Merge pull request #9357 from BerriAI/litellm_dev_03_18_2025_p2

fix(lowest_tpm_rpm_v2.py): support batch writing increments to redis

litellm/constants.py

@@ -7,6 +7,7 @@ DEFAULT_MAX_RETRIES = 2
 DEFAULT_FAILURE_THRESHOLD_PERCENT = (
     0.5  # default cooldown a deployment if 50% of requests fail in a given minute
 )
+DEFAULT_REDIS_SYNC_INTERVAL = 1
 DEFAULT_COOLDOWN_TIME_SECONDS = 5
 DEFAULT_REPLICATE_POLLING_RETRIES = 5
 DEFAULT_REPLICATE_POLLING_DELAY_SECONDS = 1

litellm/proxy/_new_secret_config.yaml

@@ -3,10 +3,12 @@ model_list:
    litellm_params:
     model: azure/chatgpt-v-2
     api_key: os.environ/AZURE_API_KEY
-    api_base: os.environ/AZURE_API_BASE
+    api_base: http://0.0.0.0:8090
+    rpm: 3
     
 litellm_settings:
-  callbacks: ["prometheus"]
+  num_retries: 0
+  callbacks: ["otel"]
 
 router_settings:
   routing_strategy: usage-based-routing-v2 # 👈 KEY CHANGE

litellm/router_strategy/base_routing_strategy.py

@@ -0,0 +1,190 @@
+"""
+Base class across routing strategies to abstract commmon functions like batch incrementing redis
+"""
+
+import asyncio
+import threading
+from abc import ABC
+from typing import List, Optional, Set, 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] = []
+        if should_batch_redis_writes:
+            try:
+                # Try to get existing event loop
+                loop = asyncio.get_event_loop()
+                if loop.is_running():
+                    # If loop exists and is running, create task in existing loop
+                    loop.create_task(
+                        self.periodic_sync_in_memory_spend_with_redis(
+                            default_sync_interval=default_sync_interval
+                        )
+                    )
+                else:
+                    self._create_sync_thread(default_sync_interval)
+            except RuntimeError:  # No event loop in current thread
+                self._create_sync_thread(default_sync_interval)
+
+        self.in_memory_keys_to_update: set[str] = (
+            set()
+        )  # Set with max size of 1000 keys
+
+    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:
+                asyncio.create_task(
+                    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_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
+            cache_keys = self.get_in_memory_keys_to_update()
+
+            cache_keys_list = 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)}"
+            )
+
+    def _create_sync_thread(self, default_sync_interval):
+        """Helper method to create a new thread for periodic sync"""
+        thread = threading.Thread(
+            target=asyncio.run,
+            args=(
+                self.periodic_sync_in_memory_spend_with_redis(
+                    default_sync_interval=default_sync_interval
+                ),
+            ),
+            daemon=True,
+        )
+        thread.start()

litellm/router_strategy/lowest_tpm_rpm_v2.py

@@ -15,6 +15,8 @@ from litellm.types.router import RouterErrors
 from litellm.types.utils import LiteLLMPydanticObjectBase, StandardLoggingPayload
 from litellm.utils import get_utc_datetime, print_verbose
 
+from .base_routing_strategy import BaseRoutingStrategy
+
 if TYPE_CHECKING:
     from opentelemetry.trace import Span as _Span
 
@@ -27,7 +29,7 @@ class RoutingArgs(LiteLLMPydanticObjectBase):
     ttl: int = 1 * 60  # 1min (RPM/TPM expire key)
 
 
-class LowestTPMLoggingHandler_v2(CustomLogger):
+class LowestTPMLoggingHandler_v2(BaseRoutingStrategy, CustomLogger):
     """
     Updated version of TPM/RPM Logging.
 
@@ -51,6 +53,12 @@ class LowestTPMLoggingHandler_v2(CustomLogger):
         self.router_cache = router_cache
         self.model_list = model_list
         self.routing_args = RoutingArgs(**routing_args)
+        BaseRoutingStrategy.__init__(
+            self,
+            dual_cache=router_cache,
+            should_batch_redis_writes=True,
+            default_sync_interval=0.1,
+        )
 
     def pre_call_check(self, deployment: Dict) -> Optional[Dict]:
         """
@@ -107,6 +115,7 @@ class LowestTPMLoggingHandler_v2(CustomLogger):
                 )
             else:
                 # if local result below limit, check redis ## prevent unnecessary redis checks
+
                 result = self.router_cache.increment_cache(
                     key=rpm_key, value=1, ttl=self.routing_args.ttl
                 )
@@ -191,11 +200,8 @@ class LowestTPMLoggingHandler_v2(CustomLogger):
                 )
             else:
                 # if local result below limit, check redis ## prevent unnecessary redis checks
-                result = await self.router_cache.async_increment_cache(
-                    key=rpm_key,
-                    value=1,
-                    ttl=self.routing_args.ttl,
-                    parent_otel_span=parent_otel_span,
+                result = await self._increment_value_in_current_window(
+                    key=rpm_key, value=1, ttl=self.routing_args.ttl
                 )
                 if result is not None and result > deployment_rpm:
                     raise litellm.RateLimitError(

tests/litellm/router_strategy/test_base_routing_strategy.py

@@ -0,0 +1,134 @@
+import json
+import os
+import sys
+
+import pytest
+
+sys.path.insert(
+    0, os.path.abspath("../../..")
+)  # Adds the parent directory to the system path
+
+import asyncio
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from litellm.caching.caching import DualCache
+from litellm.caching.redis_cache import RedisPipelineIncrementOperation
+from litellm.router_strategy.base_routing_strategy import BaseRoutingStrategy
+
+
+@pytest.fixture
+def mock_dual_cache():
+    dual_cache = MagicMock(spec=DualCache)
+    dual_cache.in_memory_cache = MagicMock()
+    dual_cache.redis_cache = MagicMock()
+
+    # Set up async method mocks to return coroutines
+    future1 = asyncio.Future()
+    future1.set_result(None)
+    dual_cache.in_memory_cache.async_increment.return_value = future1
+
+    future2 = asyncio.Future()
+    future2.set_result(None)
+    dual_cache.redis_cache.async_increment_pipeline.return_value = future2
+
+    future3 = asyncio.Future()
+    future3.set_result(None)
+    dual_cache.in_memory_cache.async_set_cache.return_value = future3
+
+    # Fix for async_batch_get_cache
+    batch_future = asyncio.Future()
+    batch_future.set_result({"key1": "10.0", "key2": "20.0"})
+    dual_cache.redis_cache.async_batch_get_cache.return_value = batch_future
+
+    return dual_cache
+
+
+@pytest.fixture
+def base_strategy(mock_dual_cache):
+    return BaseRoutingStrategy(
+        dual_cache=mock_dual_cache,
+        should_batch_redis_writes=False,
+        default_sync_interval=1,
+    )
+
+
+@pytest.mark.asyncio
+async def test_increment_value_in_current_window(base_strategy, mock_dual_cache):
+    # Test incrementing value in current window
+    key = "test_key"
+    value = 10.0
+    ttl = 3600
+
+    await base_strategy._increment_value_in_current_window(key, value, ttl)
+
+    # Verify in-memory cache was incremented
+    mock_dual_cache.in_memory_cache.async_increment.assert_called_once_with(
+        key=key, value=value, ttl=ttl
+    )
+
+    # Verify operation was queued for Redis
+    assert len(base_strategy.redis_increment_operation_queue) == 1
+    queued_op = base_strategy.redis_increment_operation_queue[0]
+    assert isinstance(queued_op, dict)
+    assert queued_op["key"] == key
+    assert queued_op["increment_value"] == value
+    assert queued_op["ttl"] == ttl
+
+
+@pytest.mark.asyncio
+async def test_push_in_memory_increments_to_redis(base_strategy, mock_dual_cache):
+    # Add some operations to the queue
+    base_strategy.redis_increment_operation_queue = [
+        RedisPipelineIncrementOperation(key="key1", increment_value=10, ttl=3600),
+        RedisPipelineIncrementOperation(key="key2", increment_value=20, ttl=3600),
+    ]
+
+    await base_strategy._push_in_memory_increments_to_redis()
+
+    # Verify Redis pipeline was called
+    mock_dual_cache.redis_cache.async_increment_pipeline.assert_called_once()
+    # Verify queue was cleared
+    assert len(base_strategy.redis_increment_operation_queue) == 0
+
+
+@pytest.mark.asyncio
+async def test_sync_in_memory_spend_with_redis(base_strategy, mock_dual_cache):
+    # Setup test data
+    base_strategy.in_memory_keys_to_update = {"key1", "key2"}
+
+    # No need to set return_value here anymore as it's set in the fixture
+    await base_strategy._sync_in_memory_spend_with_redis()
+
+    # Verify Redis batch get was called with sorted list for consistent testing
+    key_list = mock_dual_cache.redis_cache.async_batch_get_cache.call_args.kwargs[
+        "key_list"
+    ]
+
+    sorted(key_list) == sorted(["key1", "key2"])
+    # mock_dual_cache.redis_cache.async_batch_get_cache.assert_called_once_with(
+    #     key_list=sorted()
+    # )
+
+    # Verify in-memory cache was updated
+    assert mock_dual_cache.in_memory_cache.async_set_cache.call_count == 2
+
+    # Verify cache keys were reset
+    assert len(base_strategy.in_memory_keys_to_update) == 0
+
+
+def test_cache_keys_management(base_strategy):
+    # Test adding and getting cache keys
+    base_strategy.add_to_in_memory_keys_to_update("key1")
+    base_strategy.add_to_in_memory_keys_to_update("key2")
+    base_strategy.add_to_in_memory_keys_to_update("key1")  # Duplicate should be ignored
+
+    cache_keys = base_strategy.get_in_memory_keys_to_update()
+    assert len(cache_keys) == 2
+    assert "key1" in cache_keys
+    assert "key2" in cache_keys
+
+    # Test resetting cache keys
+    base_strategy.reset_in_memory_keys_to_update()
+    assert len(base_strategy.get_in_memory_keys_to_update()) == 0