1. 背景
* MySQL數據庫的集中化運維，可以通過在一臺服務器上，部署運行多個MySQL服務進程，通過不同的socket監聽不同的服務端口來提供各自的服務。各個實例之間是相互獨立的，每個實例的datadir, port, socket, pid都是不同的。
* 網上多實例一般通過實例版本相同實現，此次以不同版本來實現多實例部署(5.5、5.6、5.7)。
2. 多實例特點
* 有效利用服務器資源，當單個服務器資源有剩餘時，可以充分利用剩餘的資源提供更多的服務。
* 資源互相搶佔問題，當某個服務實例服務併發很高時或者開啓慢查詢時，會消耗更多的內存、CPU、磁盤IO資源，導致服務器上的其他實例提供服務的質量下降。
3. 環境 [ 關閉SeLinux ]
[root@MySQL ~]# cat /etc/redhat-release CentOS release 6.9 (Final) [root@MySQL ~]# uname -r 2.6.32-504.el6.x86_64 [root@MySQL ~]# getenforce Disabled
4. MySQL 二進制包準備
* 下載官方5.5二進制安裝包
[root@MySQL ~]# wget https://dev.mysql.com/get/Downloads/MySQL-5.5/mysql-5.5.57-linux-glibc2.12-x86_64.tar.gz
* 下載官方5.6二進制安裝包
[root@MySQL ~]# wget https://dev.mysql.com/get/Downloads/MySQL-5.6/mysql-5.6.37-linux-glibc2.12-x86_64.tar.gz
* 下載官方5.7二進制安裝包
[root@MySQL ~]# wget https://dev.mysql.com/get/Downloads/MySQL-5.7/mysql-5.7.19-linux-glibc2.12-x86_64.tar
5. mysql 版本初始化並統一修改密碼
* 創建 MySQL 用戶
[root@MySQL ~]# useradd -r -s /sbin/nologin mysql
* 創建MySQL數據目錄
[root@MySQL ~]# mkdir -vp /data/mysql_data_{5..7}
mkdir: created directory `/data'
mkdir: created directory `/data/mysql_data_5'
mkdir: created directory `/data/mysql_data_6'
mkdir: created directory `/data/mysql_data_7'* 修改MySQL 數據目錄所屬用戶與所屬組
[root@MySQL ~]# chown mysql.mysql -R /data/mysql_data_*
* 解壓MySQL 各版本至 /usr/local 目錄
[root@MySQL ~]# tar zxf mysql-5.5.57-linux-glibc2.12-x86_64.tar.gz -C /usr/local/ [root@MySQL ~]# tar zxf mysql-5.6.37-linux-glibc2.12-x86_64.tar.gz -C /usr/local/ [root@MySQL ~]# tar xf mysql-5.7.19-linux-glibc2.12-x86_64.tar -C /usr/local/
* MySQL 5.5 初始化
[root@MySQL ~]# chown mysql.mysql -R /usr/local/mysql-5.5.57-linux-glibc2.12-x86_64 [root@MySQL ~]# /usr/local/mysql-5.5.57-linux-glibc2.12-x86_64/scripts/mysql_install_db --user=mysql --datadir=/data/mysql_data_5 --basedir=/usr/local/mysql-5.5.57-linux-glibc2.12-x86_64
* MySQL 5.5 修改密碼
[root@MySQL ~]# /usr/local/mysql-5.5.57-linux-glibc2.12-x86_64/bin/mysqld_safe --datadir=/data/mysql_data_5 &
[root@MySQL ~]# /usr/local/mysql-5.5.57-linux-glibc2.12-x86_64/bin/mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.57 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, 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 = password('123');
Query OK, 0 rows affected (0.00 sec)
mysql> quit
Bye
[root@MySQL ~]# killall mysqld* MySQL 5.6 初始化
[root@MySQL ~]# chown mysql.mysql -R /usr/local/mysql-5.6.37-linux-glibc2.12-x86_64 [root@MySQL ~]# /usr/local/mysql-5.6.37-linux-glibc2.12-x86_64/scripts/mysql_install_db --user=mysql --datadir=/data/mysql_data_6 --basedir=/usr/local/mysql-5.6.37-linux-glibc2.12-x86_64
* MySQL 5.6修改密碼
[root@MySQL ~]# /usr/local/mysql-5.6.37-linux-glibc2.12-x86_64/bin/mysqld_safe --datadir=/data/mysql_data_6 &
[root@MySQL ~]# /usr/local/mysql-5.6.37-linux-glibc2.12-x86_64/bin/mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.37 MySQL Community Server (GPL)
Copyright (c) 2000, 2017, 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 = password('123');
Query OK, 0 rows affected (0.00 sec)
mysql> quit
Bye
[root@MySQL ~]# killall mysqld* MySQL 5.7 初始化 [ 注意初始化提示的隨機密碼 ]
[root@MySQL ~]# mkdir /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64/mysql-files [root@MySQL ~]# chown root.mysql -R /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64 [root@MySQL ~]# chown mysql.mysql -R /data/mysql_data_7 /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64/mysql-files [root@MySQL ~]# /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64/bin/mysqld --initialize --user=mysql --datadir=/data/mysql_data_7 --basedir=/usr/local/mysql-5.7.19-linux-glibc2.12-x86_64
* MySQL 5.7修改密碼
[root@MySQL ~]# /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64/bin/mysqld_safe --datadir=/data/mysql_data_7 & [root@MySQL ~]# /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64/bin/mysql -p'INoGk(hoj9>/' 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 4 Server version: 5.7.18 Copyright (c) 2000, 2017, 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 = '123'; Query OK, 0 rows affected (0.00 sec) mysql> quit Bye [root@MySQL ~]# killall mysqld
6. 多版本部署
* 編輯/etc/my.cnf
[client] # 設置登陸用戶 user = root # 設置登陸用戶密碼 password = 123 [mysqld] # mysql 運行用戶 user = mysql # 設置 mysql 監聽 IP 地址 bind_address = 0.0.0.0 # 關閉 DNS 反解析 skip-name-resolve = 0 # 關閉監聽 performance_schema = off # 設置buffer pool 大小 innodb_buffer_pool_size = 32M # 設置錯誤日誌文件名 log_error = error.log [mysqld_multi] # 設置multi 日誌 log = /tmp/mysql_multi.log [mysqld5] # 設置實例所在目錄 basedir = /usr/local/mysql-5.5.57-linux-glibc2.12-x86_64 # 設置mysql 運行程序所在路徑 mysqld = /usr/local/mysql-5.5.57-linux-glibc2.12-x86_64/bin/mysqld # 設置mysql 管理運行程序所在路徑 mysqladmin = /usr/local/mysql-5.5.57-linux-glibc2.12-x86_64/bin/mysqladmin # 設置實例數據目錄 -- 多實例中一定要不同 datadir = /data/mysql_data_5 # 設置socket 文件路徑 -- 多實例中一定要不同 socket = /tmp/mysql.sock5 # 設置實例監聽端口 -- 多實例中一定要不同 port = 3305 [mysqld6] basedir = /usr/local/mysql-5.6.37-linux-glibc2.12-x86_64 mysqld = /usr/local/mysql-5.6.37-linux-glibc2.12-x86_64/bin/mysqld mysqladmin = /usr/local/mysql-5.6.37-linux-glibc2.12-x86_64/bin/mysqladmin datadir = /data/mysql_data_6 socket = /tmp/mysql.sock6 port = 3306 [mysqld7] basedir = /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64 datadir = /data/mysql_data_7 socket = /tmp/mysql.sock7 port = 3307
* 從隨意版本二進制包中support-files目錄下複製mysqld_multi.server啓動腳本至 /etc/init.d/
[root@MySQL ~]# cp /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64/support-files/mysqld_multi.server /etc/init.d/mysqld_multi [root@MySQL ~]# chmod +x /etc/init.d/mysqld_multi
* 隨意版本創始軟鏈接，並設置環境變量
[root@MySQL ~]# ln -s /usr/local/mysql-5.7.19-linux-glibc2.12-x86_64 /usr/local/mysql [root@MySQL ~]# export PATH=/usr/local/mysql/bin:$PATH
7. 測試
* 查看多實例狀態
[root@MySQL ~]# /etc/init.d/mysqld_multi report Reporting MySQL servers MySQL server from group: mysqld5 is not running MySQL server from group: mysqld6 is not running MySQL server from group: mysqld7 is not running
* 啓動多實例 [ 需等候幾秒 ]
[root@MySQL ~]# /etc/init.d/mysqld_multi start [root@MySQL ~]# /etc/init.d/mysqld_multi report Reporting MySQL servers MySQL server from group: mysqld5 is running MySQL server from group: mysqld6 is running MySQL server from group: mysqld7 is running [root@MySQL ~]# netstat -lntp | grep mysqld tcp 0 0 0.0.0.0:3305 0.0.0.0:* LISTEN 43750/mysqld tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 43753/mysqld tcp 0 0 0.0.0.0:3307 0.0.0.0:* LISTEN 43756/mysqld
* 分別連接實例
[root@MySQL ~]# mysql -S /tmp/mysql.sock5 Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 4 Server version: 5.7.18 MySQL Community Server (GPL) Copyright (c) 2000, 2017, 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> quit Bye [root@MySQL ~]# mysql -S /tmp/mysql.sock6 Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 4 Server version: 5.7.18 MySQL Community Server (GPL) Copyright (c) 2000, 2017, 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> quit Bye [root@MySQL ~]# mysql -S /tmp/mysql.sock7 Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 4 Server version: 5.7.18 MySQL Community Server (GPL) Copyright (c) 2000, 2017, 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> quit Bye
* 停止多實例
[root@MySQL ~]# /etc/init.d/mysqld_multi stop [root@MySQL ~]# /etc/init.d/mysqld_multi report Reporting MySQL servers MySQL server from group: mysqld5 is not running MySQL server from group: mysqld6 is not running MySQL server from group: mysqld7 is not running
8. 總結
以需求驅動技術，技術本身沒有優略之分，只有業務之分。