I’ve only scratched the surface on Storm. The “stream” concept at the core of Storm can be taken so much further than what I’ve shown here — I didn’t talk about things like multi-streams, implicit streams, or direct groupings. I showed two of Storm’s main abstractions, spouts and bolts, but I didn’t talk about Storm’s third, and possibly most powerful abstraction, the “state spout”. I didn’t show how you do distributed RPC over Storm, and I didn’t discuss Storm’s awesome automated deploy that lets you create a Storm cluster on EC2 with just the click of a button.
(Full Story: Twitter open sources Storm a mapreduce framework)