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mcp-nextcloud/nextcloud_mcp_server/vector/qdrant_client.py
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Chris CoutinhoandClaude Opus 4.7 b97ac23228 fix(vector): address PR review round 4 — backfill resilience + degraded-mode docs
- Remove three stale `# Use numeric file ID` / `# Pass file path` comments
  in scanner.py. file_id is already normalized to str() above each call
  site, so the inline comments mislead readers.
- Wrap `_backfill_doc_id_to_string` scroll loop + sentinel upsert in
  try/except Exception. The qdrant_client singleton is assigned before
  this migration runs, so a transient scroll failure was leaving the
  process holding a usable client with int payloads permanently
  unbackfilled until the next restart. Catch broadly, log ERROR with
  exc_info, and return without writing the sentinel — next process
  restart retries from scratch.
- Note `:memory:` mode behavior near the sentinel constants so future
  readers don't read the every-start scroll as a bug.
- Document the two degraded-migration ERROR log signals in
  docs/configuration.md so operators know when a clean restart is
  required to recover indexing.
- Add unit test asserting scroll-time exceptions are logged and swallowed
  without writing the sentinel.

Closes round-4 review feedback on PR #773.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-08 23:39:37 +02:00

365 lines
15 KiB
Python

"""Qdrant client wrapper."""
import logging
from typing import Any
from qdrant_client import AsyncQdrantClient, models
from qdrant_client.http.exceptions import UnexpectedResponse
from qdrant_client.models import (
Distance,
PayloadSchemaType,
PointStruct,
VectorParams,
)
from nextcloud_mcp_server.config import get_settings
from nextcloud_mcp_server.embedding import get_embedding_service
logger = logging.getLogger(__name__)
# Payload fields filtered by exact-match in scanner/processor/placeholder/eviction.
# Qdrant requires a payload index for any field used in a FieldCondition; without
# one, queries fail with HTTP 400 ("Index required but not found"). All three
# carry string values after producer normalization, so a KEYWORD index is the
# correct schema (see ADR notes in commit message).
_KEYWORD_PAYLOAD_FIELDS: tuple[str, ...] = ("doc_id", "user_id", "doc_type")
# Sentinel point that records "this collection has been backfilled to str
# doc_id". Written after a successful pass of _backfill_doc_id_to_string so
# subsequent restarts can short-circuit the O(N) scroll. Carries no
# user_id/doc_id/doc_type, so production search filters (which always
# require user_id) never see it. In :memory: mode the sentinel does not
# survive a restart — the scroll runs every start, but is a no-op against
# an empty in-memory collection.
_DOC_ID_BACKFILL_SENTINEL_ID: str = "00000000-0000-0000-0000-d0c1d0d1d0c1"
_DOC_ID_BACKFILL_SENTINEL_PAYLOAD: dict[str, str] = {"_migration_marker": "doc_id_v1"}
# Singleton instance
_qdrant_client: AsyncQdrantClient | None = None
async def _ensure_keyword_payload_indexes(
client: AsyncQdrantClient, collection_name: str
) -> None:
"""Create KEYWORD payload indexes for fields used in exact-match filters.
Pre-fetches the existing payload schema and skips fields that are
already indexed, so routine restarts make no Qdrant write round-trips
and emit no INFO log lines. Schema conflicts (a pre-existing index
with a different type) still surface as a 400 — log loudly so
operators can intervene, but keep going so the remaining fields still
get indexed.
"""
collection_info = await client.get_collection(collection_name)
existing_schema = collection_info.payload_schema or {}
for field in _KEYWORD_PAYLOAD_FIELDS:
if field in existing_schema:
# Index already present — silent skip. Logging here on every
# restart would be noise that hides the genuinely interesting
# "first-time creation" line below.
continue
try:
await client.create_payload_index(
collection_name=collection_name,
field_name=field,
field_schema=PayloadSchemaType.KEYWORD,
wait=True,
)
logger.info("Created KEYWORD payload index on '%s'", field)
except UnexpectedResponse as e:
body = getattr(e, "content", b"") or b""
body_text = body.decode("utf-8", errors="replace")
# 400 is the expected schema-conflict path (index already exists
# with a different type). 5xx / network-shaped errors should not
# be silently downgraded — keep the loop going so the remaining
# fields still get attempted, but log at error so operators see it.
if e.status_code == 400:
logger.warning(
"Schema conflict on payload index '%s': %s", field, body_text
)
else:
logger.error(
"Unexpected error creating payload index on '%s' (status %s): %s",
field,
e.status_code,
body_text,
)
async def _backfill_doc_id_to_string(
client: AsyncQdrantClient, collection_name: str, dimension: int
) -> None:
"""Rewrite legacy integer doc_id payloads to strings.
Producers now uniformly write str(doc_id), but historical points may carry
int values from before normalization. A KEYWORD index does not match int
payloads, so any leftover int doc_ids would be silently invisible to
filters. Scrolls all points once, converts in-place, and writes a
sentinel point on success; subsequent restarts retrieve the sentinel
and skip the scroll entirely. Idempotent in both directions (a second
pass on a migrated collection short-circuits via the sentinel; a
second pass with the sentinel manually deleted is the same zero-write
scroll the first pass would do on an already-clean collection).
Within each scroll batch, points sharing the same int doc_id are batched
into a single ``set_payload`` call to minimize Qdrant round-trips.
Args:
client: Qdrant client instance.
collection_name: Target collection.
dimension: Dense-vector dimension for the sentinel point's vector
(forwarded by ``get_qdrant_client`` from the embedding model).
"""
# Sentinel guard: if the migration ran successfully against this
# collection on a previous start, retrieve() returns the marker point
# and we skip the scroll. Cheap single-key lookup vs. an O(N) scroll.
sentinel = await client.retrieve(
collection_name=collection_name,
ids=[_DOC_ID_BACKFILL_SENTINEL_ID],
with_payload=False,
with_vectors=False,
)
if sentinel:
logger.debug(
"doc_id backfill sentinel found on '%s'; skipping scroll",
collection_name,
)
return
logger.info(
"Running doc_id backfill on '%s' (one-time migration on first "
"start after upgrade; subsequent restarts skip via sentinel)",
collection_name,
)
rewritten = 0
scanned = 0
# Qdrant scroll returns next_offset as PointId | None — keep it untyped here
# so the qdrant client's full union (UUID/int/str/PointId) flows through.
next_offset = None
batch_size = 256
# A transient Qdrant failure mid-scroll (network blip, timeout) must not
# crash startup. The singleton in get_qdrant_client is already assigned
# by the time this runs, so re-raising here would leave the process in
# a half-initialized state where the next call returns the cached
# client and skips this migration entirely. Catch broadly, log with
# exc_info, and return without writing the sentinel — the next process
# restart will retry from scratch.
try:
while True:
points, next_offset = await client.scroll(
collection_name=collection_name,
limit=batch_size,
offset=next_offset,
with_payload=["doc_id"],
with_vectors=False,
)
if not points:
break
# Group by stringified value so points sharing a doc_id (one document
# → many chunks) collapse into a single set_payload call. Point IDs
# can be int/str/UUID, so widen the value type to satisfy the qdrant
# client's PointsSelector signature without re-spelling the union.
by_value: dict[str, list[Any]] = {}
for point in points:
scanned += 1
# Qdrant client typing allows None payload even when with_payload
# was requested; defensive default so the type checker is happy.
payload = point.payload or {}
value = payload.get("doc_id")
if value is None or isinstance(value, str):
continue
by_value.setdefault(str(value), []).append(point.id)
for str_val, point_ids in by_value.items():
# wait=True is required because _ensure_keyword_payload_indexes
# runs immediately after this function (see get_qdrant_client
# near the call site) and only indexes committed data —
# fire-and-forget writes would leave int payloads invisible
# to KEYWORD filters.
await client.set_payload(
collection_name=collection_name,
payload={"doc_id": str_val},
points=point_ids,
wait=True,
)
rewritten += len(point_ids)
if next_offset is None:
break
# Write the sentinel after a successful scroll so a future restart can
# short-circuit. Empty sparse vector mirrors the placeholder.py
# convention (vector/placeholder.py); zero dense vector is fine
# because the sentinel never participates in a search (no user_id /
# doc_id / doc_type payload to match).
sentinel_point = PointStruct(
id=_DOC_ID_BACKFILL_SENTINEL_ID,
vector={
"dense": [0.0] * dimension,
"sparse": models.SparseVector(indices=[], values=[]),
},
payload=dict(_DOC_ID_BACKFILL_SENTINEL_PAYLOAD),
)
await client.upsert(
collection_name=collection_name,
points=[sentinel_point],
wait=True,
)
logger.info(
"doc_id backfill complete: rewrote %d/%d payloads from int to str",
rewritten,
scanned,
)
except Exception:
logger.error(
"doc_id backfill failed on '%s'; will retry on next restart",
collection_name,
exc_info=True,
)
return
async def get_qdrant_client() -> AsyncQdrantClient:
"""
Get singleton Qdrant client instance.
Automatically creates collection on first use if it doesn't exist.
Supports three Qdrant modes:
- Network mode: QDRANT_URL set (e.g., http://qdrant:6333)
- In-memory mode: QDRANT_LOCATION=:memory: (default if nothing configured)
- Persistent local mode: QDRANT_LOCATION=/path/to/data
Returns:
Configured AsyncQdrantClient instance
Raises:
Exception: If Qdrant connection fails or collection creation fails
"""
global _qdrant_client
if _qdrant_client is None:
settings = get_settings()
# Detect mode and initialize client accordingly
if settings.qdrant_url:
# Network mode
logger.info(f"Using Qdrant network mode: {settings.qdrant_url}")
_qdrant_client = AsyncQdrantClient(
url=settings.qdrant_url,
api_key=settings.qdrant_api_key,
timeout=30,
)
elif settings.qdrant_location:
# Local mode (either :memory: or persistent path)
if settings.qdrant_location == ":memory:":
logger.info("Using Qdrant in-memory mode: :memory:")
_qdrant_client = AsyncQdrantClient(":memory:")
else:
# Persistent local mode - use path parameter
logger.info(f"Using Qdrant persistent mode: {settings.qdrant_location}")
_qdrant_client = AsyncQdrantClient(path=settings.qdrant_location)
else:
# Should not happen due to __post_init__ validation, but handle gracefully
logger.warning("No Qdrant mode configured, defaulting to :memory:")
_qdrant_client = AsyncQdrantClient(":memory:")
# Get collection name (auto-generated from deployment ID + model)
collection_name = settings.get_collection_name()
embedding_service = get_embedding_service()
# Detect dimension dynamically (for OllamaEmbeddingProvider)
if hasattr(embedding_service.provider, "_detect_dimension"):
await embedding_service.provider._detect_dimension() # type: ignore[call-non-callable]
expected_dimension = embedding_service.get_dimension()
# Explicitly check if collection exists
logger.debug(f"Checking if collection '{collection_name}' exists...")
collections = await _qdrant_client.get_collections()
collection_names = [c.name for c in collections.collections]
if collection_name in collection_names:
# Collection exists - validate dimensions
logger.debug(
f"Collection '{collection_name}' found, validating dimensions..."
)
collection_info = await _qdrant_client.get_collection(collection_name)
# Handle both named vectors (dict) and legacy single vector
vectors = collection_info.config.params.vectors
if isinstance(vectors, dict):
actual_dimension = vectors["dense"].size
else:
# Type narrowing: vectors must be VectorParams if not dict
assert isinstance(vectors, VectorParams)
actual_dimension = vectors.size
# Validate dimension matches
if actual_dimension != expected_dimension:
embedding_model = settings.get_embedding_model_name()
raise ValueError(
f"Dimension mismatch for collection '{collection_name}':\n"
f" Expected: {expected_dimension} (from embedding model '{embedding_model}')\n"
f" Found: {actual_dimension}\n"
f"This usually means you changed the embedding model.\n"
f"Solutions:\n"
f" 1. Delete the old collection: Collection will be recreated with new dimensions\n"
f" 2. Set QDRANT_COLLECTION to use a different collection name\n"
f" 3. Revert to the original embedding model"
)
logger.info(
f"Using existing Qdrant collection: {collection_name} "
f"(dimension={actual_dimension}, model={settings.get_embedding_model_name()})"
)
# Existing collections may pre-date the doc_id normalization /
# payload-index work. Backfill before creating the index so the
# index covers every point.
await _backfill_doc_id_to_string(
_qdrant_client, collection_name, expected_dimension
)
await _ensure_keyword_payload_indexes(_qdrant_client, collection_name)
else:
# Collection doesn't exist - create it
embedding_model = settings.get_embedding_model_name()
logger.info(
f"Collection '{collection_name}' not found, creating with "
f"dimension={expected_dimension}, model={embedding_model}..."
)
await _qdrant_client.create_collection(
collection_name=collection_name,
vectors_config={
"dense": VectorParams(
size=expected_dimension,
distance=Distance.COSINE,
),
},
sparse_vectors_config={
"sparse": models.SparseVectorParams(
index=models.SparseIndexParams(
on_disk=False,
)
),
},
)
logger.info(
f"Created Qdrant collection: {collection_name}\n"
f" Dense vector dimension: {expected_dimension}\n"
f" Dense embedding model: {embedding_model}\n"
f" Sparse vectors: BM25 (for hybrid search)\n"
f" Distance: COSINE\n"
f"Background sync will index all documents with dense + sparse vectors."
)
await _ensure_keyword_payload_indexes(_qdrant_client, collection_name)
return _qdrant_client