- Describe a dataflow graph just like Timely
- Comes from a more "semantic dataflow" kind of heritage (frp, composition, flow-of-flows, algebraic operators, proof-oriented) as opposed to the more operationally minded background of Timely
- Has a (very) different notion of "progress" than Timely, focused instead of ensuring the compositions are generative in light of potentially unbounded streaming inputs
- In fact, Flo doesn't really have any notion of "timeliness", no timestamping at all
- Supports nested looping like Timely, though via a very different mechanism. The basic algebra is extremely non-cyclic, but the nested streams/graphs formalism allows for iteration.
The paper also makes a direct comparison with DBSP, which as I understand it, is also part of the Timely/Naiad heritage. Similar to Timely, the authors suggest that Flo could be a unifying semantic framework for several other similar systems (Flink, LVars, DBSP).
So I'd say that the authors of Flo are aware of Naiad/Timely and took inspiration of nested iterative graphs, but little else.
Flo lead-author here! This is spot on :) Flo aims to be a bit less opinionated than Timely in how the runtime should behave, so in particular we don't support the type of "time-traveling" computation that Timely needs when you have iterative computations on datasets with retractions.
This is also one of the core differences of Timely compared to DBSP, which uses a flat representation (z-sets) to store retractions rather than using versioned elements. This allows retractions to be propagated as just negative item counts which fits into the Flo model (and therefore Hydro).
- Describe a dataflow graph just like Timely - Comes from a more "semantic dataflow" kind of heritage (frp, composition, flow-of-flows, algebraic operators, proof-oriented) as opposed to the more operationally minded background of Timely - Has a (very) different notion of "progress" than Timely, focused instead of ensuring the compositions are generative in light of potentially unbounded streaming inputs - In fact, Flo doesn't really have any notion of "timeliness", no timestamping at all - Supports nested looping like Timely, though via a very different mechanism. The basic algebra is extremely non-cyclic, but the nested streams/graphs formalism allows for iteration.
The paper also makes a direct comparison with DBSP, which as I understand it, is also part of the Timely/Naiad heritage. Similar to Timely, the authors suggest that Flo could be a unifying semantic framework for several other similar systems (Flink, LVars, DBSP).
So I'd say that the authors of Flo are aware of Naiad/Timely and took inspiration of nested iterative graphs, but little else.