Files
catonline_ai/vw-agentic-rag/service/memory/redis_memory.py
2025-09-26 17:15:54 +08:00

138 lines
4.8 KiB
Python

"""
Redis-based memory implementation using LangGraph built-in components.
Provides session-level chat history with 7-day TTL.
"""
import logging
import ssl
from typing import Dict, Any, Optional
try:
import redis
from redis.exceptions import ConnectionError, TimeoutError
from langgraph.checkpoint.redis import RedisSaver
REDIS_AVAILABLE = True
except ImportError as e:
logging.warning(f"Redis packages not available: {e}")
REDIS_AVAILABLE = False
redis = None
RedisSaver = None
from langgraph.checkpoint.memory import InMemorySaver
from ..config import get_config
logger = logging.getLogger(__name__)
class RedisMemoryManager:
"""
Redis-based memory manager using LangGraph's built-in components.
Falls back to in-memory storage if Redis is not available.
"""
def __init__(self):
self.config = get_config()
self.redis_config = self.config.redis
self._checkpointer: Optional[Any] = None
self._redis_available = REDIS_AVAILABLE
def _get_redis_client_kwargs(self) -> Dict[str, Any]:
"""Get Redis client configuration for Azure Redis compatibility."""
if not self._redis_available:
return {}
kwargs = {
"host": self.redis_config.host,
"port": self.redis_config.port,
"password": self.redis_config.password,
"db": self.redis_config.db,
"decode_responses": False, # Required for RedisSaver
"socket_timeout": 30,
"socket_connect_timeout": 10,
"retry_on_timeout": True,
"health_check_interval": 30,
}
if self.redis_config.use_ssl:
kwargs.update({
"ssl": True,
"ssl_cert_reqs": ssl.CERT_REQUIRED,
"ssl_check_hostname": True,
})
return kwargs
def _get_ttl_config(self) -> Dict[str, Any]:
"""Get TTL configuration for automatic cleanup."""
ttl_days = self.redis_config.ttl_days
ttl_minutes = ttl_days * 24 * 60 # Convert days to minutes
return {
"default_ttl": ttl_minutes,
"refresh_on_read": True, # Refresh TTL when accessed
}
def get_checkpointer(self):
"""Get checkpointer for conversation history (Redis if available, else in-memory)."""
if self._checkpointer is None:
if self._redis_available:
try:
ttl_config = self._get_ttl_config()
# Create Redis client with proper configuration for Azure Redis
redis_client = redis.Redis(**self._get_redis_client_kwargs())
# Test connection
redis_client.ping()
logger.info("Redis connection established successfully")
# Create checkpointer with TTL support
self._checkpointer = RedisSaver(
redis_client=redis_client,
ttl=ttl_config
)
# Initialize indices (required for first-time setup)
self._checkpointer.setup()
logger.info(f"Redis checkpointer initialized with {self.redis_config.ttl_days}-day TTL")
except Exception as e:
logger.error(f"Failed to initialize Redis checkpointer, falling back to in-memory: {e}")
self._checkpointer = InMemorySaver()
else:
logger.info("Redis not available, using in-memory checkpointer")
self._checkpointer = InMemorySaver()
return self._checkpointer
def test_connection(self) -> bool:
"""Test Redis connection and return True if successful."""
if not self._redis_available:
logger.warning("Redis packages not available")
return False
try:
redis_client = redis.Redis(**self._get_redis_client_kwargs())
redis_client.ping()
logger.info("Redis connection test successful")
return True
except Exception as e:
logger.error(f"Redis connection test failed: {e}")
return False
# Global memory manager instance
_memory_manager: Optional[RedisMemoryManager] = None
def get_memory_manager() -> RedisMemoryManager:
"""Get global Redis memory manager instance."""
global _memory_manager
if _memory_manager is None:
_memory_manager = RedisMemoryManager()
return _memory_manager
def get_checkpointer():
"""Get checkpointer for conversation history."""
return get_memory_manager().get_checkpointer()