234b1b559f
Assistant: codex Assistant-Model: gpt-6-astra Assistant-Session: 01a06ecb-456a-71c2-b41e-0755d336e883
2.5 KiB
| id | title | status | revision | owner | date | last_reviewed | review_interval |
|---|---|---|---|---|---|---|---|
| RPLAT-ADR-0005 | ADR-0005 — Reuse existing storage and defer unrequested stateful services | accepted | 1.0 | railiance-platform | 2026-09-05 | 2026-09-05 | 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.