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# Architectural Invariants
**Type:** standing review checklist
**Status:** living document
**Audience:** anyone proposing, reviewing, or implementing an OmniGraph change
This file is intentionally short. It records the rules that should be in
working memory for every non-trivial change. Detailed mechanics live in the
area docs linked below.
Use it this way:
- Review the change against **Hard Invariants** and the **Deny-list** .
- If code and docs disagree, either fix the code or add/update a **Known Gap** .
- Keep implementation ledgers, roadmap detail, and historical MR notes in the
per-area docs. This file is the filter, not the encyclopedia.
## Hard Invariants
1. **Respect the substrate.** Lance owns columnar storage, per-dataset
versioning, fragments, branches, compaction, cleanup, and index primitives.
DataFusion should own relational execution where it fits. Do not add custom
WALs, transaction managers, buffer pools, page formats, or local clones of
substrate behavior. Read [lance.md ](lance.md ) before guessing.
2. **Graph visibility is manifest-atomic.** Lance commits are per dataset.
OmniGraph's graph-level atomicity comes from publishing one manifest update
for the whole graph, guarded by expected table versions and sidecar recovery.
No write path may make a subset of touched node/edge tables visible as a
graph commit.
3. **A query reads one snapshot.** Query execution captures a manifest snapshot
for its lifetime. Do not re-read branch head mid-query to discover newer
table versions.
4. **Mutations publish at one boundary.** A `mutate_as` or `load` operation
accumulates constructive writes, commits each touched table at the end, then
publishes one manifest update. Do not commit per statement. Delete-only
queries are the documented inline residual; the parse-time D2 rule prevents
mixing deletes with insert/update until Lance exposes two-phase delete.
2026-05-30 23:20:56 +02:00
Read [writes.md ](writes.md ) and [execution.md ](execution.md ).
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5. **Recovery is part of the commit protocol.** Writers that can advance Lance
HEAD before manifest publish must write `__recovery/{ulid}.json` sidecars.
Recovery liveness, storage fault-injection matrix, and one storage implementation over object_store (#203)
* test(engine): pin the long-lived-handle heal contract for sidecar-covered drift
A Phase B -> Phase C failure (commit_staged advanced Lance HEAD, manifest
publish did not land, recovery sidecar persists) currently wedges every
subsequent staged write on the same engine handle: the commit-time drift
guard rejects with 'run omnigraph repair', but repair itself refuses
while a recovery sidecar is pending, so a long-lived server can only
recover by restart. The documented contract (writes.md 'Long-running
servers', invariants.md invariant 5) says refresh-time roll-forward
closes this residual without restart -- but no write path runs it.
Two red tests pin the intended contract at the write entry points:
a follow-up load (the POST /ingest shape: shared handle, no reopen)
and a follow-up mutation must heal roll-forward-eligible sidecars
in-process and then succeed.
Currently failing with:
table 'node:Company' has Lance HEAD version 2 ahead of manifest
version 1; run `omnigraph repair` before writing
The fix lands in the next commit.
* fix(engine): heal pending recovery sidecars at the staged-write entry points
Close the long-lived-process gap in the recovery protocol: a Phase B ->
Phase C residual (per-table commit_staged landed, manifest publish did
not, sidecar persists) previously recovered only at the next ReadWrite
open or via an explicit refresh() that no production write path called,
so a long-lived server wedged every subsequent write on the commit-time
drift guard until restart.
New recovery::heal_pending_sidecars_roll_forward:
- one list_dir of __recovery/ at write entry (empty -> immediate
return, the steady state), so the per-write cost is one storage list;
- per sidecar, acquires the same per-(table_key, table_branch) write
queues every sidecar writer holds from before write_sidecar until
after delete_sidecar, then re-checks sidecar existence -- this
serializes the heal against live writers instead of rolling an
in-flight sidecar forward from under its writer (which would fail
that writer's publish CAS spuriously). Lock order queues ->
coordinator matches every writer's commit->publish path. This is the
queue-acquisition design recovery.rs and write_queue.rs already
documented for in-process recovery;
- processes in RollForwardOnly mode: the common residual rolls forward
in-process; rollback-eligible sidecars still defer to the next
ReadWrite open (Dataset::restore is unsafe under concurrency).
Wire it into load_as and mutate_as (before the inline delete path can
advance any HEAD), and rebase Omnigraph::refresh onto the same helper
so refresh stops racing live writers' sidecars.
The maintenance entry points (apply_schema_as, branch_merge_as,
ensure_indices) intentionally keep their strict fail-loud preconditions
for now; wiring the same heal there is a follow-up with its own tests.
Turns the previous commit's two red tests green.
* fix(engine): name the right recovery path in the commit-time drift guard
The drift guard's 'run omnigraph repair before writing' advice is a
dead end when the drift is covered by a pending recovery sidecar:
repair refuses while a sidecar is pending. With the write-entry heal in
place, reaching this guard with sidecar-covered drift means the heal
deferred it (rollback-eligible), and the actual recovery path is a
read-write reopen. Distinguish the two classes on the error path only
(one sidecar list, after the conflict is already certain); a listing
failure falls back to the uncovered-drift wording rather than masking
the conflict.
Pinned by extending refresh_defers_rollback_eligible_sidecar_to_next_open
with a write attempt against the deferred sidecar.
* docs: write-entry in-process sidecar heal — contract and coverage
Update the recovery contract docs to match the previous two commits:
invariant 5 now states that the staged-write entry points and refresh
run in-process roll-forward recovery (long-lived processes converge on
the next write, not at restart); writes.md 'Long-running servers'
describes the heal's queue-acquisition concurrency contract, the
improved drift-guard error, and the entry points that intentionally do
not heal yet; testing.md indexes the new failpoint tests; AGENTS.md
capability matrix drops the claim that in-process recovery is entirely
future work (only the rollback path remains with the background
reconciler).
* test(engine): pin the entry heal contract for schema apply and branch merge
Without the write-entry heal, the two maintenance writers do worse than
wedge on sidecar-covered drift -- they proceed and decide its fate
implicitly:
- schema apply re-plans table rewrites from the manifest pin, orphaning
the drifted Phase-B commit (its rows silently vanish from the
rewritten table) while the stale sidecar lingers to misclassify
against the post-apply pins;
- branch merge publishes over the drift, making the failed writer's
commit visible as an unattributed side effect (no recovery audit
row), and leaves the stale sidecar behind.
Two red tests pin the intended contract: both entry points heal the
sidecar first (attributed roll-forward), then run on the converged
state. Currently failing on the stale-sidecar / dropped-rows
assertions; the fix lands in the next commit.
* fix(engine): heal pending recovery sidecars at the schema-apply and branch-merge entries
Extend the write-entry heal to the remaining two write entry points.
Unlike load/mutate (which wedge on the drift guard), these proceeded
over sidecar-covered drift and decided its fate implicitly:
- schema apply re-planned table rewrites from the manifest pin,
orphaning the drifted Phase-B commit -- its rows silently vanished
from the rewritten table -- while the stale sidecar lingered to
misclassify against the post-apply pins;
- branch merge published over the drift, making the failed writer's
commit visible without a recovery audit row, and left the stale
sidecar behind.
Both now run the same queue-serialized roll-forward heal at entry,
before their own sidecar exists, so recovery is attributed (audit row)
and deterministic. ensure_indices stays heal-free: it runs inside the
load / schema-apply flows after their entry heal.
Turns the previous commit's two red tests green. Docs updated in the
same change (invariant 5, writes.md, testing.md, AGENTS.md).
* test(engine): pin Phase A sidecar-write failure semantics
Storage fault-injection matrix, row 1: a sidecar PUT failure (S3
PutObject / fs write) in Phase A. New failpoint recovery.sidecar_write
at the top of write_sidecar -- the single choke point all five sidecar
writers go through -- models the storage error backend-generically.
Also adds the other three storage-fault failpoints used by the
following commits (recovery.sidecar_delete, recovery.sidecar_list,
recovery.record_audit); each is a no-op without the failpoints feature.
Pinned contract: every writer writes its sidecar BEFORE its first
HEAD-advancing commit, so a put failure aborts with zero drift (no
sidecar, Lance HEAD == manifest pin, no rows) and a transient fault
never wedges the graph -- the same handle writes/merges normally once
it clears. Covered for load (the staging writer) and branch_merge (the
multi-table writer, forced onto the RewriteMerged path by diverging
both sides).
* test(engine): pin Phase D delete, list, and audit-append storage-fault semantics
Storage fault-injection matrix, rows 2/3/5, plus the real-backend run:
- recovery.sidecar_delete: a Phase D delete failure (S3 DeleteObject)
must NOT fail the user's write -- the manifest publish already
landed, so the caller's data is durable. The swallowed failure
leaves a stale sidecar; the next write's entry heal consumes it via
the stale-sidecar audit-recovery path (RolledForward, attributed).
- recovery.sidecar_list: a __recovery/ list failure (S3 ListObjectsV2)
is loud at every consumer -- the write-entry heal fails the write
and the open-time sweep fails the open. Silently skipping recovery
over a pending sidecar would be consumer tolerance of drift. Once
the fault clears, open recovers the pending sidecar normally.
- recovery.record_audit: an audit write failure after the
roll-forward's manifest publish aborts that recovery attempt and
keeps the sidecar; re-entry detects the already-published manifest,
records exactly ONE RolledForward audit row, and converges -- the
retry tolerance documented on record_audit, exercised end-to-end.
- s3_load_recovers_after_publisher_failure_without_reopen: the
same-handle heal scenario on a real bucket (gated on
OMNIGRAPH_S3_TEST_BUCKET, skips locally), exercising sidecar
put/list/delete through S3StorageAdapter instead of the local-FS
adapter. CI wiring lands in a follow-up commit.
* test(engine): refuse corrupt recovery sidecars loudly
Storage fault-injection matrix, row 4 (no failpoint needed -- the
corrupt file is written by hand, sibling to the unknown-schema-version
refusal test): a truncated/garbage __recovery/{ulid}.json must be
refused loudly by both the write-entry heal (the write fails naming
the parse error) and the open-time sweep (ReadWrite open fails naming
the file), with the file left on disk for operator inspection.
Read-only opens still work -- the sweep is skipped there.
* test(engine): run the S3 sidecar-lifecycle coverage in CI + document the fault matrix
- ci.yml rustfs_integration: new step running the bucket-gated
failpoints tests (name filter s3_) against the RustFS container, so
sidecar put/list/delete are exercised through S3StorageAdapter on
every storage-affecting PR.
- writes.md: sidecar I/O failure semantics -- Phase A put failure
aborts with zero drift; Phase D delete failure is swallowed (write
already durable) and healed by the next write; list failures are
loud at heal and open; corrupt sidecars are refused with the file
kept for inspection; audit-append failures are retried to exactly
one audit row.
- testing.md: index the storage-fault matrix in the failpoints.rs row
and the new RustFS CI line.
* test(engine): pin read-visibility of acknowledged local if-absent writes
The cluster lib test import_missing_state_creates_state_with_graph_-
observation flakes at ~50% under full-workspace load ('EOF while
parsing a value' reading back the state.json its own import just
acknowledged). Root cause is in the engine's local storage adapter:
write_text_if_absent writes through a buffered tokio::fs::File and
returns when write_all resolves -- which, per tokio's documented File
semantics, means the bytes reached tokio's internal buffer, not the
file. The actual write completes in a background blocking task after
drop, so a caller that acknowledges success and reads the object back
can see an empty or partial file. Under load the window widens; the
red run fails at iteration 0 with 0 of 8192 bytes on disk.
The regression test pins the contract at the adapter boundary: when
write_text_if_absent resolves, the full contents are visible to any
reader; a losing second claim leaves the winner's object untouched.
The fix lands in the next commit.
* fix(engine): publish local storage writes with atomic visibility
Close the class, not the instance. The local adapter admitted three
ways for a reader to observe a write that was acknowledged or visible
before its bytes were complete:
1. write_text_if_absent acknowledged success when the buffered
tokio::fs::File write_all resolved -- i.e. when the bytes reached
tokio's internal buffer, not the file. A caller reading back its own
acknowledged write could see an empty object (the ~50% cluster
import flake under full-workspace load; the regression test failed
at iteration 0 with 0 of 8192 bytes visible).
2. The same call published its CLAIM (create_new) before its CONTENT,
so concurrent readers saw an empty claimed file in the window.
3. write_text (plain tokio::fs::write) exposed truncated content
mid-replace -- silently falsifying write_sidecar's 'readers either
see the complete sidecar or none' contract on local FS (true on S3,
where PutObject is atomic).
A flush in write_text_if_absent would have fixed only (1). Instead,
both local write paths now publish complete temp files atomically:
rename for replace (write_text -- the idiom write_text_if_match
already used) and hard_link for no-replace (write_text_if_absent --
link fails AlreadyExists, so exactly one of N concurrent claimants
wins and the winner's object is fully readable at the instant it
becomes visible). The local adapter now honors the same object-level
atomic-visibility contract as the S3 adapter, which is what every
caller (recovery sidecar protocol, cluster state CAS) was written
against. Crash-orphaned *.tmp.* files are inert: the sidecar sweep
filters to .json, and cluster state reads address state.json by name.
fsync/durability policy is unchanged (no fsync before, none now);
this fix is about visibility ordering, not power-loss durability.
Pre-existing on main (landed with the multi-graph server mode change,
PR #119); surfaced by this branch's heal work only because one extra
list_dir per write shifted test timing. Cluster lib suite: 12/25
failures before, 0/25 after. Turns the previous commit's red test
green.
* refactor(engine): one storage implementation over object_store for every backend
Collapse LocalStorageAdapter (hand-rolled tokio::fs) and
S3StorageAdapter into a single ObjectStorageAdapter backed by
Arc<dyn object_store::ObjectStore> -- LocalFileSystem for local URIs,
the existing AmazonS3 build for s3://, plus a pub in_memory()
constructor (full contract including TRUE conditional updates; the
in-memory test backend testing.md asked for at the adapter level).
Why: the acknowledged-before-visible bug showed the two-impl shape has
no referee -- one prose contract, two independent answers. Upstream
LocalFileSystem::put_opts is byte-for-byte the staged-temp+rename/
hard_link idiom that fix converged on, and Lance's own commit protocol
is built on the same primitives (put-if-not-exists / rename-if-not-
exists), so the substrate-aligned move is to stop hand-rolling it.
The per-backend residue shrinks to a UriCodec (URI <-> object path)
and one capability flag.
Semantics preserved by construction, with three deliberate deltas:
- exists() is now object-store-semantics everywhere (head + non-empty
prefix fallback): an EMPTY local directory no longer 'exists'. The
only dir-shaped caller (_graph_commits.lance probes) self-heals via
ensure_commit_graph_initialized where it previously wedged loudly.
- A directory at an object path reads as NotFound, not as an IO error
('only objects exist'). The cluster unreadable-payload test used a
same-named directory as a portable non-NotFound trigger; it now uses
chmod 000, which still models genuine transient IO.
- write_text_if_match keeps content-token semantics on local
(PutMode::Update is NotImplemented upstream for LocalFileSystem in
0.12.5 and 0.13.2); the capability flag gates the token SOURCE in
read_text_versioned too -- an ETag token with content-compare writes
would lose every CAS.
delete_prefix keeps a local remove_dir_all branch: directories are a
local-FS concept, and list+delete would leave empty skeletons that
cluster graph_root_exists (raw Path::exists) reports as still present.
LocalStorageAdapter remains as a delegating shim so the pinned
contract tests gate this swap textually unchanged; the shim and the
test parameterization over local + in-memory land next. Cargo gains
the explicit 'fs' feature (already transitively enabled by lance).
* test(engine): one executable storage contract, run against every backend
Remove the LocalStorageAdapter delegation shim and migrate its
construction sites to ObjectStorageAdapter::local(). Replace the
per-backend duplicated tests with a single contract_suite asserting
the trait's promises (atomic replace, exists incl. the dataset-root
prefix probe, one-winner if_absent, versioned CAS with loud CAS-lost,
rename, list round-trip with no sibling-prefix bleed, idempotent
delete/delete_prefix), run against the local backend and the new
in-memory backend -- which implements true conditional updates, so the
strong-CAS path is exercised without a bucket. The bucket-gated S3
variant already exists (s3_adapter_conditional_writes_contract).
New local-specific pins for the deliberate semantic edges of the
collapse: empty directories are not objects (exists=false; the Lance
dataset-root probe shape is the non-empty case), file://-anchored and
spaces-in-path list output round-trips byte-identically into
read_text, dot-segment paths are lexically absolutized (the CLI's
./graph.omni shape), and upstream rename creating missing destination
parents. The acknowledged-write visibility regression test stays, now
documenting that the cross-API std::fs read-back is the point.
* refactor(cluster): drop put_json's per-backend atomicity branch
The local temp+rename dance predates the storage adapter guaranteeing
atomic visibility; now that write_text publishes via a staged temp +
rename on the filesystem (and a single atomic PUT on object stores) by
contract, the branch duplicated upstream behavior. One call, both
backends.
* docs: storage adapter collapse — contract, in-memory backend, local CAS gap
- testing.md: the 'no MemStorage backend' note is half-closed —
ObjectStorageAdapter::in_memory() covers the text-object layer with
the full contract (true conditional updates); Lance datasets bypass
the adapter, so the engine substrate ask stays open.
- invariants.md: truth-matrix Tests row updated; new Known Gap for
local write_text_if_match (upstream PutMode::Update is unimplemented
for LocalFileSystem; content-token emulation is safe only under the
cluster lock protocol — close before admitting a lock-free caller).
- writes.md: backend notes for the unified adapter (name#N staging
residue invisible to the sweep, backend-wrapped error text with
exists()-probing for missing-vs-error, loud permission failures).
* docs: finish renaming the storage adapters in user docs and test comments
storage.md's URI-scheme table and the S3 failpoint test's doc comment
still named the deleted LocalStorageAdapter/S3StorageAdapter; both now
describe the unified ObjectStorageAdapter over object_store, including
the relative-path absolutization note for local URIs.
* test(engine): pin branch-awareness of the drift guard's recovery advice
A pending sidecar on ANOTHER branch does not cover this branch's
drift: with a deferred feature-branch sidecar on disk and genuinely
uncovered drift on main, the main write's error must still point at
omnigraph repair -- a read-write reopen recovers the sidecar but
cannot repair main's uncovered drift. Currently red: the guard
matches sidecar pins by table_key only, so the feature sidecar flips
main's advice to the reopen path. Fix in the next commit.
Surfaced by external review of the drift-guard change.
* fix(engine): branch-aware sidecar matching in the drift guard's advice
The commit-time drift guard's sidecar-covered check matched pins by
table_key alone, so a pending sidecar on another branch flipped this
branch's uncovered-drift advice from 'run omnigraph repair' to the
reopen path -- and a reopen recovers that sidecar but cannot repair
this branch's drift. Compare the pin's table_branch too. Turns the
previous commit's red test green.
Surfaced by external review of the drift-guard change.
* test(engine): pin heal non-interference with a live schema apply
The write-entry heal's schema-staging reconcile runs before any queue
acquisition, so a load on the same handle, overlapping a schema apply
parked between its staging write and manifest commit, promotes the
apply's staging files (new catalog live against the old manifest),
classifies the LIVE apply's sidecar, and publishes its registrations
out from under it. The resumed apply then collides with its own stolen
commit. Currently red with:
Lance("Concurrent modification: table version 3 already exists for
node:Tag")
The fix (per-sidecar reconcile under the sidecar's write-queue guards,
plus a serialization key the schema-apply writer and the heal both
acquire) lands in the next commit.
Surfaced by external review of the write-entry heal.
* fix(engine): serialize the heal's schema-staging reconcile with live schema applies
The write-entry heal ran recover_schema_state_files up front, before
acquiring any queue guards. Overlapping a live schema apply parked
between its staging write and manifest commit, the heal promoted the
apply's staging files (new catalog live against the old manifest),
classified the LIVE apply's sidecar, and published its registrations —
the resumed apply then collided with its own stolen commit.
Correct by construction:
- New schema-apply serialization queue key, acquired by the schema-
apply writer (alongside its per-table keys) from before write_sidecar
until after delete_sidecar. Per-table keys alone don't cover a
registration-only migration, which pins no existing tables but has a
sidecar and staging files on disk.
- The heal reconciles schema staging lazily, PER SchemaApply sidecar,
after acquiring that sidecar's guards (including the serialization
key) and re-confirming the sidecar exists — a sidecar that survives
the queue wait belongs to a dead writer, so the reconcile can no
longer race a live apply. Recomputing per sidecar also removes the
staleness of one up-front result across a multi-sidecar pass.
- Omnigraph::refresh drops its up-front reconcile-and-pass-through
(same race, and a pre-promoted result would make the heal's guarded
reconcile see clean staging and wrongly defer the sidecar): it now
reconciles standalone only when NO sidecar exists — which cannot
race a live apply, whose sidecar always precedes its staging files —
and otherwise defers entirely to the heal.
The open-time sweep keeps its precomputed reconcile: open has no
concurrent writers. Turns the previous commit's red test green.
Surfaced by external review of the write-entry heal.
Self-audit addendum folded in: refresh's no-sidecar gate had a TOCTOU
(a live apply could write its sidecar + staging between the empty
check and the reconcile) — the standalone reconcile now holds the
serialization key across the list-then-reconcile pair. The remaining
residual is cross-process only (in-process queues cannot serialize
against a writer in another process; the open-time sweep has the same
pre-existing exposure) and is now an explicit Known Gap in
invariants.md rather than an implicit one.
* test(engine): pin catalog reload after the heal recovers a schema apply
When the write-entry heal rolls a crashed apply's SchemaApply sidecar
forward on the same handle, disk and manifest move to the new schema
(staging promoted, registrations published) but the handle's in-memory
schema_source/catalog do not. Subsequent writes then validate against
the stale catalog and reject rows of types the graph already has.
Currently red with:
record 1: unknown node type 'Tag'
refresh() reloads after its heal; the write entry points must too.
Fix in the next commit.
Surfaced by external review of the write-entry heal.
* fix(engine): reload the in-memory catalog after the heal recovers a schema apply
heal_pending_recovery_sidecars refreshed the coordinator and
invalidated the runtime cache after processing sidecars, but never
reloaded schema_source/catalog — so a write whose entry heal rolled a
crashed SchemaApply sidecar forward proceeded to validate against the
OLD schema while disk and manifest were already on the new one.
reload_schema_if_source_changed is the same post-heal step refresh()
already runs; it no-ops on the (overwhelmingly common) non-schema heal
because the on-disk source is unchanged. Turns the previous commit's
red test green.
Surfaced by external review of the write-entry heal.
* test(engine): pin that a deleted-branch sidecar cannot wedge the graph
A rollback-eligible sidecar pinned to a branch is deferred by every
roll-forward-only pass; if the branch is then deleted, the sidecar
survives, referencing a branch with no manifest tree. The heal (every
write entry) and the open-time sweep (every ReadWrite open) both fail
opening the dead branch, and repair refuses while a sidecar is pending
-- a terminal read-only state with manual sidecar surgery as the only
exit. Currently red with:
Lance("Not found: .../__manifest/tree/feature/_versions")
The branch's tree and forks are already reclaimed, so the pinned drift
is unreachable and the sidecar is provably moot; the fix classifies it
as an orphaned-branch terminal state (audit + discard) in both passes.
Surfaced by review (P1, verified by repro).
* fix(engine): classify deleted-branch sidecars as orphaned instead of wedging
A deferred (rollback-eligible) sidecar pinned to a branch survives
branch_delete; both the write-entry heal and the open-time sweep then
failed unconditionally opening the dead branch -- every write and
every ReadWrite open errored, and repair refuses while a sidecar
pends. Terminal state, manual sidecar surgery the only exit.
The branch's tree and per-table forks are already reclaimed at delete,
so the drift the sidecar pins is unreachable and the sidecar is
provably moot. Both passes now check the sidecar's branch against the
manifest's branch list (the authority -- deliberately NOT inferred
from a Not-found on open, which could be a transient storage error
masking real recovery intent) and discard orphans with an
OrphanedBranchDiscarded audit row, commit appended on main since the
sidecar's own branch no longer has a commit graph.
The open-time half is pre-existing; the write-entry heal made it hot.
Turns the previous commit's red test green.
Surfaced by review (P1, verified by repro).
* chore: harden review nits — vacuous CI filter, root-runner skip, liveness note
- ci.yml: the RustFS sidecar-lifecycle step now fails loudly if the
's3_' name filter matches zero tests (cargo passes vacuously on an
empty filter; the step exists specifically to prove S3 sidecar I/O
coverage). The pre-existing CLI smoke step has the same shape and is
left for a follow-up.
- cluster unreadable-payload test: cfg(unix) + a skip-with-log when
running as root (mode 000 is still readable to root, common in
container dev runners), so the test degrades instead of failing.
- refresh: document the one-pass-late convergence for legacy staging
residue while non-SchemaApply sidecars pend, so nobody 'fixes' it by
re-running the reconcile unserialized — the exact race the
serialization key closes.
* test(engine): pin orphan-discard idempotency across a delete fault
discard_orphaned_branch_sidecar writes its audit row and main commit
before deleting the sidecar; a Phase D delete fault leaves the sidecar
on disk with the audit already durable, and the retry repeated the
whole path -- a second OrphanedBranchDiscarded audit row (and commit)
for the same operation. Currently red: 2 rows after one fault + retry.
The retry must only finish the delete. Fix next.
Also promotes the recovery-audit kinds reader into the shared test
helpers (it was recovery.rs-local).
Surfaced by external review of the orphan-discard fix.
* fix(engine): orphan-discard idempotency + heal reports acted-vs-deferred
Two review findings on the recovery surface:
- discard_orphaned_branch_sidecar now checks the audit table for an
existing (operation_id, OrphanedBranchDiscarded) row before appending
the commit + audit pair, so a Phase D delete fault retries ONLY the
delete instead of duplicating audit rows and commit-graph entries.
Cold path: the list scan runs only when an orphaned sidecar exists.
Turns the previous commit's red test green (exactly one audit row
across fault + retry).
- process_sidecar returns whether durable state changed; the heal sets
processed_any only for sidecars that were actually rolled forward /
rolled back / audit-recovered (orphan discards count). Deferred
sidecars (rollback-eligible, invariant-violating, unpromoted
SchemaApply) no longer trigger a per-write schema reload + full
runtime-cache invalidation while they pend -- the cache is
snapshot-keyed so this was waste, not corruption, but it was paid on
every write until reopen. Acted-paths' processed=true remains pinned
by load_after_schema_apply_phase_b_failure_uses_recovered_catalog
(the reload depends on it).
Surfaced by external review.
* test(engine): pin the orphan-discard audit-append fault leg as documented tolerance
The orphan discard's commit append and audit append are two writes; a
failure between them leaves a recovery commit with no audit row, and
the retry (keyed on the audit row, the operator-facing record) appends
a second commit before the audit lands. This is the same
not-atomic-pair-write tolerance record_audit documents and the
manifest->commit-graph Known Gap covers for every publish: bounded
commit-graph noise, audit row exactly-once under clean failures.
Keying idempotency on commit rows instead would need an operation_id
column on _graph_commits, and audit-before-commit would dangle the
graph_commit_id join -- both worse than the documented residual.
Make the tolerance explicit instead of implicit: docstring names the
window, a failpoint sits inside it, and the new test pins convergence
across the fault (sidecar consumed, exactly one audit row), completing
the orphan-discard fault matrix alongside the delete-fault leg.
Surfaced by external review of the orphan-discard idempotency.
* test(engine): pin honest drift-guard advice when sidecar listing fails
The guard's unwrap_or(false) conflated 'classified as uncovered' with
'could not classify': a transient list fault on the guard's second
list (the entry heal's first list having succeeded) confidently routed
the operator to omnigraph repair even when the heal had just deferred
a rollback-eligible sidecar -- and repair refuses while a sidecar is
pending. Currently red: the error says 'run omnigraph repair' with no
mention of the reopen path. The fix names both paths plus the failure
cause when classification is impossible.
Surfaced by external review of the drift-guard fallback.
* fix(engine): admit ambiguity in the drift guard when sidecar listing fails
Replace the unwrap_or(false) fallback with a tri-state: covered ->
reopen advice; uncovered -> repair advice; listing FAILED -> say the
drift could not be classified, name the cause, and give both paths in
order ('run repair, or reopen read-write if repair reports a pending
sidecar'). The old fallback confidently routed a transient list fault
to repair, which refuses while a sidecar is pending -- a self-
correcting but pointless detour. The conflict itself is still always
raised; only the advice degrades honestly. Turns the previous commit's
red test green.
Surfaced by external review of the drift-guard fallback.
2026-06-13 11:20:08 +02:00
`Omnigraph::open` in read-write mode runs the all-or-nothing sweep; the
write entry points (`load_as` , `mutate_as` , `apply_schema_as` ,
`branch_merge_as` ) and `refresh` run roll-forward-only recovery in-process,
so a long-lived process converges on its next write rather than at restart. Do not add a new writer kind without
sidecar coverage or an explicit proof that no Lance HEAD can move before
manifest publish.
2026-05-15 03:45:22 +03:00
6. **Strong consistency is the default.** Reads are snapshot-isolated, writes
are durable before acknowledgement, and branch reads observe the current
committed graph state. Any eventual-consistency mode must be explicit,
read-only, auditable, and non-default.
7. **Indexes are derived state.** Reads must see the correct result for the
branch they read even when index coverage is partial. Expensive index work
should converge from manifest state instead of extending the critical write
path. Scalar staged index builds and vector inline residuals are documented
docs(user): restructure user docs into topic sections (Phase 1) (#223)
Move the 23 flat docs/user/*.md files into topic subdirectories so the
user guide is organized by area (schema, queries, search, branching, cli,
operations, clusters, concepts, reference) instead of a flat list. This is
a pure structural move — whole files relocated, every cross-doc link
recomputed, no prose rewrites or content splits (those follow in Phase 2).
- 19 `git mv`s (install.md, deployment.md stay top-level); history preserved
(renames detected at 92–100% similarity).
- All intra-doc links, AGENTS.md's topic table (52 pointers), and the
docs/dev + docs/releases back-links recomputed via relpath from each
file's new location.
- docs/user/index.md rewritten as a sectioned nav hub.
- Fixed 5 doc-path references in Rust (comments + two user-facing server
settings error strings) to point at the new locations.
Verified: zero broken .md links across tracked docs; check-agents-md.sh
green (with the untracked scratch docs set aside); touched crates build.
Note: the public site (omnigraph-web) imports docs/ via a flat-only script;
its import-docs.mjs needs a subdir-aware update before the next re-sync.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-14 13:52:14 +03:00
in [writes.md ](writes.md ) and [indexes.md ](../user/search/indexes.md ).
2026-05-15 03:45:22 +03:00
8. **Schema identity survives renames.** Accepted schema identity must remain
stable across type and property renames. Rename support belongs in migration
planning, not in "drop and recreate" behavior. See the known gap below.
9. **Schema/data integrity failures are loud.** Type errors, required-field
misses, invalid edge endpoints, cardinality violations, and unsupported
mixed mutation modes fail before a graph commit is published. The system must
not invent placeholder nodes or silently weaken integrity.
10. **Query semantics are first-class IR concepts.** Search modes, mutations,
polymorphism, traversal, retrieval scores, imports, and policy predicates
belong in typed AST/IR/planner structures. Do not smuggle semantics through
strings, side tables, global state, or transport-specific flags.
11. **Transport/auth stay at the boundary.** Kernel crates should not depend on
HTTP, OpenAPI, bearer-token parsing, or future transport protocols. The
server resolves bearer tokens to actors; clients cannot set actor identity
directly.
12. **Bearer-token plaintext is not retained.** Server startup hashes bearer
tokens, authentication uses constant-time comparison, and request handling
carries only the resolved actor identity and hash-derived match state.
13. **Operational failures are bounded and observable.** Timeout, memory, OOM,
partial result, recovery, and conflict paths must fail loudly or degrade in
a documented way. If a metric affects plan choice or operator behavior, it
must be exposed through the relevant trait or observability surface.
14. **Tests match the boundary being changed.** Prefer extending the existing
test that owns the area. Planner changes need planner-level coverage,
storage changes need storage/recovery coverage, and end-to-end tests are not
a substitute for missing lower-level assertions. Read [testing.md ](testing.md )
before adding tests.
## Current Truth Matrix
| Area | Current state | Source |
|---|---|---|
2026-05-30 23:20:56 +02:00
| Multi-table commit | Manifest CAS plus recovery sidecars; not a single Lance primitive | [writes.md ](writes.md ), [architecture.md ](architecture.md ) |
| Constructive mutations | In-memory `MutationStaging` , one end-of-query table commit per touched table, then one manifest publish | [writes.md ](writes.md ), [execution.md ](execution.md ) |
docs(user): restructure user docs into topic sections (Phase 1) (#223)
Move the 23 flat docs/user/*.md files into topic subdirectories so the
user guide is organized by area (schema, queries, search, branching, cli,
operations, clusters, concepts, reference) instead of a flat list. This is
a pure structural move — whole files relocated, every cross-doc link
recomputed, no prose rewrites or content splits (those follow in Phase 2).
- 19 `git mv`s (install.md, deployment.md stay top-level); history preserved
(renames detected at 92–100% similarity).
- All intra-doc links, AGENTS.md's topic table (52 pointers), and the
docs/dev + docs/releases back-links recomputed via relpath from each
file's new location.
- docs/user/index.md rewritten as a sectioned nav hub.
- Fixed 5 doc-path references in Rust (comments + two user-facing server
settings error strings) to point at the new locations.
Verified: zero broken .md links across tracked docs; check-agents-md.sh
green (with the untracked scratch docs set aside); touched crates build.
Note: the public site (omnigraph-web) imports docs/ via a flat-only script;
its import-docs.mjs needs a subdir-aware update before the next re-sync.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-14 13:52:14 +03:00
| Deletes | Inline-commit residual; delete-only queries allowed, mixed insert/update/delete rejected by D2 | [query-language.md ](../user/queries/index.md ), [writes.md ](writes.md ) |
| Branch delete | Manifest is the single authority, flipped atomically first; per-table forks + commit-graph branch are derived state, reclaimed best-effort (`force_delete_branch` ) with the `cleanup` reconciler as the guaranteed backstop. Reusing a name whose reclaim failed before `cleanup` surfaces an actionable error | [branches-commits.md ](../user/branching/index.md ), [maintenance.md ](../user/operations/maintenance.md ) |
| Schema validation | Type checks, required fields, defaults, edge endpoint checks, and edge cardinality are enforced on write paths | [schema-language.md ](../user/schema/index.md ), [execution.md ](execution.md ) |
| Unique constraints | Intra-batch and write-path checks exist; intake and branch-merge derive the composite key through one shared function (`loader::composite_unique_key` , a separator-free `Vec<String>` tuple) and fail loudly on an un-keyable column type rather than silently exempting it; full cross-version uniqueness against already-committed rows is still a gap | [schema-language.md ](../user/schema/index.md ) |
(feat) convert engine call sites to &dyn TableStorage; demote legacy TableStore methods to pub(crate) (#86)
* MR-854: convert engine call sites to &dyn TableStorage; demote legacy methods
Phase 1b: every db.table_store.X(...) call site converts to
db.storage().X(...), reaching the storage layer through the sealed
TableStorage trait (returns &dyn TableStorage). Opaque SnapshotHandle
and StagedHandle replace bare lance::Dataset and Transaction in the
threaded values.
Phase 9: the inherent inline-commit methods on TableStore
(append_batch, merge_insert_batch{,es}, overwrite_batch,
create_btree_index, create_inverted_index) demote from pub to
pub(crate). Their only remaining direct users are table_store.rs
itself and the bulk loader's LoadMode::{Append, Overwrite, Merge}
concurrent fast-paths in loader::write_batch_to_dataset (no
two-phase shape in Lance 4.0.0 — closes after lance#6658 and #6666).
Docs:
- invariants.md \u00a7VI.23: drop "at the writer-trait surface"
qualifier; staged primitives are now the only engine surface.
- runs.md: residual matrix shrinks to delete_where and
create_vector_index (the two upstream-blocked residuals).
- forbidden_apis.rs: replace transitional language with the
current allow-list shape (table_store.rs + loader concurrent
fast-path only).
Files touched:
- changes/mod.rs, db/omnigraph.rs (+export/optimize/schema_apply/
table_ops.rs), exec/{merge,mod,mutation,staging}.rs,
loader/mod.rs, storage_layer.rs, table_store.rs,
tests/forbidden_apis.rs, docs/{invariants,runs}.md.
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: replace test-only inline-commit append callers with local Lance helpers
After demoting TableStore::append_batch from pub to pub(crate), the
integration tests in tests/recovery.rs and tests/staged_writes.rs
that previously called store.append_batch(...) directly to simulate
HEAD-ahead-of-manifest drift can no longer access the inherent
method. Replace those calls with small in-test helpers that do a raw
Dataset::append (the same body the inherent method runs).
- tests/helpers/mod.rs gains lance_append_inline (shared helper).
- tests/staged_writes.rs gets a file-local lance_append_inline_local
(staged_writes.rs does not import helpers::).
- tests/recovery.rs drops the unused TableStore import in the one
function whose store binding became unused after the conversion.
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: retrigger CI for flaky Test Workspace job
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: convert remaining table_store call sites in export.rs / read_blob
Two leftover `self.table_store.X` / `db.table_store.X` call sites were
missed in the initial sweep — flagged by Devin Review on PR #86. Both
now go through the trait surface:
- `entity_from_snapshot` (db/omnigraph/export.rs): switch from
`db.table_store.open_snapshot_table` + `db.table_store.scan` to
`db.storage().open_snapshot_at_table` + `db.storage().scan`.
- `read_blob` (db/omnigraph.rs): replace
`snapshot.open(table_key)` + `self.table_store.first_row_id_for_filter`
with `self.storage().open_snapshot_at_table` +
`self.storage().first_row_id_for_filter`. The follow-up
`take_blobs` call still needs an `Arc<Dataset>` (it's a Lance blob
accessor not surfaced through the trait), so we hand off via
`SnapshotHandle::into_arc()` with a comment.
After this commit, no engine code outside `table_store.rs` reaches the
inherent `TableStore` API — the docs/runs.md and docs/invariants.md
claim is now uniformly true.
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: post-rebase doc fixes (Lance 6.0.1, MR-A framing, into_dataset note)
Reviewer feedback on the rebased PR:
* docs/dev/writes.md residuals matrix: drop demoted methods from the trait-surface table (now `pub(crate)`); keep only the two genuine trait-surface residuals (`delete_where`, `create_vector_index`); reframe under MR-A (Lance v7.x bump) per docs/dev/lance.md.
* tests/forbidden_apis.rs: update transitional allow-list header to (a) drop the truncate_table mislabel (truncate_table is a Lance Dataset method, not a TableStore method — overwrite_batch's internal call), (b) reframe trait-surface residuals under MR-A / Lance #6666.
* crates/omnigraph/src/storage_layer.rs::SnapshotHandle::{into_arc, into_dataset}: add single-ref invariant doc — both consume Arc via try_unwrap-or-clone; sibling SnapshotHandle clones across an await point force a deep Dataset clone.
* Replace lance-4.0.0 version refs with lance-6.0.1 in active source/test/dev-doc comments (storage_layer.rs, table_store.rs, table_ops.rs, schema_apply.rs, merge.rs, recovery.rs, staged_writes.rs, consistency.rs, docs/dev/execution.md, docs/user/query-language.md). Historical refs in docs/releases/v0.4.1.md and the canonical "Lance 4.0.0 → 6.0.1 migration" line in docs/dev/lance.md left intact.
No engine code changes.
* MR-854: update docs/dev/invariants.md Storage trait row + gap entry
Reviewer feedback: the docs reorg landed; the invariant row now lives in
docs/dev/invariants.md with stable headings (no more numbered §VI.23).
Update two pieces to reflect MR-854 completion:
* Status table 'Storage trait' row: was 'full call-site migration ... incomplete';
now 'engine call sites all route through db.storage() (MR-854); inline-commit
inherent methods are pub(crate)-demoted; capability/stat surfaces are roadmap'.
* 'Known Gaps' 'Storage abstraction' entry: was 'older inherent TableStore call
sites and inline residuals remain'; now names the closed scope (MR-854 — call
sites migrated, methods demoted, loader fast-paths) and the remaining
trait-surface residuals under MR-A (Lance v7.x bump) and Lance #6666.
Cross-links to docs/dev/lance.md and docs/dev/writes.md so the framing stays
co-located with the canonical Lance surface tracking.
* MR-854: remove dead inline-commit methods from the storage surface
The loader concurrent fast-path (write_batch_to_dataset) is only reached
for LoadMode::Overwrite — Append/Merge route through MutationStaging — so
its Append/Merge arms were unreachable. Collapse it to overwrite-only and
drop the now-unused mode params, which removes the only callers of:
- TableStorage::append_batch + TableStorage::merge_insert_batches (trait)
- TableStore::merge_insert_batch + merge_insert_batches (inherent)
create_btree_index / create_inverted_index had zero callers anywhere
(scalar index builds use the stage_* primitives). Remove both from the
trait and the inherent impl.
Inherent append_batch stays pub(crate): overwrite_batch and recovery
tests use it. Migrate the one trait-append_batch test caller
(seed_person_row) to stage_append + commit_staged. The merge_insert
FirstSeen-workaround rationale moves from the deleted merge_insert_batch
into stage_merge_insert (now the sole merge path). No behavior change.
Also corrects the inaccurate loader residual comment (the prior text
blamed Lance #6658/#6666, which are the delete and vector-index issues,
for keeping overwrite inline; a stage_overwrite primitive already exists
and schema_apply uses it).
* MR-854: seal db.storage() to staged-only; move residuals to InlineCommitResidual
Split the three remaining inline-commit writes (overwrite_batch,
delete_where, create_vector_index) off the TableStorage trait onto a new
sealed InlineCommitResidual trait, reachable only via the explicit
Omnigraph::storage_inline_residual() accessor. db.storage() now exposes
only staged primitives + reads, so engine code cannot couple a write
with a Lance HEAD advance through the default surface — MR-793 acceptance
§1 ("no public method commits as a side effect of writing") now holds by
construction, not by review + naming.
Call sites moved to storage_inline_residual(): loader overwrite
fast-path, the three mutation delete_where paths, the branch-merge
delete, and the vector-index build. Impl bodies are unchanged (same
delegation to the pub(crate) inherent methods); this is a pure surface
reshape with no behavior change.
The residual trait holds two genuinely upstream-blocked methods
(delete_where -> Lance #6658/v7.x, create_vector_index -> Lance #6666)
plus overwrite_batch, kept for the loader's cross-table bulk-overwrite
concurrency until its staged migration lands (tracked follow-up).
* MR-854 docs: describe the staged-only seal; fix stale Lance index URLs
- writes.md / invariants.md / AGENTS.md: the inline-commit residuals now
live on InlineCommitResidual behind db.storage_inline_residual(), so
acceptance §1 holds by construction rather than 'option (b)' per-method
enumeration. Drop the inaccurate 'until Lance exposes
Operation::Overwrite { fragments }' claim (that op exists; stage_overwrite
already builds it) and reframe overwrite_batch as a removable legacy
residual gated on the loader's bulk-overwrite concurrency.
- forbidden_apis.rs: rewrite the allow-list doc for the split surface.
- lance.md: the index spec pages moved from /format/table/index/ to
/format/index/ in Lance 6.x (the old paths 404). Fix all 13 URLs.
* MR-854: fix stale lance-4.0.0 comment refs flagged in review
Addresses greptile (exec/merge.rs) and aaltshuler's stale-version blocker:
update lance-4.0.0 -> 6.0.1 in the comment/doc refs within this PR's
footprint (exec/merge.rs, exec/mutation.rs, docs/dev/writes.md). Also
corrects exec/merge.rs to cite lance#6666 (not #6658) for
build_index_metadata_from_segments — that is the vector-index segment-commit
API; #6658 is the two-phase delete. (Pre-existing 4.0.0 refs in untouched
files like architecture.md/storage.md are main's incomplete migration
cleanup, left out of scope.)
* fix(storage): stage loader overwrites
* fix(storage): stage empty schema rewrites
---------
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Ragnor Comerford <ragnor.comerford@gmail.com>
Co-authored-by: Ragnor Comerford <hello@ragnor.co>
2026-06-09 23:03:08 +02:00
| Storage trait | `TableStorage` (via `db.storage()` ) is staged-only; the inline-commit residuals (`delete_where` , `create_vector_index` ) are split onto a separate sealed `InlineCommitResidual` trait reached via `db.storage_inline_residual()` (MR-854), so §1 holds by construction; capability/stat surfaces are roadmap | [writes.md ](writes.md ), [architecture.md ](architecture.md ) |
fix(engine): scalar index coverage + filter literal coercion (query latency) (#216)
* fix(engine): lower date/datetime filter literals as typed Arrow scalars
`literal_to_expr` lowered `Date`/`DateTime` query literals as Utf8 strings,
relying on DataFusion implicit casts. Against a physical `Date32`/`Date64`
column that can coerce the column side (`CAST(col AS Utf8)`), which defeats a
scalar BTREE and degrades the scan to a full filtered read. Lower to typed
`Date32`/`Date64` scalars instead (reusing the loader's
`parse_date32_literal`/`parse_date64_literal`, already used by the in-memory
comparison arm), so the predicate stays a direct column comparison and the
index is used. Malformed literals fall back to the Utf8 string so pushdown
behavior never regresses.
Tests: unit goldens asserting the lowered literal is typed (red before, green
after) + inline-binding pushdown equality in literal_filters confirming the
epoch conversion selects the right rows.
* fix(engine): build scalar BTREE for enum and orderable-scalar @index columns
`build_indices_on_dataset_for_catalog` only handled `String` (-> FTS) and
`Vector` (-> vector). Enums are physically `String`, so an enum `@index`
column (e.g. `status`) got an FTS inverted index, which Lance never consults
for `=`; and `DateTime`/`Date`/numeric/`Bool` `@index` columns fell through
and built nothing. Both meant equality/range filters degraded to full scans
with `indices_loaded=0`.
Dispatch index kind by property type via a shared `node_prop_index_kind`:
enum + orderable scalar -> BTREE, free-text String -> FTS, Vector -> vector,
list/Blob -> none. The helper is shared by the builder and
`needs_index_work_node` so they cannot drift — the latter decides recovery-
sidecar pinning, and under-reporting would leave a HEAD-advancing index build
uncovered (invariant 5).
Tests: scalar_indexes.rs asserts enum/DateTime/numeric @index columns report
`IndexCoverage::Indexed` while free-text String/un-annotated columns stay
`Degraded` (negative control). Docs: docs/user/indexes.md.
* feat(engine): reindex in optimize to keep index coverage current
A scalar/FTS/vector index only covers the fragments it was built over. Rows
appended after the build (e.g. `ingest --mode merge`, whose commit does not
rebuild an existing index) are scanned unindexed, and `compact_files` rewrites
fragments out of coverage. Nothing folded them back in, so coverage decayed as
the graph grew — even the id/src/dst BTREEs that power traversal.
`optimize_one_table` now runs Lance `optimize_indices` after `compact_files`
(incremental merge, not retrain — the same compact->optimize_indices sequence
LanceDB's `optimize()` uses) and enters the publish path on compaction work OR
stale index coverage (new `TableStore::has_unindexed_fragments`, reusing the
fragment_bitmap logic). `optimize_indices` is a committing call with no
uncommitted variant in lance-6.0.1, so it is an inline-commit residual covered
by the existing `SidecarKind::Optimize` recovery sidecar spanning both ops.
Blob-bearing tables are still skipped (the Lance blob-compaction bug is
compaction-specific; reindex-for-blob deferred as a noted follow-up).
Tests: maintenance.rs asserts an appended fragment is uncovered before and
covered after optimize, and idempotency holds (second pass is a no-op).
lance_surface_guards pins the `optimize_indices` signature and its incremental-
coverage behavior. The existing optimize Phase-B recovery failpoint now also
exercises a crash after reindex. Docs: maintenance.md, writes.md, invariants.md,
lance.md, AGENTS.md.
* fix(engine): coerce pushdown filter literals to the column type
Filter literals were pushed to Lance in their natural Arrow type (every integer
Int64, every float Float64). Against a narrower indexed column DataFusion widens
to the literal's type and casts the COLUMN (`CAST(n32 AS Int64)`), which defeats
the scalar BTREE and degrades to a full filtered read. A physical-plan probe
confirms it: an Int32 column filtered by an i32 literal uses `ScalarIndexQuery`;
by an i64 literal it does not.
Thread the scan's `arrow_schema` through `build_lance_filter_expr` ->
`ir_filter_to_expr` and coerce each literal operand to the opposite column's
exact Arrow type, reusing `projection::literal_to_array` + `arrow_cast` (the same
path the in-memory arm uses, so the two arms agree). Coercion never demotes a
filter to None: on failure it falls back to the natural literal, because a node
scan has no in-memory fallback for inline filters.
Supersedes the date-specific change in e4ef67b (PR1): the probe shows dates were
never index-defeated — temporal coercion casts the LITERAL, not the column — so
PR1's index-use rationale was wrong though harmless. The generic coercion
subsumes it; `literal_to_expr`'s date arms revert to the natural Utf8 fallback,
and its unit tests now assert the live coerced path.
Tests: surface guard `scalar_index_use_requires_matched_literal_type` pins the
substrate behavior (matched -> index, widened -> column-cast full scan); unit
tests cover Int32/UInt32/Float32 coercion, range op, reversed operand order, and
the natural fallback; `literal_filters` adds an I32 column with equality + range
and an F32 pushdown case.
* fix(engine): only coerce filter literals when the cast is lossless
The literal coercion in f064121 narrowed unconditionally. typecheck permits
numeric cross-type comparisons (`types_compatible`), so an out-of-domain literal
reaches `literal_to_typed_expr` and casts lossily: a fractional float vs an
integer column truncates (`{ count: 2.7 }` -> `count = 2`, wrongly matching the
count=2 row) and an out-of-range integer overflows to null (`count < 3e9` on I32
-> `count < NULL` -> empty). Both silently change results, and a node scan has no
in-memory fallback for inline filters.
Add a lossless guard for integer targets: round-trip the cast back to the natural
type and, on mismatch, return None so the caller keeps the natural literal
(correct via DataFusion coercion; the index is just unused for that out-of-domain
predicate). Float targets stay coerced -- narrowing F64 -> F32 is the column's own
precision domain, not a value error.
Resolves the two valid review findings on PR #216 (Codex float truncation, Greptile
out-of-range). Tests: unit cases for fractional/out-of-range fallback vs
whole-float/in-range coerce vs F32 exemption; e2e `{ count: 2.7 }` returns no rows.
2026-06-14 16:31:19 +02:00
| Index lifecycle | Index *creation* per `@index` /`@key` property is dispatched by type (enum + orderable scalar → BTREE, free-text String → FTS, Vector → vector) via `node_prop_index_kind` ; index *coverage maintenance* exists — `optimize` runs Lance `optimize_indices` after compaction to fold appended/rewritten fragments into existing indexes (still an explicit maintenance call, not yet a background reconciler) | [indexes.md ](../user/search/indexes.md ), [maintenance.md ](../user/operations/maintenance.md ) |
docs(user): restructure user docs into topic sections (Phase 1) (#223)
Move the 23 flat docs/user/*.md files into topic subdirectories so the
user guide is organized by area (schema, queries, search, branching, cli,
operations, clusters, concepts, reference) instead of a flat list. This is
a pure structural move — whole files relocated, every cross-doc link
recomputed, no prose rewrites or content splits (those follow in Phase 2).
- 19 `git mv`s (install.md, deployment.md stay top-level); history preserved
(renames detected at 92–100% similarity).
- All intra-doc links, AGENTS.md's topic table (52 pointers), and the
docs/dev + docs/releases back-links recomputed via relpath from each
file's new location.
- docs/user/index.md rewritten as a sectioned nav hub.
- Fixed 5 doc-path references in Rust (comments + two user-facing server
settings error strings) to point at the new locations.
Verified: zero broken .md links across tracked docs; check-agents-md.sh
green (with the untracked scratch docs set aside); touched crates build.
Note: the public site (omnigraph-web) imports docs/ via a flat-only script;
its import-docs.mjs needs a subdir-aware update before the next re-sync.
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-14 13:52:14 +03:00
| Traversal IDs | Runtime still builds `TypeIndex` ; Lance stable row-id based graph IDs are roadmap | [architecture.md ](architecture.md ), [query-language.md ](../user/queries/index.md ) |
| Auth | Bearer token hashing and server-side actor resolution are implemented at the HTTP boundary | [server.md ](../user/operations/server.md ), [policy.md ](../user/operations/policy.md ) |
Recovery liveness, storage fault-injection matrix, and one storage implementation over object_store (#203)
* test(engine): pin the long-lived-handle heal contract for sidecar-covered drift
A Phase B -> Phase C failure (commit_staged advanced Lance HEAD, manifest
publish did not land, recovery sidecar persists) currently wedges every
subsequent staged write on the same engine handle: the commit-time drift
guard rejects with 'run omnigraph repair', but repair itself refuses
while a recovery sidecar is pending, so a long-lived server can only
recover by restart. The documented contract (writes.md 'Long-running
servers', invariants.md invariant 5) says refresh-time roll-forward
closes this residual without restart -- but no write path runs it.
Two red tests pin the intended contract at the write entry points:
a follow-up load (the POST /ingest shape: shared handle, no reopen)
and a follow-up mutation must heal roll-forward-eligible sidecars
in-process and then succeed.
Currently failing with:
table 'node:Company' has Lance HEAD version 2 ahead of manifest
version 1; run `omnigraph repair` before writing
The fix lands in the next commit.
* fix(engine): heal pending recovery sidecars at the staged-write entry points
Close the long-lived-process gap in the recovery protocol: a Phase B ->
Phase C residual (per-table commit_staged landed, manifest publish did
not, sidecar persists) previously recovered only at the next ReadWrite
open or via an explicit refresh() that no production write path called,
so a long-lived server wedged every subsequent write on the commit-time
drift guard until restart.
New recovery::heal_pending_sidecars_roll_forward:
- one list_dir of __recovery/ at write entry (empty -> immediate
return, the steady state), so the per-write cost is one storage list;
- per sidecar, acquires the same per-(table_key, table_branch) write
queues every sidecar writer holds from before write_sidecar until
after delete_sidecar, then re-checks sidecar existence -- this
serializes the heal against live writers instead of rolling an
in-flight sidecar forward from under its writer (which would fail
that writer's publish CAS spuriously). Lock order queues ->
coordinator matches every writer's commit->publish path. This is the
queue-acquisition design recovery.rs and write_queue.rs already
documented for in-process recovery;
- processes in RollForwardOnly mode: the common residual rolls forward
in-process; rollback-eligible sidecars still defer to the next
ReadWrite open (Dataset::restore is unsafe under concurrency).
Wire it into load_as and mutate_as (before the inline delete path can
advance any HEAD), and rebase Omnigraph::refresh onto the same helper
so refresh stops racing live writers' sidecars.
The maintenance entry points (apply_schema_as, branch_merge_as,
ensure_indices) intentionally keep their strict fail-loud preconditions
for now; wiring the same heal there is a follow-up with its own tests.
Turns the previous commit's two red tests green.
* fix(engine): name the right recovery path in the commit-time drift guard
The drift guard's 'run omnigraph repair before writing' advice is a
dead end when the drift is covered by a pending recovery sidecar:
repair refuses while a sidecar is pending. With the write-entry heal in
place, reaching this guard with sidecar-covered drift means the heal
deferred it (rollback-eligible), and the actual recovery path is a
read-write reopen. Distinguish the two classes on the error path only
(one sidecar list, after the conflict is already certain); a listing
failure falls back to the uncovered-drift wording rather than masking
the conflict.
Pinned by extending refresh_defers_rollback_eligible_sidecar_to_next_open
with a write attempt against the deferred sidecar.
* docs: write-entry in-process sidecar heal — contract and coverage
Update the recovery contract docs to match the previous two commits:
invariant 5 now states that the staged-write entry points and refresh
run in-process roll-forward recovery (long-lived processes converge on
the next write, not at restart); writes.md 'Long-running servers'
describes the heal's queue-acquisition concurrency contract, the
improved drift-guard error, and the entry points that intentionally do
not heal yet; testing.md indexes the new failpoint tests; AGENTS.md
capability matrix drops the claim that in-process recovery is entirely
future work (only the rollback path remains with the background
reconciler).
* test(engine): pin the entry heal contract for schema apply and branch merge
Without the write-entry heal, the two maintenance writers do worse than
wedge on sidecar-covered drift -- they proceed and decide its fate
implicitly:
- schema apply re-plans table rewrites from the manifest pin, orphaning
the drifted Phase-B commit (its rows silently vanish from the
rewritten table) while the stale sidecar lingers to misclassify
against the post-apply pins;
- branch merge publishes over the drift, making the failed writer's
commit visible as an unattributed side effect (no recovery audit
row), and leaves the stale sidecar behind.
Two red tests pin the intended contract: both entry points heal the
sidecar first (attributed roll-forward), then run on the converged
state. Currently failing on the stale-sidecar / dropped-rows
assertions; the fix lands in the next commit.
* fix(engine): heal pending recovery sidecars at the schema-apply and branch-merge entries
Extend the write-entry heal to the remaining two write entry points.
Unlike load/mutate (which wedge on the drift guard), these proceeded
over sidecar-covered drift and decided its fate implicitly:
- schema apply re-planned table rewrites from the manifest pin,
orphaning the drifted Phase-B commit -- its rows silently vanished
from the rewritten table -- while the stale sidecar lingered to
misclassify against the post-apply pins;
- branch merge published over the drift, making the failed writer's
commit visible without a recovery audit row, and left the stale
sidecar behind.
Both now run the same queue-serialized roll-forward heal at entry,
before their own sidecar exists, so recovery is attributed (audit row)
and deterministic. ensure_indices stays heal-free: it runs inside the
load / schema-apply flows after their entry heal.
Turns the previous commit's two red tests green. Docs updated in the
same change (invariant 5, writes.md, testing.md, AGENTS.md).
* test(engine): pin Phase A sidecar-write failure semantics
Storage fault-injection matrix, row 1: a sidecar PUT failure (S3
PutObject / fs write) in Phase A. New failpoint recovery.sidecar_write
at the top of write_sidecar -- the single choke point all five sidecar
writers go through -- models the storage error backend-generically.
Also adds the other three storage-fault failpoints used by the
following commits (recovery.sidecar_delete, recovery.sidecar_list,
recovery.record_audit); each is a no-op without the failpoints feature.
Pinned contract: every writer writes its sidecar BEFORE its first
HEAD-advancing commit, so a put failure aborts with zero drift (no
sidecar, Lance HEAD == manifest pin, no rows) and a transient fault
never wedges the graph -- the same handle writes/merges normally once
it clears. Covered for load (the staging writer) and branch_merge (the
multi-table writer, forced onto the RewriteMerged path by diverging
both sides).
* test(engine): pin Phase D delete, list, and audit-append storage-fault semantics
Storage fault-injection matrix, rows 2/3/5, plus the real-backend run:
- recovery.sidecar_delete: a Phase D delete failure (S3 DeleteObject)
must NOT fail the user's write -- the manifest publish already
landed, so the caller's data is durable. The swallowed failure
leaves a stale sidecar; the next write's entry heal consumes it via
the stale-sidecar audit-recovery path (RolledForward, attributed).
- recovery.sidecar_list: a __recovery/ list failure (S3 ListObjectsV2)
is loud at every consumer -- the write-entry heal fails the write
and the open-time sweep fails the open. Silently skipping recovery
over a pending sidecar would be consumer tolerance of drift. Once
the fault clears, open recovers the pending sidecar normally.
- recovery.record_audit: an audit write failure after the
roll-forward's manifest publish aborts that recovery attempt and
keeps the sidecar; re-entry detects the already-published manifest,
records exactly ONE RolledForward audit row, and converges -- the
retry tolerance documented on record_audit, exercised end-to-end.
- s3_load_recovers_after_publisher_failure_without_reopen: the
same-handle heal scenario on a real bucket (gated on
OMNIGRAPH_S3_TEST_BUCKET, skips locally), exercising sidecar
put/list/delete through S3StorageAdapter instead of the local-FS
adapter. CI wiring lands in a follow-up commit.
* test(engine): refuse corrupt recovery sidecars loudly
Storage fault-injection matrix, row 4 (no failpoint needed -- the
corrupt file is written by hand, sibling to the unknown-schema-version
refusal test): a truncated/garbage __recovery/{ulid}.json must be
refused loudly by both the write-entry heal (the write fails naming
the parse error) and the open-time sweep (ReadWrite open fails naming
the file), with the file left on disk for operator inspection.
Read-only opens still work -- the sweep is skipped there.
* test(engine): run the S3 sidecar-lifecycle coverage in CI + document the fault matrix
- ci.yml rustfs_integration: new step running the bucket-gated
failpoints tests (name filter s3_) against the RustFS container, so
sidecar put/list/delete are exercised through S3StorageAdapter on
every storage-affecting PR.
- writes.md: sidecar I/O failure semantics -- Phase A put failure
aborts with zero drift; Phase D delete failure is swallowed (write
already durable) and healed by the next write; list failures are
loud at heal and open; corrupt sidecars are refused with the file
kept for inspection; audit-append failures are retried to exactly
one audit row.
- testing.md: index the storage-fault matrix in the failpoints.rs row
and the new RustFS CI line.
* test(engine): pin read-visibility of acknowledged local if-absent writes
The cluster lib test import_missing_state_creates_state_with_graph_-
observation flakes at ~50% under full-workspace load ('EOF while
parsing a value' reading back the state.json its own import just
acknowledged). Root cause is in the engine's local storage adapter:
write_text_if_absent writes through a buffered tokio::fs::File and
returns when write_all resolves -- which, per tokio's documented File
semantics, means the bytes reached tokio's internal buffer, not the
file. The actual write completes in a background blocking task after
drop, so a caller that acknowledges success and reads the object back
can see an empty or partial file. Under load the window widens; the
red run fails at iteration 0 with 0 of 8192 bytes on disk.
The regression test pins the contract at the adapter boundary: when
write_text_if_absent resolves, the full contents are visible to any
reader; a losing second claim leaves the winner's object untouched.
The fix lands in the next commit.
* fix(engine): publish local storage writes with atomic visibility
Close the class, not the instance. The local adapter admitted three
ways for a reader to observe a write that was acknowledged or visible
before its bytes were complete:
1. write_text_if_absent acknowledged success when the buffered
tokio::fs::File write_all resolved -- i.e. when the bytes reached
tokio's internal buffer, not the file. A caller reading back its own
acknowledged write could see an empty object (the ~50% cluster
import flake under full-workspace load; the regression test failed
at iteration 0 with 0 of 8192 bytes visible).
2. The same call published its CLAIM (create_new) before its CONTENT,
so concurrent readers saw an empty claimed file in the window.
3. write_text (plain tokio::fs::write) exposed truncated content
mid-replace -- silently falsifying write_sidecar's 'readers either
see the complete sidecar or none' contract on local FS (true on S3,
where PutObject is atomic).
A flush in write_text_if_absent would have fixed only (1). Instead,
both local write paths now publish complete temp files atomically:
rename for replace (write_text -- the idiom write_text_if_match
already used) and hard_link for no-replace (write_text_if_absent --
link fails AlreadyExists, so exactly one of N concurrent claimants
wins and the winner's object is fully readable at the instant it
becomes visible). The local adapter now honors the same object-level
atomic-visibility contract as the S3 adapter, which is what every
caller (recovery sidecar protocol, cluster state CAS) was written
against. Crash-orphaned *.tmp.* files are inert: the sidecar sweep
filters to .json, and cluster state reads address state.json by name.
fsync/durability policy is unchanged (no fsync before, none now);
this fix is about visibility ordering, not power-loss durability.
Pre-existing on main (landed with the multi-graph server mode change,
PR #119); surfaced by this branch's heal work only because one extra
list_dir per write shifted test timing. Cluster lib suite: 12/25
failures before, 0/25 after. Turns the previous commit's red test
green.
* refactor(engine): one storage implementation over object_store for every backend
Collapse LocalStorageAdapter (hand-rolled tokio::fs) and
S3StorageAdapter into a single ObjectStorageAdapter backed by
Arc<dyn object_store::ObjectStore> -- LocalFileSystem for local URIs,
the existing AmazonS3 build for s3://, plus a pub in_memory()
constructor (full contract including TRUE conditional updates; the
in-memory test backend testing.md asked for at the adapter level).
Why: the acknowledged-before-visible bug showed the two-impl shape has
no referee -- one prose contract, two independent answers. Upstream
LocalFileSystem::put_opts is byte-for-byte the staged-temp+rename/
hard_link idiom that fix converged on, and Lance's own commit protocol
is built on the same primitives (put-if-not-exists / rename-if-not-
exists), so the substrate-aligned move is to stop hand-rolling it.
The per-backend residue shrinks to a UriCodec (URI <-> object path)
and one capability flag.
Semantics preserved by construction, with three deliberate deltas:
- exists() is now object-store-semantics everywhere (head + non-empty
prefix fallback): an EMPTY local directory no longer 'exists'. The
only dir-shaped caller (_graph_commits.lance probes) self-heals via
ensure_commit_graph_initialized where it previously wedged loudly.
- A directory at an object path reads as NotFound, not as an IO error
('only objects exist'). The cluster unreadable-payload test used a
same-named directory as a portable non-NotFound trigger; it now uses
chmod 000, which still models genuine transient IO.
- write_text_if_match keeps content-token semantics on local
(PutMode::Update is NotImplemented upstream for LocalFileSystem in
0.12.5 and 0.13.2); the capability flag gates the token SOURCE in
read_text_versioned too -- an ETag token with content-compare writes
would lose every CAS.
delete_prefix keeps a local remove_dir_all branch: directories are a
local-FS concept, and list+delete would leave empty skeletons that
cluster graph_root_exists (raw Path::exists) reports as still present.
LocalStorageAdapter remains as a delegating shim so the pinned
contract tests gate this swap textually unchanged; the shim and the
test parameterization over local + in-memory land next. Cargo gains
the explicit 'fs' feature (already transitively enabled by lance).
* test(engine): one executable storage contract, run against every backend
Remove the LocalStorageAdapter delegation shim and migrate its
construction sites to ObjectStorageAdapter::local(). Replace the
per-backend duplicated tests with a single contract_suite asserting
the trait's promises (atomic replace, exists incl. the dataset-root
prefix probe, one-winner if_absent, versioned CAS with loud CAS-lost,
rename, list round-trip with no sibling-prefix bleed, idempotent
delete/delete_prefix), run against the local backend and the new
in-memory backend -- which implements true conditional updates, so the
strong-CAS path is exercised without a bucket. The bucket-gated S3
variant already exists (s3_adapter_conditional_writes_contract).
New local-specific pins for the deliberate semantic edges of the
collapse: empty directories are not objects (exists=false; the Lance
dataset-root probe shape is the non-empty case), file://-anchored and
spaces-in-path list output round-trips byte-identically into
read_text, dot-segment paths are lexically absolutized (the CLI's
./graph.omni shape), and upstream rename creating missing destination
parents. The acknowledged-write visibility regression test stays, now
documenting that the cross-API std::fs read-back is the point.
* refactor(cluster): drop put_json's per-backend atomicity branch
The local temp+rename dance predates the storage adapter guaranteeing
atomic visibility; now that write_text publishes via a staged temp +
rename on the filesystem (and a single atomic PUT on object stores) by
contract, the branch duplicated upstream behavior. One call, both
backends.
* docs: storage adapter collapse — contract, in-memory backend, local CAS gap
- testing.md: the 'no MemStorage backend' note is half-closed —
ObjectStorageAdapter::in_memory() covers the text-object layer with
the full contract (true conditional updates); Lance datasets bypass
the adapter, so the engine substrate ask stays open.
- invariants.md: truth-matrix Tests row updated; new Known Gap for
local write_text_if_match (upstream PutMode::Update is unimplemented
for LocalFileSystem; content-token emulation is safe only under the
cluster lock protocol — close before admitting a lock-free caller).
- writes.md: backend notes for the unified adapter (name#N staging
residue invisible to the sweep, backend-wrapped error text with
exists()-probing for missing-vs-error, loud permission failures).
* docs: finish renaming the storage adapters in user docs and test comments
storage.md's URI-scheme table and the S3 failpoint test's doc comment
still named the deleted LocalStorageAdapter/S3StorageAdapter; both now
describe the unified ObjectStorageAdapter over object_store, including
the relative-path absolutization note for local URIs.
* test(engine): pin branch-awareness of the drift guard's recovery advice
A pending sidecar on ANOTHER branch does not cover this branch's
drift: with a deferred feature-branch sidecar on disk and genuinely
uncovered drift on main, the main write's error must still point at
omnigraph repair -- a read-write reopen recovers the sidecar but
cannot repair main's uncovered drift. Currently red: the guard
matches sidecar pins by table_key only, so the feature sidecar flips
main's advice to the reopen path. Fix in the next commit.
Surfaced by external review of the drift-guard change.
* fix(engine): branch-aware sidecar matching in the drift guard's advice
The commit-time drift guard's sidecar-covered check matched pins by
table_key alone, so a pending sidecar on another branch flipped this
branch's uncovered-drift advice from 'run omnigraph repair' to the
reopen path -- and a reopen recovers that sidecar but cannot repair
this branch's drift. Compare the pin's table_branch too. Turns the
previous commit's red test green.
Surfaced by external review of the drift-guard change.
* test(engine): pin heal non-interference with a live schema apply
The write-entry heal's schema-staging reconcile runs before any queue
acquisition, so a load on the same handle, overlapping a schema apply
parked between its staging write and manifest commit, promotes the
apply's staging files (new catalog live against the old manifest),
classifies the LIVE apply's sidecar, and publishes its registrations
out from under it. The resumed apply then collides with its own stolen
commit. Currently red with:
Lance("Concurrent modification: table version 3 already exists for
node:Tag")
The fix (per-sidecar reconcile under the sidecar's write-queue guards,
plus a serialization key the schema-apply writer and the heal both
acquire) lands in the next commit.
Surfaced by external review of the write-entry heal.
* fix(engine): serialize the heal's schema-staging reconcile with live schema applies
The write-entry heal ran recover_schema_state_files up front, before
acquiring any queue guards. Overlapping a live schema apply parked
between its staging write and manifest commit, the heal promoted the
apply's staging files (new catalog live against the old manifest),
classified the LIVE apply's sidecar, and published its registrations —
the resumed apply then collided with its own stolen commit.
Correct by construction:
- New schema-apply serialization queue key, acquired by the schema-
apply writer (alongside its per-table keys) from before write_sidecar
until after delete_sidecar. Per-table keys alone don't cover a
registration-only migration, which pins no existing tables but has a
sidecar and staging files on disk.
- The heal reconciles schema staging lazily, PER SchemaApply sidecar,
after acquiring that sidecar's guards (including the serialization
key) and re-confirming the sidecar exists — a sidecar that survives
the queue wait belongs to a dead writer, so the reconcile can no
longer race a live apply. Recomputing per sidecar also removes the
staleness of one up-front result across a multi-sidecar pass.
- Omnigraph::refresh drops its up-front reconcile-and-pass-through
(same race, and a pre-promoted result would make the heal's guarded
reconcile see clean staging and wrongly defer the sidecar): it now
reconciles standalone only when NO sidecar exists — which cannot
race a live apply, whose sidecar always precedes its staging files —
and otherwise defers entirely to the heal.
The open-time sweep keeps its precomputed reconcile: open has no
concurrent writers. Turns the previous commit's red test green.
Surfaced by external review of the write-entry heal.
Self-audit addendum folded in: refresh's no-sidecar gate had a TOCTOU
(a live apply could write its sidecar + staging between the empty
check and the reconcile) — the standalone reconcile now holds the
serialization key across the list-then-reconcile pair. The remaining
residual is cross-process only (in-process queues cannot serialize
against a writer in another process; the open-time sweep has the same
pre-existing exposure) and is now an explicit Known Gap in
invariants.md rather than an implicit one.
* test(engine): pin catalog reload after the heal recovers a schema apply
When the write-entry heal rolls a crashed apply's SchemaApply sidecar
forward on the same handle, disk and manifest move to the new schema
(staging promoted, registrations published) but the handle's in-memory
schema_source/catalog do not. Subsequent writes then validate against
the stale catalog and reject rows of types the graph already has.
Currently red with:
record 1: unknown node type 'Tag'
refresh() reloads after its heal; the write entry points must too.
Fix in the next commit.
Surfaced by external review of the write-entry heal.
* fix(engine): reload the in-memory catalog after the heal recovers a schema apply
heal_pending_recovery_sidecars refreshed the coordinator and
invalidated the runtime cache after processing sidecars, but never
reloaded schema_source/catalog — so a write whose entry heal rolled a
crashed SchemaApply sidecar forward proceeded to validate against the
OLD schema while disk and manifest were already on the new one.
reload_schema_if_source_changed is the same post-heal step refresh()
already runs; it no-ops on the (overwhelmingly common) non-schema heal
because the on-disk source is unchanged. Turns the previous commit's
red test green.
Surfaced by external review of the write-entry heal.
* test(engine): pin that a deleted-branch sidecar cannot wedge the graph
A rollback-eligible sidecar pinned to a branch is deferred by every
roll-forward-only pass; if the branch is then deleted, the sidecar
survives, referencing a branch with no manifest tree. The heal (every
write entry) and the open-time sweep (every ReadWrite open) both fail
opening the dead branch, and repair refuses while a sidecar is pending
-- a terminal read-only state with manual sidecar surgery as the only
exit. Currently red with:
Lance("Not found: .../__manifest/tree/feature/_versions")
The branch's tree and forks are already reclaimed, so the pinned drift
is unreachable and the sidecar is provably moot; the fix classifies it
as an orphaned-branch terminal state (audit + discard) in both passes.
Surfaced by review (P1, verified by repro).
* fix(engine): classify deleted-branch sidecars as orphaned instead of wedging
A deferred (rollback-eligible) sidecar pinned to a branch survives
branch_delete; both the write-entry heal and the open-time sweep then
failed unconditionally opening the dead branch -- every write and
every ReadWrite open errored, and repair refuses while a sidecar
pends. Terminal state, manual sidecar surgery the only exit.
The branch's tree and per-table forks are already reclaimed at delete,
so the drift the sidecar pins is unreachable and the sidecar is
provably moot. Both passes now check the sidecar's branch against the
manifest's branch list (the authority -- deliberately NOT inferred
from a Not-found on open, which could be a transient storage error
masking real recovery intent) and discard orphans with an
OrphanedBranchDiscarded audit row, commit appended on main since the
sidecar's own branch no longer has a commit graph.
The open-time half is pre-existing; the write-entry heal made it hot.
Turns the previous commit's red test green.
Surfaced by review (P1, verified by repro).
* chore: harden review nits — vacuous CI filter, root-runner skip, liveness note
- ci.yml: the RustFS sidecar-lifecycle step now fails loudly if the
's3_' name filter matches zero tests (cargo passes vacuously on an
empty filter; the step exists specifically to prove S3 sidecar I/O
coverage). The pre-existing CLI smoke step has the same shape and is
left for a follow-up.
- cluster unreadable-payload test: cfg(unix) + a skip-with-log when
running as root (mode 000 is still readable to root, common in
container dev runners), so the test degrades instead of failing.
- refresh: document the one-pass-late convergence for legacy staging
residue while non-SchemaApply sidecars pend, so nobody 'fixes' it by
re-running the reconcile unserialized — the exact race the
serialization key closes.
* test(engine): pin orphan-discard idempotency across a delete fault
discard_orphaned_branch_sidecar writes its audit row and main commit
before deleting the sidecar; a Phase D delete fault leaves the sidecar
on disk with the audit already durable, and the retry repeated the
whole path -- a second OrphanedBranchDiscarded audit row (and commit)
for the same operation. Currently red: 2 rows after one fault + retry.
The retry must only finish the delete. Fix next.
Also promotes the recovery-audit kinds reader into the shared test
helpers (it was recovery.rs-local).
Surfaced by external review of the orphan-discard fix.
* fix(engine): orphan-discard idempotency + heal reports acted-vs-deferred
Two review findings on the recovery surface:
- discard_orphaned_branch_sidecar now checks the audit table for an
existing (operation_id, OrphanedBranchDiscarded) row before appending
the commit + audit pair, so a Phase D delete fault retries ONLY the
delete instead of duplicating audit rows and commit-graph entries.
Cold path: the list scan runs only when an orphaned sidecar exists.
Turns the previous commit's red test green (exactly one audit row
across fault + retry).
- process_sidecar returns whether durable state changed; the heal sets
processed_any only for sidecars that were actually rolled forward /
rolled back / audit-recovered (orphan discards count). Deferred
sidecars (rollback-eligible, invariant-violating, unpromoted
SchemaApply) no longer trigger a per-write schema reload + full
runtime-cache invalidation while they pend -- the cache is
snapshot-keyed so this was waste, not corruption, but it was paid on
every write until reopen. Acted-paths' processed=true remains pinned
by load_after_schema_apply_phase_b_failure_uses_recovered_catalog
(the reload depends on it).
Surfaced by external review.
* test(engine): pin the orphan-discard audit-append fault leg as documented tolerance
The orphan discard's commit append and audit append are two writes; a
failure between them leaves a recovery commit with no audit row, and
the retry (keyed on the audit row, the operator-facing record) appends
a second commit before the audit lands. This is the same
not-atomic-pair-write tolerance record_audit documents and the
manifest->commit-graph Known Gap covers for every publish: bounded
commit-graph noise, audit row exactly-once under clean failures.
Keying idempotency on commit rows instead would need an operation_id
column on _graph_commits, and audit-before-commit would dangle the
graph_commit_id join -- both worse than the documented residual.
Make the tolerance explicit instead of implicit: docstring names the
window, a failpoint sits inside it, and the new test pins convergence
across the fault (sidecar consumed, exactly one audit row), completing
the orphan-discard fault matrix alongside the delete-fault leg.
Surfaced by external review of the orphan-discard idempotency.
* test(engine): pin honest drift-guard advice when sidecar listing fails
The guard's unwrap_or(false) conflated 'classified as uncovered' with
'could not classify': a transient list fault on the guard's second
list (the entry heal's first list having succeeded) confidently routed
the operator to omnigraph repair even when the heal had just deferred
a rollback-eligible sidecar -- and repair refuses while a sidecar is
pending. Currently red: the error says 'run omnigraph repair' with no
mention of the reopen path. The fix names both paths plus the failure
cause when classification is impossible.
Surfaced by external review of the drift-guard fallback.
* fix(engine): admit ambiguity in the drift guard when sidecar listing fails
Replace the unwrap_or(false) fallback with a tri-state: covered ->
reopen advice; uncovered -> repair advice; listing FAILED -> say the
drift could not be classified, name the cause, and give both paths in
order ('run repair, or reopen read-write if repair reports a pending
sidecar'). The old fallback confidently routed a transient list fault
to repair, which refuses while a sidecar is pending -- a self-
correcting but pointless detour. The conflict itself is still always
raised; only the advice degrades honestly. Turns the previous commit's
red test green.
Surfaced by external review of the drift-guard fallback.
2026-06-13 11:20:08 +02:00
| Tests | Tempdir-backed Lance tests are the current substrate; the storage adapter has an in-memory backend for adapter-level contract tests, but Lance datasets bypass it | [testing.md ](testing.md ) |
2026-05-15 03:45:22 +03:00
fix(branch): make branch delete correct under partial failure (#137)
* test(lance): pin force_delete_branch surface guard
Pin the Lance 6.0.1 force_delete_branch behavior the branch-delete
single-authority redesign relies on: plain delete_branch errors on a
missing ref, force_delete_branch removes an existing forked branch, and
the local-store quirk where force_delete on a fully-absent branch still
errors (worked around by the upcoming TableStore::force_delete_branch).
Re-pin the docs/dev/lance.md alignment stanza (9 guards; 4 runtime).
* feat(storage): add force branch-delete to TableStore + CommitGraph
Add TableStore::force_delete_branch and CommitGraph::force_delete_branch
(idempotent: tolerate an already-absent branch via Lance RefNotFound /
NotFound), plus CommitGraph::list_branches for the cleanup reconciler to
diff against the manifest authority. RefConflict (referencing
descendants) is still surfaced. Unused until the branch-delete rewire.
* test(maintenance): red — cleanup reconciles orphaned branch forks
Forge a Lance branch on the Person table that the manifest never
references (a zombie fork from an incomplete prior delete) and assert
cleanup reclaims it while leaving main intact. Fails today: cleanup does
not yet reconcile orphaned forks. Goes green with the next commit.
* fix(maintenance): reconcile orphaned branch forks in cleanup
Add reconcile_orphaned_branches: force_delete_branch every per-table and
commit-graph Lance branch absent from the manifest branch set (the
authority), children-before-parents. Folded into cleanup_all_tables,
runs before version GC. Idempotent and authority-derived; no-ops once
nothing is orphaned, and would harmlessly find nothing if a future Lance
atomic multi-dataset branch op prevented orphans. Adds TableStore::list_branches
and exposes graph_commits_uri(pub crate). Turns the maintenance red test green.
* test(failpoints): red — branch_delete partial failure converges
Add the branch_delete.before_table_cleanup failpoint hook (inert without
the feature) and a regression test: a cleanup-step failure after the
manifest authority flip must leave branch_delete returning Ok, the branch
gone, the orphan stranded, then reclaimed by cleanup, and the name
reusable. Fails today: cleanup_deleted_branch_tables propagates the error
as a hard failure. Goes green with the next commit.
* fix(branch): best-effort fork reclaim after the manifest flip
Make branch_delete treat per-table forks and the commit-graph branch as
derived state reclaimed best-effort with force_delete_branch after the
manifest authority flip. A reclaim failure (transient error, or the
branch_delete.before_table_cleanup failpoint) is logged via tracing::warn
and swallowed: the branch is already gone and the cleanup reconciler
converges the orphan. cleanup_deleted_branch_tables no longer returns an
error or blocks the call. Turns the partial-failure recovery test green.
* test(failpoints): red — recreate over orphaned fork is actionable
After a partial-failure delete leaves a fork orphaned, recreating the
branch name and writing to the previously-forked table before cleanup
runs currently surfaces the opaque ExpectedVersionMismatch ("stale view
... expected manifest table version N"). Assert instead a clear error
pointing the user at cleanup. Goes green with the next commit.
* fix(branch): actionable orphan-collision error in fork_branch_from_state
When a fork's create_branch collides with an existing target ref, reuse
it only if its head matches source_version (a legitimate concurrent
first-write). A version mismatch means a zombie fork from an incomplete
prior delete: return a manifest_conflict pointing the user at
`omnigraph cleanup`, instead of the opaque ExpectedVersionMismatch.
Turns the recreate-over-orphan red test green.
* docs(invariants): single-authority branch-lifecycle + Lance forward-compat
Record branch delete in the Current Truth Matrix: manifest is the single
authority flipped atomically first, per-table forks + commit-graph branch
are derived state reclaimed best-effort with the cleanup reconciler as
backstop, and reusing a name whose reclaim failed surfaces an actionable
error. Note the reconciler is authority-derived and degrades to a no-op
under a future Lance atomic multi-dataset branch op, the same shape as
invariant 7.
* test(failpoints): red — cleanup isolates a single-table failure
Add the cleanup.table_gc failpoint hook (inert without the feature) and
an error: Option<String> field on TableCleanupStats (mechanical, always
None for now). Regression test: a one-shot version-GC failure for one
table must not abort the whole cleanup — assert cleanup still succeeds,
surfaces the failure per-table in stats, and the independent reconcile
pass still reclaimed an orphan. Fails today: the version-GC collect
aborts on the first table error. Goes green with the next commit.
* fix(maintenance): fault-isolate cleanup per table
Make the cleanup sweep do as much as it can and converge on re-run
instead of aborting wholesale on one table's transient error
(invariant 13). The version-GC loop now records a per-table failure on
its stats row (error: Some) and logs it rather than collecting into a
Result that aborts; reconcile_orphaned_branches isolates per-table and
commit-graph failures into BranchReconcileStats.failures. The CLI reports
any failed tables and tells the user to rerun cleanup. Addresses the
Devin review finding. Turns the single-table-failure test green.
* test(failpoints): red — branch_create heals commit-graph zombie + is atomic
Add the branch_delete.before_commit_graph_reclaim failpoint hook and two
regression tests: (a) recreating a name whose delete left a commit-graph
zombie must succeed (today it dies on Lance's internal Clone error), and
(b) branch_create must roll back the manifest branch when the derived
commit-graph branch fails (today it leaves the manifest branch created
while returning Err). Both fail now; green with the next commit. The
existing branch_create_failpoint_triggers test still passes.
* fix(branch): make branch_create atomic + heal commit-graph zombie
branch_create now flips the manifest authority first, then creates the
derived commit-graph branch in create_commit_graph_branch, force-dropping
any orphaned commit-graph ref left by an incomplete prior delete (the
manifest branch is fresh, so a same-named commit-graph branch is provably
a zombie). If commit-graph creation fails, the manifest branch is rolled
back so the name never half-exists. Addresses the Codex review finding.
Turns the two branch_create red tests green; existing tests unaffected.
* test(failpoints): red — fork collision misclassifies live concurrent fork
Add the fork.before_classify failpoint hook and a concurrency test: when
a concurrent first-write legitimately wins the fork race, the loser must
get a retryable refresh-and-retry, not the misleading run-cleanup orphan
error. Today the version-comparison misclassifies the live fork as an
orphan (the Cursor finding). Goes green with the next commit.
* fix(branch): manifest-arbitrated fork-collision classification
Classify a fork collision by the manifest authority instead of comparing
Lance branch versions. Before forking, open_owned_dataset_for_branch_write
re-reads the live manifest: if the table is already forked on the active
branch, a concurrent first-write won and the loser gets a retryable
refresh-and-retry (not a misleading orphan error). fork_branch_from_state
no longer guesses from versions — a create collision past that check is
an orphan, so it returns the actionable cleanup error. Addresses the
Cursor finding; turns the live-concurrent-fork test green, zombie path
unchanged.
* test(failpoints): close branch-lifecycle test gaps
Three coverage additions for the branch-delete work (behavior already
correct; these lock it in and catch regressions):
- cleanup_isolates_reconcile_failure: inject a force-delete failure into
the reconcile loop (new cleanup.reconcile_fork hook) and assert the
sweep continues + converges on re-run. Directly covers the reconcile
loop the Devin finding was about (previously only version-GC was).
- cleanup_reclaims_orphaned_commit_graph_branch: forge a commit-graph
orphan via the delete reclaim failpoint and assert cleanup's
reconcile_commit_graph_orphans drops it (previously untested).
- fork_collision_with_live_concurrent_fork_is_retryable: replace the
fixed 300ms sleep with a deterministic readiness signal (cfg_callback +
compare_exchange atomics) so the two-writer ordering can't flake.
Full failpoints suite 31/0.
2026-06-01 13:28:38 +02:00
The branch-delete reconciler is authority-derived: it reclaims orphaned forks
today and degrades to a no-op if Lance ships an atomic multi-dataset branch
operation, so the design composes with that future rather than blocking it. This
is the same shape as invariant 7 (indexes are derived state); prefer it over a
recovery-sidecar-style approach for any new multi-dataset metadata operation,
since the sidecar would be scaffolding to remove once the substrate closes the gap.
2026-05-15 03:45:22 +03:00
## Known Gaps
Do not hide these behind invariant wording. Either move them forward or keep
them explicit.
- **Rename-stable schema identity:** the invariant is that accepted IDs survive
renames. The current compiler still derives type IDs from `kind:name` ; this
must be fixed before relying on renamed IDs across accepted schemas.
- **Storage abstraction:** `TableStorage` is present, sealed, and canonical for
(feat) convert engine call sites to &dyn TableStorage; demote legacy TableStore methods to pub(crate) (#86)
* MR-854: convert engine call sites to &dyn TableStorage; demote legacy methods
Phase 1b: every db.table_store.X(...) call site converts to
db.storage().X(...), reaching the storage layer through the sealed
TableStorage trait (returns &dyn TableStorage). Opaque SnapshotHandle
and StagedHandle replace bare lance::Dataset and Transaction in the
threaded values.
Phase 9: the inherent inline-commit methods on TableStore
(append_batch, merge_insert_batch{,es}, overwrite_batch,
create_btree_index, create_inverted_index) demote from pub to
pub(crate). Their only remaining direct users are table_store.rs
itself and the bulk loader's LoadMode::{Append, Overwrite, Merge}
concurrent fast-paths in loader::write_batch_to_dataset (no
two-phase shape in Lance 4.0.0 — closes after lance#6658 and #6666).
Docs:
- invariants.md \u00a7VI.23: drop "at the writer-trait surface"
qualifier; staged primitives are now the only engine surface.
- runs.md: residual matrix shrinks to delete_where and
create_vector_index (the two upstream-blocked residuals).
- forbidden_apis.rs: replace transitional language with the
current allow-list shape (table_store.rs + loader concurrent
fast-path only).
Files touched:
- changes/mod.rs, db/omnigraph.rs (+export/optimize/schema_apply/
table_ops.rs), exec/{merge,mod,mutation,staging}.rs,
loader/mod.rs, storage_layer.rs, table_store.rs,
tests/forbidden_apis.rs, docs/{invariants,runs}.md.
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: replace test-only inline-commit append callers with local Lance helpers
After demoting TableStore::append_batch from pub to pub(crate), the
integration tests in tests/recovery.rs and tests/staged_writes.rs
that previously called store.append_batch(...) directly to simulate
HEAD-ahead-of-manifest drift can no longer access the inherent
method. Replace those calls with small in-test helpers that do a raw
Dataset::append (the same body the inherent method runs).
- tests/helpers/mod.rs gains lance_append_inline (shared helper).
- tests/staged_writes.rs gets a file-local lance_append_inline_local
(staged_writes.rs does not import helpers::).
- tests/recovery.rs drops the unused TableStore import in the one
function whose store binding became unused after the conversion.
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: retrigger CI for flaky Test Workspace job
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: convert remaining table_store call sites in export.rs / read_blob
Two leftover `self.table_store.X` / `db.table_store.X` call sites were
missed in the initial sweep — flagged by Devin Review on PR #86. Both
now go through the trait surface:
- `entity_from_snapshot` (db/omnigraph/export.rs): switch from
`db.table_store.open_snapshot_table` + `db.table_store.scan` to
`db.storage().open_snapshot_at_table` + `db.storage().scan`.
- `read_blob` (db/omnigraph.rs): replace
`snapshot.open(table_key)` + `self.table_store.first_row_id_for_filter`
with `self.storage().open_snapshot_at_table` +
`self.storage().first_row_id_for_filter`. The follow-up
`take_blobs` call still needs an `Arc<Dataset>` (it's a Lance blob
accessor not surfaced through the trait), so we hand off via
`SnapshotHandle::into_arc()` with a comment.
After this commit, no engine code outside `table_store.rs` reaches the
inherent `TableStore` API — the docs/runs.md and docs/invariants.md
claim is now uniformly true.
Co-Authored-By: Ragnor Comerford <ragnor.comerford@gmail.com>
* MR-854: post-rebase doc fixes (Lance 6.0.1, MR-A framing, into_dataset note)
Reviewer feedback on the rebased PR:
* docs/dev/writes.md residuals matrix: drop demoted methods from the trait-surface table (now `pub(crate)`); keep only the two genuine trait-surface residuals (`delete_where`, `create_vector_index`); reframe under MR-A (Lance v7.x bump) per docs/dev/lance.md.
* tests/forbidden_apis.rs: update transitional allow-list header to (a) drop the truncate_table mislabel (truncate_table is a Lance Dataset method, not a TableStore method — overwrite_batch's internal call), (b) reframe trait-surface residuals under MR-A / Lance #6666.
* crates/omnigraph/src/storage_layer.rs::SnapshotHandle::{into_arc, into_dataset}: add single-ref invariant doc — both consume Arc via try_unwrap-or-clone; sibling SnapshotHandle clones across an await point force a deep Dataset clone.
* Replace lance-4.0.0 version refs with lance-6.0.1 in active source/test/dev-doc comments (storage_layer.rs, table_store.rs, table_ops.rs, schema_apply.rs, merge.rs, recovery.rs, staged_writes.rs, consistency.rs, docs/dev/execution.md, docs/user/query-language.md). Historical refs in docs/releases/v0.4.1.md and the canonical "Lance 4.0.0 → 6.0.1 migration" line in docs/dev/lance.md left intact.
No engine code changes.
* MR-854: update docs/dev/invariants.md Storage trait row + gap entry
Reviewer feedback: the docs reorg landed; the invariant row now lives in
docs/dev/invariants.md with stable headings (no more numbered §VI.23).
Update two pieces to reflect MR-854 completion:
* Status table 'Storage trait' row: was 'full call-site migration ... incomplete';
now 'engine call sites all route through db.storage() (MR-854); inline-commit
inherent methods are pub(crate)-demoted; capability/stat surfaces are roadmap'.
* 'Known Gaps' 'Storage abstraction' entry: was 'older inherent TableStore call
sites and inline residuals remain'; now names the closed scope (MR-854 — call
sites migrated, methods demoted, loader fast-paths) and the remaining
trait-surface residuals under MR-A (Lance v7.x bump) and Lance #6666.
Cross-links to docs/dev/lance.md and docs/dev/writes.md so the framing stays
co-located with the canonical Lance surface tracking.
* MR-854: remove dead inline-commit methods from the storage surface
The loader concurrent fast-path (write_batch_to_dataset) is only reached
for LoadMode::Overwrite — Append/Merge route through MutationStaging — so
its Append/Merge arms were unreachable. Collapse it to overwrite-only and
drop the now-unused mode params, which removes the only callers of:
- TableStorage::append_batch + TableStorage::merge_insert_batches (trait)
- TableStore::merge_insert_batch + merge_insert_batches (inherent)
create_btree_index / create_inverted_index had zero callers anywhere
(scalar index builds use the stage_* primitives). Remove both from the
trait and the inherent impl.
Inherent append_batch stays pub(crate): overwrite_batch and recovery
tests use it. Migrate the one trait-append_batch test caller
(seed_person_row) to stage_append + commit_staged. The merge_insert
FirstSeen-workaround rationale moves from the deleted merge_insert_batch
into stage_merge_insert (now the sole merge path). No behavior change.
Also corrects the inaccurate loader residual comment (the prior text
blamed Lance #6658/#6666, which are the delete and vector-index issues,
for keeping overwrite inline; a stage_overwrite primitive already exists
and schema_apply uses it).
* MR-854: seal db.storage() to staged-only; move residuals to InlineCommitResidual
Split the three remaining inline-commit writes (overwrite_batch,
delete_where, create_vector_index) off the TableStorage trait onto a new
sealed InlineCommitResidual trait, reachable only via the explicit
Omnigraph::storage_inline_residual() accessor. db.storage() now exposes
only staged primitives + reads, so engine code cannot couple a write
with a Lance HEAD advance through the default surface — MR-793 acceptance
§1 ("no public method commits as a side effect of writing") now holds by
construction, not by review + naming.
Call sites moved to storage_inline_residual(): loader overwrite
fast-path, the three mutation delete_where paths, the branch-merge
delete, and the vector-index build. Impl bodies are unchanged (same
delegation to the pub(crate) inherent methods); this is a pure surface
reshape with no behavior change.
The residual trait holds two genuinely upstream-blocked methods
(delete_where -> Lance #6658/v7.x, create_vector_index -> Lance #6666)
plus overwrite_batch, kept for the loader's cross-table bulk-overwrite
concurrency until its staged migration lands (tracked follow-up).
* MR-854 docs: describe the staged-only seal; fix stale Lance index URLs
- writes.md / invariants.md / AGENTS.md: the inline-commit residuals now
live on InlineCommitResidual behind db.storage_inline_residual(), so
acceptance §1 holds by construction rather than 'option (b)' per-method
enumeration. Drop the inaccurate 'until Lance exposes
Operation::Overwrite { fragments }' claim (that op exists; stage_overwrite
already builds it) and reframe overwrite_batch as a removable legacy
residual gated on the loader's bulk-overwrite concurrency.
- forbidden_apis.rs: rewrite the allow-list doc for the split surface.
- lance.md: the index spec pages moved from /format/table/index/ to
/format/index/ in Lance 6.x (the old paths 404). Fix all 13 URLs.
* MR-854: fix stale lance-4.0.0 comment refs flagged in review
Addresses greptile (exec/merge.rs) and aaltshuler's stale-version blocker:
update lance-4.0.0 -> 6.0.1 in the comment/doc refs within this PR's
footprint (exec/merge.rs, exec/mutation.rs, docs/dev/writes.md). Also
corrects exec/merge.rs to cite lance#6666 (not #6658) for
build_index_metadata_from_segments — that is the vector-index segment-commit
API; #6658 is the two-phase delete. (Pre-existing 4.0.0 refs in untouched
files like architecture.md/storage.md are main's incomplete migration
cleanup, left out of scope.)
* fix(storage): stage loader overwrites
* fix(storage): stage empty schema rewrites
---------
Co-authored-by: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Co-authored-by: Ragnor Comerford <ragnor.comerford@gmail.com>
Co-authored-by: Ragnor Comerford <hello@ragnor.co>
2026-06-09 23:03:08 +02:00
staged writes. MR-854 sealed it: `db.storage()` exposes only staged primitives
+ reads, and the inline-commit residuals are split onto a separate sealed
`InlineCommitResidual` trait reached via `db.storage_inline_residual()` , so a
new writer cannot couple a write with a HEAD advance through the default
surface. The dead legacy methods (`append_batch` on the trait,
`merge_insert_batch{,es}` , `create_{btree,inverted}_index` ) were removed. The
build(deps): bump Lance 6.0.1 → 7.0.0 (correct-by-design substrate alignment) (#229)
* build(deps): bump Lance 6.0.1 → 7.0.0 (object_store 0.13.2, roaring 0.11.4)
Arrow stays 58 and DataFusion stays 53 (no change). The only transitive bump
is object_store 0.12.5 → 0.13.2. 141 upstream commits reviewed; no fixes lost
(the 6.0.x release-branch backports are all forward-ported into 7.0.0).
- object_store 0.13 moved get/put/head/rename/delete behind a new ObjectStoreExt
trait (list/list_with_delimiter/put_opts stay on the core trait). Add
`use object_store::ObjectStoreExt` in storage.rs and db/manifest/namespace.rs;
no call-site changes. Mirrors Lance's own migration in PR #6672.
- roaring pinned to 0.11.4 (cargo update -p roaring --precise 0.11.4). Lance
7.0.0's UpdatedFragmentOffsets newtype (lance#6650) derives Eq over
HashMap<u64, RoaringBitmap>, which needs RoaringBitmap: Eq, added in roaring
0.11.4; the loose `roaring = "0.11"` constraint otherwise resolves 0.11.3 and
lance itself fails to compile.
- lance#6774: merge-insert INSERT rows now stamp _row_created_at_version with the
commit version (was a fallback of 1). Flip the lance_version_columns assertion
to `== v2` and correct the changes/mod.rs rationale comment. Production
change-detection keys on _row_last_updated_at_version + ID membership, so its
logic is unaffected.
Refs lance#6650, lance#6774, lance#6672.
* fix(storage): pin WriteParams::auto_cleanup = None (lance#6755 default flip)
lance#6755 flipped the WriteParams::auto_cleanup default from on (a full cleanup
pass every 20th commit) to None. On 6.0.1 the on-by-default hook could silently
GC versions that __manifest pins for snapshots/time-travel. OmniGraph owns
cleanup explicitly (optimize.rs::cleanup_all_tables) and never set auto_cleanup,
so it was relying on a default that is both wrong for our snapshot model and now
changed upstream.
Pin auto_cleanup: None explicitly at all 11 production WriteParams sites
(table_store ×6, commit_graph ×2, recovery_audit ×1, manifest/graph ×2 — the
__manifest + sub-table Create paths). Removes the dependency on a default-flag
value and locks in the snapshot-safe behavior regardless of future upstream
re-flips.
Refs lance#6755.
* test(lance): pin BTREE range-boundary correctness (lance#6796)
lance#6796 (issue #6792) fixed a BTREE scalar-index range-query bound
inclusiveness bug: `x <= hi AND x > lo` returned the wrong boundary row.
Add lance_surface_guards.rs::btree_range_query_boundary_is_correct, which
reproduces the exact #6792 shape (5 rows + an explicit BTREE drives the index
path even on tiny data) and pins the corrected inclusive-<= / exclusive->
semantics. It turns red if a future Lance regression reintroduces the bug.
OmniGraph today builds BTREE only on string @key columns and queries them by
equality/IN, so its current patterns do not hit this; the guard protects any
future BTREE-range path (BTREE-on-properties, range-on-key).
Refs lance#6796.
* docs(dev): align Lance docs + invariants to 7.0.0
- docs/dev/lance.md: new 2026-06-14 alignment stanza for the 6.0.1 → 7.0.0 bump
(object_store ObjectStoreExt move, roaring 0.11.4, #6774/#6796/#6755 behavior,
#6658 shipped → MR-A unblocked but separate, #6666 + blob compaction still
open); prior 6.0.1 stanza demoted to historical.
- AGENTS.md: storage substrate 6.x → 7.x (line + architecture diagram).
- docs/dev/invariants.md: deletes/vector known gap updated — the staged
two-phase delete API (lance#6658) now exists and MR-A is unblocked, but
delete_where stays inline and D2 stays in place until the migration lands;
create_vector_index still gated on lance#6666.
* fix(storage): skip Lance auto-cleanup on commit paths for legacy datasets
Addresses PR #229 review (Codex P1). `WriteParams::auto_cleanup` is create-time
config with no effect on existing datasets (Lance write.rs docs), so the previous
`auto_cleanup: None` change alone did NOT protect graphs created before the v7
bump: 6.0.1 defaulted auto_cleanup ON, leaving `lance.auto_cleanup.*` config on
those datasets, and Lance's per-commit hook (io/commit.rs: `if
!commit_config.skip_auto_cleanup`) fires off that stored config — so omnigraph's
own writes would GC versions the __manifest pins for snapshots/time-travel.
Skip the hook on every commit path, covering new and legacy datasets alike:
- commit_staged: CommitBuilder::with_skip_auto_cleanup(true) — the staged data path.
- __manifest publisher: MergeInsertBuilder::skip_auto_cleanup(true).
- all 11 WriteParams: skip_auto_cleanup: true (direct Dataset::write/append paths;
auto_cleanup: None retained so new datasets store no cleanup config at all).
Tests:
- lance_surface_guards::skip_auto_cleanup_suppresses_version_gc — substrate:
negative control (config GCs v1 without skip) + with-skip survival.
- staged_writes::commit_staged_skips_auto_cleanup_so_pinned_versions_survive —
omnigraph usage: commit_staged on a legacy-config dataset preserves the pinned
create version.
Refs lance#6755.
* test(lance): assert created_at-preserved + updated_at-bumped on merge_insert UPDATE
Addresses PR #229 review follow-up. `lance_merge_insert_update_preserves_created_at_version`
documented (in a comment) that a merge_insert UPDATE preserves created_at and
bumps updated_at, but only asserted the value change — leaving the change-feed
invariant unguarded. Add the two missing assertions:
- bob created_at == v1 (preserved across UPDATE; what the test name promises;
lance#6774 only changed INSERT-row stamping).
- bob updated_at == v2 (bumped to the commit version) — the invariant
OmniGraph's insert/update classification relies on (changes/mod.rs keys on
_row_last_updated_at_version). A regression here would silently drop updates
from the diff/change feed.
2026-06-14 20:42:24 +02:00
remaining residuals are `delete_where` and `create_vector_index` . The Lance
6.0.1 → 7.0.0 bump landed, so the staged two-phase delete API
(`DeleteBuilder::execute_uncommitted` , Lance #6658 ) is now available and MR-A
is unblocked — but the migration itself is still pending, so `delete_where`
stays inline for now. `create_vector_index` remains gated on Lance #6666
(still open). See [lance.md ](lance.md ) and [writes.md ](writes.md ). New write
paths should use the staged shape unless a documented Lance blocker applies.
2026-05-15 03:45:22 +03:00
- **Deletes and vector indexes:** `delete_where` and vector index creation still
build(deps): bump Lance 6.0.1 → 7.0.0 (correct-by-design substrate alignment) (#229)
* build(deps): bump Lance 6.0.1 → 7.0.0 (object_store 0.13.2, roaring 0.11.4)
Arrow stays 58 and DataFusion stays 53 (no change). The only transitive bump
is object_store 0.12.5 → 0.13.2. 141 upstream commits reviewed; no fixes lost
(the 6.0.x release-branch backports are all forward-ported into 7.0.0).
- object_store 0.13 moved get/put/head/rename/delete behind a new ObjectStoreExt
trait (list/list_with_delimiter/put_opts stay on the core trait). Add
`use object_store::ObjectStoreExt` in storage.rs and db/manifest/namespace.rs;
no call-site changes. Mirrors Lance's own migration in PR #6672.
- roaring pinned to 0.11.4 (cargo update -p roaring --precise 0.11.4). Lance
7.0.0's UpdatedFragmentOffsets newtype (lance#6650) derives Eq over
HashMap<u64, RoaringBitmap>, which needs RoaringBitmap: Eq, added in roaring
0.11.4; the loose `roaring = "0.11"` constraint otherwise resolves 0.11.3 and
lance itself fails to compile.
- lance#6774: merge-insert INSERT rows now stamp _row_created_at_version with the
commit version (was a fallback of 1). Flip the lance_version_columns assertion
to `== v2` and correct the changes/mod.rs rationale comment. Production
change-detection keys on _row_last_updated_at_version + ID membership, so its
logic is unaffected.
Refs lance#6650, lance#6774, lance#6672.
* fix(storage): pin WriteParams::auto_cleanup = None (lance#6755 default flip)
lance#6755 flipped the WriteParams::auto_cleanup default from on (a full cleanup
pass every 20th commit) to None. On 6.0.1 the on-by-default hook could silently
GC versions that __manifest pins for snapshots/time-travel. OmniGraph owns
cleanup explicitly (optimize.rs::cleanup_all_tables) and never set auto_cleanup,
so it was relying on a default that is both wrong for our snapshot model and now
changed upstream.
Pin auto_cleanup: None explicitly at all 11 production WriteParams sites
(table_store ×6, commit_graph ×2, recovery_audit ×1, manifest/graph ×2 — the
__manifest + sub-table Create paths). Removes the dependency on a default-flag
value and locks in the snapshot-safe behavior regardless of future upstream
re-flips.
Refs lance#6755.
* test(lance): pin BTREE range-boundary correctness (lance#6796)
lance#6796 (issue #6792) fixed a BTREE scalar-index range-query bound
inclusiveness bug: `x <= hi AND x > lo` returned the wrong boundary row.
Add lance_surface_guards.rs::btree_range_query_boundary_is_correct, which
reproduces the exact #6792 shape (5 rows + an explicit BTREE drives the index
path even on tiny data) and pins the corrected inclusive-<= / exclusive->
semantics. It turns red if a future Lance regression reintroduces the bug.
OmniGraph today builds BTREE only on string @key columns and queries them by
equality/IN, so its current patterns do not hit this; the guard protects any
future BTREE-range path (BTREE-on-properties, range-on-key).
Refs lance#6796.
* docs(dev): align Lance docs + invariants to 7.0.0
- docs/dev/lance.md: new 2026-06-14 alignment stanza for the 6.0.1 → 7.0.0 bump
(object_store ObjectStoreExt move, roaring 0.11.4, #6774/#6796/#6755 behavior,
#6658 shipped → MR-A unblocked but separate, #6666 + blob compaction still
open); prior 6.0.1 stanza demoted to historical.
- AGENTS.md: storage substrate 6.x → 7.x (line + architecture diagram).
- docs/dev/invariants.md: deletes/vector known gap updated — the staged
two-phase delete API (lance#6658) now exists and MR-A is unblocked, but
delete_where stays inline and D2 stays in place until the migration lands;
create_vector_index still gated on lance#6666.
* fix(storage): skip Lance auto-cleanup on commit paths for legacy datasets
Addresses PR #229 review (Codex P1). `WriteParams::auto_cleanup` is create-time
config with no effect on existing datasets (Lance write.rs docs), so the previous
`auto_cleanup: None` change alone did NOT protect graphs created before the v7
bump: 6.0.1 defaulted auto_cleanup ON, leaving `lance.auto_cleanup.*` config on
those datasets, and Lance's per-commit hook (io/commit.rs: `if
!commit_config.skip_auto_cleanup`) fires off that stored config — so omnigraph's
own writes would GC versions the __manifest pins for snapshots/time-travel.
Skip the hook on every commit path, covering new and legacy datasets alike:
- commit_staged: CommitBuilder::with_skip_auto_cleanup(true) — the staged data path.
- __manifest publisher: MergeInsertBuilder::skip_auto_cleanup(true).
- all 11 WriteParams: skip_auto_cleanup: true (direct Dataset::write/append paths;
auto_cleanup: None retained so new datasets store no cleanup config at all).
Tests:
- lance_surface_guards::skip_auto_cleanup_suppresses_version_gc — substrate:
negative control (config GCs v1 without skip) + with-skip survival.
- staged_writes::commit_staged_skips_auto_cleanup_so_pinned_versions_survive —
omnigraph usage: commit_staged on a legacy-config dataset preserves the pinned
create version.
Refs lance#6755.
* test(lance): assert created_at-preserved + updated_at-bumped on merge_insert UPDATE
Addresses PR #229 review follow-up. `lance_merge_insert_update_preserves_created_at_version`
documented (in a comment) that a merge_insert UPDATE preserves created_at and
bumps updated_at, but only asserted the value change — leaving the change-feed
invariant unguarded. Add the two missing assertions:
- bob created_at == v1 (preserved across UPDATE; what the test name promises;
lance#6774 only changed INSERT-row stamping).
- bob updated_at == v2 (bumped to the commit version) — the invariant
OmniGraph's insert/update classification relies on (changes/mod.rs keys on
_row_last_updated_at_version). A regression here would silently drop updates
from the diff/change feed.
2026-06-14 20:42:24 +02:00
advance Lance HEAD inline. The public delete two-phase API now exists (Lance
#6658 shipped in 7.0.0), so the delete residual is unblocked pending the MR-A
migration; vector index creation is still blocked (Lance #6666 open). Keep D2
and recovery coverage in place until those residuals are removed.
fix(optimize): skip blob-bearing tables to avoid Lance compaction crash (#138)
* test(optimize): pin Lance blob-column compaction failure as a surface guard
Lance compact_files mis-decodes blob-v2 columns under its forced BlobHandling::AllBinary read ("more fields in the schema than provided column indices"), failing even a pristine uniform-V2_2 multi-fragment blob table; reads use descriptor handling and are unaffected.
Guard 10 reproduces this and is self-retiring: it turns red on the Lance bump that fixes the bug, forcing LANCE_SUPPORTS_BLOB_COMPACTION to flip.
* fix(optimize): skip blob-bearing tables instead of crashing compaction
omnigraph optimize aborted the whole sweep when any node/edge table had a Blob property: Lance compact_files cannot decode blob-v2 columns under AllBinary (the column-index error pinned by the surface guard). Skip blob-bearing tables behind a LANCE_SUPPORTS_BLOB_COMPACTION gate and report them via TableOptimizeStats.skipped / SkipReason (surfaced in the CLI and a tracing::warn) instead of erroring, which also isolates the failure so the other tables still compact.
Reads/writes are unaffected; only fragment/space reclamation on blob tables is deferred until the upstream Lance fix. Adds a maintenance.rs regression test (validated red with the column-index symptom before the fix, green after), a concise v0.6.1 release note, and updates docs (maintenance, cli-reference, AGENTS capability matrix, invariants Known Gaps, lance.md audit, constants).
* refactor(optimize): make TableOptimizeStats and SkipReason non_exhaustive
Both are returned result types, never built by callers, so #[non_exhaustive] makes this the last field/variant addition that can break downstream literal construction and keeps future ones non-breaking (review feedback on the public-field addition). The v0.6.1 Compatibility Notes call out the source-level change.
Also drops the now-stale "RED today / GREEN after the fix lands" narration in the optimize_skips_blob_table_and_reports_skip test (historical regression context now that the fix is in this branch), and folds in the expanded v0.6.1 release note.
* chore(release): bump workspace to v0.6.1
Coherent version bump to accompany the v0.6.1 release note: all five crate manifests + path-dependency constraints, Cargo.lock, the AGENTS.md surveyed-version line, and openapi.json info.version move 0.6.0 -> 0.6.1. Matches the established release pattern (#118 landed the v0.6.0 note + bump together) and resolves the Codex/Devin review flag that a v0.6.1 note without a bump leaves CARGO_PKG_VERSION reporting 0.6.0 and mixed package versions.
2026-06-02 17:12:00 +02:00
- **Blob-column compaction:** Lance `compact_files` mis-decodes blob-v2 columns
under its forced `BlobHandling::AllBinary` read ("more fields in the schema
than provided column indices"), so `optimize` skips any table with a `Blob`
property — reporting `SkipReason::BlobColumnsUnsupportedByLance` (loud, not a
silent drop) behind the `LANCE_SUPPORTS_BLOB_COMPACTION` gate. Reads and writes
are unaffected; only space/fragment reclamation on blob tables is deferred.
Remove the skip when the upstream Lance fix lands — the
`lance_surface_guards.rs::compact_files_still_fails_on_blob_columns` guard
turns red on that bump to force it.
Recovery liveness, storage fault-injection matrix, and one storage implementation over object_store (#203)
* test(engine): pin the long-lived-handle heal contract for sidecar-covered drift
A Phase B -> Phase C failure (commit_staged advanced Lance HEAD, manifest
publish did not land, recovery sidecar persists) currently wedges every
subsequent staged write on the same engine handle: the commit-time drift
guard rejects with 'run omnigraph repair', but repair itself refuses
while a recovery sidecar is pending, so a long-lived server can only
recover by restart. The documented contract (writes.md 'Long-running
servers', invariants.md invariant 5) says refresh-time roll-forward
closes this residual without restart -- but no write path runs it.
Two red tests pin the intended contract at the write entry points:
a follow-up load (the POST /ingest shape: shared handle, no reopen)
and a follow-up mutation must heal roll-forward-eligible sidecars
in-process and then succeed.
Currently failing with:
table 'node:Company' has Lance HEAD version 2 ahead of manifest
version 1; run `omnigraph repair` before writing
The fix lands in the next commit.
* fix(engine): heal pending recovery sidecars at the staged-write entry points
Close the long-lived-process gap in the recovery protocol: a Phase B ->
Phase C residual (per-table commit_staged landed, manifest publish did
not, sidecar persists) previously recovered only at the next ReadWrite
open or via an explicit refresh() that no production write path called,
so a long-lived server wedged every subsequent write on the commit-time
drift guard until restart.
New recovery::heal_pending_sidecars_roll_forward:
- one list_dir of __recovery/ at write entry (empty -> immediate
return, the steady state), so the per-write cost is one storage list;
- per sidecar, acquires the same per-(table_key, table_branch) write
queues every sidecar writer holds from before write_sidecar until
after delete_sidecar, then re-checks sidecar existence -- this
serializes the heal against live writers instead of rolling an
in-flight sidecar forward from under its writer (which would fail
that writer's publish CAS spuriously). Lock order queues ->
coordinator matches every writer's commit->publish path. This is the
queue-acquisition design recovery.rs and write_queue.rs already
documented for in-process recovery;
- processes in RollForwardOnly mode: the common residual rolls forward
in-process; rollback-eligible sidecars still defer to the next
ReadWrite open (Dataset::restore is unsafe under concurrency).
Wire it into load_as and mutate_as (before the inline delete path can
advance any HEAD), and rebase Omnigraph::refresh onto the same helper
so refresh stops racing live writers' sidecars.
The maintenance entry points (apply_schema_as, branch_merge_as,
ensure_indices) intentionally keep their strict fail-loud preconditions
for now; wiring the same heal there is a follow-up with its own tests.
Turns the previous commit's two red tests green.
* fix(engine): name the right recovery path in the commit-time drift guard
The drift guard's 'run omnigraph repair before writing' advice is a
dead end when the drift is covered by a pending recovery sidecar:
repair refuses while a sidecar is pending. With the write-entry heal in
place, reaching this guard with sidecar-covered drift means the heal
deferred it (rollback-eligible), and the actual recovery path is a
read-write reopen. Distinguish the two classes on the error path only
(one sidecar list, after the conflict is already certain); a listing
failure falls back to the uncovered-drift wording rather than masking
the conflict.
Pinned by extending refresh_defers_rollback_eligible_sidecar_to_next_open
with a write attempt against the deferred sidecar.
* docs: write-entry in-process sidecar heal — contract and coverage
Update the recovery contract docs to match the previous two commits:
invariant 5 now states that the staged-write entry points and refresh
run in-process roll-forward recovery (long-lived processes converge on
the next write, not at restart); writes.md 'Long-running servers'
describes the heal's queue-acquisition concurrency contract, the
improved drift-guard error, and the entry points that intentionally do
not heal yet; testing.md indexes the new failpoint tests; AGENTS.md
capability matrix drops the claim that in-process recovery is entirely
future work (only the rollback path remains with the background
reconciler).
* test(engine): pin the entry heal contract for schema apply and branch merge
Without the write-entry heal, the two maintenance writers do worse than
wedge on sidecar-covered drift -- they proceed and decide its fate
implicitly:
- schema apply re-plans table rewrites from the manifest pin, orphaning
the drifted Phase-B commit (its rows silently vanish from the
rewritten table) while the stale sidecar lingers to misclassify
against the post-apply pins;
- branch merge publishes over the drift, making the failed writer's
commit visible as an unattributed side effect (no recovery audit
row), and leaves the stale sidecar behind.
Two red tests pin the intended contract: both entry points heal the
sidecar first (attributed roll-forward), then run on the converged
state. Currently failing on the stale-sidecar / dropped-rows
assertions; the fix lands in the next commit.
* fix(engine): heal pending recovery sidecars at the schema-apply and branch-merge entries
Extend the write-entry heal to the remaining two write entry points.
Unlike load/mutate (which wedge on the drift guard), these proceeded
over sidecar-covered drift and decided its fate implicitly:
- schema apply re-planned table rewrites from the manifest pin,
orphaning the drifted Phase-B commit -- its rows silently vanished
from the rewritten table -- while the stale sidecar lingered to
misclassify against the post-apply pins;
- branch merge published over the drift, making the failed writer's
commit visible without a recovery audit row, and left the stale
sidecar behind.
Both now run the same queue-serialized roll-forward heal at entry,
before their own sidecar exists, so recovery is attributed (audit row)
and deterministic. ensure_indices stays heal-free: it runs inside the
load / schema-apply flows after their entry heal.
Turns the previous commit's two red tests green. Docs updated in the
same change (invariant 5, writes.md, testing.md, AGENTS.md).
* test(engine): pin Phase A sidecar-write failure semantics
Storage fault-injection matrix, row 1: a sidecar PUT failure (S3
PutObject / fs write) in Phase A. New failpoint recovery.sidecar_write
at the top of write_sidecar -- the single choke point all five sidecar
writers go through -- models the storage error backend-generically.
Also adds the other three storage-fault failpoints used by the
following commits (recovery.sidecar_delete, recovery.sidecar_list,
recovery.record_audit); each is a no-op without the failpoints feature.
Pinned contract: every writer writes its sidecar BEFORE its first
HEAD-advancing commit, so a put failure aborts with zero drift (no
sidecar, Lance HEAD == manifest pin, no rows) and a transient fault
never wedges the graph -- the same handle writes/merges normally once
it clears. Covered for load (the staging writer) and branch_merge (the
multi-table writer, forced onto the RewriteMerged path by diverging
both sides).
* test(engine): pin Phase D delete, list, and audit-append storage-fault semantics
Storage fault-injection matrix, rows 2/3/5, plus the real-backend run:
- recovery.sidecar_delete: a Phase D delete failure (S3 DeleteObject)
must NOT fail the user's write -- the manifest publish already
landed, so the caller's data is durable. The swallowed failure
leaves a stale sidecar; the next write's entry heal consumes it via
the stale-sidecar audit-recovery path (RolledForward, attributed).
- recovery.sidecar_list: a __recovery/ list failure (S3 ListObjectsV2)
is loud at every consumer -- the write-entry heal fails the write
and the open-time sweep fails the open. Silently skipping recovery
over a pending sidecar would be consumer tolerance of drift. Once
the fault clears, open recovers the pending sidecar normally.
- recovery.record_audit: an audit write failure after the
roll-forward's manifest publish aborts that recovery attempt and
keeps the sidecar; re-entry detects the already-published manifest,
records exactly ONE RolledForward audit row, and converges -- the
retry tolerance documented on record_audit, exercised end-to-end.
- s3_load_recovers_after_publisher_failure_without_reopen: the
same-handle heal scenario on a real bucket (gated on
OMNIGRAPH_S3_TEST_BUCKET, skips locally), exercising sidecar
put/list/delete through S3StorageAdapter instead of the local-FS
adapter. CI wiring lands in a follow-up commit.
* test(engine): refuse corrupt recovery sidecars loudly
Storage fault-injection matrix, row 4 (no failpoint needed -- the
corrupt file is written by hand, sibling to the unknown-schema-version
refusal test): a truncated/garbage __recovery/{ulid}.json must be
refused loudly by both the write-entry heal (the write fails naming
the parse error) and the open-time sweep (ReadWrite open fails naming
the file), with the file left on disk for operator inspection.
Read-only opens still work -- the sweep is skipped there.
* test(engine): run the S3 sidecar-lifecycle coverage in CI + document the fault matrix
- ci.yml rustfs_integration: new step running the bucket-gated
failpoints tests (name filter s3_) against the RustFS container, so
sidecar put/list/delete are exercised through S3StorageAdapter on
every storage-affecting PR.
- writes.md: sidecar I/O failure semantics -- Phase A put failure
aborts with zero drift; Phase D delete failure is swallowed (write
already durable) and healed by the next write; list failures are
loud at heal and open; corrupt sidecars are refused with the file
kept for inspection; audit-append failures are retried to exactly
one audit row.
- testing.md: index the storage-fault matrix in the failpoints.rs row
and the new RustFS CI line.
* test(engine): pin read-visibility of acknowledged local if-absent writes
The cluster lib test import_missing_state_creates_state_with_graph_-
observation flakes at ~50% under full-workspace load ('EOF while
parsing a value' reading back the state.json its own import just
acknowledged). Root cause is in the engine's local storage adapter:
write_text_if_absent writes through a buffered tokio::fs::File and
returns when write_all resolves -- which, per tokio's documented File
semantics, means the bytes reached tokio's internal buffer, not the
file. The actual write completes in a background blocking task after
drop, so a caller that acknowledges success and reads the object back
can see an empty or partial file. Under load the window widens; the
red run fails at iteration 0 with 0 of 8192 bytes on disk.
The regression test pins the contract at the adapter boundary: when
write_text_if_absent resolves, the full contents are visible to any
reader; a losing second claim leaves the winner's object untouched.
The fix lands in the next commit.
* fix(engine): publish local storage writes with atomic visibility
Close the class, not the instance. The local adapter admitted three
ways for a reader to observe a write that was acknowledged or visible
before its bytes were complete:
1. write_text_if_absent acknowledged success when the buffered
tokio::fs::File write_all resolved -- i.e. when the bytes reached
tokio's internal buffer, not the file. A caller reading back its own
acknowledged write could see an empty object (the ~50% cluster
import flake under full-workspace load; the regression test failed
at iteration 0 with 0 of 8192 bytes visible).
2. The same call published its CLAIM (create_new) before its CONTENT,
so concurrent readers saw an empty claimed file in the window.
3. write_text (plain tokio::fs::write) exposed truncated content
mid-replace -- silently falsifying write_sidecar's 'readers either
see the complete sidecar or none' contract on local FS (true on S3,
where PutObject is atomic).
A flush in write_text_if_absent would have fixed only (1). Instead,
both local write paths now publish complete temp files atomically:
rename for replace (write_text -- the idiom write_text_if_match
already used) and hard_link for no-replace (write_text_if_absent --
link fails AlreadyExists, so exactly one of N concurrent claimants
wins and the winner's object is fully readable at the instant it
becomes visible). The local adapter now honors the same object-level
atomic-visibility contract as the S3 adapter, which is what every
caller (recovery sidecar protocol, cluster state CAS) was written
against. Crash-orphaned *.tmp.* files are inert: the sidecar sweep
filters to .json, and cluster state reads address state.json by name.
fsync/durability policy is unchanged (no fsync before, none now);
this fix is about visibility ordering, not power-loss durability.
Pre-existing on main (landed with the multi-graph server mode change,
PR #119); surfaced by this branch's heal work only because one extra
list_dir per write shifted test timing. Cluster lib suite: 12/25
failures before, 0/25 after. Turns the previous commit's red test
green.
* refactor(engine): one storage implementation over object_store for every backend
Collapse LocalStorageAdapter (hand-rolled tokio::fs) and
S3StorageAdapter into a single ObjectStorageAdapter backed by
Arc<dyn object_store::ObjectStore> -- LocalFileSystem for local URIs,
the existing AmazonS3 build for s3://, plus a pub in_memory()
constructor (full contract including TRUE conditional updates; the
in-memory test backend testing.md asked for at the adapter level).
Why: the acknowledged-before-visible bug showed the two-impl shape has
no referee -- one prose contract, two independent answers. Upstream
LocalFileSystem::put_opts is byte-for-byte the staged-temp+rename/
hard_link idiom that fix converged on, and Lance's own commit protocol
is built on the same primitives (put-if-not-exists / rename-if-not-
exists), so the substrate-aligned move is to stop hand-rolling it.
The per-backend residue shrinks to a UriCodec (URI <-> object path)
and one capability flag.
Semantics preserved by construction, with three deliberate deltas:
- exists() is now object-store-semantics everywhere (head + non-empty
prefix fallback): an EMPTY local directory no longer 'exists'. The
only dir-shaped caller (_graph_commits.lance probes) self-heals via
ensure_commit_graph_initialized where it previously wedged loudly.
- A directory at an object path reads as NotFound, not as an IO error
('only objects exist'). The cluster unreadable-payload test used a
same-named directory as a portable non-NotFound trigger; it now uses
chmod 000, which still models genuine transient IO.
- write_text_if_match keeps content-token semantics on local
(PutMode::Update is NotImplemented upstream for LocalFileSystem in
0.12.5 and 0.13.2); the capability flag gates the token SOURCE in
read_text_versioned too -- an ETag token with content-compare writes
would lose every CAS.
delete_prefix keeps a local remove_dir_all branch: directories are a
local-FS concept, and list+delete would leave empty skeletons that
cluster graph_root_exists (raw Path::exists) reports as still present.
LocalStorageAdapter remains as a delegating shim so the pinned
contract tests gate this swap textually unchanged; the shim and the
test parameterization over local + in-memory land next. Cargo gains
the explicit 'fs' feature (already transitively enabled by lance).
* test(engine): one executable storage contract, run against every backend
Remove the LocalStorageAdapter delegation shim and migrate its
construction sites to ObjectStorageAdapter::local(). Replace the
per-backend duplicated tests with a single contract_suite asserting
the trait's promises (atomic replace, exists incl. the dataset-root
prefix probe, one-winner if_absent, versioned CAS with loud CAS-lost,
rename, list round-trip with no sibling-prefix bleed, idempotent
delete/delete_prefix), run against the local backend and the new
in-memory backend -- which implements true conditional updates, so the
strong-CAS path is exercised without a bucket. The bucket-gated S3
variant already exists (s3_adapter_conditional_writes_contract).
New local-specific pins for the deliberate semantic edges of the
collapse: empty directories are not objects (exists=false; the Lance
dataset-root probe shape is the non-empty case), file://-anchored and
spaces-in-path list output round-trips byte-identically into
read_text, dot-segment paths are lexically absolutized (the CLI's
./graph.omni shape), and upstream rename creating missing destination
parents. The acknowledged-write visibility regression test stays, now
documenting that the cross-API std::fs read-back is the point.
* refactor(cluster): drop put_json's per-backend atomicity branch
The local temp+rename dance predates the storage adapter guaranteeing
atomic visibility; now that write_text publishes via a staged temp +
rename on the filesystem (and a single atomic PUT on object stores) by
contract, the branch duplicated upstream behavior. One call, both
backends.
* docs: storage adapter collapse — contract, in-memory backend, local CAS gap
- testing.md: the 'no MemStorage backend' note is half-closed —
ObjectStorageAdapter::in_memory() covers the text-object layer with
the full contract (true conditional updates); Lance datasets bypass
the adapter, so the engine substrate ask stays open.
- invariants.md: truth-matrix Tests row updated; new Known Gap for
local write_text_if_match (upstream PutMode::Update is unimplemented
for LocalFileSystem; content-token emulation is safe only under the
cluster lock protocol — close before admitting a lock-free caller).
- writes.md: backend notes for the unified adapter (name#N staging
residue invisible to the sweep, backend-wrapped error text with
exists()-probing for missing-vs-error, loud permission failures).
* docs: finish renaming the storage adapters in user docs and test comments
storage.md's URI-scheme table and the S3 failpoint test's doc comment
still named the deleted LocalStorageAdapter/S3StorageAdapter; both now
describe the unified ObjectStorageAdapter over object_store, including
the relative-path absolutization note for local URIs.
* test(engine): pin branch-awareness of the drift guard's recovery advice
A pending sidecar on ANOTHER branch does not cover this branch's
drift: with a deferred feature-branch sidecar on disk and genuinely
uncovered drift on main, the main write's error must still point at
omnigraph repair -- a read-write reopen recovers the sidecar but
cannot repair main's uncovered drift. Currently red: the guard
matches sidecar pins by table_key only, so the feature sidecar flips
main's advice to the reopen path. Fix in the next commit.
Surfaced by external review of the drift-guard change.
* fix(engine): branch-aware sidecar matching in the drift guard's advice
The commit-time drift guard's sidecar-covered check matched pins by
table_key alone, so a pending sidecar on another branch flipped this
branch's uncovered-drift advice from 'run omnigraph repair' to the
reopen path -- and a reopen recovers that sidecar but cannot repair
this branch's drift. Compare the pin's table_branch too. Turns the
previous commit's red test green.
Surfaced by external review of the drift-guard change.
* test(engine): pin heal non-interference with a live schema apply
The write-entry heal's schema-staging reconcile runs before any queue
acquisition, so a load on the same handle, overlapping a schema apply
parked between its staging write and manifest commit, promotes the
apply's staging files (new catalog live against the old manifest),
classifies the LIVE apply's sidecar, and publishes its registrations
out from under it. The resumed apply then collides with its own stolen
commit. Currently red with:
Lance("Concurrent modification: table version 3 already exists for
node:Tag")
The fix (per-sidecar reconcile under the sidecar's write-queue guards,
plus a serialization key the schema-apply writer and the heal both
acquire) lands in the next commit.
Surfaced by external review of the write-entry heal.
* fix(engine): serialize the heal's schema-staging reconcile with live schema applies
The write-entry heal ran recover_schema_state_files up front, before
acquiring any queue guards. Overlapping a live schema apply parked
between its staging write and manifest commit, the heal promoted the
apply's staging files (new catalog live against the old manifest),
classified the LIVE apply's sidecar, and published its registrations —
the resumed apply then collided with its own stolen commit.
Correct by construction:
- New schema-apply serialization queue key, acquired by the schema-
apply writer (alongside its per-table keys) from before write_sidecar
until after delete_sidecar. Per-table keys alone don't cover a
registration-only migration, which pins no existing tables but has a
sidecar and staging files on disk.
- The heal reconciles schema staging lazily, PER SchemaApply sidecar,
after acquiring that sidecar's guards (including the serialization
key) and re-confirming the sidecar exists — a sidecar that survives
the queue wait belongs to a dead writer, so the reconcile can no
longer race a live apply. Recomputing per sidecar also removes the
staleness of one up-front result across a multi-sidecar pass.
- Omnigraph::refresh drops its up-front reconcile-and-pass-through
(same race, and a pre-promoted result would make the heal's guarded
reconcile see clean staging and wrongly defer the sidecar): it now
reconciles standalone only when NO sidecar exists — which cannot
race a live apply, whose sidecar always precedes its staging files —
and otherwise defers entirely to the heal.
The open-time sweep keeps its precomputed reconcile: open has no
concurrent writers. Turns the previous commit's red test green.
Surfaced by external review of the write-entry heal.
Self-audit addendum folded in: refresh's no-sidecar gate had a TOCTOU
(a live apply could write its sidecar + staging between the empty
check and the reconcile) — the standalone reconcile now holds the
serialization key across the list-then-reconcile pair. The remaining
residual is cross-process only (in-process queues cannot serialize
against a writer in another process; the open-time sweep has the same
pre-existing exposure) and is now an explicit Known Gap in
invariants.md rather than an implicit one.
* test(engine): pin catalog reload after the heal recovers a schema apply
When the write-entry heal rolls a crashed apply's SchemaApply sidecar
forward on the same handle, disk and manifest move to the new schema
(staging promoted, registrations published) but the handle's in-memory
schema_source/catalog do not. Subsequent writes then validate against
the stale catalog and reject rows of types the graph already has.
Currently red with:
record 1: unknown node type 'Tag'
refresh() reloads after its heal; the write entry points must too.
Fix in the next commit.
Surfaced by external review of the write-entry heal.
* fix(engine): reload the in-memory catalog after the heal recovers a schema apply
heal_pending_recovery_sidecars refreshed the coordinator and
invalidated the runtime cache after processing sidecars, but never
reloaded schema_source/catalog — so a write whose entry heal rolled a
crashed SchemaApply sidecar forward proceeded to validate against the
OLD schema while disk and manifest were already on the new one.
reload_schema_if_source_changed is the same post-heal step refresh()
already runs; it no-ops on the (overwhelmingly common) non-schema heal
because the on-disk source is unchanged. Turns the previous commit's
red test green.
Surfaced by external review of the write-entry heal.
* test(engine): pin that a deleted-branch sidecar cannot wedge the graph
A rollback-eligible sidecar pinned to a branch is deferred by every
roll-forward-only pass; if the branch is then deleted, the sidecar
survives, referencing a branch with no manifest tree. The heal (every
write entry) and the open-time sweep (every ReadWrite open) both fail
opening the dead branch, and repair refuses while a sidecar is pending
-- a terminal read-only state with manual sidecar surgery as the only
exit. Currently red with:
Lance("Not found: .../__manifest/tree/feature/_versions")
The branch's tree and forks are already reclaimed, so the pinned drift
is unreachable and the sidecar is provably moot; the fix classifies it
as an orphaned-branch terminal state (audit + discard) in both passes.
Surfaced by review (P1, verified by repro).
* fix(engine): classify deleted-branch sidecars as orphaned instead of wedging
A deferred (rollback-eligible) sidecar pinned to a branch survives
branch_delete; both the write-entry heal and the open-time sweep then
failed unconditionally opening the dead branch -- every write and
every ReadWrite open errored, and repair refuses while a sidecar
pends. Terminal state, manual sidecar surgery the only exit.
The branch's tree and per-table forks are already reclaimed at delete,
so the drift the sidecar pins is unreachable and the sidecar is
provably moot. Both passes now check the sidecar's branch against the
manifest's branch list (the authority -- deliberately NOT inferred
from a Not-found on open, which could be a transient storage error
masking real recovery intent) and discard orphans with an
OrphanedBranchDiscarded audit row, commit appended on main since the
sidecar's own branch no longer has a commit graph.
The open-time half is pre-existing; the write-entry heal made it hot.
Turns the previous commit's red test green.
Surfaced by review (P1, verified by repro).
* chore: harden review nits — vacuous CI filter, root-runner skip, liveness note
- ci.yml: the RustFS sidecar-lifecycle step now fails loudly if the
's3_' name filter matches zero tests (cargo passes vacuously on an
empty filter; the step exists specifically to prove S3 sidecar I/O
coverage). The pre-existing CLI smoke step has the same shape and is
left for a follow-up.
- cluster unreadable-payload test: cfg(unix) + a skip-with-log when
running as root (mode 000 is still readable to root, common in
container dev runners), so the test degrades instead of failing.
- refresh: document the one-pass-late convergence for legacy staging
residue while non-SchemaApply sidecars pend, so nobody 'fixes' it by
re-running the reconcile unserialized — the exact race the
serialization key closes.
* test(engine): pin orphan-discard idempotency across a delete fault
discard_orphaned_branch_sidecar writes its audit row and main commit
before deleting the sidecar; a Phase D delete fault leaves the sidecar
on disk with the audit already durable, and the retry repeated the
whole path -- a second OrphanedBranchDiscarded audit row (and commit)
for the same operation. Currently red: 2 rows after one fault + retry.
The retry must only finish the delete. Fix next.
Also promotes the recovery-audit kinds reader into the shared test
helpers (it was recovery.rs-local).
Surfaced by external review of the orphan-discard fix.
* fix(engine): orphan-discard idempotency + heal reports acted-vs-deferred
Two review findings on the recovery surface:
- discard_orphaned_branch_sidecar now checks the audit table for an
existing (operation_id, OrphanedBranchDiscarded) row before appending
the commit + audit pair, so a Phase D delete fault retries ONLY the
delete instead of duplicating audit rows and commit-graph entries.
Cold path: the list scan runs only when an orphaned sidecar exists.
Turns the previous commit's red test green (exactly one audit row
across fault + retry).
- process_sidecar returns whether durable state changed; the heal sets
processed_any only for sidecars that were actually rolled forward /
rolled back / audit-recovered (orphan discards count). Deferred
sidecars (rollback-eligible, invariant-violating, unpromoted
SchemaApply) no longer trigger a per-write schema reload + full
runtime-cache invalidation while they pend -- the cache is
snapshot-keyed so this was waste, not corruption, but it was paid on
every write until reopen. Acted-paths' processed=true remains pinned
by load_after_schema_apply_phase_b_failure_uses_recovered_catalog
(the reload depends on it).
Surfaced by external review.
* test(engine): pin the orphan-discard audit-append fault leg as documented tolerance
The orphan discard's commit append and audit append are two writes; a
failure between them leaves a recovery commit with no audit row, and
the retry (keyed on the audit row, the operator-facing record) appends
a second commit before the audit lands. This is the same
not-atomic-pair-write tolerance record_audit documents and the
manifest->commit-graph Known Gap covers for every publish: bounded
commit-graph noise, audit row exactly-once under clean failures.
Keying idempotency on commit rows instead would need an operation_id
column on _graph_commits, and audit-before-commit would dangle the
graph_commit_id join -- both worse than the documented residual.
Make the tolerance explicit instead of implicit: docstring names the
window, a failpoint sits inside it, and the new test pins convergence
across the fault (sidecar consumed, exactly one audit row), completing
the orphan-discard fault matrix alongside the delete-fault leg.
Surfaced by external review of the orphan-discard idempotency.
* test(engine): pin honest drift-guard advice when sidecar listing fails
The guard's unwrap_or(false) conflated 'classified as uncovered' with
'could not classify': a transient list fault on the guard's second
list (the entry heal's first list having succeeded) confidently routed
the operator to omnigraph repair even when the heal had just deferred
a rollback-eligible sidecar -- and repair refuses while a sidecar is
pending. Currently red: the error says 'run omnigraph repair' with no
mention of the reopen path. The fix names both paths plus the failure
cause when classification is impossible.
Surfaced by external review of the drift-guard fallback.
* fix(engine): admit ambiguity in the drift guard when sidecar listing fails
Replace the unwrap_or(false) fallback with a tri-state: covered ->
reopen advice; uncovered -> repair advice; listing FAILED -> say the
drift could not be classified, name the cause, and give both paths in
order ('run repair, or reopen read-write if repair reports a pending
sidecar'). The old fallback confidently routed a transient list fault
to repair, which refuses while a sidecar is pending -- a self-
correcting but pointless detour. The conflict itself is still always
raised; only the advice degrades honestly. Turns the previous commit's
red test green.
Surfaced by external review of the drift-guard fallback.
2026-06-13 11:20:08 +02:00
- **Recovery is serialized against live writers in-process only:** the
write-entry heal (and `refresh` ) serialize against a live writer's sidecar
lifetime via the per-`(table, branch)` write queues plus the schema-apply
serialization key — all in-process primitives. A recovery pass in one
process cannot serialize against a live writer in another (the open-time
sweep has the same exposure, and always has): it may roll a live foreign
writer's sidecar forward, which degrades to publisher-CAS contention for
data writes but can race the schema-staging promotion for a foreign live
schema apply. Multi-process writers on one graph are already documented
one-winner-CAS territory; closing this fully needs a cross-process
serialization primitive (e.g. lease-based use of the schema-apply lock
branch) — design it before promoting multi-process write topologies.
- **Local `write_text_if_match` is not a cross-process CAS:** object-store
backends use a true conditional put (ETag If-Match; the in-memory test
backend too), but upstream `object_store` leaves `PutMode::Update`
unimplemented for `LocalFileSystem` , so the local path emulates CAS with
a content-token compare followed by an atomic replace — a check-then-act
gap plus content-token ABA. Every current caller goes through the cluster
lock protocol first, which makes this safe. A lock-free caller would get
S3-correct but local-racy behavior — the same divergence shape as the
acknowledged-before-visible bug this branch fixed. Close it (local CAS
primitive, or a trait-level lock requirement) before admitting any
lock-free `if_match` caller.
2026-06-09 14:42:54 +02:00
- **Manifest→commit-graph publish atomicity:** a graph commit advances
`__manifest` (the visibility authority) and then appends `_graph_commits` as
two separate writes (`commit_updates_with_actor_with_expected` , failpoint
`graph_publish.before_commit_append` ). A crash between them leaves the manifest
at version N with no commit-graph row for N. Live reads and durability are
unaffected — the live version resolves via the manifest
(`GraphCoordinator::version()` ), not the commit-graph head — and the open-time
recovery sweep does NOT repair it (`lance_head == manifest_pinned` classifies
`NoMovement` ; a recovery sidecar would not change this). Impact is bounded to
commit history: `commit list` misses N, time-travel by commit id to N fails,
and merge-base loses a node (a likely-benign off-by-one re-merge). This affects
every publish, not a specific maintenance command. Eventual fix: make the
commit graph reconcilable from the manifest (or the two writes atomic) — not a
recovery-sidecar concern.
2026-05-15 03:45:22 +03:00
- **Planner capability/stat surfaces:** cost-aware planning, complete
capability advertisement, and explain-with-cost are roadmap. Do not describe
them as implemented.
- **Traversal execution:** current multi-hop execution still uses `TypeIndex` ,
ad-hoc ID filtering, and eager materialization in places. Stable row IDs, SIP,
and factorization are target patterns, not current fact.
- **Retrieval ranks:** hybrid search works, but rank/score are not yet carried
everywhere as ordinary columns through the plan.
- **Policy pushdown and `Source` :** Cedar enforcement is at the HTTP boundary
today, and imports are still loader-shaped. Planner predicates and a unified
`Source` operator are roadmap.
- **Resource bounds:** some operations still lack enforced per-query memory or
time budgets. New long-running work should add explicit bounds rather than
widening the gap.
## Deny-list
If a proposal fits one of these, the burden is on the proposer to prove why the
case is exceptional.
- Custom WAL, transaction manager, buffer pool, page format, or storage engine.
- Per-table graph publishing outside the manifest publisher.
- Re-reading current branch head during a query instead of using the captured
snapshot.
- New write paths that can advance Lance HEAD before manifest publish without a
recovery sidecar.
- Cross-query `BEGIN` /`COMMIT` transactions in the OSS engine. Use branches and
merges for multi-query workflows.
- Acknowledging writes before durable Lance and manifest persistence.
- Silent fallback to eventual consistency, partial results, or dropped rows.
- State that drifts from Lance or the manifest when it can be derived.
- Job queues for manifest-derivable state where a reconciler is the right shape.
- Synchronous inline vector/FTS index rebuilds on the query commit path, except
for documented Lance API residuals.
- Side-channels for query semantics: hidden globals, magic strings, transport
flags, or out-of-band metadata.
- Cost-blind plan choice when statistics are available or required.
- Hidden statistics for behavior that affects planning or operator choice.
- Hash-map iteration order in result ordering, plan choice, or migration output.
- String-flattened SQL/filter generation when a structured pushdown API is
available.
- Eager multi-hop cross-product materialization when factorization fits.
- Ad-hoc `IN` -list filtering where SIP or another structured selectivity path
fits.
- Discarding retrieval score/rank before fusion or projection decisions.
- Auto-creating placeholder nodes for orphan edges.
feat(cluster): the storage: root — state, catalog, and graph roots relocatable
cluster.yaml gains an optional storage: URI deciding where everything the
cluster STORES lives: the state ledger, lock, content-addressed catalog,
recovery sidecars, approval artifacts, and the derived graph roots
(<storage>/graphs/<id>.omni). Absent, it defaults to the config directory
itself — the original layout, byte-compatible, so pre-existing clusters and
the whole test suite are untouched. Declared configuration always stays in
the working tree (Terraform's config-local/state-remote split); credentials
are env-only, never in cluster.yaml.
Every command resolves its store from the declared root (a bad root is a
loud invalid_storage_root). Graph-root derivation, the delete executor
(prefix delete via the adapter), the sweep's existence probes, the catalog
payload write/verify/read paths, and the serving snapshot all flow through
ClusterStore — the last raw-fs holdouts for stored state are gone, and the
deny-list gains the rule that keeps it that way.
Tests: default-layout byte-compat, a file:// root relocating the entire
cluster (ledger+catalog+graphs under the new root, nothing under the config
dir, serving snapshot follows), invalid-root validation. 98 in-crate + 9
failpoints + full workspace gate green. The s3:// flavor lands with PR 3's
gated RustFS e2e.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-06-11 14:28:04 +03:00
- Raw filesystem I/O for cluster-stored state (ledger, lock, sidecars,
approvals, catalog) outside the cluster crate's storage module — every
stored byte goes through the engine `StorageAdapter` so `file://` and
`s3://` stay one code path.
2026-05-15 03:45:22 +03:00
- Wire-protocol-specific code in compiler or engine crates.
- Cloud-only correctness fixes or forks of the OSS engine for correctness.
- Mutating immutable substrate state in place, including Lance fragments or
index segments.
- Shipping observable behavior as if it were not part of the contract. Output
ordering, error text, timestamp precision, defaults, and latency profiles all
become dependencies once exposed.
## Review Checklist
Use this as yes/no/NA for any non-trivial design or PR:
- Does it respect Lance/DataFusion instead of rebuilding them?
- Does it preserve manifest-atomic graph visibility?
- Does every query keep one snapshot for its lifetime?
- Do mutations publish once at the commit boundary?
- Can every Lance-HEAD-before-manifest gap recover all-or-nothing?
- Are schema and edge integrity checks strict by default?
- Are query semantics represented in AST/IR/planner structures?
- Are transport, auth, and policy boundaries preserved?
- Are failures bounded, typed, and observable?
- Are result ordering and plan choices deterministic within a snapshot?
- Are stats/capabilities exposed when behavior depends on them?
- Are existing known gaps left no worse and documented if touched?
- Does the test live at the same boundary as the change?
- Does the change avoid every deny-list pattern, or justify the exception?
## Maintenance Policy
Update this file when an invariant changes, a known gap opens or closes, or a
new review anti-pattern deserves deny-list treatment. Prefer stable headings
over numbered sections so other docs can link here without churn.
Removing or relaxing a hard invariant requires the same review process as code.
Adding a known gap is acceptable when it makes reality explicit; leaving stale
claims is not.
