Add option to run a faster/cheaper LLM for secondary flows (#742)

backend/danswer/configs/model_configs.py

@@ -70,6 +70,11 @@ INTENT_MODEL_VERSION = "danswer/intent-model"
 GEN_AI_MODEL_PROVIDER = os.environ.get("GEN_AI_MODEL_PROVIDER") or "openai"
 # If using Azure, it's the engine name, for example: Danswer
 GEN_AI_MODEL_VERSION = os.environ.get("GEN_AI_MODEL_VERSION") or "gpt-3.5-turbo"
+# For secondary flows like extracting filters or deciding if a chunk is useful, we don't need
+# as powerful of a model as say GPT-4 so we can use an alternative that is faster and cheaper
+FAST_GEN_AI_MODEL_VERSION = (
+    os.environ.get("FAST_GEN_AI_MODEL_VERSION") or GEN_AI_MODEL_VERSION
+)
 
 # If the Generative AI model requires an API key for access, otherwise can leave blank
 GEN_AI_API_KEY = (

backend/danswer/llm/factory.py

@@ -1,5 +1,7 @@
 from danswer.configs.app_configs import QA_TIMEOUT
+from danswer.configs.model_configs import FAST_GEN_AI_MODEL_VERSION
 from danswer.configs.model_configs import GEN_AI_MODEL_PROVIDER
+from danswer.configs.model_configs import GEN_AI_MODEL_VERSION
 from danswer.llm.chat_llm import DefaultMultiLLM
 from danswer.llm.custom_llm import CustomModelServer
 from danswer.llm.gpt_4_all import DanswerGPT4All
@@ -8,18 +10,23 @@ from danswer.llm.utils import get_gen_ai_api_key
 
 
 def get_default_llm(
+    gen_ai_model_provider: str = GEN_AI_MODEL_PROVIDER,
     api_key: str | None = None,
     timeout: int = QA_TIMEOUT,
+    use_fast_llm: bool = False,
 ) -> LLM:
     """A single place to fetch the configured LLM for Danswer
     Also allows overriding certain LLM defaults"""
+    model_version = FAST_GEN_AI_MODEL_VERSION if use_fast_llm else GEN_AI_MODEL_VERSION
     if api_key is None:
         api_key = get_gen_ai_api_key()
 
-    if GEN_AI_MODEL_PROVIDER.lower() == "custom":
+    if gen_ai_model_provider.lower() == "custom":
         return CustomModelServer(api_key=api_key, timeout=timeout)
 
-    if GEN_AI_MODEL_PROVIDER.lower() == "gpt4all":
-        return DanswerGPT4All(timeout=timeout)
+    if gen_ai_model_provider.lower() == "gpt4all":
+        return DanswerGPT4All(model_version=model_version, timeout=timeout)
 
-    return DefaultMultiLLM(api_key=api_key, timeout=timeout)
+    return DefaultMultiLLM(
+        model_version=model_version, api_key=api_key, timeout=timeout
+    )

backend/danswer/main.py

@@ -30,6 +30,7 @@ from danswer.configs.constants import AuthType
 from danswer.configs.model_configs import ASYM_PASSAGE_PREFIX
 from danswer.configs.model_configs import ASYM_QUERY_PREFIX
 from danswer.configs.model_configs import DOCUMENT_ENCODER_MODEL
+from danswer.configs.model_configs import FAST_GEN_AI_MODEL_VERSION
 from danswer.configs.model_configs import GEN_AI_API_ENDPOINT
 from danswer.configs.model_configs import GEN_AI_MODEL_PROVIDER
 from danswer.configs.model_configs import GEN_AI_MODEL_VERSION
@@ -173,6 +174,10 @@ def get_application() -> FastAPI:
         else:
             logger.info(f"Using LLM Provider: {GEN_AI_MODEL_PROVIDER}")
             logger.info(f"Using LLM Model Version: {GEN_AI_MODEL_VERSION}")
+            if GEN_AI_MODEL_VERSION != FAST_GEN_AI_MODEL_VERSION:
+                logger.info(
+                    f"Using Fast LLM Model Version: {FAST_GEN_AI_MODEL_VERSION}"
+                )
             if GEN_AI_API_ENDPOINT:
                 logger.info(f"Using LLM Endpoint: {GEN_AI_API_ENDPOINT}")
 

backend/danswer/secondary_llm_flows/chunk_usefulness.py

@@ -35,7 +35,9 @@ def llm_eval_chunk(query: str, chunk_content: str) -> bool:
     # When running in a batch, it takes as long as the longest thread
     # And when running a large batch, one may fail and take the whole timeout
     # instead cap it to 5 seconds
-    model_output = get_default_llm(timeout=5).invoke(filled_llm_prompt)
+    model_output = get_default_llm(use_fast_llm=True, timeout=5).invoke(
+        filled_llm_prompt
+    )
     logger.debug(model_output)
 
     return _extract_usefulness(model_output)

backend/danswer/secondary_llm_flows/source_filter.py

@@ -155,7 +155,7 @@ def extract_source_filter(
 
     messages = _get_source_filter_messages(query=query, valid_sources=valid_sources)
     filled_llm_prompt = dict_based_prompt_to_langchain_prompt(messages)
-    model_output = get_default_llm().invoke(filled_llm_prompt)
+    model_output = get_default_llm(use_fast_llm=True).invoke(filled_llm_prompt)
     logger.debug(model_output)
 
     return _extract_source_filters_from_llm_out(model_output)

backend/danswer/secondary_llm_flows/time_filter.py

@@ -147,7 +147,7 @@ def extract_time_filter(query: str) -> tuple[datetime | None, bool]:
 
     messages = _get_time_filter_messages(query)
     filled_llm_prompt = dict_based_prompt_to_langchain_prompt(messages)
-    model_output = get_default_llm().invoke(filled_llm_prompt)
+    model_output = get_default_llm(use_fast_llm=True).invoke(filled_llm_prompt)
     logger.debug(model_output)
 
     return _extract_time_filter_from_llm_out(model_output)

deployment/docker_compose/docker-compose.dev.yml

@@ -18,6 +18,7 @@ services:
     environment:
       - GEN_AI_MODEL_PROVIDER=${GEN_AI_MODEL_PROVIDER:-openai}
       - GEN_AI_MODEL_VERSION=${GEN_AI_MODEL_VERSION:-gpt-3.5-turbo}
+      - FAST_GEN_AI_MODEL_VERSION=${FAST_GEN_AI_MODEL_VERSION:-}
       - GEN_AI_API_KEY=${GEN_AI_API_KEY:-}
       - GEN_AI_API_ENDPOINT=${GEN_AI_API_ENDPOINT:-}
       - GEN_AI_API_VERSION=${GEN_AI_API_VERSION:-}
@@ -76,6 +77,7 @@ services:
     environment:
       - GEN_AI_MODEL_PROVIDER=${GEN_AI_MODEL_PROVIDER:-openai}
       - GEN_AI_MODEL_VERSION=${GEN_AI_MODEL_VERSION:-gpt-3.5-turbo}
+      - FAST_GEN_AI_MODEL_VERSION=${FAST_GEN_AI_MODEL_VERSION:-}
       - GEN_AI_API_KEY=${GEN_AI_API_KEY:-}
       - GEN_AI_API_ENDPOINT=${GEN_AI_API_ENDPOINT:-}
       - GEN_AI_API_VERSION=${GEN_AI_API_VERSION:-}