Revert "[Feature]: Replace HTTPException with ParallelRequestLimitError in pa…" (#15095)

This reverts commit 71b9b58fa9.

litellm/__init__.py

@@ -1301,7 +1301,6 @@ from .exceptions import (
     ImageFetchError,
     NotFoundError,
     RateLimitError,
-    ParallelRequestLimitError,
     ServiceUnavailableError,
     OpenAIError,
     ContextWindowExceededError,

litellm/exceptions.py

@@ -353,49 +353,6 @@ class RateLimitError(openai.RateLimitError):  # type: ignore
         return _message
 
 
-class ParallelRequestLimitError(RateLimitError):  # type: ignore
-    def __init__(
-        self,
-        message: str,
-        llm_provider: Optional[str] = "litellm",
-        model: Optional[str] = "unknown",
-        headers: Optional[dict] = None,
-        response: Optional[httpx.Response] = None,
-        litellm_debug_info: Optional[str] = None,
-        max_retries: Optional[int] = None,
-        num_retries: Optional[int] = None,
-    ):
-        # Store headers for later access (similar to FastAPI HTTPException)
-        self.headers = headers or {}
-        
-        # Create a response with custom headers if provided
-        if response is None:
-            response_headers = headers
-            response = httpx.Response(
-                status_code=429,
-                headers=response_headers,
-                request=httpx.Request(
-                    method="POST",
-                    url="https://litellm.ai/parallel-request-limiter",
-                ),
-            )
-        
-        # Initialize parent with appropriate defaults for parallel request limiting
-        super().__init__(
-            message=message,
-            llm_provider=llm_provider or "litellm",
-            model=model or "unknown",
-            response=response,
-            litellm_debug_info=litellm_debug_info,
-            max_retries=max_retries,
-            num_retries=num_retries,
-        )
-        
-        # Update the message prefix to be more specific
-        self.message = "litellm.ParallelRequestLimitError: {}".format(message)
-        self.detail = message  # Store original detail for FastAPI compatibility
-
-
 # sub class of rate limit error - meant to give more granularity for error handling context window exceeded errors
 class ContextWindowExceededError(BadRequestError):  # type: ignore
     def __init__(
@@ -791,7 +748,6 @@ LITELLM_EXCEPTION_TYPES = [
     Timeout,
     PermissionDeniedError,
     RateLimitError,
-    ParallelRequestLimitError,
     ContextWindowExceededError,
     RejectedRequestError,
     ContentPolicyViolationError,

litellm/proxy/hooks/parallel_request_limiter_v3.py

@@ -22,7 +22,6 @@ from typing import (
 
 from litellm import DualCache
 from litellm._logging import verbose_proxy_logger
-from litellm.exceptions import ParallelRequestLimitError
 from litellm.integrations.custom_logger import CustomLogger
 from litellm.proxy._types import UserAPIKeyAuth
 from litellm.types.llms.openai import BaseLiteLLMOpenAIResponseObject
@@ -701,8 +700,9 @@ class _PROXY_MaxParallelRequestsHandler_v3(CustomLogger):
                             f"Limit resets at: {reset_time_formatted}"
                         )
 
-                        raise ParallelRequestLimitError(
-                            message=detail,
+                        raise HTTPException(
+                            status_code=429,
+                            detail=detail,
                             headers={
                                 "retry-after": str(self.window_size),
                                 "rate_limit_type": str(status["rate_limit_type"]),

tests/test_litellm/proxy/hooks/test_parallel_request_limiter_v3.py

@@ -14,7 +14,6 @@ from fastapi import HTTPException
 import litellm
 from litellm import Router
 from litellm.caching.caching import DualCache
-from litellm.exceptions import ParallelRequestLimitError
 from litellm.proxy._types import UserAPIKeyAuth
 from litellm.proxy.hooks.parallel_request_limiter_v3 import (
     _PROXY_MaxParallelRequestsHandler_v3 as _PROXY_MaxParallelRequestsHandler,
@@ -93,7 +92,7 @@ async def test_sliding_window_rate_limit_v3(monkeypatch):
     )
 
     # Fourth request should fail (counter would be 4, limit is 3, so 4 > 3)
-    with pytest.raises(ParallelRequestLimitError) as exc_info:
+    with pytest.raises(HTTPException) as exc_info:
         await parallel_request_handler.async_pre_call_hook(
             user_api_key_dict=user_api_key_dict,
             cache=local_cache,
@@ -375,7 +374,7 @@ async def test_normal_router_call_tpm_v3(monkeypatch, rate_limit_object):
     await local_cache.async_increment_cache(key=counter_key, value=15, ttl=2)  # Use up most of our 10 token limit
     
     # Make another request to test rate limiting - this should fail as we've consumed tokens
-    with pytest.raises(ParallelRequestLimitError) as exc_info:
+    with pytest.raises(HTTPException) as exc_info:
         await parallel_request_handler.async_pre_call_hook(
             user_api_key_dict=user_api_key_dict,
             cache=local_cache,
@@ -778,7 +777,7 @@ async def test_tpm_api_key_rate_limits_v3():
     async def mock_should_rate_limit(descriptors, **kwargs):
         nonlocal captured_descriptors
         captured_descriptors = descriptors
-        # Return Error response to ensure ParallelRequestLimitError
+        # Return Error response to ensure HTTPException
         return {
             "overall_code": "OVER_LIMIT",
             "statuses": [{'code': 'OK', 'current_limit': 2, 'limit_remaining': 1, 'rate_limit_type': 'requests', 'descriptor_key': 'model_per_key'},
@@ -796,7 +795,7 @@ async def test_tpm_api_key_rate_limits_v3():
             data={"model": model},
             call_type="",
         )
-    except ParallelRequestLimitError as e:
+    except HTTPException as e:
         error=e
         assert e.status_code == 429
         assert "rate_limit_type" in e.headers
@@ -854,7 +853,7 @@ async def test_rpm_api_key_rate_limits_v3():
     async def mock_should_rate_limit(descriptors, **kwargs):
         nonlocal captured_descriptors
         captured_descriptors = descriptors
-        # Return Error response to ensure ParallelRequestLimitError
+        # Return Error response to ensure HTTPException
         return {
             "overall_code": "OVER_LIMIT",
             "statuses": [{'code': 'OVER_LIMIT', 'current_limit': 2, 'limit_remaining': -2, 'rate_limit_type': 'requests', 'descriptor_key': 'model_per_key'},
@@ -872,7 +871,7 @@ async def test_rpm_api_key_rate_limits_v3():
             data={"model": model},
             call_type="",
         )
-    except ParallelRequestLimitError as e:
+    except HTTPException as e:
         error=e
         assert e.status_code == 429
         assert "rate_limit_type" in e.headers
@@ -923,7 +922,7 @@ async def test_team_member_rate_limits_v3():
     async def mock_should_rate_limit(descriptors, **kwargs):
         nonlocal captured_descriptors
         captured_descriptors = descriptors
-        # Return OK response to avoid ParallelRequestLimitError
+        # Return OK response to avoid HTTPException
         return {
             "overall_code": "OK",
             "statuses": []