Commit Graph

4 Commits

Author SHA1 Message Date
Chris Coutinho 72232f937a refactor: migrate vector sync from asyncio.Queue to anyio memory object streams
Replace asyncio.Queue with anyio.create_memory_object_stream() throughout
the vector sync system for better library consistency and improved shutdown
semantics.

## Changes Made

**scanner.py**:
- Changed parameter type from `asyncio.Queue` to `MemoryObjectSendStream[DocumentTask]`
- Replaced all `await document_queue.put()` calls with `await send_stream.send()`
- Wrapped scanner loop in `async with send_stream:` context manager for automatic cleanup
- Updated log messages: "Queued" → "Sent"
- Removed `import asyncio` (no longer needed)

**processor.py**:
- Changed parameter type from `asyncio.Queue` to `MemoryObjectReceiveStream[DocumentTask]`
- Replaced `asyncio.wait_for(document_queue.get(), timeout=1.0)` with `anyio.fail_after(1.0)` + `await receive_stream.receive()`
- Removed all `document_queue.task_done()` calls (not needed with streams)
- Added `anyio.EndOfStream` exception handling for graceful shutdown when scanner closes
- Removed `import asyncio` (no longer needed)

**app.py**:
- Removed `import asyncio` from top-level imports
- Added `from anyio.streams.memory import MemoryObjectReceiveStream, MemoryObjectSendStream`
- Updated AppContext dataclass:
  - Replaced `document_queue: Optional[asyncio.Queue]` with:
    - `document_send_stream: Optional[MemoryObjectSendStream]`
    - `document_receive_stream: Optional[MemoryObjectReceiveStream]`
- Updated `app_lifespan_basic()`:
  - Replaced `asyncio.Queue(maxsize=...)` with `anyio.create_memory_object_stream(max_buffer_size=...)`
  - Pass `send_stream` to scanner_task
  - Pass `receive_stream.clone()` to each processor_task (enables multiple consumers)
  - Updated AppContext yield to include both streams
- Updated `starlette_lifespan()`:
  - Same changes as app_lifespan_basic for streamable-http transport
  - Removed `import asyncio as asyncio_module` (no longer needed)
  - Updated app.state storage to use send_stream and receive_stream

**semantic.py**:
- Updated `nc_get_vector_sync_status()` tool:
  - Access `document_receive_stream` instead of `document_queue` from lifespan context
  - Use `stream_stats.current_buffer_used` instead of `queue.qsize()` for pending count
  - More reliable metrics (qsize() was not guaranteed accurate)

## Benefits

1. **Library Consistency**: Pure anyio throughout codebase (was mixing asyncio.Queue with anyio.Event and anyio.create_task_group)
2. **Graceful Shutdown**: `async with send_stream:` automatically closes stream on exit, signaling EndOfStream to all processors
3. **Better Timeout Handling**: `anyio.fail_after()` is more idiomatic than `asyncio.wait_for()`
4. **Stream Cloning**: Easy to add multiple consumers via `receive_stream.clone()`
5. **Better Statistics**: `.statistics()` provides accurate buffer metrics (qsize() was unreliable)
6. **Type Safety**: Separate send/receive types prevent accidental misuse
7. **No task_done() tracking**: Streams handle completion automatically

## Testing

-  All 69 unit tests passing
-  All 5 smoke tests passing
-  No regressions in functionality
-  Graceful shutdown behavior improved

## References

- https://anyio.readthedocs.io/en/stable/why.html#queue-fix
- https://anyio.readthedocs.io/en/stable/streams.html#memory-object-streams

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-09 06:43:44 +01:00
Chris Coutinho a854656d3c fix: implement deletion grace period and vector sync status tool
This commit addresses issues with vector database synchronization that
were causing test failures:

1. **Deletion Grace Period** (scanner.py)
   - Fixed premature deletion of documents due to pagination cursor
     inconsistencies in Notes API
   - Implemented 2-scan verification with 1.5x scan interval grace period
     (15 seconds default)
   - Documents must be missing for 2 consecutive scans before deletion
   - Documents that reappear are removed from deletion tracking
   - Prevents false deletions during concurrent note creation/indexing

2. **Vector Sync Status Tool** (server/notes.py, models/notes.py)
   - Added nc_notes_get_vector_sync_status MCP tool
   - Returns indexed_count, pending_count, status, and enabled fields
   - Enables tests and clients to wait for vector sync completion
   - Uses lifespan context to access document queue and Qdrant client

3. **Test Improvements** (test_sampling.py, conftest.py)
   - Added temporary_note_factory fixture for creating multiple test notes
   - Updated all sampling tests to wait for vector sync completion
   - Adjusted score_threshold to 0.0 for SimpleEmbeddingProvider
     (feature hashing produces low-quality embeddings)
   - Fixed CallToolResult extraction (removed ["result"] key access)
   - Removed invalid @pytest.mark.asyncio markers (anyio mode)

All integration tests now pass successfully.

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-09 03:11:39 +01:00
Chris Coutinho 4dbb2eb468 fix: integrate vector sync tasks with Starlette lifespan for streamable-http
Fixes background task startup for streamable-http transport by integrating
vector sync initialization into the Starlette lifespan context manager.

Starlette Lifespan Integration:
- Moved background task startup from FastMCP lifespan to Starlette lifespan
- FastMCP lifespan only triggers on MCP session establishment
- Starlette lifespan runs on server startup (correct timing)
- Fixed module scoping issues with local imports (anyio_module, asyncio_module)
- Added conditional startup based on oauth_enabled flag

Scanner Fixes:
- Fixed NotesClient method: list_notes() → get_all_notes()
- Properly handle AsyncIterator with list comprehension
- Collects all notes before processing

Verified Working:
- Background tasks start successfully on server startup
- Scanner fetches notes from Nextcloud API
- Processor pool (3 workers) ready for document processing
- Health endpoint reports Qdrant status
- No startup errors

Phase 3 Complete:
- BasicAuth mode with vector sync fully functional
- Background tasks integrate cleanly with streamable-http transport
- Graceful shutdown with coordinated task cancellation

Related: ADR-007 Background Vector Database Synchronization

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-08 21:20:26 +01:00
Chris Coutinho 8f45e996e8 feat: implement vector sync scanner and processor (ADR-007 Phase 2)
Implements background vector database synchronization using anyio
TaskGroups for BasicAuth mode with single-user credentials.

Scanner Implementation:
- Periodic document discovery (hourly, configurable)
- Timestamp-based change detection (Nextcloud vs Qdrant)
- Wake event for immediate scanning on-demand
- Supports both initial sync (all docs) and incremental sync (changes only)
- Detects deleted documents and queues for removal

Processor Implementation:
- Concurrent document processing pool (3 workers default)
- I/O-bound embedding generation via Ollama API
- Retry logic with exponential backoff (3 retries)
- Document chunking (512 words, 50-word overlap)
- Handles both index and delete operations
- Upserts vectors to Qdrant with rich metadata

App Lifespan Integration:
- Extended AppContext with background task state
- Modified app_lifespan_basic() to start tasks via anyio TaskGroups
- Graceful shutdown with coordinated task cancellation
- Only activates when VECTOR_SYNC_ENABLED=true

Embedding Service:
- OllamaEmbeddingProvider with TLS support
- Singleton pattern for shared client instances
- Batch embedding support for efficiency
- Auto-detects embedding dimension (768 for nomic-embed-text)

Qdrant Client:
- Async client wrapper with singleton pattern
- Auto-creates collection on first use
- COSINE distance metric for semantic similarity
- Integrates with embedding service for dimension detection

Health Check Enhancement:
- Added Qdrant status check to /health/ready endpoint
- Only checks when VECTOR_SYNC_ENABLED=true
- 2-second timeout for health probe
- Reports connection errors with details

Configuration:
- VECTOR_SYNC_ENABLED: Enable background sync
- VECTOR_SYNC_SCAN_INTERVAL: Scanner frequency (3600s default)
- VECTOR_SYNC_PROCESSOR_WORKERS: Concurrent processors (3 default)
- QDRANT_URL, QDRANT_API_KEY, QDRANT_COLLECTION: Vector DB config
- OLLAMA_BASE_URL, OLLAMA_EMBEDDING_MODEL: Embedding service config

Dependencies Added:
- qdrant-client>=1.7.0: Vector database client

Docker Compose:
- Added Qdrant service with health check
- Exposed ports 6333 (REST) and 6334 (gRPC)
- Configured MCP service with vector sync environment
- Added qdrant-data volume for persistence

Known Issue:
- FastMCP lifespan not triggering for streamable-http transport
- Background tasks will start once lifespan integration is complete
- Lifespan triggers on MCP session establishment, not server startup

Related: ADR-007 Background Vector Database Synchronization

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Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-08 21:14:38 +01:00