Tiny add stuck simulation (#15613)

python/sglang/srt/environ.py

@@ -150,6 +150,9 @@ class Envs:
     # Test & Debug
     SGLANG_IS_IN_CI = EnvBool(False)
     SGLANG_IS_IN_CI_AMD = EnvBool(False)
+    SGLANG_TEST_STUCK_DETOKENIZER = EnvFloat(0)
+    SGLANG_TEST_STUCK_DP_CONTROLLER = EnvFloat(0)
+    SGLANG_TEST_STUCK_TOKENIZER = EnvFloat(0)
     IS_BLACKWELL = EnvBool(False)
     SGLANG_SET_CPU_AFFINITY = EnvBool(False)
     SGLANG_PROFILE_WITH_STACK = EnvBool(True)

python/sglang/srt/managers/data_parallel_controller.py

@@ -27,6 +27,7 @@ import psutil
 import setproctitle
 import zmq
 
+from sglang.srt.environ import envs
 from sglang.srt.layers.dp_attention import compute_dp_attention_world_info
 from sglang.srt.managers.io_struct import (
     BlockReqInput,
@@ -178,6 +179,7 @@ class DataParallelController:
             debug_name="DataParallelController",
             watchdog_timeout=server_args.soft_watchdog_timeout,
             soft=True,
+            test_stuck_time=envs.SGLANG_TEST_STUCK_DP_CONTROLLER.get(),
         )
 
     def send_to_all_workers(self, obj):

python/sglang/srt/managers/detokenizer_manager.py

@@ -25,6 +25,7 @@ import pybase64
 import setproctitle
 import zmq
 
+from sglang.srt.environ import envs
 from sglang.srt.managers.io_struct import (
     BatchEmbeddingOutput,
     BatchMultimodalDecodeReq,
@@ -116,6 +117,7 @@ class DetokenizerManager(MultiHttpWorkerDetokenizerMixin):
             debug_name="DetokenizerManager",
             watchdog_timeout=server_args.soft_watchdog_timeout,
             soft=True,
+            test_stuck_time=envs.SGLANG_TEST_STUCK_DETOKENIZER.get(),
         )
 
     def event_loop(self):

python/sglang/srt/managers/tokenizer_manager.py

@@ -409,6 +409,7 @@ class TokenizerManager(TokenizerCommunicatorMixin, TokenizerManagerMultiItemMixi
             debug_name="TokenizerManager",
             watchdog_timeout=server_args.soft_watchdog_timeout,
             soft=True,
+            test_stuck_time=envs.SGLANG_TEST_STUCK_TOKENIZER.get(),
         )
 
     async def generate_request(

python/sglang/srt/utils/watchdog.py

@@ -21,13 +21,18 @@ class Watchdog:
         debug_name: str,
         watchdog_timeout: Optional[float],
         soft: bool = False,
+        test_stuck_time: float = 0,
     ) -> Watchdog:
         if watchdog_timeout is None:
+            assert (
+                test_stuck_time == 0
+            ), f"stuck tester can be enabled only if soft watchdog is enabled."
             return _WatchdogNoop()
         return _WatchdogReal(
             debug_name=debug_name,
             watchdog_timeout=watchdog_timeout,
             soft=soft,
+            test_stuck_time=test_stuck_time,
         )
 
     def feed(self):
@@ -44,9 +49,11 @@ class _WatchdogReal(Watchdog):
         debug_name: str,
         watchdog_timeout: float,
         soft: bool = False,
+        test_stuck_time: float = 0,
     ):
         self._counter = 0
         self._active = True
+        self._test_stuck_time = test_stuck_time
         self._raw = WatchdogRaw(
             debug_name=debug_name,
             get_counter=lambda: self._counter,
@@ -55,8 +62,21 @@ class _WatchdogReal(Watchdog):
             soft=soft,
         )
         logger.info(f"Watchdog {self._raw.debug_name} initialized.")
+        if self._test_stuck_time > 0:
+            logger.info(
+                f"Watchdog {self._raw.debug_name} is configured to use {test_stuck_time=}."
+            )
 
     def feed(self):
+        if self._test_stuck_time > 0:
+            logger.info(
+                f"Watchdog {self._raw.debug_name} start deliberately stuck for {self._test_stuck_time}s"
+            )
+            time.sleep(self._test_stuck_time)
+            logger.info(
+                f"Watchdog {self._raw.debug_name} end deliberately stuck for {self._test_stuck_time}s"
+            )
+
         self._counter += 1
 
     @contextmanager