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构建高可用LVS+keepalived+httpd和双主模型的keepalived方案

作者:vi123456  发布日期:2013-09-27 09:37:37

keepalived简介

keepalived是一个类似于layer3, 4 & 5交换机制的软件,也就是我们平时说的第3层、第4层和第5层交换。Keepalived的作用是检测web服务器的状态,如果有一台web服务器死机,或工作出现故障,Keepalived将检测到,并将有故障的web服务器从系统中剔除,当web服务器工作正常后Keepalived自动将web服务器加入到服务器群中,通过ping来监测对方的状态。

 

拓扑图:

223808630.gif

 

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实验环境:

centos-6.4

所需的安装包:

主的和备的Director上都安装上keepalived

后端的两个realserver上都安装上htppd服务

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1.先同步个节点上的时间


[root@yulong]# ntpdate  172.16.0.1

2.在主的和从的上面安装keepalived
 

[root@yulong ~]# yum install keepalived -y

3.编辑keepalived配置文件
 

[root@yulong keepalived]# vim  keepalived.conf 
修改一下参数为自己所用的 
global_defs { 
   notification_email { 
                                                                                                                                                                        
    root@localhost        收件人 
                                                                                                                                                                        
   } 
                                                                                                                                                                        
   notification_email_from  keep@localhost  发件人 
   smtp_server 127.0.0.1       邮件服务器 
   smtp_connect_timeout 10   链接超时时间 
   router_id LVS_DEVEL 
添加如下字段设置可以手动切换故障转移: 
vrrp_script chk_maintainace { 
                                                                                                                                                                        
  script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
                                                                                                                                                                        
  interval 1
  weight   -2
                                                                                                                                                                        
 } 
这段脚本的意思就是如果在这个目录下存在down的这个一个文件就把vip给转移到BAKPUP节点.这个文件可以手动创建来实现调试. 
以下用文字注释的都是需要修改的地方 
vrrp_instance VI_1 { 
    state MASTER                   设置主节点 
    interface eth0               网卡类型 
    virtual_router_id 51  虚拟路由ID 
    priority 100                    设置权重,权重必须大于BACKUP的权重 
    advert_int 1
    authentication {     
        auth_type PASS       加密方法 
        auth_pass 1111       密码 
    } 
    virtual_ipaddress { 
                                                                                                                                                                        
      172.16.8.100     设置访问的虚拟IP 
    } 
  track_script { 
                                                                                                                                                                        
  chk_maintainace     这个是定义刚才添加的那段代码生效 
    } 
}

4.配置完毕以上内容后复制到从节点上一份
 

[root@yulong keepalived]# scp  keepalived.conf   yu:/etc/keepalived/

5.然后在从节点上需要修改下如下两项
 

[root@www ~]# vim  /etc/keepalived/keepalived.conf 
state BACKUP            设置为备用节点 
priority 99              权重设置为比主节点的小

6.然后主备都启动keepalived服务
 

[root@yulong keepalived]# service keepalived restart 
Stopping keepalived:                                       [  OK  ] 
Starting keepalived:                                       [  OK  ]

7.然后查看master上的状态
 

[root@yulong keepalived]# ip addr show 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:0e:d7:4d brd ff:ff:ff:ff:ff:ff 
    inet 172.16.8.17/16 brd 172.16.255.255 scope global eth0 
    inet 172.16.8.100/32 scope global eth0        刚才配置的虚拟ip已经生效 
    inet6 fe80::20c:29ff:fe0e:d74d/64 scope link 
       valid_lft forever preferred_lft forever

8.然后我们把master上的节点给停掉看看能不能转移
 

root@yulong keepalived]# touch  down 
[root@yulong keepalived]# ip addr show 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:0e:d7:4d brd ff:ff:ff:ff:ff:ff 
    inet 172.16.8.17/16 brd 172.16.255.255 scope global eth0 
    inet6 fe80::20c:29ff:fe0e:d74d/64 scope link 
       valid_lft forever preferred_lft forever 
在keepalived目录下Touch  down 文件是我们写的那条脚本,很强大哟 
在次ip addr  show查看vip已经没有了

9.在备节点上查看vip有没有转移过来
 

[root@www ~]# ip  addr show 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:6a:51:21 brd ff:ff:ff:ff:ff:ff 
    inet 172.16.8.18/16 brd 172.16.255.255 scope global eth0 
    inet 172.16.8.100/32 scope global eth0         OK,已经转移过来了,说明是正常的. 
    inet6 fe80::20c:29ff:fe6a:5121/64 scope link 
       valid_lft forever preferred_lft forever

10.下面在主节点上配置keepalivedrealserver能调度上游的服务器
 

[root@yulong keepalived]# vim  keepalived.conf 
virtual_server 172.16.8.100 80 {      虚拟IP,就是一会要访问的IP 
    delay_loop 6
    lb_algo rr        调度算法                
    lb_kind DR         lvs的模式 
    nat_mask 255.255.0.0
    persistence_timeout 50
    protocol TCP    使用的协议 
                                                                                                                                   
    real_server 172.16.8.10 80 {    realserver的ip地址 这个别写错了 
        weight 1      权重                         
                                                                                                                                   
   TCP_CHECK {       realserver的状态监测 
                                                                                                                                   
   connect_timeout 3     响应超时时间,默认3秒 
   nb_get_retry 3            重试次数 
   delay_before_retry 3  重试间隔时间 
        } 
    } 
                                                                                                                                   
  real_server  172.16.8.11 80 {     第二个realserver的定义 和上面的一样 
                                                                                                                                   
   TCP_CHECK { 
                                                                                                                                   
   connect_timeout 3
   nb_get_retry 3
   delay_before_retry 3
      } 
                                                                                                                                   
    } 
}

11.配置完毕以后复制到备服务器上一份
 

[root@yulong keepalived]# scp   keepalived.conf   yu:/etc/keepalived/ 
然后在备的上面编辑keepalived.conf修改如下两项 
state BACKUP            设置为备用节点 
priority 99              权重设置为比主节点的小

12.上面的配置好以后我们来配置realserver服务器,两个realserver上都配置如下命令
 

[root@node1 ~]# ifconfig lo:0 172.16.8.100 broadcast 172.16.8.100   netmask 255.255.255.255  up 
由于我们使用的DR模型配置DR模型的vip,在lo上配置就行 
[root@node1 ~]# echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore 
[root@node1 ~]# echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore 
[root@node1 ~]# echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce 
[root@node1 ~]# echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce 
关闭arp广播 
[root@node1 ~]# echo  "<h1> you are word</h1>" > /var/www/html/index.html 
设置访问的网页主页内容

13.配置完成后两个realserver服务器上都启动web服务器进行测试
 

[root@node1 ~]# service  httpd   restart 
Stopping httpd:                                            [  OK  ] 
Starting httpd:                                            [  OK  ] 
多点击几下看看是不是均衡

223332971.png

223336271.png

访问成功,看来是均衡的

14.下面我们来通过ipvsadm查看下访问的状态


[root@yulong keepalived]# yum install  ipvsadm 
[root@yulong keepalived]# ipvsadm -L  -n --stats 
IP Virtual Server version 1.2.1 (size=4096) 
Prot LocalAddress:Port               Conns   InPkts  OutPkts  InBytes OutBytes 
  -> RemoteAddress:Port 
TCP  172.16.8.100:80                     3        3        0      156        0
  -> 172.16.8.10:80                      2        2        0      104        0
  -> 172.16.8.11:80                      1        1        0       52        0

Ok 看来是通过keepalived调用的

下面来配置keepalived双主模型

 

1.在主的上面添加如下内容


[root@yulong keepalived]# vim   keepalived.conf 
vrrp_instance VI_2 {  
    state BACKUP 
    interface eth0 
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication { 
        auth_type PASS 
        auth_pass 2111
    } 
    virtual_ipaddress { 
                                                                                  
      172.16.8.200
    } 
  track_script { 
                                                                                  
  chk_maintainace 
    } 
}

2.在备的上面添加如下内容
 

vrrp_instance VI_2 { 
    state MASTER 
    interface eth0 
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication { 
        auth_type PASS 
        auth_pass 2111
    } 
    virtual_ipaddress { 
      172.16.8.200
    } 
  track_script { 
  chk_maintainace 
    } 
}

3.重启主备的keepalived的服务
 

[root@yulong keepalived]# service keepalived  restart

4.查看备的上面虚拟主ip有木有生效
 

[root@www ~]# ip addr show 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:6a:51:21 brd ff:ff:ff:ff:ff:ff 
    inet 172.16.8.18/16 brd 172.16.255.255 scope global eth0 
    inet 172.16.8.200/32 scope global eth0      已经生效 
    inet6 fe80::20c:29ff:fe6a:5121/64 scope link 
       valid_lft forever preferred_lft forever

5.下面我们把备的masterdown掉看看是否会转移
 

root@www ~]# cd /etc/keepalived/ 
[root@www keepalived]# touch  down 
[root@www keepalived]# ip addr show 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:6a:51:21 brd ff:ff:ff:ff:ff:ff 
    inet 172.16.8.18/16 brd 172.16.255.255 scope global eth0 
    inet6 fe80::20c:29ff:fe6a:5121/64 scope link 
       valid_lft forever preferred_lft forever

172.16.8.200 的虚拟ip已经看不到了

 

 

6.下面在主的上面看看是否转移过来


[root@yulong keepalived]# ip addr show 
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:0e:d7:4d brd ff:ff:ff:ff:ff:ff 
    inet 172.16.8.17/16 brd 172.16.255.255 scope global eth0 
    inet 172.16.8.100/32 scope global eth0 
    inet 172.16.8.200/32 scope global eth0 
    inet6 fe80::20c:29ff:fe0e:d74d/64 scope link 
       valid_lft forever preferred_lft forever

两个虚拟ip都在,证明是正常的,此次双主模型搞定!
 

Tag标签: LVS   keepalived   httpd   双主模型  
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