perf(pd): omit unused output logprob metadata

lightllm/server/api_openai.py

@@ -349,6 +349,9 @@ async def chat_completions_impl(request: ChatCompletionRequest, raw_request: Req
 
     sampling_params = SamplingParams()
     sampling_params.init(tokenizer=g_objs.httpserver_manager.tokenizer, **sampling_params_dict)
+    # The chat API does not expose output-token logprobs. PD nodes use this
+    # transport-only marker to avoid forwarding unused per-token metadata.
+    sampling_params.return_output_logprobs = False
 
     sampling_params.verify()
     results_generator = g_objs.httpserver_manager.generate(
@@ -843,6 +846,7 @@ async def completions_impl(request: CompletionRequest, raw_request: Request) ->
 
     sampling_params = SamplingParams()
     sampling_params.init(tokenizer=g_objs.httpserver_manager.tokenizer, **sampling_params_dict)
+    sampling_params.return_output_logprobs = request.logprobs is not None
     sampling_params.verify()
 
     # v1/completions does not support multimodal inputs, so we use an empty MultimodalParams
@@ -880,6 +884,7 @@ async def process_single_prompt(prompt: Union[str, List[int]]):
         if len(prompts) > 1:
             individual_sampling_params = SamplingParams()
             individual_sampling_params.init(tokenizer=g_objs.httpserver_manager.tokenizer, **sampling_params_dict)
+            individual_sampling_params.return_output_logprobs = request.logprobs is not None
             individual_sampling_params.verify()
         else:
             individual_sampling_params = sampling_params

lightllm/server/httpserver/pd_loop.py

@@ -234,6 +234,7 @@ async def _pd_process_generate(
     pd_upload_websocket: ClientConnection,
     pd_event: asyncio.Event,
 ):
+    return_output_logprobs = getattr(sampling_params, "return_output_logprobs", True)
     try:
         async for sub_req_id, request_output, metadata, finish_status in manager.generate(
             prompt=prompt,
@@ -244,6 +245,9 @@ async def _pd_process_generate(
             pd_event=pd_event,
         ):
             metadata["node_mode"] = manager.args.run_mode
+            if not return_output_logprobs:
+                for key in ("id", "logprob", "cumlogprob", "special", "logprobs"):
+                    metadata.pop(key, None)
             await forwarding_queue.put((sub_req_id, request_output, metadata, finish_status))
     except PDPrefillNodeStopGenToken as e:
         logger.info(f"pd prefill node stop gen token for group_request_id {e.group_request_id}")

lightllm/server/httpserver_for_pd_master/manager.py

@@ -160,7 +160,9 @@ async def _generate(
             self, prompt_ids=fake_prompt_ids, sampling_params=sampling_params
         )
 
+        return_output_logprobs = getattr(sampling_params, "return_output_logprobs", True)
         origin_sampling_params = SamplingParams.from_buffer_copy(sampling_params)
+        origin_sampling_params.return_output_logprobs = return_output_logprobs
         origin_group_request_id = self.id_gen.generate_id()
 
         # Record one user request even when it is expanded into multiple independent
@@ -174,6 +176,7 @@ async def _generate(
         generators = []
         for choice_index in range(choice_count):
             choice_sampling_params = SamplingParams.from_buffer_copy(origin_sampling_params)
+            choice_sampling_params.return_output_logprobs = return_output_logprobs
             choice_sampling_params.n = 1
             choice_sampling_params.best_of = 1
             generators.append(
@@ -224,6 +227,7 @@ async def _generate_one(
 
             for iter_index, block_max_new_tokens in enumerate(max_new_tokens_list):
                 sampling_params = SamplingParams.from_buffer_copy(origin_sampling_params)
+                sampling_params.return_output_logprobs = getattr(origin_sampling_params, "return_output_logprobs", True)
                 block_group_request_id = self.id_gen.generate_id()
                 sampling_params.group_request_id = block_group_request_id
                 logger.info(f"pd log gen sub req id {block_group_request_id} for main req id {origin_request_id}")