LVS+keepalived 的DR模式的两种做法

LVS DR模式搭建

准备工作

三台机器：

dr：192.168.13.15
rs1：192.168.13.16
rs2: 192.168.13.17

vip:192.168.13.100

修改DR上的/etc/sysctl.conf文件

net.ipv4.ip_forward=0改为net.ipv4.ip_forward=1

第一种做法lo

Dr上的配置

! Configuration File for Keepalived
! ---------------------------------------------------------------------------
! GLOBAL
! ---------------------------------------------------------------------------
global_defs {
	! this is who emails will go to on alerts
	notification_email {
		wan@os.cn
		! add a few more email addresses here if you would like
	}
	notification_email_from wan@os.cn
	
	! mail relay server
	smtp_server 127.0.0.1
	smtp_connect_timeout 30
	! each load balancer should have a different ID
	! this will be used in SMTP alerts, so you should make
	! each router easily identifiable
	router_id LVS_13.100
}
vrrp_instance VI1_LVS_CN {
	state MASTER
	interface eth1
	! interface to run LVS sync daemon on
	lvs_sync_daemon_interface eth1
	!mcast_src_ip 192.168.13.15
	virtual_router_id 100
	priority 100
	advert_int 1
	smtp_alert
	authentication {
		auth_type PASS
		auth_pass qw_web
	}
	! these are the IP addresses that keepalived will setup on this
	! machine. Later in the config we will specify which real
	! servers  are behind these IPs without this block, keepalived
	! will not setup and takedown any IP addresses
	virtual_ipaddress {
		192.168.13.100
	}
}

virtual_server 192.168.13.100 80 {
	! interval between checks in seconds
	delay_loop 5
	! use weighted least connection as a load balancing algorithm
	lb_algo wrr
	! lvs_sched wrr
	! we are doing Direct Routing
	lb_kind DR
	! lvs_method DR
	protocol TCP
	! WEB01
	real_server 192.168.13.16 80 {
		weight 100
		HTTP_GET {
			url {
				path /.keepalived
				status_code 200
			}
			connect_timeout 10
			nb_get_retry 3
			delay_before_retry 5
		}
	}
	! WEB02
	real_server 192.168.13.17 80 {
		weight 100

		HTTP_GET {
			url {
				path /.keepalived
				status_code 200
			}
			connect_timeout 10
			nb_get_retry 3
			delay_before_retry 5
		}
	}
}

两台Rs上的这配置

[root@local shell]# more realserver.sh 
#!/bin/bash
vip=192.168.13.100
case "$1" in
start)
	ifdown lo
	ifup lo
	ifconfig lo:0 $vip broadcast $vip netmask 255.255.255.255 up
	/sbin/route add -host $vip lo:0
	echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
	echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
	echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
	echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
	;;
stop)
	ifdown lo
        ifup lo
        /sbin/route del -host $vip lo:0
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/lo/arp_announce
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_ignore
        echo "0" >/proc/sys/net/ipv4/conf/all/arp_announce
        ;;
*) 
        echo "Usage: $0 {start|stop}" 
        exit 1 
esac  
exit 0 

第二种做法iptables

Dr上的配置（同第一种一致）

! Configuration File for Keepalived
! ---------------------------------------------------------------------------
! GLOBAL
! ---------------------------------------------------------------------------
global_defs {
	! this is who emails will go to on alerts
	notification_email {
		wan@os.cn
		! add a few more email addresses here if you would like
	}
	notification_email_from wan@os.cn
	
	! mail relay server
	smtp_server 127.0.0.1
	smtp_connect_timeout 30
	! each load balancer should have a different ID
	! this will be used in SMTP alerts, so you should make
	! each router easily identifiable
	router_id LVS_13.100
}
vrrp_instance VI1_LVS_CN {
	state MASTER
	interface eth1
	! interface to run LVS sync daemon on
	lvs_sync_daemon_interface eth1
	!mcast_src_ip 192.168.13.15
	virtual_router_id 100
	priority 100
	advert_int 1
	smtp_alert
	authentication {
		auth_type PASS
		auth_pass qw_web
	}
	! these are the IP addresses that keepalived will setup on this
	! machine. Later in the config we will specify which real
	! servers  are behind these IPs without this block, keepalived
	! will not setup and takedown any IP addresses
	virtual_ipaddress {
		192.168.13.100
	}
}

virtual_server 192.168.13.100 80 {
	! interval between checks in seconds
	delay_loop 5
	! use weighted least connection as a load balancing algorithm
	lb_algo wrr
	! lvs_sched wrr
	! we are doing Direct Routing
	lb_kind DR
	! lvs_method DR
	protocol TCP
	! WEB01
	real_server 192.168.13.16 80 {
		weight 100
		HTTP_GET {
			url {
				path /.keepalived
				status_code 200
			}
			connect_timeout 10
			nb_get_retry 3
			delay_before_retry 5
		}
	}
	! WEB02
	real_server 192.168.13.17 80 {
		weight 100

		HTTP_GET {
			url {
				path /.keepalived
				status_code 200
			}
			connect_timeout 10
			nb_get_retry 3
			delay_before_retry 5
		}
	}
}

两台Rs上的这配置

[root@local shell]# iptables -t nat -A PREROUTING -p tcp -d 192.168.13.100 --dport 80 -j REDIRECT
[root@local shell]# iptables -t nat -A OUTPUT -p tcp -d 192.168.13.100 --dport 80 -j REDIRECT

 以上两种方式均可实现DR模式。