168 lines
6.2 KiB
Python
168 lines
6.2 KiB
Python
import logging
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from json import loads, dumps
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from contextlib import contextmanager
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from time import sleep
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from redis import Redis, RedisError, ConnectionError as RedisConnectionError
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from config import RedisConfig
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logger = logging.getLogger('RedisHandler')
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@contextmanager
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def safe_redis_operation(redis_client: Redis, operation_name: str = "Redis operation"):
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"""
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Context manager for safely executing Redis operations with error handling
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"""
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try:
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yield redis_client
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except RedisConnectionError as e:
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logger.error(f"{operation_name} failed due to Redis connection error: {str(e)}")
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raise
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except RedisError as e:
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logger.error(f"{operation_name} failed due to Redis error: {str(e)}")
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raise
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except Exception as e:
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logger.error(f"{operation_name} failed with unexpected error: {str(e)}")
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raise
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class RedisHandler:
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"""Singleton Redis handler class for centralized Redis operations"""
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_instance = None
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REDIS_EXCEPTIONS = (RedisConnectionError, RedisError)
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def __new__(cls):
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if cls._instance is None:
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cls._instance = super(RedisHandler, cls).__new__(cls)
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cls._instance._initialized = False
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return cls._instance
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def __init__(self):
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# Initialize only once
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if self._initialized:
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return
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# Initialize Redis client with retry logic
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self.redis_client = self._create_redis_client()
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self.redis_connected = self._check_redis_connection()
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self._initialized = True
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def _create_redis_client(self):
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"""Create a Redis client with connection retry"""
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max_retries = 5
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retry_delay = 5
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for attempt in range(max_retries):
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try:
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client = Redis(**RedisConfig.as_dict())
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client.ping() # Test the connection
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logger.info("Redis connection established successfully")
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return client
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except (RedisConnectionError, RedisError) as e:
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if attempt < max_retries - 1:
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logger.warning(f"Redis connection attempt {attempt + 1} failed: {str(e)}. Retrying in {retry_delay} seconds...")
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sleep(retry_delay)
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retry_delay *= 2 # Exponential backoff
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else:
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logger.error(f"Failed to connect to Redis after {max_retries} attempts: {str(e)}")
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# Continue with a new Redis client instance even if ping fails
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# This allows the service to start and retry connections later
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return Redis(**RedisConfig.as_dict())
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def _check_redis_connection(self) -> bool:
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"""Check if Redis connection is alive"""
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try:
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self.ping()
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return True
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except Exception as e:
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return False
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def ping(self):
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"""Ping Redis server to check connection"""
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return self.redis_client.ping()
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def sadd(self, key: str, value):
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"""Add a value to a Redis set"""
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return self.redis_client.sadd(key, value)
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def ismember(self, key: str, value):
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"""Check if a value is a member of a Redis set"""
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return self.redis_client.sismember(key, value)
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def get(self, key: str):
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"""Get a value from Redis by key"""
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return self.redis_client.get(key)
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def set(self, key: str, value):
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"""Set a key-value pair in Redis"""
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return self.redis_client.set(key, value)
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def delete_value(self, key: str, value):
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"""Delete a value from a Redis value by finding key"""
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get_redis = self.get(key)
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if get_redis:
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get_redis: dict = loads(get_redis)
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get_redis.pop(value)
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self.set(key, dumps(get_redis))
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def rpush(self, key: str, value):
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"""Append a value to a Redis list"""
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return self.redis_client.rpush(key, value)
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def lindex(self, key: str, index: int):
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"""Get an element from a Redis list by its index"""
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return self.redis_client.lindex(key, index)
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def spop(self, key: str, count=1):
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"""Remove and return random members from a Redis set"""
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return self.redis_client.spop(key, count)
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def srem(self, key: str, value):
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"""Remove a specific member from a Redis set"""
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return self.redis_client.srem(key, value)
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def ensure_connection(self) -> bool:
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"""Check if Redis connection is alive and reconnect if needed"""
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if not self.redis_connected:
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try:
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self.redis_client = self._create_redis_client()
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self.redis_connected = self._check_redis_connection()
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if self.redis_connected:
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logger.info("Redis connection re-established successfully")
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return self.redis_connected
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except Exception as e:
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logger.error(f"Failed to re-establish Redis connection: {str(e)}")
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return False
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return True
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@classmethod
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def handle_reconnection(cls, consecutive_errors=0, max_consecutive_errors=5):
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"""
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Handle Redis reconnection with exponential backoff based on consecutive errors
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Args:
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consecutive_errors: Number of consecutive errors encountered
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max_consecutive_errors: Threshold for extended sleep time
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Returns:
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tuple: (RedisHandler instance, bool indicating if extended sleep is needed)
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"""
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try:
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# Get a fresh instance (will reconnect internally)
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instance = cls()
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instance.redis_connected = instance._check_redis_connection()
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logger.info("Recreated Redis handler using singleton pattern")
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# Determine if extended sleep is needed
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need_extended_sleep = consecutive_errors >= max_consecutive_errors
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if need_extended_sleep:
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logger.warning(f"Hit {max_consecutive_errors} consecutive Redis errors, taking longer pause")
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return instance, need_extended_sleep
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except Exception as redis_retry_error:
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logger.error(f"Failed to recreate Redis handler: {str(redis_retry_error)}")
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return None, consecutive_errors >= max_consecutive_errors
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