Files
LEANN/packages/leann-backend-hnsw/leann_backend_hnsw/hnsw_embedding_server.py
2025-09-23 02:04:27 -07:00

464 lines
19 KiB
Python

"""
HNSW-specific embedding server
"""
import argparse
import json
import logging
import os
import sys
import threading
import time
from pathlib import Path
from typing import Any, Optional
import msgpack
import numpy as np
import zmq
# Set up logging based on environment variable
LOG_LEVEL = os.getenv("LEANN_LOG_LEVEL", "WARNING").upper()
logger = logging.getLogger(__name__)
# Force set logger level (don't rely on basicConfig in subprocess)
log_level = getattr(logging, LOG_LEVEL, logging.WARNING)
logger.setLevel(log_level)
# Ensure we have handlers if none exist
if not logger.handlers:
stream_handler = logging.StreamHandler()
formatter = logging.Formatter("%(asctime)s - %(levelname)s - %(message)s")
stream_handler.setFormatter(formatter)
logger.addHandler(stream_handler)
log_path = os.getenv("LEANN_HNSW_LOG_PATH")
if log_path:
try:
file_handler = logging.FileHandler(log_path, mode="a", encoding="utf-8")
file_formatter = logging.Formatter(
"%(asctime)s - %(levelname)s - [pid=%(process)d] %(message)s"
)
file_handler.setFormatter(file_formatter)
logger.addHandler(file_handler)
except Exception as exc: # pragma: no cover - best effort logging
logger.warning(f"Failed to attach file handler for log path {log_path}: {exc}")
logger.propagate = False
_RAW_PROVIDER_OPTIONS = os.getenv("LEANN_EMBEDDING_OPTIONS")
try:
PROVIDER_OPTIONS: dict[str, Any] = (
json.loads(_RAW_PROVIDER_OPTIONS) if _RAW_PROVIDER_OPTIONS else {}
)
except json.JSONDecodeError:
logger.warning("Failed to parse LEANN_EMBEDDING_OPTIONS; ignoring provider options")
PROVIDER_OPTIONS = {}
def create_hnsw_embedding_server(
passages_file: Optional[str] = None,
zmq_port: int = 5555,
model_name: str = "sentence-transformers/all-mpnet-base-v2",
distance_metric: str = "mips",
embedding_mode: str = "sentence-transformers",
):
"""
Create and start a ZMQ-based embedding server for HNSW backend.
Simplified version using unified embedding computation module.
"""
logger.info(f"Starting HNSW server on port {zmq_port} with model {model_name}")
logger.info(f"Using embedding mode: {embedding_mode}")
# Add leann-core to path for unified embedding computation
current_dir = Path(__file__).parent
leann_core_path = current_dir.parent.parent / "leann-core" / "src"
sys.path.insert(0, str(leann_core_path))
try:
from leann.api import PassageManager
from leann.embedding_compute import compute_embeddings
logger.info("Successfully imported unified embedding computation module")
except ImportError as e:
logger.error(f"Failed to import embedding computation module: {e}")
return
finally:
sys.path.pop(0)
# Check port availability
import socket
def check_port(port):
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
return s.connect_ex(("localhost", port)) == 0
if check_port(zmq_port):
logger.error(f"Port {zmq_port} is already in use")
return
# Only support metadata file, fail fast for everything else
if not passages_file or not passages_file.endswith(".meta.json"):
raise ValueError("Only metadata files (.meta.json) are supported")
# Load metadata to get passage sources
with open(passages_file) as f:
meta = json.load(f)
# Let PassageManager handle path resolution uniformly. It supports fallback order:
# 1) path/index_path; 2) *_relative; 3) standard siblings next to meta
passages = PassageManager(meta["passage_sources"], metadata_file_path=passages_file)
# Dimension from metadata for shaping responses
try:
embedding_dim: int = int(meta.get("dimensions", 0))
except Exception:
embedding_dim = 0
logger.info(f"Loaded PassageManager with {len(passages)} passages from metadata")
# (legacy ZMQ thread removed; using shutdown-capable server only)
def zmq_server_thread_with_shutdown(shutdown_event):
"""ZMQ server thread that respects shutdown signal.
Creates its own REP socket bound to zmq_port and polls with timeouts
to allow graceful shutdown.
"""
logger.info("ZMQ server thread started with shutdown support")
context = zmq.Context()
rep_socket = context.socket(zmq.REP)
rep_socket.bind(f"tcp://*:{zmq_port}")
logger.info(f"HNSW ZMQ REP server listening on port {zmq_port}")
rep_socket.setsockopt(zmq.RCVTIMEO, 1000)
# Keep sends from blocking during shutdown; fail fast and drop on close
rep_socket.setsockopt(zmq.SNDTIMEO, 1000)
rep_socket.setsockopt(zmq.LINGER, 0)
# Track last request type/length for shape-correct fallbacks
last_request_type = "unknown" # 'text' | 'distance' | 'embedding' | 'unknown'
last_request_length = 0
try:
while not shutdown_event.is_set():
try:
e2e_start = time.time()
logger.debug("🔍 Waiting for ZMQ message...")
request_bytes = rep_socket.recv()
# Rest of the processing logic (same as original)
request = msgpack.unpackb(request_bytes)
if len(request) == 1 and request[0] == "__QUERY_MODEL__":
response_bytes = msgpack.packb([model_name])
rep_socket.send(response_bytes)
continue
# Handle direct text embedding request
if (
isinstance(request, list)
and request
and all(isinstance(item, str) for item in request)
):
last_request_type = "text"
last_request_length = len(request)
embeddings = compute_embeddings(
request,
model_name,
mode=embedding_mode,
provider_options=PROVIDER_OPTIONS,
)
rep_socket.send(msgpack.packb(embeddings.tolist()))
e2e_end = time.time()
logger.info(f"⏱️ Text embedding E2E time: {e2e_end - e2e_start:.6f}s")
continue
# Handle distance calculation request: [[ids], [query_vector]]
if (
isinstance(request, list)
and len(request) == 2
and isinstance(request[0], list)
and isinstance(request[1], list)
):
node_ids = request[0]
# Handle nested [[ids]] shape defensively
if len(node_ids) == 1 and isinstance(node_ids[0], list):
node_ids = node_ids[0]
query_vector = np.array(request[1], dtype=np.float32)
last_request_type = "distance"
last_request_length = len(node_ids)
logger.debug("Distance calculation request received")
logger.debug(f" Node IDs: {node_ids}")
logger.debug(f" Query vector dim: {len(query_vector)}")
# Gather texts for found ids
texts: list[str] = []
found_indices: list[int] = []
for idx, nid in enumerate(node_ids):
try:
passage_data = passages.get_passage(str(nid))
txt = passage_data.get("text", "")
if isinstance(txt, str) and len(txt) > 0:
texts.append(txt)
found_indices.append(idx)
else:
logger.error(f"Empty text for passage ID {nid}")
except KeyError:
logger.error(f"Passage ID {nid} not found")
except Exception as e:
logger.error(f"Exception looking up passage ID {nid}: {e}")
# Prepare full-length response with large sentinel values
large_distance = 1e9
response_distances = [large_distance] * len(node_ids)
if texts:
try:
embeddings = compute_embeddings(
texts,
model_name,
mode=embedding_mode,
provider_options=PROVIDER_OPTIONS,
)
logger.info(
f"Computed embeddings for {len(texts)} texts, shape: {embeddings.shape}"
)
if distance_metric == "l2":
partial = np.sum(
np.square(embeddings - query_vector.reshape(1, -1)), axis=1
)
else: # mips or cosine
partial = -np.dot(embeddings, query_vector)
for pos, dval in zip(found_indices, partial.flatten().tolist()):
response_distances[pos] = float(dval)
except Exception as e:
logger.error(f"Distance computation error, using sentinels: {e}")
# Send response in expected shape [[distances]]
rep_socket.send(msgpack.packb([response_distances], use_single_float=True))
e2e_end = time.time()
logger.info(f"⏱️ Distance calculation E2E time: {e2e_end - e2e_start:.6f}s")
continue
# Fallback: treat as embedding-by-id request
if (
isinstance(request, list)
and len(request) == 1
and isinstance(request[0], list)
):
node_ids = request[0]
elif isinstance(request, list):
node_ids = request
else:
node_ids = []
last_request_type = "embedding"
last_request_length = len(node_ids)
logger.info(f"ZMQ received {len(node_ids)} node IDs for embedding fetch")
# Preallocate zero-filled flat data for robustness
if embedding_dim <= 0:
dims = [0, 0]
flat_data: list[float] = []
else:
dims = [len(node_ids), embedding_dim]
flat_data = [0.0] * (dims[0] * dims[1])
# Collect texts for found ids
texts: list[str] = []
found_indices: list[int] = []
for idx, nid in enumerate(node_ids):
try:
passage_data = passages.get_passage(str(nid))
txt = passage_data.get("text", "")
if isinstance(txt, str) and len(txt) > 0:
texts.append(txt)
found_indices.append(idx)
else:
logger.error(f"Empty text for passage ID {nid}")
except KeyError:
logger.error(f"Passage with ID {nid} not found")
except Exception as e:
logger.error(f"Exception looking up passage ID {nid}: {e}")
if texts:
try:
embeddings = compute_embeddings(
texts,
model_name,
mode=embedding_mode,
provider_options=PROVIDER_OPTIONS,
)
logger.info(
f"Computed embeddings for {len(texts)} texts, shape: {embeddings.shape}"
)
if np.isnan(embeddings).any() or np.isinf(embeddings).any():
logger.error(
f"NaN or Inf detected in embeddings! Requested IDs: {node_ids[:5]}..."
)
dims = [0, embedding_dim]
flat_data = []
else:
emb_f32 = np.ascontiguousarray(embeddings, dtype=np.float32)
flat = emb_f32.flatten().tolist()
for j, pos in enumerate(found_indices):
start = pos * embedding_dim
end = start + embedding_dim
if end <= len(flat_data):
flat_data[start:end] = flat[
j * embedding_dim : (j + 1) * embedding_dim
]
except Exception as e:
logger.error(f"Embedding computation error, returning zeros: {e}")
response_payload = [dims, flat_data]
response_bytes = msgpack.packb(response_payload, use_single_float=True)
rep_socket.send(response_bytes)
e2e_end = time.time()
logger.info(f"⏱️ ZMQ E2E time: {e2e_end - e2e_start:.6f}s")
except zmq.Again:
# Timeout - check shutdown_event and continue
continue
except Exception as e:
if not shutdown_event.is_set():
logger.error(f"Error in ZMQ server loop: {e}")
# Shape-correct fallback
try:
if last_request_type == "distance":
large_distance = 1e9
fallback_len = max(0, int(last_request_length))
safe = [[large_distance] * fallback_len]
elif last_request_type == "embedding":
bsz = max(0, int(last_request_length))
dim = max(0, int(embedding_dim))
safe = (
[[bsz, dim], [0.0] * (bsz * dim)] if dim > 0 else [[0, 0], []]
)
elif last_request_type == "text":
safe = [] # direct text embeddings expectation is a flat list
else:
safe = [[0, int(embedding_dim) if embedding_dim > 0 else 0], []]
rep_socket.send(msgpack.packb(safe, use_single_float=True))
except Exception:
pass
else:
logger.info("Shutdown in progress, ignoring ZMQ error")
break
finally:
try:
rep_socket.close(0)
except Exception:
pass
try:
context.term()
except Exception:
pass
logger.info("ZMQ server thread exiting gracefully")
# Add shutdown coordination
shutdown_event = threading.Event()
def shutdown_zmq_server():
"""Gracefully shutdown ZMQ server."""
logger.info("Initiating graceful shutdown...")
shutdown_event.set()
if zmq_thread.is_alive():
logger.info("Waiting for ZMQ thread to finish...")
zmq_thread.join(timeout=5)
if zmq_thread.is_alive():
logger.warning("ZMQ thread did not finish in time")
# Clean up ZMQ resources
try:
# Note: socket and context are cleaned up by thread exit
logger.info("ZMQ resources cleaned up")
except Exception as e:
logger.warning(f"Error cleaning ZMQ resources: {e}")
# Clean up other resources
try:
import gc
gc.collect()
logger.info("Additional resources cleaned up")
except Exception as e:
logger.warning(f"Error cleaning additional resources: {e}")
logger.info("Graceful shutdown completed")
sys.exit(0)
# Register signal handlers within this function scope
import signal
def signal_handler(sig, frame):
logger.info(f"Received signal {sig}, shutting down gracefully...")
shutdown_zmq_server()
signal.signal(signal.SIGTERM, signal_handler)
signal.signal(signal.SIGINT, signal_handler)
# Pass shutdown_event to ZMQ thread
zmq_thread = threading.Thread(
target=lambda: zmq_server_thread_with_shutdown(shutdown_event),
daemon=False, # Not daemon - we want to wait for it
)
zmq_thread.start()
logger.info(f"Started HNSW ZMQ server thread on port {zmq_port}")
# Keep the main thread alive
try:
while not shutdown_event.is_set():
time.sleep(0.1) # Check shutdown more frequently
except KeyboardInterrupt:
logger.info("HNSW Server shutting down...")
shutdown_zmq_server()
return
# If we reach here, shutdown was triggered by signal
logger.info("Main loop exited, process should be shutting down")
if __name__ == "__main__":
import sys
# Signal handlers are now registered within create_hnsw_embedding_server
parser = argparse.ArgumentParser(description="HNSW Embedding service")
parser.add_argument("--zmq-port", type=int, default=5555, help="ZMQ port to run on")
parser.add_argument(
"--passages-file",
type=str,
help="JSON file containing passage ID to text mapping",
)
parser.add_argument(
"--model-name",
type=str,
default="sentence-transformers/all-mpnet-base-v2",
help="Embedding model name",
)
parser.add_argument(
"--distance-metric", type=str, default="mips", help="Distance metric to use"
)
parser.add_argument(
"--embedding-mode",
type=str,
default="sentence-transformers",
choices=["sentence-transformers", "openai", "mlx", "ollama"],
help="Embedding backend mode",
)
args = parser.parse_args()
# Create and start the HNSW embedding server
create_hnsw_embedding_server(
passages_file=args.passages_file,
zmq_port=args.zmq_port,
model_name=args.model_name,
distance_metric=args.distance_metric,
embedding_mode=args.embedding_mode,
)