1. 确保IP转发功能开启
# sysctl -a | grep ip_forward net.ipv4.ip_forward = 1
方法有三种
1)sysctl net.ipv4.ip_forward=1
2) echo "1" > /proc/sys/net/ipv4/ip_forward
3) 修改sysctl.conf, net.ipv4.ip_forward = 1, 执行sysctl -p命令
2. virtual ip的配置
keepalived 采用RD转发模式
测试拓扑结构
linux director
ip:192.168.1.199
vip:192.168.1.210
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++
| |
real server real server
ip: 192.168.1.13 ip: 192.168.1.14
vip: 192.168.1.210 vip: 192.168.1.210
lvs客户端也就是real server的vip,要和linux director的vip保持一致
lvs-real.sh
#!/bin/bash VIP=192.168.1.210 /etc/rc.d/init.d/functions case "$1" in start) ifconfig lo:0 $VIP netmask 255.255.255.255 broadcast $VIP /sbin/route add -host $VIP dev 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 sysctl -p >/dev/null 2>&1 echo "RealServer Start OK" ;; stop) ifconfig lo:0 down route del $VIP >/dev/null 2>&1 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 "RealServer Stoped" ;; *) echo "Usage: $0 {start|stop}" exit 1 esac exit 0
linux director上keepalived.conf
! Configuration File for keepalived global_defs { notification_email { #[email protected] } #notification_email_from [email protected] #smtp_server 127.0.0.1 #smtp_connect_timeout 30 router_id LVS_DEVEL } virtual_server 192.168.1.210 80 { delay_loop 3 lb_algo rr lb_kind DR persistence_timeout 120 protocol TCP real_server 192.168.1.13 80 { weight 100 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } real_server 192.168.1.14 80 { weight 100 TCP_CHECK { connect_timeout 3 nb_get_retry 3 delay_before_retry 3 connect_port 80 } } }
说明:由于是测试lvs负责均衡功能,没有配置vrrp_instance,在实际应用中,可以配置双linux director。所以在linux director上手工添加vip:192.168.1.210,可以使用如下方法
# ip addr add 192.168.1.210 dev eth0
3. keepalived DR转发模式,需要将real server的ip与virtual ip设定在同一个网段
4. linux director 需要安装ipvsadm,当ipvsadm启动后可以查看它是否被加载
# lsmod | grep ip_vs ip_vs 94742 5 #lpvsadm -ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 192.168.1.210:80 rr persistent 120 -> 192.168.1.13:80 Route 100 0 0 -> 192.168.1.14:80 Route 100 0 0
5. 如果配置都正确,需要考虑是否将ipvs框架编译进keepalived
6. 如还不行,考虑其它原因
二. NAT转发模式的配置
1. linux director需要两块网卡,一块对外提供服务,一块对内作为转发用,对内ip作为real server的网关
2. real server 不需要配置成lvs客户端,只要将网关配置为linux director的对内ip即可
3. 如果开启了iptables,请注意调整iptables FORWARD链的规则
参考:
1. lvs + keepalived 系统架构测试
2. Keepalived+LVS-DR模式配置高可用负载均衡集群
3. Linux Virtual Server Tutorial
4. The Keepalived Solution