memcached的高可用集群

memcached的高可用集群

1.实验环境

• VMware Workstation
• centos7（memcached主服务器），IP地址：192.168.73.200
• centos7（memcached从服务器），IP地址：192.168.73.201
• centos7（memcached客户端），IP地址：192.168.73.202
• VIP（漂移地址）：192.168.73.100

2.实验目的

• 搭建memcached高可用集群，实现memcached的主从同步和高可用

3.memcached主从服务器的搭建

3.1memcached需要安装的服务

• 主服务器：memcached、libevent、keepalived、magent
• 从服务器：memcached、libevent、keepalived

3.2memcached主从服务器的搭建

'//解压源码包'
[root@master ~]# mount.cifs //192.168.23.1/ccc /mnt
Password for root@//192.168.23.1/ccc:  
[root@master ~]# cd /mnt/memcache/
[root@master memcache]# tar zxvf libevent-2.1.8-stable.tar.gz -C /opt
[root@master memcache]# tar zxvf memcached-1.5.6.tar.gz -C /opt
[root@master memcache]# mkdir /opt/magent	'//此步骤从服务器不需要操作'
[root@master memcache]# tar zxvf magent-0.5.tar.gz -C /opt/magent/	'//此步骤从服务器不需要操作'
'//编译安装libevent和memcached'
[root@master memcache]# yum install gcc gcc-c++ make -y
[root@master memcache]# cd /opt/libevent-2.1.8-stable/
[root@master libevent-2.1.8-stable]# ./configure --prefix=/usr	'//路径不在/usr的话，后面magent在make的时候会报错：magent.c:64:19: 致命错误：event.h：没有那个文件或目录'
[root@master libevent-2.1.8-stable]# make && make install
[root@master libevent-2.1.8-stable]# cd /opt/memcached-1.5.6/
[root@master memcached-1.5.6]# ./configure \
> --prefix=/usr/local/memcached \
> --with-libevent=/usr/local/libevent
[root@master memcached-1.5.6]# make && make install
'//关闭防火墙'
[root@master memcached-1.5.6]# systemctl stop firewalld.service 
[root@master memcached-1.5.6]# setenforce 0

3.2.1 主服务安装magent代理

[root@master memcached-1.5.6]# cd /opt/magent/
[root@master magent]# ls
ketama.c  ketama.h  magent.c  Makefile
[root@master magent]# vim ketama.h	'//修改magent配置文件'
    '//前两行修改如下'
#ifndef SSIZE_MAX
#define SSIZE_MAX 32767
...省略内容
[root@master magent]# vim Makefile 	'//修改Makefile配置文件'
 LIBS = -levent -lm	'//首行后面添加-lm'
...省略内容
[root@master magent]# make	'//编译后会产生一个magent可执行程序'
[root@master magent]# yum install openssh-clients -y
[root@master magent]# cp magent /usr/bin/	'//将magent可执行程序复制到/usr/bin中'
[root@master magent]# scp magent [email protected]:/usr/bin	'//将magent可执行程序复制到从服务器的/usr/bin中'
'//此命令需要输入yes，输入从服务器的密码才能将文件拷贝过去，根据提示操作即可'

3.3安装keepalived

• 主服务器

[root@master ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
    '//此段落为：定义一个函数脚本，稍后我们需要创建它'
vrrp_script magent {	
                script "/opt/shell/magent.sh"
                interval 2
            }
'//全局配置'
global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id MAGENT_HA	'//router_id自定义，不可与从服务器相同'
}
'//实例区域'
vrrp_instance VI_1 {	
    state MASTER	'//主服务器为MASTER，从服务器要改为BACKUP'
    interface ens33	'//网卡改为本机网卡ens33'
    virtual_router_id 51	'//主不可相同，从服务器需要修改'
    priority 100	'//优先级要高于从服务器'
    advert_int 1
    track_script {	'//此三行为调用函数的段落，配置文件开头已经添加了函数，此处需要调用'
                magent
    }
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.73.100	'//定义漂移地址'
    }
}

• 从服务器

[root@slave ~]# cd /etc/keepalived/
[root@slave keepalived]# mv keepalived.conf keepalived.conf.bak	'//备份配置文件'
    '//回到主服务器，将配置文件复制到从服务器'
[root@master ~]# scp /etc/keepalived/keepalived.conf [email protected]:/etc/keepalived
[root@slave keepalived]# vim keepalived.conf
     '//其他配置都相同，只需要修改如下几个配置'
router_id MAGENT_HB         '//id名和第一台要不一样，从服务器改为MAGENT_HB'
state BACKUP               '//从服务器为BACKUP'
virtual_router_id 52       '//id号和第一台不一样即可'
priority 90                 '//优先级低与主服务器 '

• 创建magent脚本（主从都要）

'//主从服务器都要创建magent脚本'
[root@master ~]# mkdir /opt/shell
[root@master ~]# cd /opt/shell/
[root@master 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 192.168.79.100 -p 12000 -s 192.168.79.133:11211 -b 192.168.79.134:11211
else
pkill -9 magent
fi
'//如下解释'
-n 51200             '//定义用户最大连接数'
-l 192.168.79.100   '//指定虚拟IP'
-p 12000             '//指定端口号'
-s                   '//指定主缓存服务器192.168.79.133:11211'
-b                   '//指定从缓存服务器192.168.79.134:11211'
11211				'//端口号'

• 开启服务

'//主从服务器都要做'
[root@master shell]# chmod +x magent.sh 	'//增加magent脚本执行权限'
[root@master shell]# systemctl start keepalived.service	'//开启keepalived服务'
[root@master shell]# netstat -ntap |grep 12000	'//keepalived启动会有点慢，我们需要稍等一下'
tcp        0      0 192.168.73.100:12000    0.0.0.0:*               LISTEN      67513/magent  

• keepalived的漂移地址

[root@master shell]# vim /var/log/messages 
搜索'//Transition to MASTER STATE'，有即成功
[root@master shell]# ip addr	'//查看漂移地址是否绑定成功'
...省略内容
 inet 192.168.73.100/32 scope global ens33	'//绑定成功 '
...省略内容
[root@slave keepalived]# vim /var/log/messages 
搜索'//Entering BACKUP STATE'，有即成功
[root@slave keepalived]# ip addr	'//查看漂移地址是否绑定成功'
...省略内容
 inet 192.168.73.100/32 scope global ens33	'//绑定成功 '
...省略内容

3.4开启memcached并进行测试

'//主服务器开启'
[root@master ~]# ln -s /usr/local/memcached/bin/* /usr/local/bin/
[root@master ~]# memcached -m 512k -u root -d -l 192.168.73.200 -p 11211
[root@master ~]# netstat -ntap |grep 11211
tcp        0      0 192.168.73.200:11211    0.0.0.0:*               LISTEN      88178/memcached     
[root@master ~]# 
'//从服务器开启'
[root@slave keepalived]# ln -s /usr/local/memcached/bin/* /usr/local/bin/
[root@slave keepalived]# memcached -m 512k -u root -d -l 192.168.73.201 -p 11211
[root@slave keepalived]# netstat -ntap |grep 11211
tcp        0      0 192.168.73.201:11211    0.0.0.0:*               LISTEN      124927/memcached  

'//主服务器测试'
[root@master ~]# yum install telnet -y	'//安装Telnet远程登陆程序'
[root@master ~]# telnet 192.168.73.200 11211
Trying 192.168.73.200...	'//连接成功'
Connected to 192.168.73.200.
Escape character is '^]'.
quit	'//退出'
Connection closed by foreign host.
'//从服务器测试'
[root@slave keepalived]# yum install telnet -y
[root@slave keepalived]# telnet 192.168.73.201 11211
Trying 192.168.73.201...	'//连接成功'
Connected to 192.168.73.201.
Escape character is '^]'.
quit	'//退出'
Connection closed by foreign host.

4memcached客户端测试

• 客户端登录memcached

[root@client ~]# yum install telnet -y	
[root@client ~]# telnet 192.168.73.100 12000	'//使用漂移地址登陆'
Trying 192.168.73.100...
Connected to 192.168.73.100.
Escape character is '^]'.

• 测试主从同步

[root@client ~]# telnet 192.168.73.100 12000	
Trying 192.168.73.100...
Connected to 192.168.73.100.
Escape character is '^]'.
add username 0 0 5	'//客户端连接并新建一个数据'
12345
STORED
'//返回主服务器查看是否同步生成数据'
[root@master ~]# telnet 192.168.73.200 11211
Trying 192.168.73.200...
Connected to 192.168.73.200.
Escape character is '^]'.
get username
VALUE username 0 5	
12345	'//主服务器成功生成'
END
'//返回从服务器查看是否同步生成数据'
[root@slave keepalived]# telnet 192.168.73.201 11211
Trying 192.168.73.201...
Connected to 192.168.73.201.
Escape character is '^]'.
get username
VALUE username 0 5	
12345	'//从服务器成功生成'
END
'//测试成功，主从都成功生成数据'

• 测试高可用

'//宕机主服务器，看从服务器是否正常使用'
[root@master ~]# systemctl stop keepalived.service 	'//关闭主服务器keepalived服务'
[root@client ~]# telnet 192.168.73.100 12000	'//客户端登陆成功'
Trying 192.168.73.100...
Connected to 192.168.73.100.
Escape character is '^]'.
set username 
UNSUPPORTED COMMAND
set username 0 0 4	'//修改一下数据'
1234
STORED
'//从服务器查看数据是否同步'
get username
VALUE username 0 4
1234	'//成功同步'
END