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构建Mysql服务器

时间：2022-03-15 17:03

《综合》构建Mysql服务器

1 构建MySQL服务器

1.1 问题

本案例要求熟悉MySQL官方安装包的使用，快速构建一台数据库服务器：

安装MySQL-server、MySQl-client软件包
修改数据库用户root的密码
确认MySQL服务程序运行、root可控

1.2 方案

本课程将使用64位的RHEL 7操作系统，MySQL数据库的版本是5.7.17。

访问http://dev.mysql.com/downloads/mysql/，找到MySQL Community Server下载页面，平台选择“Red Hat Enterprise Linux 7 / Oracle Linux”，然后选择64位的bundle整合包下载，如图-1所示。

技术图片

图-1

注意：下载MySQL软件时需要以Oracle网站账户登录，如果没有请根据页面提示先注册一个（免费）。

1.3 步骤

实现此案例需要按照如下步骤进行。

步骤一：准备工作

1）卸载系统自带的mariadb-server、mariadb软件包（如果有的话）

[root@dbsvr1 ~]# yum -y remove mariadb-server mariadb
Setting up Remove Process
No Match for argument: mariadb-server
rhel7dvd | 3.9 kB 00:00 ...
Package(s) mariadb-server available, but not installed.
No Match for argument: mariadb
Package(s) mariadb available, but not installed.
No Packages marked for removal

2）清理/etc/my.cnf配置文件

此配置文件由RHEL自带的mariadb-libs库提供：

[root@dbsvr1 ~]# rpm -qf /etc/my.cnf
mariadb-libs-5.5.35-3.el7.x86_64

大量的系统软件包都需要用到mariadb-libs库，因此不建议直接卸载此软件包。最好是安装新的MySQL数据库软件时，采用 -U 升级的方式来进行替换。

配置文件/etc/my.cnf若不需要使用，可以直接删除。或者保险起见，也可以将其改名备份：

[root@dbsvr1 ~]# mv /etc/my.cnf /etc/my.cnf.old

步骤二：安装mysql-community-client、mysql-community-server软件包

1）释放bundle整合包

[root@dbsvr1 ~]# cd /var/ftp/pub/
[root@dbsvr1 pub]# tar xvf mysql-5.7.17-1.el7.x86_64.rpm-bundle.tar
mysql-community-client-5.7.17-1.el7.x86_64.rpm
//MySQL 数据库客户端应用程序和工具
mysql-community-common-5.7.17-1.el7.x86_64.rpm
//MySQL 数据库和客户端库共享文件
mysql-community-devel-5.7.17-1.el7.x86_64.rpm
//MySQL 数据库客户端应用程序的库和头文件
mysql-community-embedded-5.7.17-1.el7.x86_64.rpm
//MySQL嵌入式函数库
mysql-community-embedded-compat-5.7.17-1.el7.x86_64.rpm
//MySQL嵌入式兼容函数库
mysql-community-embedded-devel-5.7.17-1.el7.x86_64.rpm
//头文件和库文件作为Mysql的嵌入式库文件
mysql-community-libs-5.7.17-1.el7.x86_64.rpm
//MySQL 数据库客户端应用程序的共享库
mysql-community-libs-compat-5.7.17-1.el7.x86_64.rpm
//MySQL 5.6.31 数据库客户端应用程序的共享兼容库
mysql-community-minimal-debuginfo-5.7.17-1.el7.x86_64.rpm
//mysql最小安装包的调试信息
mysql-community-server-5.7.17-1.el7.x86_64.rpm
//非常快速和可靠的 SQL 数据库服务器
mysql-community-server-minimal-5.7.17-1.el7.x86_64.rpm
//非常快速和可靠的 SQL 数据库服务器(最小化安装)
mysql-community-test-5.7.17-1.el7.x86_64.rpm
//MySQL 数据库服务器的测试套件

2）安装MySQL数据库

在bundle的整合包中，并不是所有的rpm包都会用到，将一些重复的删除。

安装mysql时可能会缺少某些依赖包，需提前单独安装

[root@dbsvr1 pub]#yum -y install perl-Data-Dumper perl-JSON perl-Time-HiRes
[root@dbsvr1 pub]# rpm -Uvh mysql-community-*.rpm
准备中... ################################# [100%]
正在升级/安装...
1:mysql-community-common-5.7.17-1.e################################# [ 9%]
2:mysql-community-libs-5.7.17-1.el7################################# [ 18%]
3:mysql-community-client-5.7.17-1.e################################# [ 27%]
4:mysql-community-server-5.7.17-1.e################################# [ 36%]
5:mysql-community-devel-5.7.17-1.el################################# [ 45%]
6:mysql-community-embedded-5.7.17-1################################# [ 55%]
7:mysql-community-embedded-devel-5.################################# [ 64%]
8:mysql-community-test-5.7.17-1.el7################################# [ 73%]
9:mysql-community-libs-compat-5.7.1################################# [ 82%]
10:mysql-community-minimal-debuginfo################################# [ 91%]
正在清理/删除...
11:mariadb-libs-1:5.5.35-3.el7 ################################# [100%]
[root@dbsvr1 pub]#systemctl start mysqld.service

安装过程中会尝试做一些检测，然后完成基本的初始化任务，期间会给出相关的提示。比如由于MySQL 5.7对TIMESTAMP时间戳的处理不同于之前的版本，会给出警告和提示出解决办法（使用--explicit_defaults_for_timestamp选项）：

2017-04-04T15:59:07.324470Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).

MySQL 5.7默认采用的存储引擎不再是MyISAM，而是InnoDB。初始化时若相关的文件不存在，会自动创建并设置相关参数：

2017-04-04T15:59:09.075698Z 0 [Warning] InnoDB: New log files created, LSN=45790
2017-04-04T15:59:09.381634Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2017-04-04T15:59:09.579733Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: a3973917-194f-11e7-a75b-52540018542e.
2017-04-04T15:59:09.703759Z 0 [Warning] Gtid table is not ready to be used. Table ‘mysql.gtid_executed‘ cannot be opened.
2017-04-04T15:59:09.711439Z 1 [Note] A temporary password is generated for root@localhost: ;%7SDdD)quOI
2017-04-04T15:59:29.758102Z 1 [ERROR] Failed to open the bootstrap file /tmp/install-validate-password-plugin.xqy7Ay.sql
2017-04-04T15:59:29.758122Z 1 [ERROR] 1105 Bootstrap file error, return code (0). Nearest query: ‘LSE SET @sys.tmp.table_exists.SQL = CONCAT(‘SELECT COUNT(*) FROM `‘, in_db, ‘`.`‘, in_table, ‘`‘); prePARE stmt_select FROM @sys.tmp.table_exists.SQL; IF (NOT v_error) THEN DEALLOCATE prePARE stmt_select; SET out_exists = ‘TEMPORARY‘; END IF; END IF; END;
‘
2017-04-04T15:59:29.758336Z 0 [ERROR] Aborting
2017-04-04T15:59:33.078575Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2017-04-04T15:59:33.092082Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.17) starting as process 3326 ...
2017-04-04T15:59:33.095074Z 0 [Note] InnoDB: PUNCH HOLE support available
2017-04-04T15:59:33.095104Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2017-04-04T15:59:33.095109Z 0 [Note] InnoDB: Uses event mutexes
2017-04-04T15:59:33.095112Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2017-04-04T15:59:33.095115Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.3
2017-04-04T15:59:33.095120Z 0 [Note] InnoDB: Using Linux native AIO
2017-04-04T15:59:33.095340Z 0 [Note] InnoDB: Number of pools: 1
2017-04-04T15:59:33.095428Z 0 [Note] InnoDB: Not using CPU crc32 instructions
2017-04-04T15:59:33.096904Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2017-04-04T15:59:33.106888Z 0 [Note] InnoDB: Completed initialization of buffer pool
2017-04-04T15:59:33.108711Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2017-04-04T15:59:33.120189Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2017-04-04T15:59:33.454908Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2017-04-04T15:59:33.455034Z 0 [Note] InnoDB: Setting file ‘./ibtmp1‘ size to 12 MB. Physically writing the file full; Please wait ...
2017-04-04T15:59:34.057704Z 0 [Note] InnoDB: File ‘./ibtmp1‘ size is now 12 MB.
2017-04-04T15:59:34.058603Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2017-04-04T15:59:34.058615Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2017-04-04T15:59:34.063078Z 0 [Note] InnoDB: Waiting for purge to start
2017-04-04T15:59:34.113304Z 0 [Note] InnoDB: 5.7.17 started; log sequence number 2536157
2017-04-04T15:59:34.113841Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2017-04-04T15:59:34.114310Z 0 [Note] Plugin ‘FEDERATED‘ is disabled.
2017-04-04T15:59:34.118690Z 0 [Note] Found ca.pem, server-cert.pem and server-key.pem in data directory. Trying to enable SSL support using them.
2017-04-04T15:59:34.118921Z 0 [Warning] CA certificate ca.pem is self signed.
2017-04-04T15:59:34.119582Z 0 [Note] InnoDB: Buffer pool(s) load completed at 170404 23:59:34
2017-04-04T15:59:34.237643Z 0 [Note] Server hostname (bind-address): ‘*‘; port: 3306
2017-04-04T15:59:34.241687Z 0 [Note] IPv6 is available.
2017-04-04T15:59:34.241727Z 0 [Note] - ‘::‘ resolves to ‘::‘;
2017-04-04T15:59:34.241753Z 0 [Note] Server socket created on IP: ‘::‘.
2017-04-04T15:59:34.313591Z 0 [Note] Event Scheduler: Loaded 0 events
2017-04-04T15:59:34.313686Z 0 [Note] Executing ‘SELECT * FROM INFORMATION_SCHEMA.TABLES;‘ to get a list of tables using the deprecated partition engine. You may use the startup option ‘--disable-partition-engine-check‘ to skip this check.
2017-04-04T15:59:34.313693Z 0 [Note] Beginning of list of non-natively partitioned tables
2017-04-04T15:59:34.322126Z 0 [Note] End of list of non-natively partitioned tables
2017-04-04T15:59:34.322261Z 0 [Note] /usr/sbin/mysqld: ready for connections.
Version: ‘5.7.17‘ socket: ‘/var/lib/mysql/mysql.sock‘ port: 3306 MySQL Community Server (GPL)

关于MySQL数据库的管理员账号root，其密码也不再是空，而是安装时随机生成一个，这种处理方式一定程度上增强了MySQl服务器的安全性。随机生成的密码字串可以从保存到mysql日志文件中找到：

[root@dbsvr1 pub]#grep ‘temporary password‘ /var/log/mysqld.log
2017-04-04T15:59:09.711439Z 1 [Note] A temporary password is generated for root@localhost: ;%7SDdD)quOI

3）确认安装后的服务单元文件、服务状态

查看服务单元文件

[root@dbsvr1 pub]# ls -lh /usr/lib/systemd/system/mysqld.service
-rw-r--r--. 1 root root 1.6K 11月 29 04:30 /usr/lib/systemd/system/mysqld.service

mysql服务的自启状态为enabled：

[root@dbsvr1 ~]# # systemctl is-enabled mysqld.service
enabled

步骤三：查看Mysql服务的运行状态

服务器进程为mysqld，监听的默认端口为TCP 3306：

[root@dbsvr1 pub]# netstat -antpu | grep mysql
tcp6 0 0 :::3306 :::* LISTEN 3913/mysqld

查看Mysql服务的状态

[root@dbsvr1 pub]#systemctl is-active mysqld.service
active
[root@dbsvr1 pub]#systemctl status mysqld.service
mysqld.service - MySQL Server
Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled)
Active: active (running) since 日 2017-04-23 08:56:24 CST; 1s ago
Docs: man:mysqld(8)
http://dev.mysql.com/doc/refman/en/using-systemd.html
Process: 13753 ExecStart=/usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS (code=exited, status=0/SUCCESS)
Process: 13732 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
Main PID: 13757 (mysqld)
CGroup: /system.slice/mysqld.service
└─13757 /usr/sbin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid

数据库的默认存放位置为 /var/lib/mysql：

[root@dbsvr1 pub]# ls /var/lib/mysql
auto.cnf client-cert.pem ibdata1 ibtmp1 mysql.sock.lock public_key.pem sys
ca-key.pem client-key.pem ib_logfile0 mysql performance_schema server-cert.pem
ca.pem ib_buffer_pool ib_logfile1 mysql.sock private_key.pem server-key.pem

步骤四：连接MySQL服务器，修改密码

查看随机生成的root管理密码

[root@dbsvr1 pub]#grep ‘temporary password‘ /var/log/mysqld.log
2017-04-01T18:10:42.948679Z 1 [Note] A temporary password is generated for root@localhost: GWphBZ_g+1& //密码为GWphBZ_g+1&

2）使用客户端命令mysql连接到MySQL服务器

提示验证时，填入前一步获得的随机密码，验证成功后即可进入“mysql> ”环境：

[root@dbsvr1 pub]# mysql -u root -p
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 14
Server version: 5.7.17
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> //登录成功后，进入SQL操作环境

用该密码登录到服务端后，必须马上修改密码，不然会报如下错误：

mysql> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

3）执行SET PASSWORD命令修改密码

这个其实与validate_password_policy的值有关，默认为1，所以刚开始设置的密码必须符合长度，且必须含有数字，小写或大写字母，特殊字符。如果我们不希望密码设置的那么复杂，需要修改两个全局参数：validate_password_policy与validate_password_length。validate_password_length默认值为8,最小值为4，如果你显性指定validate_password_length的值小于4，尽管不会报错，但validate_password_length的值将设为4。

可参考下列指令：

mysql>set global validate_password_policy=0;
mysql>set global validate_password_length=4；
mysql> SET PASSWORD FOR ‘root‘@‘localhost‘=PASSWORD(‘1234567‘);
Query OK, 0 rows affected, 1 warning (0.00 sec)

上述操作的结果是——更改数据库用户root从本机访问时的密码，设为1234567。

退出“mysql> ”环境，重新登录验证，必须采用新的密码才能登入：

mysql> exit //退出 mysql> 环境
Bye
[root@dbsvr1 ~]# mysql -u root –p //重新登录
Enter password: //输入新设置的密码
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 5.7.17 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.07 sec)

2 数据库基本管理

2.1 问题

本案例要求熟悉MySQL的连接及数据库表的增删改查等基本管理操作，主要完成以下几个方便的操作：

使用mysql命令连接数据库
练习查看/删除/创建库的相关操作
练习查看/删除/创建表的相关操作，表数据参考如表-1所示内容

表－1 测试用表数据

技术图片

2.2 步骤

实现此案例需要按照如下步骤进行。

步骤一：使用mysql命令连接数据库

连接MySQL服务器时，最基本的用法是通过 -u 选项指定用户名、-p指定密码。密码可以写在命令行（如果不写，则出现交互，要求用户输入），当然基于安全考虑一般不推荐这么做：

[root@dbsvr1 ~]# mysql -uroot -p123456 //紧挨着选项，不要空格
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 16
Server version: 5.7.17 MySQL Community Server (GPL)
Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> exit //退出已登录的mysql> 环境
Bye

默认情况下，msyql命令会连接本机的MySQL服务。但在需要的时候，可以通过 -h 选项指定远程主机；如果端口不是3306，还可以通过大写的 -P 选项指定：

[root@dbsvr1 ~]# mysql -u root -p -h 127.0.0.1 -P 3306
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 17
Server version: 5.7.17 MySQL Community Server (GPL)
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> exit //退出已登录的mysql> 环境
Bye

连接其他主机的MySQL服务，有一个前提条件——对方已经添加了此用户从此客户机访问的数据库授权，授权操作方法会在后续课程学习。

步骤二：练习查看/删除/创建库的相关操作

以root用户登入“mysql> ”环境后，可以执行各种MySQL指令、SQL指令。基本的用法事项如下：

操作指令不区分大小写（库名/表名、密码、变量值等除外）。
每条SQL指令以 ; 结束或分隔。
不支持 Tab 键自动补齐。
\c 可废弃当前编写错的操作指令。

1）查看现有的库

mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema | //信息概要库
| mysql | //授权库
| performance_schema | //性能结构库
| sys | //系统元数据库
+--------------------+
4 rows in set (0.15 sec)

2）切换/使用指定的库

切换到sys库：

mysql> USE sys;
Database changed
mysql> SELECT DATABASE(); //确认当前所在的库
+------------+
| DATABASE() |
+------------+
| sys |
+------------+
1 row in set (0.00 sec)

切换到mysql库：

mysql> USE mysql;
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
mysql> SELECT DATABASE(); //确认当前所在的库
+------------+
| DATABASE() |
+------------+
| mysql |
+------------+
1 row in set (0.00 sec)

3）创建新的库

新建名为mydb的库，确认结果：

mysql> CREATE DATABASE mydb;
Query OK, 1 row affected (0.00 sec)
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mydb | //新建的mydb库
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)

新建名为newdb的库，确认结果：

mysql> CREATE DATABASE newdb;
Query OK, 1 row affected (0.00 sec)
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mydb | //新建的mydb库
| mysql |
| newdb | //新建的newdb库
| performance_schema |
| sys |
+--------------------+
6 rows in set (0.00 sec)

新建数据库以后，会为每个数据库建立同名文件夹，可从命令行确认：

[root@dbsvr1 ~]# ls -l /var/lib/mysql/{my,new}db/
/var/lib/mysql/mydb/:
总用量 4
-rw-r-----. 1 mysql mysql 65 4月 2 03:14 db.opt
/var/lib/mysql/newdb/:
总用量 4
-rw-r-----. 1 mysql mysql 65 4月 2 03:15 db.opt

4）删除指定的库

删除名为newdb的库：

mysql> DROP DATABASE newdb;
Query OK, 0 rows affected (0.04 sec)
mysql> SHOW DATABASES; //确认删除结果，已无newdb表
+--------------------+
| Database |
+--------------------+
| information_schema |
| mydb |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.00 sec)

步骤三：练习查看/删除/创建表的相关操作

1）查看指定的库里有哪些表

查看mysql库里有哪些表：

mysql> USE mysql;
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
mysql> SHOW TABLES;
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| db |
| engine_cost |
| event |
| func |
| general_log |
| gtid_executed |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| ndb_binlog_index |
| plugin |
| proc |
| procs_priv |
| proxies_priv |
| server_cost |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user | //存放数据库用户的表
+---------------------------+
31 rows in set (0.00 sec)

2）查看指定表的字段结构

当前库为mysql，查看columns_priv表的结构，以列表形式展现：

mysql> DESCRIBE columns_priv\G //末尾不用分号
*************************** 1. row ***************************
Field: Host
Type: char(60)
Null: NO
Key: PRI
Default:
Extra:
*************************** 2. row ***************************
Field: Db
Type: char(64)
Null: NO
Key: PRI
Default:
Extra:
*************************** 3. row ***************************
Field: User
Type: char(32)
Null: NO
Key: PRI
Default:
Extra:
*************************** 4. row ***************************
Field: Table_name
Type: char(64)
Null: NO
Key: PRI
Default:
Extra:
*************************** 5. row ***************************
Field: Column_name
Type: char(64)
Null: NO
Key: PRI
Default:
Extra:
*************************** 6. row ***************************
Field: Timestamp
Type: timestamp
Null: NO
Key:
Default: CURRENT_TIMESTAMP
Extra: on update CURRENT_TIMESTAMP
*************************** 7. row ***************************
Field: Column_priv
Type: set(‘Select‘,‘Insert‘,‘Update‘,‘References‘)
Null: NO
Key:
Default:
Extra:
7 rows in set (0.01 sec)

查看columns_priv表的结构，以表格形式展现：

mysql> DESCRIBE columns_priv; //末尾需要有分号
+-------------+----------------------------------------------+------+-----+-------------------+-----------------------------+
| Field | Type