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| """ | |
| Base class across routing strategies to abstract commmon functions like batch incrementing redis | |
| """ | |
| import asyncio | |
| from abc import ABC | |
| from typing import List, Optional, Set, Tuple, Union | |
| from litellm._logging import verbose_router_logger | |
| from litellm.caching.caching import DualCache | |
| from litellm.caching.redis_cache import RedisPipelineIncrementOperation | |
| from litellm.constants import DEFAULT_REDIS_SYNC_INTERVAL | |
| class BaseRoutingStrategy(ABC): | |
| def __init__( | |
| self, | |
| dual_cache: DualCache, | |
| should_batch_redis_writes: bool, | |
| default_sync_interval: Optional[Union[int, float]], | |
| ): | |
| self.dual_cache = dual_cache | |
| self.redis_increment_operation_queue: List[RedisPipelineIncrementOperation] = [] | |
| self._sync_task: Optional[asyncio.Task[None]] = None | |
| if should_batch_redis_writes: | |
| self.setup_sync_task(default_sync_interval) | |
| self.in_memory_keys_to_update: set[ | |
| str | |
| ] = set() # Set with max size of 1000 keys | |
| def setup_sync_task(self, default_sync_interval: Optional[Union[int, float]]): | |
| """Setup the sync task in a way that's compatible with FastAPI""" | |
| try: | |
| loop = asyncio.get_running_loop() | |
| except RuntimeError: | |
| loop = asyncio.new_event_loop() | |
| asyncio.set_event_loop(loop) | |
| self._sync_task = loop.create_task( | |
| self.periodic_sync_in_memory_spend_with_redis( | |
| default_sync_interval=default_sync_interval | |
| ) | |
| ) | |
| async def cleanup(self): | |
| """Cleanup method to be called when shutting down""" | |
| if self._sync_task is not None: | |
| self._sync_task.cancel() | |
| try: | |
| await self._sync_task | |
| except asyncio.CancelledError: | |
| pass | |
| async def _increment_value_list_in_current_window( | |
| self, increment_list: List[Tuple[str, int]], ttl: int | |
| ) -> List[float]: | |
| """ | |
| Increment a list of values in the current window | |
| """ | |
| results = [] | |
| for key, value in increment_list: | |
| result = await self._increment_value_in_current_window( | |
| key=key, value=value, ttl=ttl | |
| ) | |
| results.append(result) | |
| return results | |
| async def _increment_value_in_current_window( | |
| self, key: str, value: Union[int, float], ttl: int | |
| ): | |
| """ | |
| Increment spend within existing budget window | |
| Runs once the budget start time exists in Redis Cache (on the 2nd and subsequent requests to the same provider) | |
| - Increments the spend in memory cache (so spend instantly updated in memory) | |
| - Queues the increment operation to Redis Pipeline (using batched pipeline to optimize performance. Using Redis for multi instance environment of LiteLLM) | |
| """ | |
| result = await self.dual_cache.in_memory_cache.async_increment( | |
| key=key, | |
| value=value, | |
| ttl=ttl, | |
| ) | |
| increment_op = RedisPipelineIncrementOperation( | |
| key=key, | |
| increment_value=value, | |
| ttl=ttl, | |
| ) | |
| self.redis_increment_operation_queue.append(increment_op) | |
| self.add_to_in_memory_keys_to_update(key=key) | |
| return result | |
| async def periodic_sync_in_memory_spend_with_redis( | |
| self, default_sync_interval: Optional[Union[int, float]] | |
| ): | |
| """ | |
| Handler that triggers sync_in_memory_spend_with_redis every DEFAULT_REDIS_SYNC_INTERVAL seconds | |
| Required for multi-instance environment usage of provider budgets | |
| """ | |
| default_sync_interval = default_sync_interval or DEFAULT_REDIS_SYNC_INTERVAL | |
| while True: | |
| try: | |
| await self._sync_in_memory_spend_with_redis() | |
| await asyncio.sleep( | |
| default_sync_interval | |
| ) # Wait for DEFAULT_REDIS_SYNC_INTERVAL seconds before next sync | |
| except Exception as e: | |
| verbose_router_logger.error(f"Error in periodic sync task: {str(e)}") | |
| await asyncio.sleep( | |
| default_sync_interval | |
| ) # Still wait DEFAULT_REDIS_SYNC_INTERVAL seconds on error before retrying | |
| async def _push_in_memory_increments_to_redis(self): | |
| """ | |
| How this works: | |
| - async_log_success_event collects all provider spend increments in `redis_increment_operation_queue` | |
| - This function pushes all increments to Redis in a batched pipeline to optimize performance | |
| Only runs if Redis is initialized | |
| """ | |
| try: | |
| if not self.dual_cache.redis_cache: | |
| return # Redis is not initialized | |
| verbose_router_logger.debug( | |
| "Pushing Redis Increment Pipeline for queue: %s", | |
| self.redis_increment_operation_queue, | |
| ) | |
| if len(self.redis_increment_operation_queue) > 0: | |
| await self.dual_cache.redis_cache.async_increment_pipeline( | |
| increment_list=self.redis_increment_operation_queue, | |
| ) | |
| self.redis_increment_operation_queue = [] | |
| except Exception as e: | |
| verbose_router_logger.error( | |
| f"Error syncing in-memory cache with Redis: {str(e)}" | |
| ) | |
| self.redis_increment_operation_queue = [] | |
| def add_to_in_memory_keys_to_update(self, key: str): | |
| self.in_memory_keys_to_update.add(key) | |
| def get_key_pattern_to_sync(self) -> Optional[str]: | |
| """ | |
| Get the key pattern to sync | |
| """ | |
| return None | |
| def get_in_memory_keys_to_update(self) -> Set[str]: | |
| return self.in_memory_keys_to_update | |
| def reset_in_memory_keys_to_update(self): | |
| self.in_memory_keys_to_update = set() | |
| async def _sync_in_memory_spend_with_redis(self): | |
| """ | |
| Ensures in-memory cache is updated with latest Redis values for all provider spends. | |
| Why Do we need this? | |
| - Optimization to hit sub 100ms latency. Performance was impacted when redis was used for read/write per request | |
| - Use provider budgets in multi-instance environment, we use Redis to sync spend across all instances | |
| What this does: | |
| 1. Push all provider spend increments to Redis | |
| 2. Fetch all current provider spend from Redis to update in-memory cache | |
| """ | |
| try: | |
| # No need to sync if Redis cache is not initialized | |
| if self.dual_cache.redis_cache is None: | |
| return | |
| # 1. Push all provider spend increments to Redis | |
| await self._push_in_memory_increments_to_redis() | |
| # 2. Fetch all current provider spend from Redis to update in-memory cache | |
| pattern = self.get_key_pattern_to_sync() | |
| cache_keys: Optional[Union[Set[str], List[str]]] = None | |
| if pattern: | |
| cache_keys = await self.dual_cache.redis_cache.async_scan_iter( | |
| pattern=pattern | |
| ) | |
| if cache_keys is None: | |
| cache_keys = ( | |
| self.get_in_memory_keys_to_update() | |
| ) # if no pattern OR redis cache does not support scan_iter, use in-memory keys | |
| if isinstance(cache_keys, set): | |
| cache_keys_list = list(cache_keys) | |
| else: | |
| cache_keys_list = cache_keys | |
| # Batch fetch current spend values from Redis | |
| redis_values = await self.dual_cache.redis_cache.async_batch_get_cache( | |
| key_list=cache_keys_list | |
| ) | |
| # Update in-memory cache with Redis values | |
| if isinstance(redis_values, dict): # Check if redis_values is a dictionary | |
| for key, value in redis_values.items(): | |
| if value is not None: | |
| await self.dual_cache.in_memory_cache.async_set_cache( | |
| key=key, value=float(value) | |
| ) | |
| verbose_router_logger.debug( | |
| f"Updated in-memory cache for {key}: {value}" | |
| ) | |
| self.reset_in_memory_keys_to_update() | |
| except Exception as e: | |
| verbose_router_logger.exception( | |
| f"Error syncing in-memory cache with Redis: {str(e)}" | |
| ) | |