Files
nextcloud-mcp-server/nextcloud_mcp_server/embedding/service.py
T
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

🤖 Generated with Claude Code (https://claude.com/claude-code)

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

103 lines
2.7 KiB
Python

"""Embedding service with provider detection."""
import logging
import os
from .base import EmbeddingProvider
from .ollama_provider import OllamaEmbeddingProvider
logger = logging.getLogger(__name__)
class EmbeddingService:
"""Unified embedding service with automatic provider detection."""
def __init__(self):
"""Initialize embedding service with auto-detected provider."""
self.provider = self._detect_provider()
def _detect_provider(self) -> EmbeddingProvider:
"""
Auto-detect available embedding provider.
Checks environment variables in order:
1. OLLAMA_BASE_URL - Use Ollama provider
Returns:
Configured embedding provider
Raises:
ValueError: If no embedding provider is configured
"""
# Ollama provider (for this deployment)
ollama_url = os.getenv("OLLAMA_BASE_URL")
if ollama_url:
return OllamaEmbeddingProvider(
base_url=ollama_url,
model=os.getenv("OLLAMA_EMBEDDING_MODEL", "nomic-embed-text"),
verify_ssl=os.getenv("OLLAMA_VERIFY_SSL", "true").lower() == "true",
)
raise ValueError(
"No embedding provider configured. "
"Set OLLAMA_BASE_URL environment variable."
)
async def embed(self, text: str) -> list[float]:
"""
Generate embedding vector for text.
Args:
text: Input text to embed
Returns:
Vector embedding as list of floats
"""
return await self.provider.embed(text)
async def embed_batch(self, texts: list[str]) -> list[list[float]]:
"""
Generate embeddings for multiple texts.
Args:
texts: List of texts to embed
Returns:
List of vector embeddings
"""
return await self.provider.embed_batch(texts)
def get_dimension(self) -> int:
"""
Get embedding dimension.
Returns:
Vector dimension
"""
return self.provider.get_dimension()
async def close(self):
"""Close provider resources."""
if hasattr(self.provider, "close") and callable(
getattr(self.provider, "close")
):
close_method = getattr(self.provider, "close")
await close_method()
# Singleton instance
_embedding_service: EmbeddingService | None = None
def get_embedding_service() -> EmbeddingService:
"""
Get singleton embedding service instance.
Returns:
Global EmbeddingService instance
"""
global _embedding_service
if _embedding_service is None:
_embedding_service = EmbeddingService()
return _embedding_service