running(0:PING_OK), master:10.0.0.8
[root@mha ~]#

检测MHA是否有效

• 关闭Master主节点

[root@master ~]#killall -9 mysqld

• MHA完成切换后，自动退出

[root@mha ~]#masterha_manager --conf=/etc/mastermha/app1.cnf 
Sun Sep 27 13:36:56 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sun Sep 27 13:36:56 2020 - [info] Reading application default configuration from /etc/mastermha/app1.cnf..
Sun Sep 27 13:36:56 2020 - [info] Reading server configuration from /etc/mastermha/app1.cnf..
  Creating /data/mastermha/app1 if not exists..    ok.
  Checking output directory is accessible or not..
   ok.
  Binlog found at /var/lib/mysql, up to mariadb-bin.000002
Sun Sep 27 13:41:00 2020 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Sun Sep 27 13:41:00 2020 - [info] Reading application default configuration from /etc/mastermha/app1.cnf..
Sun Sep 27 13:41:00 2020 - [info] Reading server configuration from /etc/mastermha/app1.cnf..
[root@mha ~]#

• 查看slave1，发现它的主节点（master）已经变为10.0.0.28，说明切换成功

MariaDB [(none)]> show slave statusG
*************************** 1. row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: 10.0.0.28
                   Master_User: rpluser
                   Master_Port: 3306
                 Connect_Retry: 60
               Master_Log_File: mariadb-bin.000002
           Read_Master_Log_Pos: 344
                Relay_Log_File: mariadb-relay-bin.000002
                 Relay_Log_Pos: 557
         Relay_Master_Log_File: mariadb-bin.000002
              Slave_IO_Running: Yes
             Slave_SQL_Running: Yes
。。。

• 并且虚拟ip（vip）也已经飘到了原来的slave2（10.0.0.28）上

[root@slave2 ~]#ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.0.28  netmask 255.255.255.0  broadcast 10.0.0.255
        inet6 fe80::20c:29ff:fedb:fe0e  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:db:fe:0e  txqueuelen 1000  (Ethernet)
        RX packets 49233  bytes 66673333 (63.5 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 7061  bytes 1118804 (1.0 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

eth0:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 10.0.0.100  netmask 255.0.0.0  broadcast 10.255.255.255
        ether 00:0c:29:db:fe:0e  txqueuelen 1000  (Ethernet)