mysql主从之基于atlas读写分离

一 mysql读写分离的概念

写在主库，主库一般只有一个,读可以分配在多个从库上，如果写压力不大的话,也能把读分配到主库上.

实现是基于atlas实现的,atlas是数据库的中间件,程序只需要连接atlas入口，无需读写单独指定,atlas决定在那个数据库进行读或者写操作,可以实现mysql的读写分离

atlas是一台独立的机器,目前实验把atlas配置在192.168.132.122上

主库+从库给予atlas读写的权限

主库:192.168.132.121
mysql> grant all privileges on *.* to 'atlas'@'192.168.132.122' identified by '';
Query OK,  rows affected,  warning (0.01 sec)
mysql> flush privileges;
从库:192.168.132.122
mysql> grant all privileges on *.* to 'atlas'@'192.168.132.122' identified by '';  #atlas连接数据库的用户名是atls,密码是1234567
Query OK,  rows affected,  warning (0.00 sec)
mysql> flush privileges;
atlas对主端和从端都有了读写权限

二安装atlas

Atlas下载地址

https://github.com/Qihoo360/Atlas/releases

[root@slave ~]# cd /usr/local/src/

[root@slave src]# yum install epel-release -y

[root@slave src]# yum install openssl-devel autoconf gcc glib2 glib2-devel libevent-devel flex-devel flex jemalloc jemalloc-devel lua-devel -y

[root@slave src]# wget https://github.com/Qihoo360/Atlas/releases/download/sharding-1.0.1/Atlas-sharding_1.0.1-el6.x86_64.rpm

[root@slave src]# rpm -ivh Atlas-sharding_1.0.1-el6.x86_64.rpm

[root@slave src]# cd /usr/local/mysql-proxy/

[root@slave mysql-proxy]# ll

[root@slave mysql-proxy]# ./bin/mysql-proxy --version

三配置读写分离

密码加密

[root@slave mysql-proxy]# /usr/local/mysql-proxy/bin/encrypt '1234567'

[root@slave mysql-proxy]# vim /usr/local/mysql-proxy/atlas.cnf

[mysql-proxy]
#主库地址
proxy-backend-addresses = 192.168.132.121:
#从库地址，@后面的数字代表权重，用来负载均衡，默认权重为1。可设置多项，用逗号分隔
proxy-read-only-backend-addresses = 192.168.132.122:@,192.168.132.121:@
#用户名和密码，密码需要使用/usr/local/mysql-proxy/bin/encrypt加密
pwds = atlas:tj+W8xntBW8=
daemon = true
#守护进程
keepalive = true
#线程数
event-threads =
#日志级别，message、warning、critical、error、debug
log-level = warning
#日志存放的路径
log-path = /usr/local/mysql-proxy/log
#SQL日志的开关，OFF代表不记录SQL日志，ON代表记录SQL日志，REALTIME代表记录SQL日志且实时写入磁盘
sql-log = OFF
#慢日志输出设置。单位：ms
sql-log-slow =
#Atlas监听端口
proxy-address = 0.0.0.0:3316    #如果是一台独立的服务器,这个端口可以和MySQL端口一样,设为3306
#管理监听端口
admin-address = 0.0.0.0:
admin-username = atlas
admin-password =
#客户端连接默认字符集，不设置的话一般还需要使用set names utf8
charset = utf8
#ip白名单
#client-ips = 127.0.0.1, 192.168.3.1

最终是这样

程序连接 atlas192.168.237.128:3316 -> 主库+从库

四启动atlas

[root@slave mysql-proxy]# /usr/local/mysql-proxy/bin/mysql-proxyd --help

[root@slave mysql-proxy]# /usr/local/mysql-proxy/bin/mysql-proxyd atlas start

[root@slave mysql-proxy]# netstat -ntlp|grep mysql-proxy

五验证

5.1 读操作验证

主端查看读操作的次数

192.168.132.121:
mysql> show global status like '%select%';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| Com_insert_select        |      |
| Com_replace_select       |      |
| Com_select               |    |
| Connection_errors_select |      |
| Select_full_join         |      |
| Select_full_range_join   |      |
| Select_range             |      |
| Select_range_check       |      |
| Select_scan              |     |
+--------------------------+-------+
192.168.132.122:
mysql> show global status like '%select%';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| Com_insert_select        |      |
| Com_replace_select       |      |
| Com_select               |    |
| Connection_errors_select |      |
| Select_full_join         |      |
| Select_full_range_join   |      |
| Select_range             |      |
| Select_range_check       |      |
| Select_scan              |     |
+--------------------------+-------+

执行读操作

192.168.132.121执行

[root@master ~]# mysql -uatlas -p1234567 -h 192.168.132.122 -P3316 -e 'select * from darren.test;'

192.168.132.121: 未执行读操作
mysql> show global status like '%select%';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| Com_insert_select        |      |
| Com_replace_select       |      |
| Com_select               |    |
| Connection_errors_select |      |
| Select_full_join         |      |
| Select_full_range_join   |      |
| Select_range             |      |
| Select_range_check       |      |
| Select_scan              |     |
+--------------------------+-------+
192.168.:  执行读操作
mysql> show global status like '%select%';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| Com_insert_select        |      |
| Com_replace_select       |      |
| Com_select               |     |
| Connection_errors_select |      |
| Select_full_join         |      |
| Select_full_range_join   |      |
| Select_range             |      |
| Select_range_check       |      |
| Select_scan              |     |
+--------------------------+-------+

多执行几次

[root@master ~]# mysql -uatlas -p1234567 -h 192.168.132.122 -P3316 -e 'select * from darren.test;'

查看结果

因为配置文件配置读取的操作权重是5:1

192.168.132.121:执行一次
mysql> show global status like '%select%';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| Com_insert_select        |      |
| Com_replace_select       |      |
| Com_select               |    |
| Connection_errors_select |      |
| Select_full_join         |      |
| Select_full_range_join   |      |
| Select_range             |      |
| Select_range_check       |      |
| Select_scan              |     |
+--------------------------+-------+
192.168.132.122 #增加7次
mysql> show global status like '%select%';
+--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| Com_insert_select        |      |
| Com_replace_select       |      |
| Com_select               |     |
| Connection_errors_select |      |
| Select_full_join         |      |
| Select_full_range_join   |      |
| Select_range             |      |
| Select_range_check       |      |
| Select_scan              |     |
+--------------------------+-------+

5.2 写操作验证

192.168.132.121使用atlat进入数据库

[root@master mysql]# mysql -uatlas -p1234567 -h 192.168.132.122 -P3316

mysql> insert into test values (5);

192.168.132.121查看

mysql> select * from test;

192.168.132.122查看:

mysql> select * from darren.test;

多执行几次

mysql> insert into test values (6);

mysql> insert into test values (7);

mysql> insert into test values (8);

mysql> insert into test values (9);

mysql> insert into test values (10);

192.168.132.121查看:

mysql> select * from test;

192.168.132.122查看

数据一直,说明写操作一直在主端192.168.132.121端.

基本读写分离的验证完成