DUNE » DUNE DAQ » dune-artdaq

When online monitoring is performed, one can imagine that some of the online monitoring processes won't need all events to run their art modules over (e.g., if an event display is being performed). While filtering could of course be done by putting filter modules upstream of analyzer modules, this is not an optimal solution since unnecessary bandwidth is consumed if all events are sent from a dispatcher process to an online monitoring process, even if only a (possibly tiny) subset of those events are actually wanted. There should be infrastructure in place so it's simple for developers of online monitoring to write a selection function on the event, which can then be executed within the dispatcher BEFORE it decides to send an event downstream to an online monitoring process.