超详细搭建Memcached主主复制+Keepalived高可用架构

简介

Memcached本身是基于内存的缓存,它的设计本身没有冗余机制。如果一个Memcached节点失去了所有的数据,应用程序可以从数据源中再次获取到数据，可以使用开源软件Magent实现Memcached集群，通过Magen缓存代理,防止单点现象。缓存代理也可以做备份,可以用keepalived软件实现高可用

实验环境

主机名	操作系统	IP地址	相关软件
master	CentOS_7.4_x86_64	192.168.100.71	libevent-2.1.8-stable.tar.gz;memcached-1.5.6.tar.gz;magent-0.5.tar.gz
backuper	CentOS_7.4_x86_64	192.168.100.72	libevent-2.1.8-stable.tar.gz;memcached-1.5.6.tar.gz;
client	CentOS_7.4_x86_64	192.168.100.73	telnet软件

搭建步骤

一、配置主机

1、安装libevent

[[email protected] ~]# tar xvfz libevent-2.1.8-stable.tar.gz
[[email protected] ~]# cd libevent-2.1.8-stable/
[[email protected] libevent-2.1.8-stable]# ./configure --prefix=/usr
[[email protected] libevent-2.1.8-stable]# make && make install

2、安装memcached

[[email protected] ~]# tar xvfz memcached-1.5.6.tar.gz
[[email protected] ~]# cd memcached-1.5.6/
[[email protected] memcached-1.5.6]# ./configure --with-libevent=/usr
[[email protected] memcached-1.5.6]# make && make install

3、优化路径

[[email protected] ~]# ln -s /usr/lib/libevent-2.1.so.6 /usr/lib64/libevent-2.1.so.6

4、安装magent

1).解压magent

[[email protected] ~]# mkdir magent
[[email protected] ~]# tar xvfz magent-0.5.tar.gz -C magent

2).编辑ketama文件

[[email protected] ~]# cd magent/
[[email protected] magent]# vim ketama.h #编辑hash算法配制文件

#第一行添加如下参数：
#ifndef SSIZE_MAX          #第1行，编辑声明SSIZE_MAX，否则编译会报错
#define SSIZE_MAX 32767    #第2行，编辑参数
#endif                     #第3行，关闭

3).编辑Makefile文件

[[email protected] magent]# vim Makefile
LIBS = -levent -lm #第1行，添加"-lm"

4).编译安装magent

[[email protected] magent]# make

gcc -Wall -O2 -g -I/usr/local/libevent/include -c -o magent.o magent.c
gcc -Wall -O2 -g -I/usr/local/libevent/include -c -o ketama.o ketama.c
gcc -Wall -O2 -g -o magent magent.o ketama.o -levent -lm -L /usr/local/libevent/lib

[[email protected] magent]# ls

[[email protected] magent]# cp magent /usr/bin/ #将执行脚本放到bin目录下，可直接执行命令

5).上传magent执行脚本给从服务器

[[email protected] magent]# scp magent [email protected]:/usr/bin/

4、配置keepalived

1).安装keepalived

[[email protected] ~]# yum -y install keepalived #安装keepalived软件

2).修改主配置文件

[[email protected] ~]# cp /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak #修改之前先进行备份
[[email protected] ~]# vim /etc/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.100.1
   smtp_connect_timeout 30
   router_id MAGENT_HA1
}

vrrp_script magent {
   script "/opt/shell/magent.sh"
   interval 2  //每2秒执行一次
   }

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    priority 200
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
       }
    track_script {    #触发脚本
        magent
       }
    virtual_ipaddress {
        192.168.100.200
       }
   }
}

5、编辑脚本
[[email protected] ~]# mkdir -p /opt/shell
[[email protected] ~]# cd /opt/shell/
[[email protected] shell]# vim magent.sh

#!/bin/bash
K=`ps -ef | grep keepalived | grep -v grep | wc -l`
if [ $K -gt 0 ]; then
magent -u root -n 51200 -l 192.168.100.200 -p 12000 -s 192.168.100.71:11211 -b 192.168.100.72:11211
else
    pkill -9 magent
fi
解析：
-u：指定用户
-n：用户最大连接数
-l：指定虚拟IP
-p：指定虚拟IP端口号
-s：主缓存节点
-b：从缓存节点
总结：主要是为memcache做了一个集群，最终虚拟出的IP是192.168.100.200

[[email protected] shell]# chmod +x magent.sh #赋予执行权限

二、配置备机

1、安装libevent、memcached

与主机配置操作相同，略…… 注意备机不需要安装magent``

2、配置keepalived

[[email protected] ~]# yum -y install keepalived
[[email protected] ~]# cd /etc/keepalived/
[[email protected] keepalived]# cp keepalived.conf keepalived.conf.bak
[[email protected] keepalived]# scp 192.168.100.71:/etc/keepalived/keepalived.conf .
[[email protected] keepalived]# vim keepalived.conf

global_defs {
……
   router_id MAGENT_HA2    #服务器名称，区别于主机服务器名称
}

vrrp_instance VI_1 {
    state BACKUP       #注意作为备机，参数为BACKUP
    priority 150       #注意作为备机，活跃值要小于主机活跃值
    ……

3、对应的创建脚本

[[email protected] ~]# mkdir -p /opt/shell
[[email protected] ~]# cd /opt/shell/
[[email protected] shell]# vim magent.sh

#!/bin/bash
K=`ip addr | grep 192.168.100.200 | grep -v grep | wc -l`
if [ $K -gt 0 ]; then
magent -u root -n 51200 -l 192.168.100.200 -p 12000 -s 192.168.100.71:11211 -b 192.168.100.72:11211
else
    pkill -9 magent
fi

[[email protected] shell]# chmod +x magent.sh

三、启动Keepalived服务

1、主机启动

[[email protected] ~]# systemctl start keepalived.service
[[email protected] ~]# netstat -anpt | grep ‘12000‘

[[email protected] ~]# ip addr show ens33

2、备机启动

[[email protected] ~]# systemctl start keepalived.service
[[email protected] ~]# ip addr show ens33

四、启动Memcached服务

1、主机启动Memcached

[[email protected] ~]# memcached -m 512k -u root -d -l 192.168.100.71 -p 11211
[[email protected] ~]# netstat -anpt | grep ‘11211‘

2、备机启动Memcached

[[email protected] ~]# memcached -m 512k -u root -d -l 192.168.100.72 -p 11211
[[email protected] ~]# netstat -anpt | grep ‘11211‘

五、测试Memcached群集

1、客户端写入数据

[[email protected] ~]# yum -y install telnet
[[email protected] ~]# telnet 192.168.100.200 12000 #连接的是虚拟IP

2、查看主、备服务器数据

1).查看主机

[[email protected] ~]# telnet 192.168.100.71 11211

2).查看备机

3、模拟主机故障

[[email protected] ~]# systemctl stop keepalived.service

4、查看备机

[[email protected] ~]# ip addr

5、客户端再次访问

[[email protected] ~]# telnet 192.168.100.200 12000

原文地址：http://blog.51cto.com/11905606/2286374

时间： 2024-10-10 18:46:25