The issue was raised by Jonathan Sick during the code review of DM-9034 and led to this ticket.

         if vdrp_measurement_doc['value'] is None:

             continue

+        if vdrp_measurement_doc['metric']['name'] not in registered_metrics:

+            metrics.append(shim_metric_definition(vdrp_measurement_doc))

@jsick:
Is it possible for a metric to appear multiple times in this list? Like, if there's multiple AM1 measurements in different bands, or multiple measurements against different specifications of a metric, then couldn't we have duplicates here?

@afausti:
That's a good point. In this implementation the metric name is unique so if there is already an AM1 registered it would not pick another AM1 with a different specification.

I see the problem when a metric, say AD1, depends on another metric specification, in this case AF1. We end up with three measurements of AD1 for each AF1 specification level, right?

I think if a metric has a different parameter or specification it should be named differently, so that we can identify each metric uniquely by its name, or perhaps have another mechanism like a composite primary key based on the metric name and specification? we should think on how to display the metric measurements in this situation too.