Storage systems · Phased project

A local archive cache with explicit integrity and capacity

Fictional media archive Ash serves generated byte fixtures through a fast local cache and slower provider stub. Both tiers run locally.

Practice brief · Version 5

Project scope: 10 tickets / 3 phases
Total focused work estimate: 24h + setup
Suggested stack: TypeScript · Filesystem adapter · Vitest

Recommended next step

Start with CTIER-101

Open the first ticket for its prerequisites, acceptance criteria, verification plan, and an editable task draft.

Open first ticket Add to My work

What the engineer takes away

Practice cache correctness, request coalescing and capacity control.

What the team gains

Inspect whether faster delivery preserves bytes and operating limits.

Before you start

Create immutable generated blobs with known digests.
Implement controllable cache and origin adapters with read failures.

Delivery agreement

Use dedicated fixture directories and publish measured local observations only.

AI tools are welcome during implementation. Record assumptions, review the result, and verify its behavior.

Delivery phases

PHASE 1
Define cache reads
Keep source authority explicit.
PHASE 2
Control cache mutation
Handle contention and eviction.
PHASE 3
Repair and observe
Recover damage without hiding uncertainty.

Define cache reads

Keep source authority explicit.

CTIER-101
Keep archive cache misses distinct from provider failures
Entry ticket; project setup still required
Estimated field mix
- Storage systems70%
- Site reliability30%
Bug · Foundational · 1hAdd to My work
CTIER-102
Key archive cache entries by immutable blob identity
Depends on CTIER-101
Estimated field mix
- Storage systems70%
- Performance engineering30%
Task · Foundational · 1h 15mAdd to My work
CTIER-103
Verify archive cache fills before promoting temporary bytes
Depends on CTIER-102
Estimated field mix
- Storage systems100%
Task · Intermediate · 2h 15mAdd to My work

Control cache mutation

Handle contention and eviction.

CTIER-104
Coalesce concurrent archive cache fills for one blob
Depends on CTIER-103
Estimated field mix
- Performance engineering50%
- Storage systems50%
Bug · Advanced · 2h 45mAdd to My work
CTIER-105
Enforce archive cache capacity before admitting a fill
Depends on CTIER-103, CTIER-104
Estimated field mix
- Storage systems50%
- Performance engineering50%
Task · Advanced · 3hAdd to My work
CTIER-106
Avoid evicting archive blobs while active readers hold them
Depends on CTIER-105
Estimated field mix
- Storage systems80%
- Backend20%
Bug · Expert · 4hAdd to My work
CTIER-107
Record archive cache recency without writing on every byte read
Depends on CTIER-104, CTIER-106
Estimated field mix
- Performance engineering60%
- Storage systems40%
Chore · Intermediate · 2hAdd to My work

Repair and observe

Recover damage without hiding uncertainty.

CTIER-108
Detect corrupted archive cache entries before serving them again
Depends on CTIER-103, CTIER-106
Estimated field mix
- Storage systems80%
- Site reliability20%
Task · Advanced · 3hAdd to My work
CTIER-109
Reconcile archive cache metadata after process restart
Depends on CTIER-105, CTIER-108
Estimated field mix
- Storage systems80%
- Site reliability20%
Bug · Advanced · 3hAdd to My work
CTIER-110
Report archive cache hit rates with a defined denominator
Depends on CTIER-107, CTIER-109
Estimated field mix
- Site reliability50%
- Performance engineering30%
- Storage systems20%
Chore · Intermediate · 1h 45mAdd to My work

Use this project

Briefs (.md) Tickets (.csv) Structured data (.json)

CSV keeps grouping and dependency keys as descriptive fields. Import mapping depends on your tracker configuration.

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Preparing the next view without exposing private workflow data.

Define cache reads

Keep source authority explicit.

CTIER-101

Keep archive cache misses distinct from provider failures

Entry ticket; project setup still required

Estimated field mix

Storage systems70%
Site reliability30%

Bug · Foundational · 1hAdd to My work

CTIER-102

Key archive cache entries by immutable blob identity

Depends on CTIER-101

Estimated field mix

Storage systems70%
Performance engineering30%

Task · Foundational · 1h 15mAdd to My work

CTIER-103

Verify archive cache fills before promoting temporary bytes

Depends on CTIER-102

Estimated field mix

Storage systems100%

Task · Intermediate · 2h 15mAdd to My work

Control cache mutation

Handle contention and eviction.

CTIER-104

Coalesce concurrent archive cache fills for one blob

Depends on CTIER-103

Estimated field mix

Performance engineering50%
Storage systems50%

Bug · Advanced · 2h 45mAdd to My work

CTIER-105

Enforce archive cache capacity before admitting a fill

Depends on CTIER-103, CTIER-104

Estimated field mix

Storage systems50%
Performance engineering50%

Task · Advanced · 3hAdd to My work

CTIER-106

Avoid evicting archive blobs while active readers hold them

Depends on CTIER-105

Estimated field mix

Storage systems80%
Backend20%

Bug · Expert · 4hAdd to My work

CTIER-107

Record archive cache recency without writing on every byte read

Depends on CTIER-104, CTIER-106

Estimated field mix

Performance engineering60%
Storage systems40%

Chore · Intermediate · 2hAdd to My work

Repair and observe

Recover damage without hiding uncertainty.

CTIER-108

Detect corrupted archive cache entries before serving them again

Depends on CTIER-103, CTIER-106

Estimated field mix

Storage systems80%
Site reliability20%

Task · Advanced · 3hAdd to My work

CTIER-109

Reconcile archive cache metadata after process restart

Depends on CTIER-105, CTIER-108

Estimated field mix

Storage systems80%
Site reliability20%

Bug · Advanced · 3hAdd to My work

CTIER-110

Report archive cache hit rates with a defined denominator

Depends on CTIER-107, CTIER-109

Estimated field mix

Site reliability50%
Performance engineering30%
Storage systems20%

Chore · Intermediate · 1h 45mAdd to My work