memcached + keepavlied + magent 实现高可用

雷锋

　　系统环境

服务器名称	IP地址	操作系统	软件包	用途	VIP地址
nosql1.linuxplus.com	172.16.216.185	Centos 7.5	libevent-devel,memcached,magent	主节点	172.16.216.200
nosql2.linuxplus.com	172.16.216.186	Centos 7.5	libevent-devel,memcached,magent	备份节点
nosql3.linuxplus.com	172.16.216.187	Centos 7.5	telnet	测试节点

　　安装magent
[root@nosql1 software]# mkdir /opt/software/magent
[root@nosql1 software]# tar xf magent-0.5.tar.gz -C /opt/software/magent
[root@nosql1 software]# cd magent/
[root@nosql1 magent]# ls
ketama.c  ketama.h  magent.c  Makefile
[root@nosql1 magent]# vim ketama.h
#ifndef _KETAMA_H
#define _KETAMA_H
添加：
#ifndef SSIZE_MAX                       
#define SSIZE_MAX 32767
#endif
[root@nosql1 magent]# vim Makefile
LIBS = -levent -lm                      #首行LIBS = -levent后加上-lm
[root@nosql1 magent]# make
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
[root@nosql1 magent]# ls
ketama.c  ketama.h  ketama.o  magent  magent.c  magent.o  Makefile
[root@nosql1 magent]# cp magent /usr/bin
[root@nosql1 magent]# scp magent root@172.16.216.186:/usr/bin　　安装配置keepalived

• 　　nosql1.linuxplus.com
  

[root@nosql1 ~]# yum install keepalived
[root@nosql1 ~]# cd /etc/keepalived/
[root@nosql1 keepalived]# vim keepalived.conf
! Configuration File for keepalived
global_defs {
  notification_email {
  devops@qq.com
  }
  notification_email_from devops@qq.com
  smtp_server mail.qq.com
  smtp_connect_timeout 30
  router_id devops_MA
  enable_script_security
}
vrrp_script magent {
       script "/opt/magent.sh"
       interval 2
       user root
}
vrrp_instance devops_ha {
   state MASTER
   interface ens33
   virtual_router_id 51
   priority 180
   advert_int 1
   nopreempt
   authentication {
       auth_type PASS
       auth_pass 1111
   }
   virtual_ipaddress {
       172.16.216.200
   }
  track_script {
       magent
  }
}
[root@nosql1 ~]# vim /opt/magent.sh
#!/bin/bash
mem=$(ps -ef | grep keepalived | grep -v grep | wc -l)
if [ $mem -gt 0 ]
  then
      magent -u devops -n 51200 -l 172.16.216.200 -p 12000 -s 172.16.216.185:11211 -b 172.16.216.186:11211
      /usr/local/memcached/bin/memcached -u devops -m 128 -d
else
pkill -9 magent
fi
[root@nosql1 ~]# systemctl start keepalived.service
[root@nosql1 ~]# netstat -ntap | grep 12000
tcp        0      0 172.16.216.200:12000    0.0.0.0:*               LISTEN      16649/magent  
[root@nosql2 keepalived]# netstat -tulnp |grep 11211
tcp        0      0 0.0.0.0:11211           0.0.0.0:*               LISTEN      13959/./memcached   
tcp6       0      0 :::11211                :::*                    LISTEN      13959/./memcached参数：

• 　　-n：定义最大连接数
  

• 　　-l：指定虚拟IP
  

• 　　-p：指定虚拟IP的端口号
  

• 　　-s：指定主缓存服务器
  

• 　　-b：指定从缓存服务器
  

　　            

• 　　nosql2.linuxplus.com
  

[root@nosql2 ~]# yum install keepalived
[root@nosql2 ~]# cd /etc/keepalived/
[root@nosql2 keepalived]# vim keepalived.conf
! Configuration File for keepalived
global_defs {
  notification_email {
  devops@qq.com
  }
  notification_email_from devops@qq.com
  smtp_server mail.qq.com
  smtp_connect_timeout 30
  router_id devops_MB
  enable_script_security
}
vrrp_script magent {
       script "/opt/magent.sh"
       interval 2
       user root
}
vrrp_instance devops_ha {
   state BACKUP
   interface ens33
   virtual_router_id 52
   priority 90
   advert_int 1
   nopreempt
   authentication {
       auth_type PASS
       auth_pass 1111
   }
   virtual_ipaddress {
       172.16.216.200
   }
   track_script {
       magent
  }
}
[root@nosql2 ~]# vim /opt/magent.sh
#!/bin/bash
mem=$(ip addr | grep 172.16.216.200 | grep -v grep | wc -l)
if [ $mem -gt 0 ]
  then
      magent -u devops -n 51200 -l 172.16.216.200 -p 12000 -s 172.16.216.185:11211 -b 172.16.216.186:11211
      /usr/local/memcached/bin/memcached -u devops -m 128 -d
else
pkill -9 magent
fi
[root@nosql2 ~]# systemctl start keepalived.service
[root@nosql2 keepalived]# netstat -tulnp |grep 12000
tcp        0      0 172.16.216.200:12000    0.0.0.0:*               LISTEN      27343/magent        
[root@nosql2 keepalived]# netstat -tulnp |grep 11211
tcp        0      0 0.0.0.0:11211           0.0.0.0:*               LISTEN      13959/./memcached   
tcp6       0      0 :::11211                :::*                    LISTEN      13959/./memcached　　            
　　测试验证
[root@nosql3 ~]# telnet 172.16.216.200 12000
Trying 172.16.216.200...
Connected to 172.16.216.200.
Escape character is '^]'.
set username 0 0 11
devopsadmin
STORED
get username
VALUE username 0 11
devopsadmin
END
[root@nosql1 bin]# telnet 172.16.216.185 11211
Trying 172.16.216.185...
Connected to 172.16.216.185.
Escape character is '^]'.
get username
VALUE username 0 11
devopsadmin
END
quit
Connection closed by foreign host.
[root@nosql2 bin]# telnet 172.16.216.186 11211
Trying 172.16.216.186...
Connected to 172.16.216.186.
Escape character is '^]'.
get username
VALUE username 0 11
devopsadmin
END
quit
Connection closed by foreign host.