NAT模式的LVS和keepalived高可用
- 说明
- 安装lvs和keepalived
- DR主节点和备节点配置
- Real Server配置
- 查看信息
- 测试
LVS+keepalived是公司里面常用的负载均衡和高可用实现方案，lvs支持3中模式：NAT，DR，Tun，下面是NAT模式的实现
说明
CentOS6.5 64位 keepalived-1.2.13 ipvsadm v1.26 NAT模式
http://zh.linuxvirtualserver.org/
http://www.linuxvirtualserver.org/Documents.html
http://www.austintek.com/LVS/LVS-HOWTO/HOWTO/index.html
lvs服务器2块网卡，real server单网卡，ip如下：
主DR 192.168.22.219
eth0 外网192.168.22.219 192.168.22.249(VIP)
eth1 内网192.168.1.1 192.168.1.5(GateWay)
备DR 192.168.22.203
eth0 外网192.168.22.203 192.168.22.249(VIP)
eth1 内网192.168.1.2 192.168.1.5(GateWay)
realserver1 192.168.1.3 192.168.1.5(GateWay)
realserver2 192.168.1.4 192.168.1.5(GateWay)
client
|
keepalived VIP
|
-------------
| |
LVS master LVS backup
| |
-------------
|
GateWay(虚拟)
|
-------------
| |
Real Server1 Real Server2
安装lvs和keepalived
yum install popt popt-devel popt-static libnl libnl-devel
yum install ipvsadm
tar -xzf keepalived-1.2.13.tar.gz
cd keepalived-1.2.13
./configure
make
make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
chmod +x /etc/rc.d/init.d/keepalived
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/keepalived
cp /usr/local/sbin/keepalived /usr/sbin/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
mv /etc/keepalived/keepalived.conf /etc/keepalived/keepalived.conf.bak
开启IP转发
net.ipv4.ip_forward=1
DR主节点和备节点配置
keepalived.conf配置
# vim /etc/keepalived/keepalived.conf
global_defs {
notification_email {
your_email@163.com
}
notification_email_from root@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id lvs_dr1
}
vrrp_sync_group lvs_1 {
group {
VI_1
VI_GATEWAY
}
notify_master "/usr/local/sbin/lvsdr.sh start"
notify_backup "/usr/local/sbin/lvsdr.sh stop"
}
vrrp_instance VI_1 {
state MASTER #backup为BACKUP
interface eth0
virtual_router_id 51
priority 101 #backup为100
advert_int 1
authentication {
auth_type PASS
auth_pass bbotte
}
virtual_ipaddress {
192.168.22.249 255.255.255.0
}
vrrp_instance VI_GATEWAY {
state MASTER #backup为BACKUP
interface eth1
virtual_router_id 52
priority 101 #backup为100
advert_int 1
authentication {
auth_type PASS
auth_pass bbotte
}
virtual_ipaddress {
192.168.1.5
}
}
}
virtual_server 192.168.1.5 80
{
delay_loop 2
lb_algo rr
lb_kind DR
nat_mask 255.255.255.0
persistence_timeout 60
protocol TCP
real_server 192.168.1.3 80
{
weight 1
TCP_CHECK
{
connect_timeout 5
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
real_server 192.168.1.4 80
{
weight 1
TCP_CHECK
{
connect_timeout 5
nb_get_retry 3
delay_before_retry 3
connect_port 80
}
}
}
vim /usr/local/sbin/lvsdr.sh
#!/bin/bash
## LVS script for VS/DR
. /etc/rc.d/init.d/functions
#
VIP=192.168.22.249
RIP1=192.168.1.3
RIP2=192.168.1.4
#
case "$1" in
start)
/sbin/ifconfig eth0:1 $VIP netmask 255.255.255.0 up
# Since this is the Director we must be able to forward packets
echo 1 > /proc/sys/net/ipv4/ip_forward
# Clear all iptables rules.
/sbin/iptables -F
# Reset iptables counters.
/sbin/iptables -Z
# Clear all ipvsadm rules/services.
/sbin/ipvsadm -C
# Add an IP virtual service for VIP 192.168.0.200 port 80
# In this recipe, we will use the round-robin scheduling method.
# In production, however, you should use a weighted, dynamic scheduling method.
/sbin/ipvsadm -A -t $VIP:80 -s rr
# Now direct packets for this VIP to
# the real server IP (RIP) inside the cluster
/sbin/ipvsadm -a -t $VIP:80 -r $RIP1 -m
/sbin/ipvsadm -a -t $VIP:80 -r $RIP2 -m
/bin/touch /var/lock/subsys/ipvsadm.lock
;;
stop)
# Stop forwarding packets
echo 0 > /proc/sys/net/ipv4/ip_forward
# Reset ipvsadm
/sbin/ipvsadm -C
# Bring down the VIP interface
ifconfig eth0:1 down
rm -rf /var/lock/subsys/ipvsadm.lock
;;
status)
[ -e /var/lock/subsys/ipvsadm.lock ] && echo "ipvs is running..." || echo "ipvsadm is stopped..."
;;
*)
echo "Usage: $0 {start|stop}"
;;
esac
Real Server配置
下面配置2台real server
两台机均为centos 6.5 yum安装httpd服务并启动，iptables对80端口开放
Real Server 1:
cat /var/www/html/index.html
web 1111111111111
Real Server 2:
cat /var/www/html/index.html
test 22222222222
开启IP转发
net.ipv4.ip_forward=1
配置网关
＃vim /etc/sysconfig/network-scripts/ifcfg-eth0添加
GATEWAY=”192.168.1.5″
realserver.sh相同，并启动此脚本
vim realserver.sh
#!/bin/bash
#
# Script to start LVS DR real server.
# description: LVS DR real server
#
. /etc/rc.d/init.d/functions
VIP=192.168.22.249
host=`/bin/hostname`
case "$1" in
start)
# Start LVS-DR real server on this machine.
/sbin/ifconfig lo down
/sbin/ifconfig lo up
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
/sbin/ifconfig lo:0 $VIP broadcast $VIP netmask 255.255.255.255 up
/sbin/route add -host $VIP dev lo:0
;;
stop)
# Stop LVS-DR real server loopback device(s).
/sbin/ifconfig lo:0 down
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
;;
status)
# Status of LVS-DR real server.
islothere=`/sbin/ifconfig lo:0 | grep $VIP`
isrothere=`netstat -rn | grep "lo:0" | grep $VIP`
if [ ! "$islothere" -o ! "isrothere" ];then
# Either the route or the lo:0 device
# not found.
echo "LVS-DR real server Stopped."
else
echo "LVS-DR real server Running."
fi
;;
*)
# Invalid entry.
echo "$0: Usage: $0 {start|status|stop}"
exit 1
;;
esac
查看信息
DR MASTER：
# ip a
eth0
inet 192.168.22.219/24 brd 192.168.22.255
inet 255.255.255.0/32
inet 192.168.22.249/24 brd 192.168.22.255
eth1
inet 192.168.1.1/24 brd 192.168.22.255
inet 192.168.1.5/32
# ipvsadm -Ln
TCP 192.168.22.249:80 rr
-> 192.168.1.3:80 Masq 1 0 5
-> 192.168.1.4:80 Masq 1 0 4
DR BACKUP：
ip没有变动，为自己原有的ip
# ipvsadm -Ln
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
-> RemoteAddress:Port
测试
1，测试Real Server挂掉一个是否影响
把Real Server1的httpd服务关闭，打开VIP页面，一直刷新
2，测试keepalived的MASTER挂掉后，BACKUP能否正常接替主继续工作
把MASTER重启，在重启的期间，一直打开VIP首页查看，MASTER重启后，keepalived开机启动，继续由MASTER提供服务
2016年03月09日 于 linux工匠 发表