- 读写分离原理图：
- 数据内部交换过程：
面对越来越大的访问压力，单台的服务器的性能成为瓶颈需要分担负载
-
主从只负责各自的读和写，极大程度的缓解 X 锁和 S 锁争用
-
从库可配置 myisam 引擎，提升查询性能以及节约系统开销
-
增加冗余，提高可用性
一般有两种方式实现
-
-
实现程序层实现指的是在应用程序内部及连接器中实现读写分离
程序层实现优点：
-
应用程序内部实现读写分离，安装即可以使用
-
减少一定部署难度
-
访问压力在一定级别以下，性能很好
程序层实现缺点：
-
架构一但调整，代码要跟着变
-
难以实现高级应用，如自动分库，分表
-
无法适用大型应用场景
中间件实现
中间件层实现是指在外部中间件程序实现读写分离
中间件优点：
-
架构设计更灵活
-
可以在程序上实现一些高级控制，如：透明化水平拆分，failover,监控
-
可以依靠技术手段提高MySQL性能
-
对业务代码的影响小，同时也安全
中间件缺点：
-
需要一定的开发运维团队的支持
- Atlas架构图
| IP地址 | 数据节点 | vip地址 | |
| db01 | 10.0.0.51 | master | 10.0.0.55 |
| db02 | 10.0.0.52 | slave-1 | |
| db03 | 10.0.0.53 | slave-2 |
#在线下载，可能会会比较慢或者失败 wget https://github.com/Qihoo360/Atlas/releases/download/2.2.1/Atlas-2.2.1.el6.x86_64.rpm #直接在MHA-2019-6.28.zip里面有 [root@db01 ~]# rpm -ivh Atlas-2.2.1.el6.x86_64.rpm Preparing... ################################# [100%] Updating / installing... 1:Atlas-2.2.1-1 ################################# [100%]
cd /usr/local/mysql-proxy/conf mv test.cnf test.cnf.bak cat > test.cnf <<EOF [mysql-proxy] admin-username = user admin-password = pwd proxy-backend-addresses = 10.0.0.55:3306 proxy-read-only-backend-addresses = 10.0.0.52:3306,10.0.0.53:3306 pwds = repl:3yb5jEku5h4=,mha:O2jBXONX098= daemon = true keepalive = true event-threads = 8 log-level = message log-path = /usr/local/mysql-proxy/log sql-log=ON proxy-address = 0.0.0.0:33060 admin-address = 0.0.0.0:2345 charset=utf8 EOF
- 启动atlas
# /usr/local/mysql-proxy/bin/mysql-proxyd test start OK: MySQL-Proxy of test is started # ps -ef |grep proxy root 10236 1 0 12:59 ? 00:00:00 /usr/local/mysql-proxy/bin/mysql-proxy --defaults-file=/usr/local/mysql-proxy/conf/test.cnf root 10237 10236 0 12:59 ? 00:00:00 /usr/local/mysql-proxy/bin/mysql-proxy --defaults-file=/usr/local/mysql-proxy/conf/test.cnf root 10253 9305 0 13:00 pts/1 00:00:00 grep --color=auto proxy
[root@db03 ~]# mysql -umha -pmha -h10.0.0.51 -P33060
- 读操作测试：
mysql> select @@server_id; +-------------+ | @@server_id | +-------------+ | 53 | +-------------+ 1 row in set (0.00 sec) mysql> select @@server_id; +-------------+ | @@server_id | +-------------+ | 52 | +-------------+ 1 row in set (0.00 sec)
注：可以看到我们的读操作分别在db2和db3上进行了操作
- 写操作测试：
mysql> begin;select @@server_id;commit; Query OK, 0 rows affected (0.00 sec) +-------------+ | @@server_id | +-------------+ | 51 | +-------------+ 1 row in set (0.00 sec) Query OK, 0 rows affected (0.00 sec) mysql> begin;select @@server_id;commit; Query OK, 0 rows affected (0.00 sec) +-------------+ | @@server_id | +-------------+ | 51 | +-------------+ 1 row in set (0.00 sec) Query OK, 0 rows affected (0.00 sec)
注：所有的写操作都在db1上进行
#登录管理 [root@db01 ~]# mysql -uuser -ppwd -h10.0.0.51 -P2345 mysql> select * from help; +----------------------------+---------------------------------------------------------+ | command | description | +----------------------------+---------------------------------------------------------+ | SELECT * FROM help | shows this help | | SELECT * FROM backends | lists the backends and their state | | SET OFFLINE $backend_id | offline backend server, $backend_id is backend_ndx's id | | SET ONLINE $backend_id | online backend server, ... | | ADD MASTER $backend | example: "add master 127.0.0.1:3306", ... | | ADD SLAVE $backend | example: "add slave 127.0.0.1:3306", ... | | REMOVE BACKEND $backend_id | example: "remove backend 1", ... | | SELECT * FROM clients | lists the clients | | ADD CLIENT $client | example: "add client 192.168.1.2", ... | | REMOVE CLIENT $client | example: "remove client 192.168.1.2", ... | | SELECT * FROM pwds | lists the pwds | | ADD PWD $pwd | example: "add pwd user:raw_password", ... | | ADD ENPWD $pwd | example: "add enpwd user:encrypted_password", ... | | REMOVE PWD $pwd | example: "remove pwd user", ... | | SAVE CONFIG | save the backends to config file | | SELECT VERSION | display the version of Atlas | +----------------------------+---------------------------------------------------------+ 16 rows in set (0.01 sec)
2. 查看数据库节点状态
mysql> select * from backends; +-------------+----------------+-------+------+ | backend_ndx | address | state | type | +-------------+----------------+-------+------+ | 1 | 10.0.0.55:3306 | up | rw | | 2 | 10.0.0.52:3306 | up | ro | | 3 | 10.0.0.53:3306 | up | ro | +-------------+----------------+-------+------+ 3 rows in set (0.00 sec)
3. 上线和下线节点
set offline $backend_id --下线例子：set offline 2; set online $backend_id --上线例子：set online 2;
4. 添加删除节点
ADD MASTER $backend --添加主节点例子：add master 10.0.0.54:3306; ADD slave $backend --添加从节点例子：add slave 10.0.0.54:3306; REMOVE BACKEND $backend_id --删除节点
5. 用户管理
select * from pwds --查看用户 ADD PWD $pwd --添加一个用户，使用的是明文 ADD ENPWD $pwd --添加一个用户，使用密文 REMOVE PWD $pwd --删除用户
6. 永久生效
mysql> save config;
- 企业用户管理案例
1. 数据库主节点
grant all on *.* to china@'10.0.0.%' identified by '123';
2. Atlas中添加数据库用户
#明文 ADD PWD china:123; #密文 /usr/local/mysql-proxy/bin/encrypt 123 [root@db01 ~]# /usr/local/mysql-proxy/bin/encrypt 123 3yb5jEku5h4= ADD ENPWD china:3yb5jEku5h4=
配置永久生效
save config;
| 实例 | 端口 | 数据目录 | |
| db01 | mysql3307 | 3307 | /data/3307/data |
| db02 | mysql3308 | 3308 | /data/3308/data |
| mysql3309 | 3309 | /data/3309/data | |
| mysql3310 | 3310 |
- 架构图：
-
环境准备
-
-
数据库版本：MySQL 5.7.28
-
两台虚拟机：db01、db02
-
每台创建四个MySQL实例：3307、3308、3309、3310
-
pkill mysqld rm -rf /data/33{07..10} mv /etc/my.cnf /etc/my.cnf.bak
3. 创建相关目录初始化数据
mkdir /data/33{07..10}/data -p mysqld --initialize-insecure --user=mysql --datadir=/data/3307/data --basedir=/app/database/mysql mysqld --initialize-insecure --user=mysql --datadir=/data/3308/data --basedir=/app/database/mysql mysqld --initialize-insecure --user=mysql --datadir=/data/3309/data --basedir=/app/database/mysql mysqld --initialize-insecure --user=mysql --datadir=/data/3310/data --basedir=/app/database/mysql
4.准备配置文件和脚本
- db01配置文件和启动脚本
#db01配置文件 cat >/data/3307/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3307/data socket=/data/3307/mysql.sock port=3307 log-error=/data/3307/mysql.log log_bin=/data/3307/mysql-bin binlog_format=row skip-name-resolve server-id=7 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3308/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3308/data port=3308 socket=/data/3308/mysql.sock log-error=/data/3308/mysql.log log_bin=/data/3308/mysql-bin binlog_format=row skip-name-resolve server-id=8 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3309/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3309/data socket=/data/3309/mysql.sock port=3309 log-error=/data/3309/mysql.log log_bin=/data/3309/mysql-bin binlog_format=row skip-name-resolve server-id=9 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3310/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3310/data socket=/data/3310/mysql.sock port=3310 log-error=/data/3310/mysql.log log_bin=/data/3310/mysql-bin binlog_format=row skip-name-resolve server-id=10 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF #db01启动文件 cat >/etc/systemd/system/mysqld3307.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3307/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3308.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3308/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3309.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3309/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3310.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf LimitNOFILE = 5000 EOF
- db02配置文件和启动文件
#配置文件 cat >/data/3307/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3307/data socket=/data/3307/mysql.sock port=3307 log-error=/data/3307/mysql.log log_bin=/data/3307/mysql-bin binlog_format=row skip-name-resolve server-id=17 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3308/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3308/data port=3308 socket=/data/3308/mysql.sock log-error=/data/3308/mysql.log log_bin=/data/3308/mysql-bin binlog_format=row skip-name-resolve server-id=18 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3309/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3309/data socket=/data/3309/mysql.sock port=3309 log-error=/data/3309/mysql.log log_bin=/data/3309/mysql-bin binlog_format=row skip-name-resolve server-id=19 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF cat >/data/3310/my.cnf<<EOF [mysqld] basedir=/app/database/mysql datadir=/data/3310/data socket=/data/3310/mysql.sock port=3310 log-error=/data/3310/mysql.log log_bin=/data/3310/mysql-bin binlog_format=row skip-name-resolve server-id=20 gtid-mode=on enforce-gtid-consistency=true log-slave-updates=1 EOF #启动文件 cat >/etc/systemd/system/mysqld3307.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3307/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3308.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3308/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3309.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3309/my.cnf LimitNOFILE = 5000 EOF cat >/etc/systemd/system/mysqld3310.service<<EOF [Unit] Description=MySQL Server Documentation=man:mysqld(8) Documentation=http://dev.mysql.com/doc/refman/en/using-systemd.html After=network.target After=syslog.target [Install] WantedBy=multi-user.target [Service] User=mysql Group=mysql ExecStart=/app/database/mysql/bin/mysqld --defaults-file=/data/3310/my.cnf LimitNOFILE = 5000 EOF
5. 修改权限，启动多实例
chown -R mysql.mysql /data/* systemctl start mysqld3307 systemctl start mysqld3308 systemctl start mysqld3309 systemctl start mysqld3310 netstat -lntup mysql -S /data/3307/mysql.sock -e "show variables like 'server_id'" mysql -S /data/3308/mysql.sock -e "show variables like 'server_id'" mysql -S /data/3309/mysql.sock -e "show variables like 'server_id'" mysql -S /data/3310/mysql.sock -e "show variables like 'server_id'"
6. 节点主从规划
箭头指向谁是主库
10.0.0.52:3308 <-----> 10.0.0.51:3308
10.0.0.52:3310 -----> 10.0.0.52:3308
10.0.0.51:3310 -----> 10.0.0.51:3308
7.开始配置
##shard1
10.0.0.51:3307 <-----> 10.0.0.52:3307
- db02
mysql -S /data/3307/mysql.sock -e "grant replication slave on *.* to repl@'10.0.0.%' identified by '123';" mysql -S /data/3307/mysql.sock -e "grant all on *.* to root@'10.0.0.%' identified by '123' with grant option;"
- db01
mysql -S /data/3307/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3307/mysql.sock -e "start slave;" mysql -S /data/3307/mysql.sock -e "show slave status\G"
- db02
mysql -S /data/3307/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3307/mysql.sock -e "start slave;" mysql -S /data/3307/mysql.sock -e "show slave status\G"
10.0.0.51:3309 ------> 10.0.0.51:3307
- db01
mysql -S /data/3309/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3309/mysql.sock -e "start slave;" mysql -S /data/3309/mysql.sock -e "show slave status\G"
10.0.0.52:3309 ------> 10.0.0.52:3307
- db02
mysql -S /data/3309/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3307, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3309/mysql.sock -e "start slave;" mysql -S /data/3309/mysql.sock -e "show slave status\G"
10.0.0.52:3308 <-----> 10.0.0.51:3308
- db01
mysql -S /data/3308/mysql.sock -e "grant replication slave on *.* to repl@'10.0.0.%' identified by '123';" mysql -S /data/3308/mysql.sock -e "grant all on *.* to root@'10.0.0.%' identified by '123' with grant option;"
- db02
mysql -S /data/3308/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3308/mysql.sock -e "start slave;" mysql -S /data/3308/mysql.sock -e "show slave status\G"
- db01
mysql -S /data/3308/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3308/mysql.sock -e "start slave;" mysql -S /data/3308/mysql.sock -e "show slave status\G"
10.0.0.52:3310 -----> 10.0.0.52:3308
- db02
mysql -S /data/3310/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.52', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3310/mysql.sock -e "start slave;" mysql -S /data/3310/mysql.sock -e "show slave status\G"
10.0.0.51:3310 -----> 10.0.0.51:3308
- db01
mysql -S /data/3310/mysql.sock -e "CHANGE MASTER TO MASTER_HOST='10.0.0.51', MASTER_PORT=3308, MASTER_AUTO_POSITION=1, MASTER_USER='repl', MASTER_PASSWORD='123';" mysql -S /data/3310/mysql.sock -e "start slave;" mysql -S /data/3310/mysql.sock -e "show slave status\G"
8. 检查主从状态
mysql -S /data/3307/mysql.sock -e "show slave status\G"|grep "Running:" mysql -S /data/3308/mysql.sock -e "show slave status\G"|grep "Running:" mysql -S /data/3309/mysql.sock -e "show slave status\G"|grep "Running:" mysql -S /data/3310/mysql.sock -e "show slave status\G"|grep "Running:"
注：(没问题不要做这部！！！！) 如果中间出现错误，在每个节点进行执行以下命令
mysql -S /data/3307/mysql.sock -e "stop slave; reset slave all;" mysql -S /data/3308/mysql.sock -e "stop slave; reset slave all;" mysql -S /data/3309/mysql.sock -e "stop slave; reset slave all;" mysql -S /data/3310/mysql.sock -e "stop slave; reset slave all;"