ADR-010 (new): the Backend trait's I/O seams pinned before any code —
'get' returns a crate-internal read cursor (kv engines materialize;
'local' pread loop; pg-lo lo_get windows), 'put' has two named forms
(whole-value kv / staged-put large); GC state is store-core-owned via
a crate-internal contract-tested engine-state seam on the SQL-backed
engines (backends never learn liveness — ADR-005 verbatim); the store
core holds the joint entry+pin transaction (corrects ADR-009 §2's
ownership statement); kv-tier fleet-validity rule added (mirror of
ADR-008 §3); ops pin-token TTL race resolved (the token IS the pin;
renewal rides have/re-put; pause-past-TTL falls to delete-then-recover);
feature graph pinned (pg-lo does not imply postgres).
ADR-011 (new): vocabulary pinned — tier (contract, exactly two) vs
engine (concrete impl, exactly five); store instance / node / fleet
split (fleet = pool-sharing, not node count — fixes requirements.md's
self-contradiction with REQ-2); mem demoted from 'backend'/'testing
tier' to the kv tier's third engine (contract-reference engine);
fs tier renamed 'large' including the feature name (last free moment
before code exists); constructor modes pinned (dual-tier default,
kv-only, mem-only) plus the composite fleet-validity predicate.
Consistency round across all specs and ADR-003/004/007/008/009: stale
pg-lo passages resolved per ADR-009's supersession; ADR-008 owner
'node id' → store-instance id; threshold wording corrected (conservative
edge, not midpoint, of the 128-256 KiB crossover zone); SweepReport
shape specced; mem classification unified; 008/009 ADR files renamed to
match the tier rename; README deferral-policy recap aligned (third
category = decided-but-sequenced work, not a parking kind); POC crate
list completed.
Verification: two independent architecture review rounds (the first
found 4 criticals — unpinned trait I/O shapes, missing fleet-state
seam, node/fleet self-contradiction, pin-token/TTL conflict — all
resolved; final round: zero criticals); all markdown links resolve;
ADR tables complete (11 ADRs).
Dissolve OQ-10's circular "standing offer" framing and record the
engine decision the POC evidence already supported:
- ADR-007 (new): kv tier ships sqlite (default) + postgres (feature
`postgres`, default-off), constructor-selected per node; records the
deployment economics (classical kv+fs+relational downstream stack
collapses to one relational engine + fs), the pg impl contract
(POC #5 B5 posture deltas), the CI sweep-safety gate under
--all-features, redb ruled out (POC #6), and posture defaults as
deferred cost in the ADR-006 pattern
- ADR-003: amended status (engine pin widened by ADR-007); kv entry
notes the widened engine set
- ADR-004: reconciliation note — the "two backends" count is tiers,
not engines
- backends-and-dispatch.md: tier≠engine distinction, pg engine
section, co-tenancy note (same-file consumer writes share sqlite's
single-writer ceiling), substitution-door precedent
- open-questions.md: OQ-10 resolved-by-ADR-007, with the
why-this-is-not-Schrödinger's-code record (a deployment running
alkblobs cannot pre-exist the pg engine — OQ-09 precedent); parked
index narrowed to OQ-07/OQ-08
- overview.md: layer map + dependency posture reflect the `postgres`
feature; README.md: ADR-007 in tables + corollary applications
- phase-0.md / pg+redb findings: promotion + supersession notes
Trigger framing survives only as deployment guidance (which engine a
node chooses — topology, not throughput), not as a gate on the crate's
own work.
Verified: cargo test, clippy --all-targets -D warnings, fmt --check.
Docs-only change (Phase 1 architecture); no implementation yet.
The backends spec read as if the Backend trait were a general storage
abstraction and 'two backends, exactly' banned other storage in a
deployment — so a downstream wanting sqlite manifests appeared forced
into implementing a third backend, the exact weld ADR-004 forbids.
- backends-and-dispatch.md: state plainly that the trait is a CAS-tier
contract (immutable digest-keyed entries, GC-shaped list/delete) and
never a host for manifest/index storage; consumer storage is
beside-the-pool. 'Two, exactly' counts trait impls shipped, not
storage per deployment. kv: tier name vs pinned sqlite engine made
explicit.
- ADR-004: add the explicit corollary under the consumer-seams point.