I would like my nightly amdump routine to "wait" for the clients to be
ready before it starts running.

My clients may have to run scripts (ex: do an oracle hot backup to
disk, run batch jobs) before they are ready to be backed up.

I'm planning to run a wrapper for amdump instead of amdump. This
wrapper would essentially wait for all the clients clients to "tell"
they're ready, and then either time out or start the real amdup.  I
know there are client wrapper kludges that have been devised, but it's
too complicated for my case.

I'm trying to find a nice way to listen for the clients, instead of
relying on some sort of "lock files" that the clients would have to
remotely remove on the amanda server when they're ready.

Does anyone have a good suggestion ? Is there a SIMPLE tool that is
usable over the network to permit simple message based communication
protocol between a server and "clients" ?

If such a tool exists, it would be really useful elsewhere.

Thanks