There will probably be less than 50 clients sending heartbeats between 1 and 5 minutes apart. It has to run on Windows as well as *nix so I thought to do it all in Perl. I have just hammered it with a multithreaded client and it takes a few secs to clear 100 beats. I have some retry now in the client. If it gets too much perhaps we will specify the server must be on *nix and use the inet way, should not be too onerous a requirement.
The heartbeat monitor itself will send its own heartbeat using IBM Tivoli events to a Tivoli Enterprise Console (T/EC) so its failure should be detected there. It will also send detected client heartbeat failures as T/EC events, records to a data warehouse and localy log them too.
Pereant, qui ante nos nostra dixerunt!