MySQL多实例(二)

一、多实例MySQL数据库原理

　　1.1：原理图

　　　　

　　1.2：多实例原理(什么是多实例)

　　　　简单来说MySQL多实例就是在一台服务器上同时开启多个不用的服务端口(如：3306、3307),同时运行多个MySQL进程，这些服务进程通过不同的socket监听不同的服务端口来提供服务，这些MySQL多实例公用一套MySQL安装程序，使用不同的my.cnf配置文件、启动程序和数据文件。在提供服务时，多实例MySQL在逻辑上看来是各自独立的，它们根据配置文件的对应设定值，获取服务器的相应数量的硬件资源。

二、多实例MySQL数据库优缺点及应用场景

　　2.1：多实例的优点

　　　　① 有效的利用资源

　　　　② 节约服务器资源

　　2.2：多实例的缺点

　　　　① 会存在资源互相抢占的问题(当某个数据库并发很高或者sql慢查询的时候，整个实例会消耗大量的CPU、磁盘I/O 导致服务器的其他数据库实例提供服务的质量一起下降)

　　2.2：多实例的应用场景

　　　　① 资金紧张型公司(公司资金紧张，业务访问量不大，又希望数据库服务隔离，同时还需要主从复制提供备份或者读写分离)

　　　　② 并发访问不是特别大的业务

　　　　③ 门户网站应用(服务器配置好，可以节省IDC空间，同时又充分利用的服务器的资源)

三、多实例MySQL数据库实现方案

　　3.1：单一配置文件、单一启动程序多实例部署方案(耦合度很高，也是官网的推荐)

　　3.2：多配置文件、多启动启动文件、多数据文件(解决了耦合度高的问题)

四、多实例MySQL数据库安装

PS：和单实例安装的方式是基本上差不多的，我很久采用二进制的安装方式来进行多实例的安装，单实例安装地址：https://www.cnblogs.com/zhujingzhi/p/9609861.html

　　4.1：3306实例安装

　　　　① 下载MySQL卸载自带Mariadb

[root@web1 ~]# wget https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.23-linux-glibc2.12-x86_64.tar.gz
[root@web1 ~]# rpm -qa | grep mariadb
mariadb-libs-5.5.56-2.el7.x86_64
mariadb-devel-5.5.56-2.el7.x86_64

[root@web1 ~]# rpm -e --nodeps mariadb-libs-5.5.56-2.el7.x86_64 mariadb-devel-5.5.56-2.el7.x86_64

　　　　② 安装配置MySQL3306

[root@web1 ~]# tar xf mysql-5.7.23-linux-glibc2.12-x86_64.tar.gz -C /usr/local/                         # 解压MySQL
[root@web1 ~]# useradd -M -s /sbin/nologin mysql                                                        # 创建MySQL用户

[root@web1 usr]# cd /usr/local/
[root@web1 local]# mv mysql-5.7.23-linux-glibc2.12-x86_64/ mysql/ 										 	

# 创建多实例的数据文件和日志文件
[root@web1 opt]# cd /home/
[root@web1 local]# mkdir -p /home/mysql/{3306,3307}/{data,log}

# 配置mysql3306的配置文件
[root@web1 3306]# vim my.cnf
[client]
port            = 3306
socket          = /home/mysql/3306/mysql.sock

[mysql]
no-auto-rehash

[mysqld]
user    = mysql
port    = 3306
socket  = /home/mysql/3306/mysql.sock
basedir = /usr/local/mysql
datadir = /home/mysql/3306/data
pid-file = /home/mysql/3306/mysql.pid
open_files_limit    = 1024
back_log = 600
max_connections = 800
max_connect_errors = 3000
external-locking = FALSE
max_allowed_packet =8M
sort_buffer_size = 1M
join_buffer_size = 1M
thread_cache_size = 100
query_cache_size = 2M
query_cache_limit = 1M
query_cache_min_res_unit = 2k
#default_table_type = InnoDB
thread_stack = 192K
#transaction_isolation = READ-COMMITTED
tmp_table_size = 2M
max_heap_table_size = 2M
long_query_time = 1
#log_long_format
log-error = /home/mysql/3306/log/error.log
#log-slow-queries = /home/mysql/3306/log/slow.log
pid-file = /home/mysql/3306/mysql.pid
#log-bin = /home/mysql/3306/mysql-bin
relay-log = /home/mysql/3306/relay-bin
relay-log-info-file = /home/mysql/3306/relay-log.info
binlog_cache_size = 1M
max_binlog_cache_size = 1M
max_binlog_size = 2M
expire_logs_days = 7
key_buffer_size = 16M
read_buffer_size = 1M
read_rnd_buffer_size = 1M
bulk_insert_buffer_size = 1M

lower_case_table_names = 1
skip-name-resolve
slave-skip-errors = 1032,1062
replicate-ignore-db=mysql

server-id = 1
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES,NO_AUTO_CREATE_USER,NO_AUTO_VALUE_ON_ZERO,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,PIPES_AS_CONCAT,ANSI_QUOTES

innodb_buffer_pool_size = 32M
innodb_thread_concurrency = 8
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 2M
innodb_log_file_size = 4M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120
innodb_file_per_table = 0

[mysqldump]
quick
max_allowed_packet = 2M

# 这里说明一下为什么要先创建这个error文件，因为这个是数据库的一个bug在启动数据库的时候会出现
2018-09-10T06:29:10.161125Z mysqld_safe error: log-error set to '/home/mysql/3306/log/error.log', however file don't exists. Create writable for user 'mysql'.
[root@web1 mysql]# touch /home/mysql/3306/log/error.log
[root@web1 mysql]# touch /home/mysql/3307/log/error.log
[root@web1 mysql]# chown -R mysql.mysql /home/mysql/   # 设置MySQL权限

[root@web1 3306]# yum install -y libaio
#  必须安装不然会报下面的错误
./bin/mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

# 设置环境比变量
[root@web1 mysql]# echo "export PATH=/usr/local/mysql/bin:$PATH" >> /etc/profile
[root@web1 mysql]# source /etc/profile    # 是环境变量生效

　　　　③ 修改密码及启动MySQL3306

# 初始化数据库，要记住初始化的密码
[root@web1 3306]# cd /usr/local/mysql/
[root@web1 mysql]# ./bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/home/mysql/3306/data
2018-09-10T03:09:58.040768Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-09-10T03:09:58.452316Z 0 [Warning] InnoDB: New log files created, LSN=45790
2018-09-10T03:09:58.515904Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2018-09-10T03:09:58.582330Z 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: ffe8e1c7-b4a6-11e8-91ba-000c296f1735.
2018-09-10T03:09:58.584298Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2018-09-10T03:09:58.585110Z 1 [Note] A temporary password is generated for root@localhost: (RKsr0Jv(H9v    # 初始化密码

# 因为5.7的安全机制必须要修改默认密码才能使用数据库，所以我们要先使用mysqld_safe启动数据库修改密码
[root@web1 3306]# cd /usr/local/mysql/
[root@web1 mysql]# ./bin/mysqld_safe  --defaults-file=/home/mysql/3306/my.cnf --user=mysql     # 启动3306数据库
[root@web1 mysql]# ./bin/mysql -u root -p -S /home/mysql/3306/mysql.sock
Enter password: (RKsr0Jv(H9v   # 初始化密码
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.23

Copyright (c) 2000, 2018, 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> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('123456');   # 修改密码
Query OK, 0 rows affected, 1 warning (0.00 sec)

# 编写MySQL启动脚本

[root@web1 3306]# vim /etc/init.d/mysql3306
#!/bin/sh

#init
port=3306
mysql_user="root"
mysql_pwd=""
CmdPath="/usr/local/mysql/bin"
mysql_sock="/home/mysql/${port}/mysql.sock"
#startup function
function_start_mysql()
{
    if [ ! -e "$mysql_sock" ];then
      printf "Starting MySQL...\n"
      /bin/sh ${CmdPath}/mysqld_safe --defaults-file=/home/mysql/${port}/my.cnf --user=mysql 2>&1 > /dev/null &
    else
      printf "MySQL is running...\n"
      exit
    fi
}

#stop function
function_stop_mysql()
{
    if [ ! -e "$mysql_sock" ];then
       printf "MySQL is stopped...\n"
       exit
    else
       printf "Stoping MySQL...\n"
       ${CmdPath}/mysqladmin -u ${mysql_user} -p${mysql_pwd} -S /home/mysql/${port}/mysql.sock shutdown
   fi
}

#restart function
function_restart_mysql()
{
    printf "Restarting MySQL...\n"
    function_stop_mysql
    sleep 2
    function_start_mysql
}

case $1 in
start)
    function_start_mysql
;;
stop)
    function_stop_mysql
;;
restart)
    function_restart_mysql
;;
*)
    printf "Usage: /home/mysql/${port}/mysql {start|stop|restart}\n"
esac

# 启动
[root@web1 mysql]# /etc/init.d/mysql3306 start

# 停止，为了安全这里需要密码
[root@web1 mysql]# /etc/init.d/mysql3307 stop
Stoping MySQL...
Enter password: 123456  # 数据库密码

　　　　④ 设置远程数据库权限

# 设置远程主机登录权限
[root@web1 mysql]# mysql -uroot -p -S /home/mysql/3306/mysql.sock
Enter password:123456
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.23 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, 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> grant all privileges on *.* to 'root' @'%' identified by '123456';   # 设置权限
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;													# 刷新权限

　　4.2：3307实例安装

　　PS：和配置3306一样只是修改一下端口 把3306改成3307

　　　　① 修改配置文件

# 拷贝配置文件
[root@web1 ~]# cp /home/mysql/3306/my.cnf /home/mysql/3307/

# 修改配置文件
[root@web1 ~]# sed -i "s#3306#3307#g" /home/mysql/3307/my.cnf

# 查看配置文件
[root@web1 ~]# cat /home/mysql/3307/my.cnf

　　　　② 修改启动脚本

# 拷贝启动文件
[root@web1 mysql]# cp /etc/init.d/mysql3306 /etc/init.d/mysql3307

# 修改启动文件
[root@web1 mysql]# sed -i "s#3306#3307#g" /etc/init.d/mysql3307

# 查看启动文件
[root@web1 mysql]# cat /etc/init.d/mysql3307

　　　　③ 初始化3307数据库

# 设置mysql权限
[root@web1 3307]# chown mysql.mysql /home/mysql/
# 初始化数据库
[root@web1 3307]# cd /usr/local/mysql/
[root@web1 mysql]# ./bin/mysqld --initialize --user=mysql --basedir=/usr/local/mysql --datadir=/home/mysql/3307/data
2018-09-10T07:02:06.000207Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2018-09-10T07:02:06.452043Z 0 [Warning] InnoDB: New log files created, LSN=45790
2018-09-10T07:02:06.498280Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2018-09-10T07:02:06.556171Z 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: 6da1081a-b4c7-11e8-be64-000c296f1735.
2018-09-10T07:02:06.557543Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2018-09-10T07:02:06.558513Z 1 [Note] A temporary password is generated for root@localhost: _ob9Hqq9:?kk

　　　　④ 启动3307数据库及修改密码

# 启动数据库
[root@web1 mysql]# cd /usr/local/mysql/
[root@web1 mysql]# ./bin/mysqld_safe  --defaults-file=/home/mysql/3307/my.cnf --user=mysql 

[root@web1 mysql]# mysql -uroot -p_ob9Hqq9:?kk -S /home/mysql/3307/
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 2
Server version: 5.7.23

Copyright (c) 2000, 2018, 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> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('123456');    # 修改密码
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> flush privileges;    # 刷新
Query OK, 0 rows affected (0.00 sec)

五、查看启动是否成功

[root@web1 ~]# netstat -lntup | grep mysql
tcp6       0      0 :::3306                 :::*                    LISTEN      20490/mysqld
tcp6       0      0 :::3307                 :::*                    LISTEN      55606/mysqld
[root@web1 ~]#

六、多实例MySQL数据库登录方式

# 登录3306数据库
[root@web1 ~]# mysql -uroot -p -S /home/mysql/3306/mysql.sock
Enter password:123456
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.23 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, 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3307数据库
[root@web1 ~]# mysql -uroot -p -S /home/mysql/3307/mysql.sock
Enter password:123456
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.23 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, 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>