Pen offers fault tolerance by automatically rerouting traffic from servers that are offline. But what if the load balancer goes down? Using VRRP, it is possible to run two load balancers in an active-passive failover configuration
[root@ ~]wget http://downloads.sourceforge.net/project/vrrpd/vrrpd/1.0/vrrpd-1.0.tar.gz?use_mirror=biznetnetworks
1. uncompress the source
2. cd in the directory
3. type 'make'(Please install gcc* before type make by "yum -y install gcc*")
[root@ ~] cp vrrpd /usr/sbin/vrrpd
Install pen and vrrpd on the two load balancer hosts. Start pen on both load balancers and check that both work by surfing to http://126.96.36.199/ and http://188.8.131.52/.
Now start vrrpd like this on both load balancers:
[root@ ~]vrrpd -i eth1 -v 1 192.168.0.3
Now try surfing to http://192.168.0.3/. One of the load balancers will be active and respond at that address
Disconnect "MASTER" .Now "SLAVE" restoring functionality.
Connect "MASTER" .Disconnect "SLAVE" ,"MASTER" restoring functionality