LightRAG/tools/migrate_llm_cache.py
yangdx 55274dde59 Add LLM cache migration tool for KV storage backends
- Supports JSON/Redis/PostgreSQL/MongoDB
- Batch migration with error tracking
- Workspace-aware data transfer
- Memory-efficient pagination
- Comprehensive migration reporting
2025-11-08 17:57:22 +08:00

721 lines
26 KiB
Python

#!/usr/bin/env python3
"""
LLM Cache Migration Tool for LightRAG
This tool migrates LLM response cache (default:extract:* and default:summary:*)
between different KV storage implementations while preserving workspace isolation.
Usage:
python tools/migrate_llm_cache.py
Supported KV Storage Types:
- JsonKVStorage
- RedisKVStorage
- PGKVStorage
- MongoKVStorage
"""
import asyncio
import os
import sys
import time
from typing import Any, Dict, List
from dataclasses import dataclass, field
from dotenv import load_dotenv
# Add parent directory to path for imports
sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
from lightrag.kg import STORAGE_ENV_REQUIREMENTS
from lightrag.namespace import NameSpace
from lightrag.utils import setup_logger
# Load environment variables
load_dotenv(dotenv_path=".env", override=False)
# Setup logger
setup_logger("lightrag", level="INFO")
# Storage type configurations
STORAGE_TYPES = {
"1": "JsonKVStorage",
"2": "RedisKVStorage",
"3": "PGKVStorage",
"4": "MongoKVStorage",
}
# Workspace environment variable mapping
WORKSPACE_ENV_MAP = {
"PGKVStorage": "POSTGRES_WORKSPACE",
"MongoKVStorage": "MONGODB_WORKSPACE",
"RedisKVStorage": "REDIS_WORKSPACE",
}
# Default batch size for migration
DEFAULT_BATCH_SIZE = 1000
@dataclass
class MigrationStats:
"""Migration statistics and error tracking"""
total_source_records: int = 0
total_batches: int = 0
successful_batches: int = 0
failed_batches: int = 0
successful_records: int = 0
failed_records: int = 0
errors: List[Dict[str, Any]] = field(default_factory=list)
def add_error(self, batch_idx: int, error: Exception, batch_size: int):
"""Record batch error"""
self.errors.append({
'batch': batch_idx,
'error_type': type(error).__name__,
'error_msg': str(error),
'records_lost': batch_size,
'timestamp': time.time()
})
self.failed_batches += 1
self.failed_records += batch_size
class MigrationTool:
"""LLM Cache Migration Tool"""
def __init__(self):
self.source_storage = None
self.target_storage = None
self.source_workspace = ""
self.target_workspace = ""
self.batch_size = DEFAULT_BATCH_SIZE
def get_workspace_for_storage(self, storage_name: str) -> str:
"""Get workspace for a specific storage type
Priority: Storage-specific env var > WORKSPACE env var > empty string
Args:
storage_name: Storage implementation name
Returns:
Workspace name
"""
# Check storage-specific workspace
if storage_name in WORKSPACE_ENV_MAP:
specific_workspace = os.getenv(WORKSPACE_ENV_MAP[storage_name])
if specific_workspace:
return specific_workspace
# Check generic WORKSPACE
workspace = os.getenv("WORKSPACE", "")
return workspace
def check_env_vars(self, storage_name: str) -> bool:
"""Check if all required environment variables exist
Args:
storage_name: Storage implementation name
Returns:
True if all required env vars exist, False otherwise
"""
required_vars = STORAGE_ENV_REQUIREMENTS.get(storage_name, [])
missing_vars = [var for var in required_vars if var not in os.environ]
if missing_vars:
print(f"✗ Missing required environment variables: {', '.join(missing_vars)}")
return False
print("✓ All required environment variables are set")
return True
def get_storage_class(self, storage_name: str):
"""Dynamically import and return storage class
Args:
storage_name: Storage implementation name
Returns:
Storage class
"""
if storage_name == "JsonKVStorage":
from lightrag.kg.json_kv_impl import JsonKVStorage
return JsonKVStorage
elif storage_name == "RedisKVStorage":
from lightrag.kg.redis_impl import RedisKVStorage
return RedisKVStorage
elif storage_name == "PGKVStorage":
from lightrag.kg.postgres_impl import PGKVStorage
return PGKVStorage
elif storage_name == "MongoKVStorage":
from lightrag.kg.mongo_impl import MongoKVStorage
return MongoKVStorage
else:
raise ValueError(f"Unsupported storage type: {storage_name}")
async def initialize_storage(self, storage_name: str, workspace: str):
"""Initialize storage instance
Args:
storage_name: Storage implementation name
workspace: Workspace name
Returns:
Initialized storage instance
"""
storage_class = self.get_storage_class(storage_name)
# Create global config
global_config = {
"working_dir": os.getenv("WORKING_DIR", "./rag_storage"),
"embedding_batch_num": 10,
}
# Initialize storage
storage = storage_class(
namespace=NameSpace.KV_STORE_LLM_RESPONSE_CACHE,
workspace=workspace,
global_config=global_config,
embedding_func=None,
)
# Initialize the storage
await storage.initialize()
return storage
async def get_default_caches_json(self, storage) -> Dict[str, Any]:
"""Get default caches from JsonKVStorage
Args:
storage: JsonKVStorage instance
Returns:
Dictionary of cache entries with default:extract:* or default:summary:* keys
"""
# Access _data directly - it's a dict from shared_storage
async with storage._storage_lock:
filtered = {}
for key, value in storage._data.items():
if key.startswith("default:extract:") or key.startswith("default:summary:"):
filtered[key] = value
return filtered
async def get_default_caches_redis(self, storage, batch_size: int = 1000) -> Dict[str, Any]:
"""Get default caches from RedisKVStorage with pagination
Args:
storage: RedisKVStorage instance
batch_size: Number of keys to process per batch
Returns:
Dictionary of cache entries with default:extract:* or default:summary:* keys
"""
import json
cache_data = {}
# Use _get_redis_connection() context manager
async with storage._get_redis_connection() as redis:
for pattern in ["default:extract:*", "default:summary:*"]:
# Add namespace prefix to pattern
prefixed_pattern = f"{storage.final_namespace}:{pattern}"
cursor = 0
while True:
# SCAN already implements cursor-based pagination
cursor, keys = await redis.scan(
cursor,
match=prefixed_pattern,
count=batch_size
)
if keys:
# Process this batch using pipeline with error handling
try:
pipe = redis.pipeline()
for key in keys:
pipe.get(key)
values = await pipe.execute()
for key, value in zip(keys, values):
if value:
key_str = key.decode() if isinstance(key, bytes) else key
# Remove namespace prefix to get original key
original_key = key_str.replace(f"{storage.final_namespace}:", "", 1)
cache_data[original_key] = json.loads(value)
except Exception as e:
# Pipeline execution failed, fall back to individual gets
print(f"⚠️ Pipeline execution failed for batch, using individual gets: {e}")
for key in keys:
try:
value = await redis.get(key)
if value:
key_str = key.decode() if isinstance(key, bytes) else key
original_key = key_str.replace(f"{storage.final_namespace}:", "", 1)
cache_data[original_key] = json.loads(value)
except Exception as individual_error:
print(f"⚠️ Failed to get individual key {key}: {individual_error}")
continue
if cursor == 0:
break
# Yield control periodically to avoid blocking
await asyncio.sleep(0)
return cache_data
async def get_default_caches_pg(self, storage, batch_size: int = 1000) -> Dict[str, Any]:
"""Get default caches from PGKVStorage with pagination
Args:
storage: PGKVStorage instance
batch_size: Number of records to fetch per batch
Returns:
Dictionary of cache entries with default:extract:* or default:summary:* keys
"""
from lightrag.kg.postgres_impl import namespace_to_table_name
cache_data = {}
table_name = namespace_to_table_name(storage.namespace)
offset = 0
while True:
# Use LIMIT and OFFSET for pagination
query = f"""
SELECT id as key, original_prompt, return_value, chunk_id, cache_type, queryparam,
EXTRACT(EPOCH FROM create_time)::BIGINT as create_time,
EXTRACT(EPOCH FROM update_time)::BIGINT as update_time
FROM {table_name}
WHERE workspace = $1
AND (id LIKE 'default:extract:%' OR id LIKE 'default:summary:%')
ORDER BY id
LIMIT $2 OFFSET $3
"""
results = await storage.db.query(
query,
[storage.workspace, batch_size, offset],
multirows=True
)
if not results:
break
for row in results:
# Map PostgreSQL fields to cache format
cache_entry = {
"return": row.get("return_value", ""),
"cache_type": row.get("cache_type"),
"original_prompt": row.get("original_prompt", ""),
"chunk_id": row.get("chunk_id"),
"queryparam": row.get("queryparam"),
"create_time": row.get("create_time", 0),
"update_time": row.get("update_time", 0),
}
cache_data[row["key"]] = cache_entry
# If we got fewer results than batch_size, we're done
if len(results) < batch_size:
break
offset += batch_size
# Yield control periodically
await asyncio.sleep(0)
return cache_data
async def get_default_caches_mongo(self, storage, batch_size: int = 1000) -> Dict[str, Any]:
"""Get default caches from MongoKVStorage with cursor-based pagination
Args:
storage: MongoKVStorage instance
batch_size: Number of documents to process per batch
Returns:
Dictionary of cache entries with default:extract:* or default:summary:* keys
"""
cache_data = {}
# MongoDB query with regex - use _data not collection
query = {"_id": {"$regex": "^default:(extract|summary):"}}
# Use cursor without to_list() - process in batches
cursor = storage._data.find(query).batch_size(batch_size)
async for doc in cursor:
# Process each document as it comes
doc_copy = doc.copy()
key = doc_copy.pop("_id")
# Filter ALL MongoDB/database-specific fields
# Following .clinerules: "Always filter deprecated/incompatible fields during deserialization"
for field_name in ["namespace", "workspace", "_id", "content"]:
doc_copy.pop(field_name, None)
cache_data[key] = doc_copy
# Periodically yield control (every batch_size documents)
if len(cache_data) % batch_size == 0:
await asyncio.sleep(0)
return cache_data
async def get_default_caches(self, storage, storage_name: str) -> Dict[str, Any]:
"""Get default caches from any storage type
Args:
storage: Storage instance
storage_name: Storage type name
Returns:
Dictionary of cache entries
"""
if storage_name == "JsonKVStorage":
return await self.get_default_caches_json(storage)
elif storage_name == "RedisKVStorage":
return await self.get_default_caches_redis(storage)
elif storage_name == "PGKVStorage":
return await self.get_default_caches_pg(storage)
elif storage_name == "MongoKVStorage":
return await self.get_default_caches_mongo(storage)
else:
raise ValueError(f"Unsupported storage type: {storage_name}")
async def count_cache_types(self, cache_data: Dict[str, Any]) -> Dict[str, int]:
"""Count cache entries by type
Args:
cache_data: Dictionary of cache entries
Returns:
Dictionary with counts for each cache type
"""
counts = {
"extract": 0,
"summary": 0,
}
for key in cache_data.keys():
if key.startswith("default:extract:"):
counts["extract"] += 1
elif key.startswith("default:summary:"):
counts["summary"] += 1
return counts
def print_header(self):
"""Print tool header"""
print("\n" + "=" * 50)
print("LLM Cache Migration Tool - LightRAG")
print("=" * 50)
def print_storage_types(self):
"""Print available storage types"""
print("\nSupported KV Storage Types:")
for key, value in STORAGE_TYPES.items():
print(f"[{key}] {value}")
def get_user_choice(self, prompt: str, valid_choices: list) -> str:
"""Get user choice with validation
Args:
prompt: Prompt message
valid_choices: List of valid choices
Returns:
User's choice
"""
while True:
choice = input(f"\n{prompt}: ").strip()
if choice in valid_choices:
return choice
print(f"✗ Invalid choice, please enter one of: {', '.join(valid_choices)}")
async def setup_storage(self, storage_type: str) -> tuple:
"""Setup and initialize storage
Args:
storage_type: Type label (source/target)
Returns:
Tuple of (storage_instance, storage_name, workspace, cache_data)
"""
print(f"\n=== {storage_type} Storage Setup ===")
# Get storage type choice
choice = self.get_user_choice(
f"Select {storage_type} storage type (1-4)",
list(STORAGE_TYPES.keys())
)
storage_name = STORAGE_TYPES[choice]
# Check environment variables
print("\nChecking environment variables...")
if not self.check_env_vars(storage_name):
return None, None, None, None
# Get workspace
workspace = self.get_workspace_for_storage(storage_name)
# Initialize storage
print(f"\nInitializing {storage_type} storage...")
try:
storage = await self.initialize_storage(storage_name, workspace)
print(f"- Storage Type: {storage_name}")
print(f"- Workspace: {workspace if workspace else '(default)'}")
print("- Connection Status: ✓ Success")
except Exception as e:
print(f"✗ Initialization failed: {e}")
return None, None, None, None
# Get cache data
print("\nCounting cache records...")
try:
cache_data = await self.get_default_caches(storage, storage_name)
counts = await self.count_cache_types(cache_data)
print(f"- default:extract: {counts['extract']:,} records")
print(f"- default:summary: {counts['summary']:,} records")
print(f"- Total: {len(cache_data):,} records")
except Exception as e:
print(f"✗ Counting failed: {e}")
return None, None, None, None
return storage, storage_name, workspace, cache_data
async def migrate_caches(
self,
source_data: Dict[str, Any],
target_storage,
target_storage_name: str
) -> MigrationStats:
"""Migrate caches in batches with error tracking
Args:
source_data: Source cache data
target_storage: Target storage instance
target_storage_name: Target storage type name
Returns:
MigrationStats object with migration results and errors
"""
stats = MigrationStats()
stats.total_source_records = len(source_data)
if stats.total_source_records == 0:
print("\nNo records to migrate")
return stats
# Convert to list for batching
items = list(source_data.items())
stats.total_batches = (stats.total_source_records + self.batch_size - 1) // self.batch_size
print("\n=== Starting Migration ===")
for batch_idx in range(stats.total_batches):
start_idx = batch_idx * self.batch_size
end_idx = min((batch_idx + 1) * self.batch_size, stats.total_source_records)
batch_items = items[start_idx:end_idx]
batch_data = dict(batch_items)
# Determine current cache type for display
current_key = batch_items[0][0]
cache_type = "extract" if "extract" in current_key else "summary"
try:
# Attempt to write batch
await target_storage.upsert(batch_data)
# Success - update stats
stats.successful_batches += 1
stats.successful_records += len(batch_data)
# Calculate progress
progress = (end_idx / stats.total_source_records) * 100
bar_length = 20
filled_length = int(bar_length * end_idx // stats.total_source_records)
bar = "" * filled_length + "" * (bar_length - filled_length)
print(f"Batch {batch_idx + 1}/{stats.total_batches}: {bar} "
f"{end_idx:,}/{stats.total_source_records:,} ({progress:.0f}%) - "
f"default:{cache_type}")
except Exception as e:
# Error - record and continue
stats.add_error(batch_idx + 1, e, len(batch_data))
print(f"Batch {batch_idx + 1}/{stats.total_batches}: ✗ FAILED - "
f"{type(e).__name__}: {str(e)}")
# Final persist
print("\nPersisting data to disk...")
try:
await target_storage.index_done_callback()
print("✓ Data persisted successfully")
except Exception as e:
print(f"✗ Persist failed: {e}")
stats.add_error(0, e, 0) # batch 0 = persist error
return stats
def print_migration_report(self, stats: MigrationStats):
"""Print comprehensive migration report
Args:
stats: MigrationStats object with migration results
"""
print("\n" + "=" * 60)
print("Migration Complete - Final Report")
print("=" * 60)
# Overall statistics
print("\n📊 Statistics:")
print(f" Total source records: {stats.total_source_records:,}")
print(f" Total batches: {stats.total_batches:,}")
print(f" Successful batches: {stats.successful_batches:,}")
print(f" Failed batches: {stats.failed_batches:,}")
print(f" Successfully migrated: {stats.successful_records:,}")
print(f" Failed to migrate: {stats.failed_records:,}")
# Success rate
success_rate = (stats.successful_records / stats.total_source_records * 100) if stats.total_source_records > 0 else 0
print(f" Success rate: {success_rate:.2f}%")
# Error details
if stats.errors:
print(f"\n⚠️ Errors encountered: {len(stats.errors)}")
print("\nError Details:")
print("-" * 60)
# Group errors by type
error_types = {}
for error in stats.errors:
err_type = error['error_type']
error_types[err_type] = error_types.get(err_type, 0) + 1
print("\nError Summary:")
for err_type, count in sorted(error_types.items(), key=lambda x: -x[1]):
print(f" - {err_type}: {count} occurrence(s)")
print("\nFirst 5 errors:")
for i, error in enumerate(stats.errors[:5], 1):
print(f"\n {i}. Batch {error['batch']}")
print(f" Type: {error['error_type']}")
print(f" Message: {error['error_msg']}")
print(f" Records lost: {error['records_lost']:,}")
if len(stats.errors) > 5:
print(f"\n ... and {len(stats.errors) - 5} more errors")
print("\n" + "=" * 60)
print("⚠️ WARNING: Migration completed with errors!")
print(" Please review the error details above.")
print("=" * 60)
else:
print("\n" + "=" * 60)
print("✓ SUCCESS: All records migrated successfully!")
print("=" * 60)
async def run(self):
"""Run the migration tool"""
try:
# Print header
self.print_header()
self.print_storage_types()
# Setup source storage
(
self.source_storage,
source_storage_name,
self.source_workspace,
source_data
) = await self.setup_storage("Source")
if not self.source_storage:
print("\n✗ Source storage setup failed")
return
if not source_data:
print("\n⚠ Source storage has no cache records to migrate")
# Cleanup
await self.source_storage.finalize()
return
# Setup target storage
(
self.target_storage,
target_storage_name,
self.target_workspace,
target_data
) = await self.setup_storage("Target")
if not self.target_storage:
print("\n✗ Target storage setup failed")
# Cleanup source
await self.source_storage.finalize()
return
# Show migration summary
print("\n" + "=" * 50)
print("Migration Confirmation")
print("=" * 50)
print(f"Source: {source_storage_name} (workspace: {self.source_workspace if self.source_workspace else '(default)'}) - {len(source_data):,} records")
print(f"Target: {target_storage_name} (workspace: {self.target_workspace if self.target_workspace else '(default)'}) - {len(target_data):,} records")
print(f"Batch Size: {self.batch_size:,} records/batch")
if target_data:
print(f"\n⚠ Warning: Target storage already has {len(target_data):,} records")
print("Migration will overwrite records with the same keys")
# Confirm migration
confirm = input("\nContinue? (y/n): ").strip().lower()
if confirm != 'y':
print("\n✗ Migration cancelled")
# Cleanup
await self.source_storage.finalize()
await self.target_storage.finalize()
return
# Perform migration with error tracking
stats = await self.migrate_caches(source_data, self.target_storage, target_storage_name)
# Print comprehensive migration report
self.print_migration_report(stats)
# Cleanup
await self.source_storage.finalize()
await self.target_storage.finalize()
except KeyboardInterrupt:
print("\n\n✗ Migration interrupted by user")
except Exception as e:
print(f"\n✗ Migration failed: {e}")
import traceback
traceback.print_exc()
finally:
# Ensure cleanup
if self.source_storage:
try:
await self.source_storage.finalize()
except Exception:
pass
if self.target_storage:
try:
await self.target_storage.finalize()
except Exception:
pass
async def main():
"""Main entry point"""
tool = MigrationTool()
await tool.run()
if __name__ == "__main__":
asyncio.run(main())