[cbsmith]

Flink looks really interesting to me. If it can get community momentum I might switch to it.

I'd definitely recommend including Storm for a POC. For any POC I'd warn that most of these streaming solutions are operationally a bit of a PITA, which tends to distort POC results.

[jonstewart]

We will be half-to-single rack scale for a while, so I'm not too too worried about operations--we also need to target solo workstations, which is the real challenge with any of these systems. If things go haywire, we can just restart processing later.

[cbsmith]

You might want to check out Kafka Streams.