e7e4e33bb8
T01 docs/tenancy-posture.md - vector set per service rather than one repo vector, with the provider-versus-consumer finding routed to net-kingdom. T02/T03/T06 docs/placement-policy.md - accepts placement ownership scoped to rule-here/number-there, records a placement owner per workload, reports the latency-critical + batch co-residency on platform-pg, marks the connection-ceiling trigger unmonitored pending railiance-telemetry, and answers the retention floor/ceiling question. T04 s3-consumer-interfaces 1.1.0 - quota disclosure per SS10.2. Surfaces that apps-pg has no backup, no resource limits and no tuned parameters. T05 docs/adr/ created with a mandatory-frontmatter convention and the first three ADRs. This repo previously held none. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
81 lines
3.7 KiB
Markdown
81 lines
3.7 KiB
Markdown
---
|
|
title: "ADR-0002 — S3 owns the placement rule; the package repo owns the number"
|
|
status: proposed
|
|
revision: "1.0"
|
|
owner: railiance-platform
|
|
date: "2026-08-17"
|
|
last_reviewed: "2026-08-17"
|
|
review_interval: 6m
|
|
---
|
|
|
|
# ADR-0002 — S3 owns the placement rule; the package repo owns the number
|
|
|
|
## Context
|
|
|
|
`net-kingdom/canon/standards/tenancy-posture_v0.1.md` §8.2 proposes that
|
|
database placement policy — dedicated versus shared, and when that changes —
|
|
be owned by `railiance-platform`, co-signed by `adaptive-pricing`.
|
|
`tenant-engine` raised the same gap independently on 2026-08-16: both patterns
|
|
are live on railiance01, neither is written down, and each new service copies
|
|
whichever neighbour it looked at.
|
|
|
|
The complication is that this repo no longer holds the specs. `RAILIANCE-WP-0012`
|
|
and `RAILIANCE-WP-0015` moved the deployable surface to the `rapp-*` repos.
|
|
`platform-pg`'s `instances`, `max_connections`, memory limit and retention are
|
|
`rapp-postgres`'s cluster CR. Tenancy Posture §19.8 nonetheless asks *this repo*
|
|
for `platform-pg`'s declared maximum size — a question one hop from where its
|
|
answer lives.
|
|
|
|
Accepting ownership without stating this would produce either an answer we
|
|
cannot substantiate or a quiet non-answer.
|
|
|
|
## Decision
|
|
|
|
**Accept placement ownership, split along rule and number.**
|
|
|
|
*This repo owns the rule:* the default placement level, what overrides it, who
|
|
is accountable for each workload's placement, that a shared cluster must publish
|
|
a ceiling and an overflow target before its third consumer, that retention has a
|
|
floor and a ceiling, and that a consumer's erasure horizon on shared substrate
|
|
is disclosed rather than inherited silently.
|
|
|
|
*The package repo owns the number:* what the ceiling actually is, which resource
|
|
binds first, what the retention values are, and the validator that enforces them
|
|
where the CR lives.
|
|
|
|
**Placement ownership per workload sits with the consuming repo; this repo
|
|
co-signs.** The consumer knows its latency requirement, erasure horizon and
|
|
compliance position; S3 knows the substrate. A placement change needs both.
|
|
Putting the decision solely here would recreate the problem §8.2 exists to
|
|
avoid — an operations-shaped repo holding a commercial decision alone.
|
|
|
|
`adaptive-pricing` co-signature is requested, not assumed.
|
|
|
|
## Consequences
|
|
|
|
- `docs/placement-policy.md` is the operative document; this ADR is the
|
|
decision behind it.
|
|
- §19.8 is answered by obligation rather than by number: Rule P-4.1 requires
|
|
`platform-pg` and `apps-pg` to declare a ceiling before their third consumer.
|
|
Both are at two consumers.
|
|
- This repo owes `apps-pg`'s ceiling under its own rule. A policy whose author
|
|
is exempt is not a policy.
|
|
- §8.1 requires triggers to be *monitored*. This repo has no monitoring plane,
|
|
so the connection-and-memory-ceiling trigger is recorded `unmonitored`
|
|
pending `railiance-telemetry`. Declaring a ceiling is a partial substitute —
|
|
a written threshold is checkable by a human at provisioning, which beats a
|
|
limit discovered by an OOM kill.
|
|
- If `adaptive-pricing` declines, this ADR is revised to record single
|
|
ownership explicitly rather than leaving an unsigned co-signature line.
|
|
|
|
## Alternatives considered
|
|
|
|
**Decline ownership; route it to `rapp-postgres`.** They hold the specs and the
|
|
operational knowledge. Rejected: placement is a cross-cluster question and
|
|
`rapp-postgres` owns one package. A policy owned by one substrate's operator
|
|
cannot govern movement between substrates.
|
|
|
|
**Accept whole, including the numbers.** Rejected: it would either re-import
|
|
the deployable surface this repo deliberately gave up, or produce numbers
|
|
restated here that drift from the CR — a second source of truth for exactly the
|
|
values a consumer must be able to trust.
|