The sketch above makes duplicated work and inefficiency very likely. It's explicitly choosing at-least-once execution. The problem with the "already scheduled"

The sketch above makes duplicated work and inefficiency very likely. It's explicitly choosing at-least-once execution. The problem with the "already scheduled" pattern is when the machine holding the task falls over. Not a good choice for bank transactions. A good option for something like a distributed build farm - it doesn't matter hugely if you compile some piece of program repeatedly, but it matters a lot if you send the only copy of some source to a machine that immediately goes offline. Mainly bringing it up as a case in which RPC works beautifully - remote machine failures can be completely hidden by a willingness to do the work locally instead.