I make my stream ids descriptive enough so that I understand what it is in the context of that spout or bolt. For wrapper bolts (like CoordinatedBolt) that add

I make my stream ids descriptive enough so that I understand what it is in the context of that spout or bolt. For wrapper bolts (like CoordinatedBolt) that add streams in addition to the wrapped bolt, I'll prepend the stream id with the name of the wrapper class to avoid naming conflicts (essentially namespacing the stream). In general I think of streams as not going to a particular bolt, but something that is provided that anyone can subscribe to. So in the WordCountTopology, the stream of words isn't "intended" for the word counting bolt, it's just data that can be used by anyone else in the topology. This is a consumer-focused way of looking at it (consumers know their inputs) rather than producer-focused (producers know their outputs).