Fix txtai nprobe fallback to avoid reloading incompatible faiss index

This commit is contained in:
ي
2026-03-09 12:21:43 +05:30
parent 39bc3e3008
commit cd8582eb8c

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@@ -57,7 +57,7 @@ class TxtaiIntelligenceService:
if not self._initialized:
self._initialize_embeddings()
def _initialize_embeddings(self):
def _initialize_embeddings(self, load_existing_index: bool = True):
"""Initialize txtai embeddings with local storage support and comprehensive error handling."""
if not TXTAI_AVAILABLE:
logger.error("txtai is not available. Please install with: pip install txtai[pipeline,similarity]")
@@ -96,7 +96,7 @@ class TxtaiIntelligenceService:
logger.info("Embeddings instance created successfully")
# Check if existing index exists and load it
if os.path.exists(self.index_path):
if load_existing_index and os.path.exists(self.index_path):
logger.info(f"Loading existing txtai index from {self.index_path}")
try:
self.embeddings.load(self.index_path)
@@ -119,8 +119,13 @@ class TxtaiIntelligenceService:
"gpu": False,
"limit": 1000
})
else:
elif load_existing_index:
logger.info(f"No existing index found. Creating new txtai index for user {self.user_id}")
else:
logger.info(
f"Skipping existing txtai index load for user {self.user_id} "
f"(backend={self._backend}, load_existing_index={load_existing_index})"
)
self._initialized = True
logger.info(f"Txtai Intelligence Service initialized successfully for user {self.user_id}")
@@ -134,6 +139,20 @@ class TxtaiIntelligenceService:
logger.error("3. Missing dependencies - try: pip install txtai[pipeline,similarity]")
self._initialized = False
@staticmethod
def _is_nprobe_incompatibility(error: Exception) -> bool:
"""Detect known FAISS IndexIDMap/nprobe incompatibility."""
message = str(error)
return "nprobe" in message and "IndexIDMap" in message
def _switch_to_numpy_backend(self, load_existing_index: bool = False):
"""Switch embedding backend to numpy and reinitialize service state."""
if self._backend != "numpy":
logger.warning(f"Switching txtai backend to numpy for user {self.user_id}")
self._backend = "numpy"
self._initialized = False
self._initialize_embeddings(load_existing_index=load_existing_index)
async def index_content(self, items: List[Tuple[str, str, Dict[str, Any]]]):
"""
Index content for semantic search and clustering.
@@ -211,14 +230,22 @@ class TxtaiIntelligenceService:
try:
results = self.embeddings.search(query, limit=limit)
except AttributeError as ae:
if "nprobe" in str(ae):
if self._is_nprobe_incompatibility(ae):
logger.error(f"Detected known txtai/faiss IndexIDMap/nprobe incompatibility for user {self.user_id}. Attempting re-init with numpy backend fallback...")
# Switch to numpy backend which doesn't have this issue
self._backend = "numpy"
self._initialized = False
self._initialize_embeddings()
# Switch to numpy backend and skip loading persisted ANN index
self._switch_to_numpy_backend(load_existing_index=False)
if self.embeddings:
results = self.embeddings.search(query, limit=limit)
try:
results = self.embeddings.search(query, limit=limit)
except AttributeError as retry_ae:
if self._is_nprobe_incompatibility(retry_ae):
logger.warning(
f"Retry still hit nprobe incompatibility for user {self.user_id}; "
f"forcing non-ANN search path."
)
results = self.embeddings.search(query, limit=limit, index=False)
else:
raise retry_ae
else:
raise ae
else:
@@ -269,14 +296,38 @@ class TxtaiIntelligenceService:
try:
similarity = self.embeddings.similarity(text1, text2)
except AttributeError as ae:
if "nprobe" in str(ae):
if self._is_nprobe_incompatibility(ae):
logger.error(f"Detected IndexIDMap nprobe error in similarity for user {self.user_id}. Falling back to numpy backend...")
# Switch to numpy backend which doesn't have this issue
self._backend = "numpy"
self._initialized = False
self._initialize_embeddings()
self._switch_to_numpy_backend(load_existing_index=False)
if self.embeddings:
similarity = self.embeddings.similarity(text1, text2)
try:
similarity = self.embeddings.similarity(text1, text2)
except AttributeError as retry_ae:
if self._is_nprobe_incompatibility(retry_ae):
logger.warning(
f"Similarity retry still hit nprobe incompatibility for user {self.user_id}; "
f"using vector cosine fallback."
)
vectors = self.embeddings.transform([text1, text2])
if vectors is None or len(vectors) < 2:
return 0.0
try:
# Handle list or numpy array vectors consistently
import math
v1, v2 = vectors[0], vectors[1]
dot_product = sum(a * b for a, b in zip(v1, v2))
norm_v1 = math.sqrt(sum(a * a for a in v1))
norm_v2 = math.sqrt(sum(b * b for b in v2))
if norm_v1 == 0 or norm_v2 == 0:
similarity = 0.0
else:
similarity = dot_product / (norm_v1 * norm_v2)
except Exception as vector_error:
logger.error(f"Cosine fallback failed for user {self.user_id}: {vector_error}")
similarity = 0.0
else:
raise retry_ae
else:
raise ae
else:
@@ -339,12 +390,10 @@ class TxtaiIntelligenceService:
try:
graph_results = self.embeddings.search(sample_query, limit=10, graph=True)
except AttributeError as ae:
if "nprobe" in str(ae):
if self._is_nprobe_incompatibility(ae):
logger.error(f"Detected IndexIDMap nprobe error in cluster for user {self.user_id}. Falling back to numpy backend...")
# Force re-initialization with numpy backend to bypass FAISS issue
self._backend = "numpy"
self._initialized = False
self._initialize_embeddings()
self._switch_to_numpy_backend(load_existing_index=False)
if self.embeddings:
# Retry with numpy backend (no graph support, so fallback)
return await self._fallback_clustering(min_score)