Hello Forum:
I am working on a load balancing project. The type of routing I am implementing is direct routing (LVS-DIR). The following is a script that sets up the Linux Virtual Server (LVS) or the load balancer:
#!/bin/bash
#description: manages load balancer
#chkconfig: 35 20 80
#processname: lvsdr
. /etc/rc.d/init.d/functions
VIPeth00=192.168.2.2 #virtual ip on eth0:0
DIPeth0=192.168.2.3 #public (I know it is not public, just to get this running) real ip for lvs or load balancer on eth0
DIPeth1=192.168.1.1 #private real ip for lvs or load balancer on eth1
RIP1=192.168.1.3 #real server 1 private ip on eth0
RIP2=192.168.1.4 #real server 2 private ip on eth0[/COLOR]
BCAST=$VIPeth0 #seeting the broadcast address to VIPeth00
NMASK=255.255.255.255
start () {
echo "Start LVS of Director Server"
#set the VIP and systcl parameter
/sbin/ifconfig eth0 $DIPeth0 up
/sbin/ifconfig eth0:0 $VIPeth00 netmask $NMASK broadcast $BCAST
/sbin/route add -host $DIPeth0 dev eth0
/sbin/ifconfig eth1 $DIPeth1 up
[COLOR="Green"]#ip forwarding on the lvs
echo "1" > /proc/sys/net/ipv4/ip_forward
/sbin/sysctl -p
#clear the IPVS table
/sbin/ipvsadm -C
#set LVS with web apache
# -t = TCP protocol
# -s = scheduler
# rr = round robin
# -p 120 = indicates the connection duration to 120 seconds
# -g = gatewaying
/sbin/ipvsadm -A -t $VIPeth00:80 -s rr # -p 120
/sbin/ipvsadm -a -t $VIPeth00:80 -r $RIP1:80 -g
/sbin/iptables -F
#run LVS
/sbin/ipvsadm -Ln
}
stop () {
echo "Close LVS Director Server"
echo "0" > /proc/sys/net/ipv4/ip_forward
/sbin/ipvsadm -C
#/sbin/ifconfig eth0:0 down
/sbin/ifconfig eth0 down
/sbin/ifconfig eth1 down
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
*)
echo "Usage: $0 (start|stop|restart)"
exit 1
esac
Next is the script to set up real server1:
#!/bin/bash
#Description: Start real server 1
#chkconfig 2345
/etc/rc.d/init.d/functions
VIPlo0=192.168.2.2 #virtual ip on lo:0
RIP1eth0=192.168.1.3 #real server1 ip on eth0
GATEWAY=192.168.1.1 # is this right???
BCAST=$VIPlo0 #broadcast equal to VIPlo0
NMASK=255.255.255.255
start () {
echo "Start real server 1"
/sbin/ifconfig eth0 $RIP1eth0 up
/sbin/ifconfig lo:0 $VIPlo0 broadcast $BCAST netmask $NMASK
/sbin/route add -host $VIPlo0 dev lo:0
/sbin/route add default gw $GATEWAY
#to disable ARP for VIP:[/COLOR]
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
echo "1" > /proc/sys/net/ipv4/conf/eth0/arp_ignore
echo "2" > /proc/sys/net/ipv4/conf/eth0/arp_announce
}
stop () {
echo "Closing LVS of real server 1"
/sbin/ifconfig eth0 down
/sbin/route del -host $VIPlo0 dev lo:0
/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
echo "0" > /proc/sys/net/ipv4/conf/eth0/arp_ignore
echo "0" > /proc/sys/net/ipv4/conf/eth0/arp_ignore
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
stop
start
;;
*)
echo "Usage: $0 (start | stop | restart)"
exit 1
esac
On the LVS:
Interface configurations:
eth0 192.168.2.3
eth0:0 192.168.2.2 (This is the VIP as an alias)
eth1 192.168.2.1
lo 127.0.0.1
Routing tables:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.2.3 0.0.0.0 255.255.255.255 UH 0 0 0 eth0
192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 0 virbr0
On the real server 1 (I only have one real server setup so far):
Interface configurations:
eth0 192.168.1.3
lo 127.0.0.1
lo:0 192.168.2.2 (This is the VIP)
Routing tables:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.2.2 0.0.0.0 255.255.255.255 UH 0 0 0 lo
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
On both, the LVS and Real Server 1, the firewalls (iptables) are not running.
A few questions I have are:
1. On the LVS, is apache supposed to be running?
2. If so, what would be the ServerName for apache on the LVS?
3. What would be the ServerName for apache on the real server1, is it the server real IP or the VIP?[/COLOR]
When I try to access the web content on real server1 in a browser on the LVS, I get “Failed to Connect”. A connection to the server cannot be established.
The load balancer has two NICS, eth0 and eth1. The real servers will connect to the load balancer via eth1, and the client will connect via eth0.
Please help me find a solution to this problem.
Thanks.
--Willie