bedrock-kv / bedrock / e53dde5036456125ac40f89bc08302ef53f79d9f

82%

Build Type

push

github

Committed by web-flow

Commit Message

Assignment verification: the committed family is the membership authority (#195)

Closes the **bedrock-q67.21.5** re-adoption residue and
**bedrock-q67.21.7** (alive-but-unadopted workers) with a single
mechanism. Draft for review; stacked on #194.

## The FDB sanity check killed the original plan

The ticket sketched a phase-a-style port: hand the distributor a
snapshot of the director's services map, interrogate every materializer
for its `:shard_id` under a deadline, and adopt matches for uncovered
tags. Checked against FDB and the current architecture, that mechanism
is redundant twice over — and a side channel besides:

- **Recovery's locking phase already locks every advertised
materializer**, and bootstrap adopts every locked survivor
(`existing_materializers_by_shard` + `prefer_family_named`). A sweep
over the same services map rediscovers only what bootstrap already
found.
- **Unnamed strays already retire themselves**: `rejoin_verdict` →
`:displaced` on the next layout push — FDB's undesired-data
self-cleanup. Nothing to add.
- FDB's DD has no process-discovery RPC sweep. Membership rides the
committed keyspace (`serverList`/`serverKeys`); DD *verifies* every
listed server. Keyspace-is-the-channel says the same.

## What actually remains — and the collapse

The one real gap is a worker the committed `materializers/` family
**names** but the epoch never **embraced**: its node missed recovery's
roll call and rejoined later. The sweep monitors it, liveness looks fine
— but it was never locked into the epoch, so the tag stays dark until
the next recovery. That is precisely q67.21.7: *liveness is not
adoption*. Candidates come from the family itself — no services
snapshot, no `:shard_id` interrogation (the entry already binds
worker→tag).

## Mechanism

At the startup sweep, each named non-placeholder assignment gets one
bounded (2s) probe of its new `:epoch` info fact — the membership check,
FDB-DD-style:

- **Current** → verified silently; the ... (continued)

Coverage Stats

64 of 67 new or added lines in 4 files covered. (95.52%)

326 existing lines in 28 files now uncovered.

6642 of 8535 relevant lines covered (77.82%)

1029.22 hits per line