---
id: RPLAT-ADR-0005
title: "ADR-0005 — Reuse existing storage and defer unrequested stateful services"
status: accepted
revision: "1.0"
owner: railiance-platform
date: "2026-09-05"
last_reviewed: "2026-09-05"
review_interval: 6m
---

# ADR-0005 — Demand-gated stateful services

## Context

INTENT includes cache, object storage and messaging. Valkey is gated in the
Makefile. CNPG already consumes an external governed S3 backup destination.
`artifact-store` has local/S3 backend code, retention/hold semantics and a
MinIO/STS assessment; its older SCOPE understates the code. The reviewed
platform queue has no accepted general cache or messaging consumer request.
Absence from this queue is not a claim that no future consumer could need one.

## Decision

- Cache: defer shared Valkey deployment. Reopen on a named consumer specifying
  latency, eviction/durability, isolation, capacity and an operating owner.
- General object storage: reuse the existing backup destination only for its
  approved backup scope. Evaluate artifact-store's existing S3 interface for
  artifact-preservation demand before proposing another gateway or engine.
  Defer a general platform S3/MinIO service until accepted demand specifies
  retention, residency, capacity, recovery, credential scope and package owner.
- Messaging: defer shared broker deployment until a named consumer defines
  delivery/replay/order guarantees, retention, throughput and recovery needs.
  Do not replace application-specific queues by assumption.

Review on a new accepted consumer request, a change in existing provider
capability, or 2027-03-05, whichever comes first. This is an S3 deployment
posture decision; it assigns no new obligation to potential consumers and
chooses no vendor or engine. The Q3 fleet-owner question stays with
railiance-master; local recovery work continues independently.

## Consequences

Keep deploy gates. Any accepted new demand creates a bounded delivery plan
covering service contract, custody, tenancy, capacity, backup/restore, telemetry,
package owner, costs and acceptance before provisioning. Existing backup
credentials are not general artifact credentials. Platform does not take over
artifact metadata lifecycle or application publication logic.

## Alternatives considered

Deploy Valkey/MinIO/RabbitMQ to satisfy the nouns in INTENT: rejected because
it adds unsupported operations without an accepted workload. Declare external
backup S3 a general object service: rejected because its scope and consumer
contract are narrower.