Files
zeekay 1b367e2b62 chore: rebase the tree onto upstream master
The tree was a debranded snapshot of upstream taken around 2026-02-20, and
upstream has moved about five months since. This replaces it with upstream
master, mechanically re-derived: bin/debrand does the rename, and the
pipeline and squashed migrations are restored from the shipped tree.

Not a merge. The previous import replaced the tree wholesale in a single
commit, so there is no shared content history to merge against. Reproducing
the rename on the new tree is what actually converges.

What survives: .hanzo/workflows, the Dockerfiles and bin/docker* entrypoints,
compose files, LLM.md, and insights/migrations. The squashed initial
migration is load-bearing — the live database records it by name, so
upstream's ~918 individual migrations cannot come back.

Nine products are dropped as unreferenced. Twenty-one more that we do not run
are kept anyway because the core app still imports them; unpicking those is a
refactor and does not belong in a rebase.

This base does not build yet, and the reasons are not in the rename:
upstream now wants Python 3.13.13 against our 3.12.12 and Django 5.2 against
our 4.2, and the dependency manifests still name upstream packages that we
republish under our own names. Those are decisions, not renames.
2026-08-01 15:44:40 -07:00

51 lines
1.8 KiB
Python

"""
Analysis-health signals for experiments. Pure functions — no I/O.
Currently evaluates one signal: asymmetric `$multiple`-exclusion bias on uneven
splits. Designed to grow (SRM, low exposures, variant drift, ...) as additional
pure evaluators when needed.
"""
from insights.schema import BiasRisk, MultipleVariantHandling
from products.experiments.backend.variant_distribution import is_evenly_distributed
MULTIPLE_VARIANT_KEY = "$multiple"
# `$multiple` share above this triggers the warning. Below this, the asymmetric-
# exclusion effect on arm means is too small to matter in practice.
MULTIPLE_VARIANT_BIAS_THRESHOLD = 0.1 # on the 0-100 scale (0.1 = 0.1%)
def evaluate_bias_risk(
flag_variants: list[dict] | None,
multiple_variant_handling: MultipleVariantHandling,
total_exposures: dict[str, int],
) -> BiasRisk | None:
"""
Empirically observed multi-variant exclusion bias risk: uneven split + EXCLUDE
handling + observed `$multiple` share above the threshold.
Returns a `BiasRisk` only when all three conditions hold; `None` otherwise.
"""
if multiple_variant_handling != MultipleVariantHandling.EXCLUDE:
return None
variants = flag_variants or []
if not variants:
return None
rollout_percentages = [variant.get("rollout_percentage", 0) for variant in variants]
if is_evenly_distributed(rollout_percentages):
return None
total_observed = sum(total_exposures.values())
if total_observed <= 0:
return None
multiple_observed = total_exposures.get(MULTIPLE_VARIANT_KEY, 0)
multiple_variant_percentage = (multiple_observed / total_observed) * 100
if multiple_variant_percentage <= MULTIPLE_VARIANT_BIAS_THRESHOLD:
return None
return BiasRisk(multiple_variant_percentage=multiple_variant_percentage)