Can we make heartbeat between two squid hosts then?
Sure. I am running such a setup. You can couple services like squid to
the availability of an IP address. The IP addresses are then handled by
heartbeat and only on the host having the right IP squid is started.
Works almost perfectly. I have one important remark: Linux HA is not
exactly "install-and-run". I strongly recommend to test the approach in
a non-production setup and emulate the failures you want to circumvent.
Otherwise, many strange things may happen. I can give more details if
interested.
Yours,
Jakob Curdes