What is Polydat?
Polydat is a variates construction engine.
More specifically, Polydat is all of:
- a function graph grammar
- a procedural generation kernel
- a function library and loader
- a runtime type-safety reifier
- a parameter space projection system
- a context layering API
- an expression language
Why? It's too many things!
Polydat is, ultimately, the distilled and sharpened variate generation system needed for systems like nb-rs. In fact, Polydat wasn't designed as a system against a set of new requirements. It evolved as a reduction of nosqlbench's core features during a rust port. Polydat is what you get when you take the essence of a complex but capable system like nosqlbench and compress it down with heat and pressure until it is forced to take a minimal, elemental shape.
Motivation
A lesson learned while evolving nosqlbench steered Polydat to where it is now:
Managing many testing and simulation parameters can be overwhelming!
In nosqlbench, users have to manage a variety of parameters in different places with different formats. Polydat's design categorically avoids this problem, since all the values used in a workload simulation are owned by the same subsystem.
- Workload parameters on the command line -> Polydat
- Template parameters in the workload -> Polydat
- Procedural generation recipes -> Polydat
- Op template fields and bindings -> Polydat
- Dimensional configuration parameters and labels -> Polydat
What this means in practice is that a single set of rules applies everywhere, and since everything is owned by the same subsystem, you can always ask it exactly where a value comes from or how it is computed. All variables used in a simulation are connected through the same substrate with a supporting grammar and a consistent set of rules.
Documentation
- Illustrations — runnable examples through the GK DSL and the programmatic Assembler API.
- Compilation — Phase 1 / 2 / 3 levels, Hybrid mode, throughput numbers, and the
jit/vectordataCargo features. - Nodes — the 250+ built-in function nodes.
- License — Apache-2.0; full text at LICENSE.
Part of the nb-rs workspace.