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NSD DBA2 DAY04

1 案例1：测试MHA集群

1.1 问题

查看MHA集群状态
测试节点之间的SSH登录
测试集群VIP的故障切换功能

1.2 步骤

实现此案例需要按照如下步骤进行。

步骤一：验证配置

1）检查配置环境，在主机52，53检查是否有同步数据的用户repluser

主机52:

mysql> select user,host from mysql.user where user="repluser";
+----------+------+
| user | host |
+----------+------+
| repluser | % |
+----------+------+
1 row in set (0.00 sec)
mysql> show grants for repluser@"%";
+--------------------------------------------------+
| Grants for repluser@% |
+--------------------------------------------------+
| GRANT REPLICATION SLAVE ON *.* TO 'repluser'@'%' |
+--------------------------------------------------+
1 row in set (0.00 sec

主机53:

mysql> select user,host from mysql.user where user="repluser";
+----------+------+
| user | host |
+----------+------+
| repluser | % |
+----------+------+
1 row in set (0.00 sec)
mysql> show grants for repluser@"%";
+--------------------------------------------------+
| Grants for repluser@% |
+--------------------------------------------------+
| GRANT REPLICATION SLAVE ON *.* TO 'repluser'@'%' |

+--------------------------------------------------+

1 row in set (0.00 sec)

2）在51的主机上做root的授权，其他的会同步（如果不做，在验证数据节点的主从同步配置时会出错）

mysql> grant all on *.* to root@"%" identified by "123456";
mysql> select user,host from mysql.user where user="root";
+------+-----------+
| user | host |
+------+-----------+
| root | % |
| root | localhost |
+------+-----------+
2 rows in set (0.00 sec)

3）验证ssh 免密登陆数据节点主机

[root@mgm56 mha4mysql-manager-0.56]# cd /usr/local/bin/
[root@mgm56 bin]# masterha_check_ssh --conf=/etc/mha_manager/app1.cnf
Wed Sep 19 09:09:33 2018 - [info] All SSH connection tests passed successfully.
//出现这个为成功

4）验证数据节点的主从同步配置（先把自动failover时候的切换脚本注释掉）

[root@mgm56 bin]# masterha_check_repl --conf=/etc/mha_manager/app1.cnf
MySQL Replication Health is OK. //验证成功

5）启动管理服务MHA_Manager

--remove_dead_master_conf //删除宕机主库配置

--ignore_last_failover //忽略xxx.health文件

[root@mgm56 bin]# masterha_manager --conf=/etc/mha_manager/app1.cnf \
--remove_dead_master_conf --ignore_last_failover
Wed Sep 19 09:24:41 2018 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Wed Sep 19 09:24:41 2018 - [info] Reading application default configuration from /etc/mha_manager/app1.cnf..
Wed Sep 19 09:24:41 2018 - [info] Reading server configuration from /etc/mha_manager/app1.cnf..

6）查看状态（另开一个终端）

[root@mgm56 ~]# masterha_check_status --conf=/etc/mha_manager/app1.cnf
app1 (pid:15745) is running(0:PING_OK), master:192.168.4.51

7）停止服务

[root@mgm56 ~]# masterha_stop --conf=/etc/mha_manager/app1.cnf
Stopped app1 successfully.

步骤二：测试故障转移

1）在主库51上面配置VIP地址

[root@master51 ~]# ifconfig eth0:1 192.168.4.100/24

2）在配置文件里面把自动failover时候的切换脚本去掉注释

3）修改 master_ip_failover 脚本，设置如下内容

34 my $vip = '192.168.4.100/24';
35 my $key = "1";
36 my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";
37 my $ssh_stop_vip = "/sbin/ifconfig eth0:$key down";

4）启动服务

[root@mgm56 bin]# masterha_manager --conf=/etc/mha_manager/app1.cnf \
--remove_dead_master_conf --ignore_last_failover
Wed Sep 19 09:50:33 2018 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.
Wed Sep 19 09:50:33 2018 - [info] Reading application default configuration from /etc/mha_manager/app1.cnf..
Wed Sep 19 09:50:33 2018 - [info] Reading server configuration from /etc/mha_manager/app1.cnf..

5）查看状态

[root@mgm56 ~]# masterha_check_status --conf=/etc/mha_manager/app1.cnf
app1 master is down and failover is running(50:FAILOVER_RUNNING). master:192.168.4.52

验证数据节点的主从同步配置报错，如图-3所示：

[root@mgm56 bin]# masterha_check_repl --conf=/etc/mha_manager/app1.cnf

图-3

解决办法：

root用户没有授权，默认只能本地连接，在主机51上面授权root用户可以远程登录，其他主机会同步

mysql> grant all on *.* to root@"%" identified by "123456";

2 案例2：视图的基本使用

2.1 问题

把/etc/passwd文件的内容存储到db9库下的user表里
添加新字段id 存储记录的行号(在所有字段的前边)
创建视图v1 结构及数据user表的字段、记录一样。
创建视图v2 只有user表shell是/bin/bash用户信息。
分别对视图表和基表执行insert update delete 操作。
删除视图v1 和 v2

2.2 步骤

实现此案例需要按照如下步骤进行。

步骤一：视图的基本使用

什么是视图：是一种虚拟存在的表

内容与真实的表相似，包含一系列带有名称的列和行数据。

视图并不在数据库中以存储的数据的形式存在。

行和列的数据来自定义视图时查询所引用的基本表，并且在具体引用视图时动态生成。

更新视图的数据，就是更新基表的数据

更新基表数据，视图的数据也会跟着改变

1）把/etc/passwd文件的内容存储到db9库下的user表里

[root@mysql51 ~]# mysql -u root -p123456
mysql> create database db9;
Query OK, 1 row affected (10.00 sec)
mysql> create table db9.user(username char(20),password char(1),uid \
int(2),gid int(2),comment char(100),homedir char(100),shell char(50));
//创建存储数据的表结构
Query OK, 0 rows affected (0.02 sec)
[root@mysql51 ~]# cp /etc/passwd /var/lib/mysql-files/
[root@mysql51 ~]# ls /var/lib/mysql-files/
passwd
mysql> load data infile "/var/lib/mysql-files/passwd" into table db9.user fields terminated by ":" lines terminated by "\n";//导入文件内容到db9.user
Query OK, 41 rows affected (0.02 sec)
Records: 41 Deleted: 0 Skipped: 0 Warnings: 0

2）添加新字段id 存储记录的行号(在所有字段的前边)

mysql> alter table db9.user add id int(2) primary key auto_increment first;
Query OK, 0 rows affected (0.04 sec)
Records: 0 Duplicates: 0 Warnings: 0
mysql> use db9;
mysql> desc user;
+----------+-----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------+-----------+------+-----+---------+----------------+
| id | int(2) | NO | PRI | NULL | auto_increment |
| username | char(20) | YES | | NULL | |
| password | char(1) | YES | | NULL | |
| uid | int(2) | YES | | NULL | |
| gid | int(2) | YES | | NULL | |
| comment | char(100) | YES | | NULL | |
| homedir | char(100) | YES | | NULL | |
| shell | char(50) | YES | | NULL | |
+----------+-----------+------+-----+---------+----------------+
8 rows in set (0.00 sec)

3）创建视图v1 结构及数据user表的字段、记录一样

mysql> create view v1 as select * from user;
Query OK, 0 rows affected (0.00 sec)

4）创建视图v2 只有user表shell是/bin/bash用户信息

mysql> create view v2 as select shell from user;
Query OK, 0 rows affected (0.01 sec)

5）分别对视图表和基表执行insert update delete 操作

mysql> insert into v1(username,uid) values("jarry",9);//插入记录
Query OK, 1 row affected (0.00 sec)
mysql> update v1 set uid=9 where username="adm";//更新记录
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> delete from v1 where uid=9;//删除记录
Query OK, 2 rows affected (0.01 sec)

6）删除视图v1 和 v2

mysql> drop view v1;
Query OK, 0 rows affected (0.00 sec)
mysql> drop view v2;
Query OK, 0 rows affected (0.00 sec)

注意：对视图操作即是对基本操作，反之亦然！！！

3 案例3：视图进阶操作

3.1 问题

练习OR REPLACE的选项使用
练习WITH LOCAL CHECK OPTION 选项的使用
练习WITH CASCADED CHECK OPTION 选项的使用

3.2 步骤

实现此案例需要按照如下步骤进行。

步骤一：视图进阶操作

1）创建视图完全格式

mysql> create table user2 select username,uid,gid from user limit 3;
//快速建表（user2表）
Query OK, 3 rows affected (0.01 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> create table info select username,uid,homedir,shell from user limit 5;
//快速建表（info表）
Query OK, 5 rows affected (0.02 sec)
Records: 5 Duplicates: 0 Warnings: 0

查询user2.username=info.username的字段

mysql> select * from user2 left join info on user2.username=info.username;
+----------+------+------+----------+------+---------+---------------+
| username | uid | gid | username | uid | homedir | shell |
+----------+------+------+----------+------+---------+---------------+
| root | 0 | 0 | root | 0 | /root | /bin/bash |
| bin | 1 | 1 | bin | 1 | /bin | /sbin/nologin |
| daemon | 2 | 2 | daemon | 2 | /sbin | /sbin/nologin |
+----------+------+------+----------+------+---------+---------------+
3 rows in set (0.00 sec)

2）关联查询建的视图默认不允许修改视图字段的值

mysql> create view v4 as select * from user2 left join info on user2.username=info.username;//创建失败
ERROR 1060 (42S21): Duplicate column name 'username'
mysql> create view v4 as select a.username as ausername,b.username as busername, a.uid as auid,b.uid as buid from user2 a left join info b on a.username=b.username;
//创建成功
Query OK, 0 rows affected (0.00 sec)
mysql> select * from v4;
+-----------+-----------+------+------+
| ausername | busername | auid | buid |
+-----------+-----------+------+------+
| root | root | 0 | 0 |
| bin | bin | 1 | 1 |
| daemon | daemon | 2 | 2 |
+-----------+-----------+------+------+
3 rows in set (0.00 sec)
mysql> desc v4;
+-----------+----------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-----------+----------+------+-----+---------+-------+
| ausername | char(20) | YES | | NULL | |
| busername | char(20) | YES | | NULL | |
| auid | int(2) | YES | | NULL | |
| buid | int(2) | YES | | NULL | |
+-----------+----------+------+-----+---------+-------+
4 rows in set (0.00 sec)

3）OR REPLACE的选项使用

创建时，若视图已存在，会替换已有的视图

语法格式：create or replace view视图名as select 查询； //达到修改已有视图的目的

mysql> create or replace view v4 as select a.username as ausername,b.username as busername, a.uid as auid,b.uid as buid from user2 a left join info b on a.username=b.username;
Query OK, 0 rows affected (0.00 sec)

4）WITH LOCAL CHECK OPTION

LOCAL和CASCADED关键字决定检查的范围

LOCAL 仅检查当前视图的限制

CASCADED 同时要满足基表的限制（默认值）

mysql> create table user1 select username,uid,shell from user where uid>=5 and uid <=40;
Query OK, 11 rows affected (0.01 sec)
Records: 11 Duplicates: 0 Warnings: 0
mysql> create view v1 as select username,uid from user1 where uid<=20;
Query OK, 0 rows affected (0.01 sec)
mysql> update v1 set uid=21 where username="sync";
//操作超过视图表的条件限制（uid<=20）之后，在视图表里面查看不到，在基表里可以查看到
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> update user1 set uid=41 where username="ftp";
//基表在超过条件限制（uid>=5 and uid <=40),在基表里依然可以查看到
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> create table a select * from user where uid < 10;
//快速创建一个新表a
Query OK, 7 rows affected (0.01 sec)
Records: 7 Duplicates: 0 Warnings: 0
mysql> create view v3 as select * from a where uid < 10 with check option;
//不写默认为CASCADED检查自己和a要满足的要求即可
Query OK, 0 rows affected (0.00 sec)
mysql> update v3 set uid=9 where username="adm";//更改成功
Query OK, 0 rows affected (0.01 sec)
Rows matched: 0 Changed: 0 Warnings: 0
mysql> create view v2 as select * from v1 where uid >= 5 with local check option;
//满足自身v2的要求
Query OK, 0 rows affected (0.00 sec)
mysql> update v2 set uid=9 where username="sync";
Query OK, 0 rows affected (0.00 sec)
Rows matched: 0 Changed: 0 Warnings: 0

5）WITH CASCADED CHECK OPTION

mysql> create view v5 as select * from v1 where uid >= 5 with cascaded check option;
Query OK, 0 rows affected (0.00 sec)

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NSD DBA2 DAY04

1 案例1：测试MHA集群

1.1 问题

1.2 步骤

2 案例2：视图的基本使用

2.1 问题

2.2 步骤

3 案例3：视图进阶操作

3.1 问题

3.2 步骤

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