Backoff Jitter RNG Reset Per Attempt Debugging Lab

Backoff Jitter RNG Reset Per AttemptReliabilityHardPreparing workspaceAutosaved

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Incident Dossier

Backoff Jitter RNG Reset Per Attempt

During a coordinated retry storm the team introduced jittered backoff to spread clients out over time, but the synchronized retry waves kept coming back at the same cadence. Their math said the jitter should spread attempts across a 100ms window, yet traces showed every client retrying within the same millisecond — the jittered component was effectively constant.

Initial failing signalJitter values are identical across attemptsExpected jitter values vary across attempts · received every attempt produces the same delay

Progress

1Reproduce the bugRun checks

2Edit the fixOpen

3Pass checksOpen

4Submit fixOpen

Reproduction Steps

Run npm test.
Inspect delayForAttempt and ask where the rngFactory is invoked.
Notice that a fresh rng is created on every call, so every attempt sees the same first draw.
Construct the rng once and reuse it across attempts.

Focus Mode

Start

src/rng.js

Likely area

src/rng.js

Progressive hints

Hints reveal broad direction first, then narrow toward the suspect path without showing hidden tests or exact solution code.

TopicReliability

DifficultyHard

Est. time26 min

Workspacecreating

Explorer

Preparing workspace files…

Evidence Map

Failing signal loaded from challenge API
Workspace files loaded from workspace API
Results rendered only after API run/submit

Autosaved

workspace

Outputread-onlyready$ workspace boot

Workspace booting...