keepalived lvs 实现lvs高可用

keepalived 简介

keepalived是借用VRRP协议来实现高可用性的，VRRP协议是解决单点故障，使路由器和层三交换机实现冗余功能。

keepalived启动后会有三个进程

父进程：内存管理，子进程管理等等

子进程：VRRP子进程

子进程：healthchecker子进程

从图上可以看出，两个子进程都被系统WatchDog看管，两个子进程各自操作自己的事，healthchecker子进程负责检查各自服务器的健康程度，例如HTTP，LVS等等，如果healthchecker子进程检查到MASTER上服务不可用了，就会通知本机上的VRRP子进程，让他删除通告，并且去掉虚拟IP，转换为BACKUP状态

 

环境准备

1 操作系统

                   centos6.4 x86_64  

2 实验拓扑

3 服务器时间同步

[root@node1 ~]#ntpdate ntp.api.bz

[root@node2 ~]#ntpdate ntp.api.bz

[root@web1 ~]#ntpdate ntp.api.bz

[root@web2 ~]#ntpdate ntp.api.bz

 

4 安装keepalived ipvsadm

[root@node1 ~]# yum install keepalived ipvsadm

 

5 修改配置文件

! 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 LVS_DEVEL
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.200.10
    }
}
virtual_server 192.168.200.10 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    net_mask 255.255.255.0
    protocol TCP
    real_server 192.168.200.138 80 {
            weight 1
            HTTP_GET {
               url {
                    path /
                    status_code 200
                   }
               connect_timeout 3
               nb_get_retry 3
               delay_before_retry 3
            }
}

    real_server 192.168.200.139 80 {
            weight 1
            HTTP_GET {
               url {
                    path /
                    status_code 200
                   }
               connect_timeout 3
               nb_get_retry 3
               delay_before_retry 3
            }
}
}

 

6 复制配置文件到从服务器

[root@node1 ~]# scp /etc/keepalived/keepalived.conf 192.168.200.18:/etc/keepalived/keepalived.conf

7 从服务器 安装keepalived ipvsadm

[root@node2 ~]# yum install keepalived ipvsadm

 

8 修改配置文件

[root@node2 ~]# vim /etc/keepalived/keepalived.conf 
state BACKUP
priority 99

 

9 开启服务

[root@node1 ~]# service keepalived start
[root@node1 ~]# chkconfig --add keepalived
[root@node1 ~]# chkconfig keepalived on

 

[root@node2 ~]# service keepalived start
[root@node2 ~]# chkconfig --add keepalived
[root@node2 ~]# chkconfig keepalived on

 

10  安装 http

[root@web1 ~]# yum install httpd

[root@web2 ~]# yum install httpd

 

11 建立测试网页

[root@web1 html]# cd /var/www/html/
[root@web1 html]# vim index.html
this is web1

[root@web2 ~]# cd /var/www/html/
[root@web2 html]# vim index.html
this is web2

 

12 启动服务

[root@web1 html]# service httpd start
[root@web1 html]# chkconfig --add httpd
[root@web1 html]# chkconfig httpd on

[root@web2 html]# service httpd start
[root@web2 html]# chkconfig --add httpd
[root@web2 html]# chkconfig httpd on

 

13 修改内存参数 配置vip

[root@web1 ~]# echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
[root@web1 ~]# echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
[root@web1 ~]# echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
[root@web1 ~]# echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
[root@web1 ~]# ifconfig lo:0 192.168.200.10 broadcast 192.168.200.10 netmask 255.255.255.255 up
[root@web1 ~]# route add -host 192.168.200.10 dev lo:0

 

[root@web2 ~]# echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
[root@web2 ~]# echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
[root@web2 ~]# echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
[root@web2 ~]# echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
[root@web2 ~]# ifconfig lo:0 192.168.200.10 broadcast 192.168.200.10 netmask 255.255.255.255 up
[root@web2 ~]# route add -host 192.168.200.10 dev lo:0

 

14 查看相关vip  ipvs规则

[root@node1 ~]# ip addr
1: lo:  mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:3e:54:30 brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.17/24 brd 192.168.200.255 scope global eth0
    inet 192.168.200.10/32 scope global eth0
    inet6 fe80::20c:29ff:fe3e:5430/64 scope link 
       valid_lft forever preferred_lft forever

 

[root@node1 ~]# ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.200.10:80 wrr
  -> 192.168.200.138:80           Route   1      0          0         
  -> 192.168.200.139:80           Route   1      0          0  

 

15 测试

web1

web2

停止master的keepalived服务 ，vip ipvs规则会切换到backup服务器上

[root@node1 ~]# service keepalived stop

[root@node2 ~]# ip addr
1: lo:  mtu 16436 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:af:d6:a0 brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.18/24 brd 192.168.200.255 scope global eth0
    inet 192.168.200.10/32 scope global eth0
    inet6 fe80::20c:29ff:feaf:d6a0/64 scope link 
       valid_lft forever preferred_lft forever

[root@node2 ~]# ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.200.10:80 wrr
  -> 192.168.200.138:80           Route   1      0          0         
  -> 192.168.200.139:80           Route   1      0          0

 

停止web1服务 ipvs规则会清除web1服务器

[root@web1 ~]# service httpd stop

[root@node1 ~]# ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.200.10:80 wrr
  -> 192.168.200.139:80           Route   1      0

 

开启web1服务 ipvs自动会添加web1服务器

[root@node1 ~]# ipvsadm -L -n
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.200.10:80 wrr
  -> 192.168.200.138:80           Route   1      0          0        
  -> 192.168.200.139:80           Route   1      0