Name: testland/cache-stampede-reference
Rating: 75.2 (1 reviews)
Author: testland

testland/cache-stampede-reference

Pure-reference catalog of cache-stampede (thundering-herd) phenomena and mitigations: parallel misses on key expiry trigger simultaneous recomputation (often congestion-collapse), countered by three families - locking, external recomputation near-expiry, and probabilistic early expiration via XFetch (`(time() - delta * beta * log(rand(0,1))) >= expiry`). Use when designing cache-refresh strategy or diagnosing a stampede incident. This is the single failure-mode pattern; for the broader multi-tier pattern catalog use cache-coherence-patterns-reference, for the stale-while-revalidate / stale-if-error extensions use stale-while-revalidate-reference; a reference consumed by redis-cache-tests, not a runnable test.

Quality

94%

Does it follow best practices?

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Securityby

Passed

No findings from the security scan

Quality

Content

85%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A well-structured reference skill: actionable thresholds and tests, a clear sequenced workflow with validation checkpoints, and clean one-level-deep progressive disclosure to a real bundle file. The only weakness is conciseness -- the Overview and Worked-example prose explain a phenomenon Claude already knows and could be trimmed.

Suggestions

Trim the Overview's Wikipedia quote block to the single defining fact (congestion collapse on parallel miss) instead of three quoted sentences; the Symptoms table already conveys the phenomenon.

Condense the Worked example to the key decision (known-hot key -> external recompute + XFetch backstop -> N=1000 load test asserts <=5 recomputes) without the "site falls over at 3 PM" narrative setup.

Move the "Combining strategies" prose paragraph into the existing layering table, since the table already states each layer's role and the paragraph largely restates it.

Dimension	Reasoning	Score
Conciseness	Mostly efficient (compact tables for Symptoms, Testable behaviours, Anti-patterns, Limitations), but the Overview quotes Wikipedia to explain what a cache stampede is and the Worked example narrates a scenario -- content Claude largely already knows and could be tightened.	2 / 3
Actionability	Gives concrete, specific guidance -- numeric thresholds ("recompute-cost-vs-traffic ratio exceeds 0.1", "beta=1"), the canonical XFetch formula, and exact test parameters ("N=1000 concurrent on cold key", "upstream sees <=5 recomputes") -- with executable implementations correctly delegated to the reference file.	3 / 3
Workflow Clarity	The "How to use" section is a clear 7-step sequence with explicit checkpoints: "Confirm a live stampede against the Symptoms table", a production-concurrency load test asserting the recompute ceiling, and an alarm step that forms a feedback loop for silent regressions.	3 / 3
Progressive Disclosure	The body is a spine that keeps summaries inline and delegates full implementations to one well-signaled, one-level-deep reference (references/stampede-mitigations.md, verified to exist) with companion/consumer skills clearly named in References.	3 / 3
	Total	11 / 12 Passed

Description

100%

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A high-quality reference-skill description: it states a concrete niche, names the three mitigation families with the XFetch formula, gives an explicit Use-when trigger, and clearly distinguishes itself from companion skills. Third-person voice is maintained throughout, so no specificity penalty applies.

Dimension	Reasoning	Score
Specificity	Lists multiple concrete mitigation families ("locking, external recomputation near-expiry, and probabilistic early expiration via XFetch") plus the canonical XFetch formula, rather than vague language.	3 / 3
Completeness	Clearly answers both what ("Pure-reference catalog of cache-stampede ... phenomena and mitigations") and when ("Use when designing cache-refresh strategy or diagnosing a stampede incident.") with an explicit trigger clause.	3 / 3
Trigger Term Quality	Covers natural terms a user would say ("cache-stampede", "thundering-herd", "stampede incident", "cache-refresh strategy") with an explicit "Use when designing cache-refresh strategy or diagnosing a stampede incident." trigger.	3 / 3
Distinctiveness Conflict Risk	A narrow, well-defined niche that explicitly disambiguates from sibling skills ("for the broader multi-tier pattern catalog use cache-coherence-patterns-reference, for the stale-while-revalidate / stale-if-error extensions use stale-while-revalidate-reference"), making wrong-skill triggering unlikely.	3 / 3
	Total	12 / 12 Passed

Validation

100%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Reviewed

5 days ago

Table of Contents

Discovery Implementation Validation