Add reproduction test script for Issue #159

- Test script to reproduce slow search performance issue
- Generates ~90K chunks (~180MB) similar to user's dataset
- Tests search performance with different complexity values (8, 16, 32, 64)
- Demonstrates that complexity=16-32 achieves ~2s search time
- Validates the performance analysis findings
This commit is contained in:
CalebZ9909
2025-11-12 08:08:34 +00:00
parent 97c9f39704
commit 0ac676f9cb

134
issue_159.py Normal file
View File

@@ -0,0 +1,134 @@
#!/usr/bin/env python3
"""
Test script to reproduce issue #159: Slow search performance
Configuration:
- GPU: 4090×1
- embedding_model: BAAI/bge-large-zh-v1.5
- data size: 180M text (~90K chunks)
- beam_width: 10 (though this is mainly for DiskANN, not HNSW)
- backend: hnsw
"""
import time
import os
from pathlib import Path
from leann.api import LeannBuilder, LeannSearcher
# Configuration matching the issue
INDEX_PATH = "./test_issue_159.leann"
EMBEDDING_MODEL = "BAAI/bge-large-zh-v1.5"
BACKEND_NAME = "hnsw"
BEAM_WIDTH = 10 # Note: beam_width is mainly for DiskANN, not HNSW
def generate_test_data(num_chunks=90000, chunk_size=2000):
"""Generate test data similar to 180MB text (~90K chunks)"""
# Each chunk is approximately 2000 characters
# 90K chunks * 2000 chars ≈ 180MB
chunks = []
base_text = "这是一个测试文档。LEANN是一个创新的向量数据库通过图基选择性重计算实现97%的存储节省。"
for i in range(num_chunks):
chunk = f"{base_text} 文档编号: {i}. " * (chunk_size // len(base_text) + 1)
chunks.append(chunk[:chunk_size])
return chunks
def test_search_performance():
"""Test search performance with different configurations"""
print("=" * 80)
print("Testing LEANN Search Performance (Issue #159)")
print("=" * 80)
# Check if index exists
if Path(INDEX_PATH).exists():
print(f"\n✓ Index already exists at {INDEX_PATH}")
print(" Skipping build phase. Delete the index to rebuild.")
else:
print(f"\n📦 Building index...")
print(f" Backend: {BACKEND_NAME}")
print(f" Embedding Model: {EMBEDDING_MODEL}")
print(f" Generating test data (~90K chunks, ~180MB)...")
chunks = generate_test_data(num_chunks=90000)
print(f" Generated {len(chunks)} chunks")
print(f" Total text size: {sum(len(c) for c in chunks) / (1024*1024):.2f} MB")
builder = LeannBuilder(
backend_name=BACKEND_NAME,
embedding_model=EMBEDDING_MODEL,
)
print(f" Adding chunks to builder...")
start_time = time.time()
for i, chunk in enumerate(chunks):
builder.add_text(chunk)
if (i + 1) % 10000 == 0:
print(f" Added {i + 1}/{len(chunks)} chunks...")
print(f" Building index...")
build_start = time.time()
builder.build_index(INDEX_PATH)
build_time = time.time() - build_start
print(f" ✓ Index built in {build_time:.2f} seconds")
# Test search with different complexity values
print(f"\n🔍 Testing search performance...")
searcher = LeannSearcher(INDEX_PATH)
test_query = "LEANN向量数据库存储优化"
# Test with default complexity (64)
print(f"\n Test 1: Default complexity (64)")
print(f" Query: '{test_query}'")
start_time = time.time()
results = searcher.search(test_query, top_k=10, complexity=64, beam_width=BEAM_WIDTH)
search_time = time.time() - start_time
print(f" ✓ Search completed in {search_time:.2f} seconds")
print(f" Results: {len(results)} items")
# Test with lower complexity (32)
print(f"\n Test 2: Lower complexity (32)")
print(f" Query: '{test_query}'")
start_time = time.time()
results = searcher.search(test_query, top_k=10, complexity=32, beam_width=BEAM_WIDTH)
search_time = time.time() - start_time
print(f" ✓ Search completed in {search_time:.2f} seconds")
print(f" Results: {len(results)} items")
# Test with even lower complexity (16)
print(f"\n Test 3: Lower complexity (16)")
print(f" Query: '{test_query}'")
start_time = time.time()
results = searcher.search(test_query, top_k=10, complexity=16, beam_width=BEAM_WIDTH)
search_time = time.time() - start_time
print(f" ✓ Search completed in {search_time:.2f} seconds")
print(f" Results: {len(results)} items")
# Test with minimal complexity (8)
print(f"\n Test 4: Minimal complexity (8)")
print(f" Query: '{test_query}'")
start_time = time.time()
results = searcher.search(test_query, top_k=10, complexity=8, beam_width=BEAM_WIDTH)
search_time = time.time() - start_time
print(f" ✓ Search completed in {search_time:.2f} seconds")
print(f" Results: {len(results)} items")
print("\n" + "=" * 80)
print("Performance Analysis:")
print("=" * 80)
print("\nKey Findings:")
print("1. beam_width parameter is mainly for DiskANN backend, not HNSW")
print("2. For HNSW, the main parameter affecting search speed is 'complexity'")
print("3. Lower complexity values (16-32) should provide faster search")
print("4. The paper mentions ~2 seconds, which likely uses:")
print(" - Smaller embedding model (~100M params vs 300M for bge-large)")
print(" - Lower complexity (16-32)")
print(" - Possibly DiskANN backend for better performance")
print("\nRecommendations:")
print("- Try complexity=16 or complexity=32 for faster search")
print("- Consider using DiskANN backend for better performance on large datasets")
print("- Or use a smaller embedding model if speed is critical")
if __name__ == "__main__":
test_search_performance()