LRU evicts the wrong tenant Debugging Lab

LRU evicts the wrong tenantCaching & PerformanceMediumPreparing workspaceAutosaved

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Incident Dossier

LRU evicts the wrong tenant

Under load, the cache drops the profile that was just read in favor of an entry that has not been touched in minutes. The hottest tenant repeatedly misses.

Initial failing signalRecently read entry is evictedExpected least-recently-used entry evicted · received most-recently-read entry evicted

Progress

1Reproduce the bugRun checks

2Edit the fixOpen

3Pass checksOpen

4Submit fixOpen

Reproduction Steps

Run npm test.
Compare what `get` does to the insertion-ordered map versus what `set` does.
Decide which entries deserve to be considered 'recent' and what changes on read.
Make sure reads (and re-sets) bump the entry to the most-recently-used position.

Focus Mode

Start

src/cache.js

Likely area

src/cache.js

Progressive hints

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

TopicCaching & Performance

DifficultyMedium

Est. time22 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...