Memcached高可用群集

Posted 2020-12-26

Memcached高可用群集

主服务器安装Memcached、magent、libevent

安装 libevent  memcached    magent  （主服务器）
[[email protected] asd] cd /opt/libevent-2.1.8-stable
[[email protected] libevent-2.1.8-stable] ./configure --prefix=/usr/

[[email protected] asd] cd /opt/memcached-1.5.6
[[email protected] memcached-1.5.6]  ./configure --with-libevent=/usr

#主服务器上需要libevent的这个模块
[[email protected] opt]# ln -s /usr/lib/libevent-2.1.so.6 /usr/lib64/libevent-2.1.so.6

#解压出来magent会解压出来以下几个文件
[[email protected] asd] tar zxvf magent-0.5.tar.gz -C /opt/
ketama.c
magent.c
ketama.h
Makefile
[[email protected] opt] vi ketama.h #修改开头两个声明，最后一行有#endif声明不需要做修改
#ifndef SSIZE_MAX
#define SSIZE_MAX 32767
#endif

[[email protected] opt] vim Makefile #修改开头声明文件
LIBS = -levent -lm

[[email protected] opt] make #把magent生成的文件让系统能识别
gcc -Wall -O2 -g  -c -o magent.o magent.c
gcc -Wall -O2 -g  -c -o ketama.o ketama.c
gcc -Wall -O2 -g -o magent magent.o ketama.o -levent -lm

在从服务器上安装openssh-clients远程连接

[[email protected] Packages] rpm -ivh openssh-clients-7.4p1-11.el7.x86_64.rpm 
warning: /mnt/Packages/openssh-clients-7.4p1-11.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
Preparing...                          ################################# [100%]
    package openssh-clients-7.4p1-11.el7.x86_64 is already installed

把主服务器上编译产生的magent的文件远程复制到从服务器上

[[email protected] opt] ls
ketama.c  ketama.o               magent    magent.o  memcached-1.5.6
ketama.h  libevent-2.1.8-stable  magent.c  Makefile
[[email protected] opt] scp magent [email protected]:/usr/bin/
The authenticity of host ‘192.168.32.218 (192.168.32.218)‘ can‘t be established.
ECDSA key fingerprint is SHA256:gJPuAr8ixvbw23RR67aEnt+w9zT1936PhJNzk0nD/Bg.
ECDSA key fingerprint is MD5:1c:34:a1:74:e8:59:a3:54:7d:cd:61:bd:2d:7e:50:32.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added ‘192.168.32.218‘ (ECDSA) to the list of known hosts.
[email protected]‘s password: 
magent                                                                 100%  112KB  10.5MB/s   00:00 

在主从服务器上安装keepalived

#主从都要装
! Configuration File for keepalived

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
}

vrrp_script magent {
    script "/opt/shell/magent.sh"
    interval 2
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    track_script {
        magent
    }
    virtual_ipaddress {
        192.168.32.188
    }
}

#下面多余的部分可以全部删除

#把从服务器上的keepalived.conf配置文件用mv修改为备份文件
[[email protected] memcached-1.5.6]# cd /etc/keepalived/
[[email protected] keepalived]# ls
keepalived.conf
[[email protected] keepalived]# mv keepalived.conf keepalived.conf.bak
[[email protected] keepalived]# ls
keepalived.conf.bak

#用scp远程复制主服务器上的keepalived.conf配置文件到从服务器上/etc/keeplived/底下
[[email protected] keepalived]# scp keepalived.conf [email protected]:/etc/keepalived/
[email protected]‘s password: 
keepalived.conf                                                        100%  634   309.0KB/s   00:00   
#查看从服务器上有没有这个配置文件
[[email protected] keepalived]# ls
keepalived.conf  keepalived.conf.bak
#修改keepalived.conf配置文件
 router_id 2 #改为2
 state BACKUP #master改为BACKUP
 priority 90 #优先级改为小于100

配置配置文件里面的magent.sh脚本（注意路径要与配置文件里面路径相同）

主
[[email protected] opt] mkdir shell
[[email protected] opt] cd 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 192.168.32.188 -p 12000 -s 192.168.32.219:11211 -b 192.168.32.218:11211
else
pkill -9 magent
fi

-n 51200 //定义用户最大连接数
-l 192.168.x.x //指定虚拟IP
-p 12000  //指定端口号
-s //指定主缓存服务器
-b //指顶从缓存服务器
[[email protected] shell] chmod +x magent.sh

从
#!/bin/bash
K=`ip addr | grep 192.168.32.188 | grep -v grep | wc -l`
if [ $K -gt 0 ]; then
        magent -u root -n 51200 -l 192.168.175.188 -p 12000 -s 192.168.175.128:11211 -b 192.168.175.132:11211
else
pkill -9 magent
fi

开启keepalived

[[email protected] shell] systemctl start keepalived.service

#用ip addr查看虚拟ip有没有绑定成功
[[email protected] shell]# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:b9:51:08 brd ff:ff:ff:ff:ff:ff
    inet 192.168.32.219/24 brd 192.168.32.255 scope global dynamic ens33
       valid_lft 1238sec preferred_lft 1238sec
    inet 192.168.32.188/32 scope global ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:feb9:5108/64 scope link 
       valid_lft forever preferred_lft forever

#查看12000端口在主服务器上有没有开启
[[email protected] shell]# netstat -ntap
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 192.168.32.219:11211    0.0.0.0:*               LISTEN      27084/memcached     
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      1005/sshd           
tcp        0      0 127.0.0.1:25            0.0.0.0:*               LISTEN      1469/master         
tcp        0      0 192.168.32.188:12000    0.0.0.0:*               LISTEN      27418/magent        
tcp        0      0 192.168.32.219:55552    192.168.32.1:445        ESTABLISHED -                   
tcp        0     52 192.168.32.219:22       192.168.32.1:52961      ESTABLISHED 26820/sshd: [email protected] 
tcp6       0      0 :::22                   :::*                    LISTEN      1005/sshd           
tcp6       0      0 ::1:25                  :::*                    LISTEN      1469/master 

这个12000端口是虚拟端口用于登陆使用
从服务器没有这个端口
如果主服务器down掉后
12000虚拟端口会自动绑定到从服务器上用于
不影响登陆

登录Memcached服务器

memcached -m 512k -u root -d -l 192.168.32.219 主 -p  11211
memcached -m 512k -u root -d -l 192.168.32.218 从 -p  11211

netstat -ntap |grep 11211

有11211端口表示服务开启成功

Memcache缓存服务器存储数据应用

add username 0 0 7 //不进行压缩和序列化标识   数据过期时间为永不过期  标识号是7就需要输入7位数。

example //输入数据

get username //获取数据
VALUE username 0 7
example

gets username
VALUE username 0 7 1     //最后一位是更新因子会自增1
example

set username 0 0 10    //更新信息，若键名不存在，则自行添加
everything

replace username 0 0 8    //更新信息，若键名不存在，则报错
12345678

gets username
VALUE username 0 8 4
12345678

cas username 0 0 7 4     //检查更新，更新因子相等则更新否则返回EXISTS
lodging
STORED

append username 0 0 7    //键值后追加数据
example
STORED

prepend username 0 0 2   //键值前追加数据
un
STORED

delete username

flush_all      //清除所有缓存数据
OK

stats //显示状态信息

quit //退出