Harvest sweep, batch 6 of 6. - #343 ratified (per the decision minuted on the issue): an override IS a topology-parameter variation — the executed run's topology_hash is the reopened topology's own, deliberately not required to resolve in the store; the manifest's params map plus the base document reconstruct the variant. C24 carries the full clause, C12/C18 cross-reference it; pinned by a bare-vs-noop-override hash test (distinct, and stable across runs). - #342 item 5: C14 pins exec's unresolved-target exit partition on the existing usage/runtime line — file-content faults (not-JSON, op-script, wrong-kind) exit 2, missing-state faults (unreadable non-id target, unregistered content id) exit 1. One sanctioned realignment: the wrong-kind refusal moves 1 → 2 to join its file-content siblings (RED-first on the updated pin); the unregistered-id row gains its missing sibling pin. - #341 item 4: the authoring guide gains a worked cost-wiring op-script (ConstantCost → CostSum via PositionManagement geometry, built and verified), honest about being a wiring reference — production cost models still come from a campaign document's cost block (C10). closes #341 closes #342 closes #343
5.5 KiB
C12 — The atomic sim unit and the four orchestration axes
Guarantee. The atomic unit is (frozen topology + param-set + data-window + RNG-seed) → deterministic run → metrics. Parameters are typed, ranged, runtime
values injected at graph build — no recompile per param-set; the optimizer sees a
generic vector of typed ranges. A bound blueprint param is that param's
default: "open" means must be bound by an axis, "bound" means default,
overridable by an axis, so a campaign axis (param-sweep) may name a bound
param — the family boundary re-opens it on the probe and on every member
reload, and the axis binds it per cell; exec's blueprint leg still requires
every param resolved (a truly open param refuses), and its own --override NODE.PARAM=VALUE (#246 residue, #319) reopens exactly the named bound param
for that one execution — the single-member analogue of a campaign axis. The
reopened execution's topology_hash is therefore the reopened topology's own,
not the pre-override document's — ratified as the deliberate reading, not a
defect (#343; full ratification in C24's
"Reproduction identity"). Identity is untouched: content_id_of (crates/aura-research/src/lib.rs) is
the one hashing primitive, read directly off the authored document by
aura_runner::member's run_signal_r/run_blueprint_member — where the
manifest's topology_hash is computed inline (#319 Task 9 retired the
CLI-side wrapper that used to duplicate this one call) — never a re-opened
probe, and each member manifest records its per-cell bindings (#246, ratified
2026-07-12; the restriction this amends — axes bind only open knobs — was an
implementation consequence of bind() shrinking the param surface, not a recorded
decision). Raw data is shared read-only across sims via Arc<[T]> (the
data-server is built for this). Four axes orchestrate the atomic unit:
(1) param-sweep (grid/random), (2) optimization (argmax metric), (3) walk-forward
(rolling in-sample optimize + out-of-sample test), (4) Monte-Carlo (N seeded
realizations perturbing input). MC = sweep over seeds; each realization is
itself deterministic given its seed.
Forbids. Baking a specific search strategy (Bayesian/genetic) into the primitive — those are pluggable policies atop the atomic unit; recompiling on a param change.
Why. A stable primitive + orchestration axes keeps "wahnsinnig schnell" (embarrassingly parallel across the unit) cleanly separated from search policy. Seed-as-input reconciles Monte-Carlo with C1. The "frozen topology" of the atomic unit is one harness instance, selected by the harness's structural axes (C20); the structural experiment matrix is the outer orchestration over this dimension, the tuning sweep the inner (C19/C20).
Current state
Harness::run is typed as a producer seam — the object-safe Source trait
(peek/next, plus bounds and a resident_records() residency probe;
crates/aura-engine/src/harness.rs) that the k-way merge drives (C3). Two source
shapes back it. The eager load_m1_window/close_stream path
(crates/aura-ingest/src/lib.rs), wrapped as VecSource, materializes a whole
stream and is retained for bounded loads. The streaming M1FieldSource
(crates/aura-ingest/src/lib.rs) pulls a data-server window lazily, borrowing one
Arc<[M1Parsed]> chunk per pull (zero-copy within a source) and decoding each
Scalar on demand, so its source ring is resident O(one chunk), not
O(window length) — resident_records() is a per-source bound, not
whole-process RSS.
Raw-data sharing is realized both within and across sims. The data-server's
FileCache retains each window's parsed chunks read-only for the pass, so process
residency is O(records-touched) — the replay-many sharing model, not a leak.
Across sims, the sweep / Monte-Carlo / walk-forward families (axes 2–4) build their
members over one shared Arc<DataServer> (one FileCache;
crates/aura-ingest/src/lib.rs), so a window is parsed once and every member's
M1FieldSource borrows the same cached Arc<[M1Parsed]> chunks. The single-pass
parse cost of a window is tracked as #95.
Axis 1 (param-sweep) is built. GridSpace enumerates a cartesian lattice over
discrete per-slot value-lists; RandomSpace draws N seeded points over typed
continuous ParamRanges (I64 inclusive [lo,hi], F64 half-open [lo,hi)),
validated against the param-space before any run; a ListSpace enumerates an
explicit point list. All implement the Space trait the disjoint sweep /
run_indexed core is generic over (crates/aura-engine/src/sweep.rs), so every
enumeration runs through one execution path (C1: results in enumeration order, not
completion order). The other axes are realized as families over that core:
walk_forward + WindowRoller (crates/aura-engine/src/walkforward.rs) for the
rolling in-sample/out-of-sample split, monte_carlo
(crates/aura-backtest/src/mc.rs) for the seed sweep; optimization is argmax over
a sweep's metrics, a policy atop the core rather than a baked-in strategy. The
seeded sampler reuses the bit-stable SplitMix64
(crates/aura-analysis/src/lib.rs) as a code-path-disjoint instance from the
data-edge seed RNG (the source-seam firewall, #52/#71: they share only the u64
type, never a path).
See also
History: c12-atomic-sim-unit.history.md