Wonderful! I feel bad that I didn't follow the work after hearing about Naiad originally. Where might I go to read more about the fault tolerance story - I note that's an ongoing area of research in the README. Also the link to the Kafka adapter is dead, is that work ongoing or does the story end at the capture/replay API? (Happy to bombard you with email if that's any more manageable for you!)
Reading the 'when not to use Timely Dataflow' section on sorting, are there any ideas from Nominal Adapton that are relevant in this distributed setting, when we're talking about small updates or inserts?
Durability is a student's research project at the moment. It's up and running for "Spark" style computations but the work has broader ambitions. In essence, all of the internal state in DD are easily (automatically) serialized LSM slabs, and it is cake to write them out and read them back (and almost cake to make sense of them).
Which Kafka link is dead? The work has quiesced because any next step seems to be involve assuming something about timestamps in the input. At the same time, it seems to take about 10 lines of code to write a Kafka source or sink, minus any careful worrying about acks for durability.
The DD and Adapton approaches may be a bit tricky to hybridize. Much incremental compute works by moving through a sequence of valid configurations, and DD's main departure is generalizing this to partial orders. So, maybe you could borrow ideas, but it would probably be original research to do so.
Email is great, as it is def no longer about skiplang.
https://github.com/frankmcsherry/differential-dataflow