Apache Storm has two REST APIs for showing topology stats, /api/v1/topology/:id and showing component stats, /api/v1/topology/:id/component/:component.
Both of APIs shows metrics aggregated by topology or each component.
It helps determining traffics between component to component, which is good for many topologies. But if users use their own topology which utilizes lots of streams, they may want to see topology stats in detail - in point of stream's view.
We already have visualization API to show the traffics between stream to stream, but it's internal API, and contains only transferred, and it shows non-aggregated result so users need to aggregate theirselves.