FA-74325 / Feature flag rollout bucketing / Member archive

Seeded weighted rollout: Buckets past the weights get no variation · case 05

When weights sum below 100000, some users evaluate to no variation at all.

Member previewVariant 5 · 3 implementations · 8 checks per implementation

Case contract

Hash text is (str(seed) if seed is not None else flag_key + "." + salt) + "." + ident, plus "." + secondary when secondary is not None (an empty string still counts). bucket = int(first 15 hex digits of sha1(text), 16) / 0xFFFFFFFFFFFFFFF. weights are in 1/100000 units; return the first index whose cumulative weight / 100000 exceeds the bucket, else the last index, as [index, round(bucket, 6)].

Why this case matters

Seeds let several flags share one bucketing so a cohort sees consistent variations.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
weights short of total go to last index	`[null, 0.233147]`	`[1, 0.233147]`	Failed

MEMBER ARCHIVE

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