Frontend: better error message handling for FINISH_ABORT in scheduler.py (#2956)

python/sglang/srt/managers/schedule_batch.py

@@ -115,14 +115,18 @@ class FINISH_LENGTH(BaseFinishReason):
 
 
 class FINISH_ABORT(BaseFinishReason):
-    def __init__(self, message="Unknown error"):
+    def __init__(self, message="Unknown error", status_code=None, err_type=None):
         super().__init__(is_error=True)
         self.message = message
+        self.status_code = status_code
+        self.err_type = err_type
 
     def to_json(self):
         return {
             "type": "abort",
             "message": self.message,
+            "status_code": self.status_code,
+            "err_type": self.err_type,
         }
 
 

python/sglang/srt/managers/scheduler.py

@@ -23,6 +23,7 @@ import warnings
 from collections import deque
 from concurrent import futures
 from dataclasses import dataclass
+from http import HTTPStatus
 from types import SimpleNamespace
 from typing import Dict, List, Optional, Tuple, Union
 
@@ -672,15 +673,16 @@ class Scheduler:
             req.extend_image_inputs(image_inputs)
 
             if len(req.origin_input_ids) >= self.max_req_input_len:
-                logger.error(
+                error_msg = (
                     "Multimodal prompt is too long after expanding multimodal tokens. "
-                    f"After expanding {len(req.origin_input_ids_unpadded)=} => {len(req.origin_input_ids)} >= {self.max_req_input_len}. "
+                    f"After expanding {len(req.origin_input_ids_unpadded)=} => {len(req.origin_input_ids)} >= {self.max_req_input_len}."
                 )
+                logger.error(error_msg)
                 req.origin_input_ids = [0]
                 req.image_inputs = None
                 req.sampling_params.max_new_tokens = 0
                 req.finished_reason = FINISH_ABORT(
-                    "Multimodal prompt is too long. Check server logs for details."
+                    error_msg, HTTPStatus.BAD_REQUEST, "BadRequestError"
                 )
                 self.waiting_queue.append(req)
                 return

python/sglang/srt/managers/tokenizer_manager.py

@@ -25,6 +25,7 @@ import threading
 import time
 import uuid
 from datetime import datetime
+from http import HTTPStatus
 from typing import Any, Awaitable, Dict, Generic, List, Optional, Tuple, TypeVar, Union
 
 import fastapi
@@ -384,6 +385,16 @@ class TokenizerManager:
                     msg = f"Finish: obj={dataclass_to_string_truncated(obj)}, out={dataclass_to_string_truncated(out)}"
                     logger.info(msg)
                 del self.rid_to_state[obj.rid]
+
+                # Check if this was an abort/error created by scheduler
+                if isinstance(out["meta_info"].get("finish_reason"), dict):
+                    finish_reason = out["meta_info"]["finish_reason"]
+                    if (
+                        finish_reason.get("type") == "abort"
+                        and finish_reason.get("status_code") == HTTPStatus.BAD_REQUEST
+                    ):
+                        raise ValueError(finish_reason["message"])
+
                 yield out
                 break
 

python/sglang/srt/managers/utils.py

@@ -1,4 +1,5 @@
 import logging
+from http import HTTPStatus
 from typing import Optional
 
 from sglang.srt.managers.schedule_batch import FINISH_ABORT, Req
@@ -35,7 +36,9 @@ def validate_input_length(
                 f"Use a shorter input or enable --allow-auto-truncate."
             )
             logger.error(error_msg)
-            req.finished_reason = FINISH_ABORT(error_msg)
+            req.finished_reason = FINISH_ABORT(
+                error_msg, HTTPStatus.BAD_REQUEST, "BadRequestError"
+            )
             return error_msg
 
     return None