The quiet-loss cure regressed recovery: the new typed torn-record error
was correct at identity-read time but threw inside init-time recovery
walks, killing opens that previously survived. The boundary, redrawn:
- IDENTITY READS (get-by-id of a specific record, CAS blob point-get):
typed TornRecordError, unchanged — a caller who asked for THAT record
can act on the answer.
- SET-SHAPED READS AND WALKS (enumeration, pagination, batch hydration —
the paths recovery rebuilds and finds page over): HEAL PAST the torn
victim. The adapter's loud floor (error log + counted gauge) fires at
the encounter; the walk serves the remaining rows. One crash casualty
can no longer kill every query on its shard — or the open itself.
- WRITES OVER TORN RECORDS ARE THE CURE: the save path's read-merge, the
commit path's before-image capture, and the operations' rollback
captures all treat a torn prior as the create sentinel, narrated — the
incoming bytes replace the unreadable ones, and history for the id
honestly restarts at that generation. Corruption can never block its
own heal.
- THE NaN SOURCE: torn mapper state (nextId/entries carrying garbage)
discards with narration and re-derives via the existing rebuild path;
the mint gains a source guard healing a non-integer counter from the
live map. The reopen and first-write RangeError shapes are dead at the
source, both authority branches.
Pinned with the exact fault-injection scenarios: a torn entity record
(including the VFS root) no longer kills the open — walks heal past it,
the keeper rows serve, and the identity read of the victim itself is
typed-or-healed; a torn mapper reopens and mints sanely on the first
post-recovery write.
Gates: tsc 0 · unit 2065/2065 · integration 828 · conformance 31/31.
Persisted entity totals inflated permanently: a delete's count decrement
was sourced from re-reading the record being removed, so a null read
(replace race, or a ghost left by a pre-8.3.1 partial delete) silently
skipped the decrement while the paired add had counted — and
Math.max(persistedTotal, scanned) meant no disk cleanup could ever
lower the reported total. Reported by a production deployment with a
write→delete→re-create repro minting drift within hours.
- The caller's pre-delete read now rides through the entire delete path
(remove()/removeMany()/plan → DeleteNoun/DeleteVerb operations →
deleteNoun/deleteVerb → deleteNounMetadata/deleteVerbMetadata): a
null internal read falls back to the known prior record instead of
skipping the decrement. StorageAdapter.deleteNoun/deleteVerb gain an
optional priorMetadata parameter (additive).
- rebuildTypeCounts() rebuilt only the type-statistics arrays and
computed the total just to LOG it — the persisted scalar
(counts.json) survived every rebuild. One canonical walk now rebuilds
every counter rollup (scalar totals + per-type maps + type
statistics) and persists them; repairIndex() runs the recount
unconditionally, since counters can be inflated over clean shelves.
Two production-reported spine fixes:
- Canonical delete is a FULL removal: remove()/removeMany() deleted the
metadata leg but never the canonical vectors.json leg or the <id>/
directory, leaving ghost rows that inflated enumerated counts forever,
read as damage scars, and caused duplicate readdir entries for
re-created VFS paths (the stale-unpost path). The delete operation now
routes through storage.deleteNoun — both legs + the entity container —
with a full two-leg before-image rollback; deleteVerb symmetric; the
blind 'no metadata file' catch that masked real faults is gone. The
generation log still holds the delete's before-image, so asOf() history
is unchanged. repairIndex() gains a conservative, loud orphan-prune
sweep (containers with no metadata content leg) + count recompute for
stores damaged by earlier versions.
- Family-scoped migration gate: every read blocked on the whole-brain
migration lock even when the migrating index was irrelevant. The gate
now scopes to the index families a read actually consults — canonical
reads never wait; find() waits only on its query shape's families;
graph traversals wait only on the graph family. Writes keep the
conservative whole-brain wait. A read that needs the migrating family
still blocks (bounded) with the retryable MigrationInProgressError.
The COW version-control surface (fork, branches, checkout, commit,
getHistory/streamHistory, asOfCommit, brain.versions) is gone, along with
its subsystems: src/versioning/, the COW object store (CommitLog,
CommitObject, RefManager, TreeObject), HistoricalStorageAdapter, and the
TypeAwareHNSWIndex path it kept alive. The Db API (now/transact/asOf/
with/persist/restore) is the one versioning model in 8.0.
Survivors and replacements:
- BlobStorage survives (the VFS stores file content through it), relocated
to src/storage/blobStorage.ts with binaryDataCodec.ts; its adapter
interface is now BlobStoreAdapter, slimmed to the consumed surface
(write/read/has/delete/getMetadata + MIME-aware compression policy).
- brain.migrate() backup branches are replaced by persist-before-migrate:
MigrateOptions.backupTo persists a hard-link snapshot of the current
generation before any transform runs; MigrationResult.backupPath reports
it, and brain.restore(path) brings it back wholesale.
- CLI: cow.ts (fork/branch/checkout/history/migrate) is replaced by
snapshot.ts — snapshot <path>, restore <path>, history (tx-log),
generation.
- New public read API: brain.transactionLog({limit}) exposes the reified
tx-log (generation/timestamp/meta, newest first) that backs the CLI
history command; TxLogEntry is exported.
Tests: superseded suites deleted; fork/commit blocks excised from shared
suites; BlobStorage tests relocated + reworked against the slimmed store;
migration tests now prove the backupTo snapshot/restore round trip; new
transactionLog coverage in db-mvcc.
- Remove detectAndRepairCorruption from init() hot path — was loading all
metadata chunks sequentially on startup. Now available via checkHealth()
and repairIndex() methods.
- Short-circuit warmCache on empty workspace — skip 4-6 wasted storage reads.
- Parallelize MetadataIndex.init() and getGraphIndex() via Promise.all().
- Defer metadata writes during rebuild to batch boundaries (every 5000
entities) instead of flushing per-entity.
- Skip pre-reads for new entities in transactions — saves 2 storage
round-trips per add() on cloud storage.
