The sticky refresh path and reservation reconciliation both took the fleet-wide
`relay_cells ... FOR UPDATE` scan to mutate one or two rows, so one busy cell
queued unrelated reconnects and migration completions behind it. Both now lock
only the rows they touch, in the same ascending cell_id order, and the sticky
grant moves its counter by a delta instead of writing back a snapshot value.
Placement keeps the ordered inventory lock: choosing the least-loaded cell is a
genuinely fleet-wide decision, and dynamically locking only the selected target
is what allowed cross-cell cycles before.
The pool's statement_timeout becomes env-configurable and a 57014 now reaches
the bounded transaction retry instead of surfacing as a terminal failure.
Schema DDL moves to its own `max: 1`, statement_timeout-free pool that is ended
before the serving pool opens, so a slow CREATE INDEX cannot inherit a request
deadline it will never fit inside.
Mirrors stablyai/orca-cloud#471 (squash c3354e8), byte-identical under cloud/.
The relay's cell-inventory lock (SELECT ... FROM relay_cells FOR UPDATE over
all 23 rows) is one global critical section shared by the assignment hot path
and every director sweep; with the pool's 1s lock_timeout a blocked waiter held
a pooled client for a full second, producing ~690 55P03 retries per 5 minutes
in production. Request paths now bound the wait at 500ms with a SET LOCAL that
is restored to the pool default before the next statement; director-only sweeps
take the lock NOWAIT and skip the tick; sweep timers are jittered; hold time is
exported as additive runtime-metrics fields so the bound can be tuned.
Phase 6 of the relay split: the relay's deploy/operate surface moves under cloud/ with 24 cloud-* workflows gated on ORCA_CLOUD_OPERATIONS_ENABLED, the Cloud SQL rollout lease action, the relay Terraform root (dual-accept identities for both repositories), scripts, docs, CODEOWNERS, and a terraform validate job in Cloud Verify.
Jinwoo Hong