litellm-mirror/litellm/router_utils/fallback_event_handlers.py

from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple

import litellm
from litellm._logging import verbose_router_logger
from litellm.integrations.custom_logger import CustomLogger
from litellm.main import verbose_logger

if TYPE_CHECKING:
    from litellm.router import Router as _Router

    LitellmRouter = _Router
else:
    LitellmRouter = Any


async def run_async_fallback(
    litellm_router: LitellmRouter,
    *args: Tuple[Any],
    fallback_model_group: List[str],
    original_model_group: str,
    original_exception: Exception,
    **kwargs,
) -> Any:
    """
    Iterate through the model groups and try calling that deployment.
    """
    error_from_fallbacks = original_exception
    for mg in fallback_model_group:
        if mg == original_model_group:
            continue
        try:
            # LOGGING
            kwargs = litellm_router.log_retry(kwargs=kwargs, e=original_exception)
            verbose_router_logger.info(f"Falling back to model_group = {mg}")
            kwargs["model"] = mg
            kwargs.setdefault("metadata", {}).update(
                {"model_group": mg}
            )  # update model_group used, if fallbacks are done
            response = await litellm_router.async_function_with_fallbacks(
                *args, **kwargs
            )
            verbose_router_logger.info("Successful fallback b/w models.")
            # callback for successfull_fallback_event():
            await log_success_fallback_event(
                original_model_group=original_model_group,
                kwargs=kwargs,
                original_exception=original_exception,
            )
            return response
        except Exception as e:
            error_from_fallbacks = e
            await log_failure_fallback_event(
                original_model_group=original_model_group,
                kwargs=kwargs,
                original_exception=original_exception,
            )
    raise error_from_fallbacks


def run_sync_fallback(
    litellm_router: LitellmRouter,
    *args: Tuple[Any],
    fallback_model_group: List[str],
    original_model_group: str,
    original_exception: Exception,
    **kwargs,
) -> Any:
    """
    Iterate through the fallback model groups and try calling each fallback deployment.
    """
    error_from_fallbacks = original_exception
    for mg in fallback_model_group:
        if mg == original_model_group:
            continue
        try:
            # LOGGING
            kwargs = litellm_router.log_retry(kwargs=kwargs, e=original_exception)
            verbose_router_logger.info(f"Falling back to model_group = {mg}")
            kwargs["model"] = mg
            kwargs.setdefault("metadata", {}).update(
                {"model_group": mg}
            )  # update model_group used, if fallbacks are done
            response = litellm_router.function_with_fallbacks(*args, **kwargs)
            verbose_router_logger.info("Successful fallback b/w models.")
            return response
        except Exception as e:
            error_from_fallbacks = e
    raise error_from_fallbacks


async def log_success_fallback_event(
    original_model_group: str, kwargs: dict, original_exception: Exception
):
    """
    Log a successful fallback event to all registered callbacks.

    This function iterates through all callbacks, initializing _known_custom_logger_compatible_callbacks  if needed,
    and calls the log_success_fallback_event method on CustomLogger instances.

    Args:
        original_model_group (str): The original model group before fallback.
        kwargs (dict): kwargs for the request

    Note:
        Errors during logging are caught and reported but do not interrupt the process.
    """
    from litellm.litellm_core_utils.litellm_logging import (
        _init_custom_logger_compatible_class,
    )

    for _callback in litellm.callbacks:
        if isinstance(_callback, CustomLogger) or (
            _callback in litellm._known_custom_logger_compatible_callbacks
        ):
            try:
                _callback_custom_logger: Optional[CustomLogger] = None
                if _callback in litellm._known_custom_logger_compatible_callbacks:
                    _callback_custom_logger = _init_custom_logger_compatible_class(
                        logging_integration=_callback,  # type: ignore
                        llm_router=None,
                        internal_usage_cache=None,
                    )
                elif isinstance(_callback, CustomLogger):
                    _callback_custom_logger = _callback
                else:
                    verbose_router_logger.exception(
                        f"{_callback} logger not found / initialized properly"
                    )
                    continue

                if _callback_custom_logger is None:
                    verbose_router_logger.exception(
                        f"{_callback} logger not found / initialized properly, callback is None"
                    )
                    continue

                await _callback_custom_logger.log_success_fallback_event(
                    original_model_group=original_model_group,
                    kwargs=kwargs,
                    original_exception=original_exception,
                )
            except Exception as e:
                verbose_router_logger.error(
                    f"Error in log_success_fallback_event: {str(e)}"
                )


async def log_failure_fallback_event(
    original_model_group: str, kwargs: dict, original_exception: Exception
):
    """
    Log a failed fallback event to all registered callbacks.

    This function iterates through all callbacks, initializing _known_custom_logger_compatible_callbacks if needed,
    and calls the log_failure_fallback_event method on CustomLogger instances.

    Args:
        original_model_group (str): The original model group before fallback.
        kwargs (dict): kwargs for the request

    Note:
        Errors during logging are caught and reported but do not interrupt the process.
    """
    from litellm.litellm_core_utils.litellm_logging import (
        _init_custom_logger_compatible_class,
    )

    for _callback in litellm.callbacks:
        if isinstance(_callback, CustomLogger) or (
            _callback in litellm._known_custom_logger_compatible_callbacks
        ):
            try:
                _callback_custom_logger: Optional[CustomLogger] = None
                if _callback in litellm._known_custom_logger_compatible_callbacks:
                    _callback_custom_logger = _init_custom_logger_compatible_class(
                        logging_integration=_callback,  # type: ignore
                        llm_router=None,
                        internal_usage_cache=None,
                    )
                elif isinstance(_callback, CustomLogger):
                    _callback_custom_logger = _callback
                else:
                    verbose_router_logger.exception(
                        f"{_callback} logger not found / initialized properly"
                    )
                    continue

                if _callback_custom_logger is None:
                    verbose_router_logger.exception(
                        f"{_callback} logger not found / initialized properly"
                    )
                    continue

                await _callback_custom_logger.log_failure_fallback_event(
                    original_model_group=original_model_group,
                    kwargs=kwargs,
                    original_exception=original_exception,
                )
            except Exception as e:
                verbose_router_logger.error(
                    f"Error in log_failure_fallback_event: {str(e)}"
                )