Use linux kernel linux virtual server (IPVS) for HA and load balancing instead HaProxy

We are may use LVS instead of HaProxy.

Advantages:
1) This is Linux kernel module, so we don't need to copy 'proxyed' data from kernel space to user space, and from user space to kernel. This is zero copy in kernel space. So we have bigger throughput and smallest latency.
2) This is L4 switching, not L7 switching with HaProxy
3) Fully implemented VRRP stack in keepalived daemon for full HA
4) External application checks for example MySQL, Keystone, Cinder or Glance