[CentOS] HA software advice

We are in need of some very basic software that will give us the ability to swing an ip address from one host to another during controlled maintenance or host failure. For now the IP address will be the only resource that is shared and there will never be a need for shared storage. Eventually we may want to monitor processes for health (probably just read in pid file) and it would be great if the recommended software had this ability as well but not completely necessary. The process monitoring part is just me trying to think ahead but it definitely wouldn't be needed in the near future.

Ideally, this should be light weight user land code that hopefully already comes easily with the distribution :)

Any suggestions? Thanks.