Configure and call dumper in main SGLang logic (#19093)

python/sglang/srt/debug_utils/dump_comparator.py

@@ -20,9 +20,7 @@ def main(args):
     )
     if args.filter:
         df_target = df_target.filter(pl.col("filename").str.contains(args.filter))
-    assert all(
-        c in df_target.columns for c in ["rank", "step", "dump_index", "name"]
-    )
+    assert all(c in df_target.columns for c in ["rank", "step", "dump_index", "name"])
 
     df_baseline = read_meta(args.baseline_path)
     print("df_target", df_target)
@@ -41,9 +39,7 @@ def main(args):
             baseline_step = location_info.baseline_step
             baseline_token_slice = location_info.baseline_token_slice
         else:
-            baseline_step = (
-                row["step"] - args.start_id + args.baseline_start_id
-            )
+            baseline_step = row["step"] - args.start_id + args.baseline_start_id
             baseline_token_slice = None
 
         tensor_dim_desc = None

python/sglang/srt/debug_utils/dumper.py

@@ -168,6 +168,10 @@ class _Dumper:
 
     # ------------------------------- public :: core ---------------------------------
 
+    @property
+    def may_enable(self) -> bool:
+        return self._config.enable or self._config.server_port_parsed is not None
+
     def step(self):
         """This should be called on all ranks at the end of each iteration."""
 
@@ -237,6 +241,7 @@ class _Dumper:
         self,
         model: "torch.nn.Module",
     ) -> Optional["_NonIntrusiveDumper"]:
+        self._ensure_http_server()
         mode = self._config.non_intrusive_mode
         if mode == "off":
             return None

python/sglang/srt/model_executor/model_runner.py

@@ -50,6 +50,7 @@ from sglang.srt.configs.load_config import LoadConfig, LoadFormat
 from sglang.srt.configs.model_config import AttentionArch, ModelConfig, ModelImpl
 from sglang.srt.configs.update_config import adjust_config_with_unaligned_cpu_tp
 from sglang.srt.constants import GPU_MEMORY_TYPE_WEIGHTS
+from sglang.srt.debug_utils.dumper import dumper
 from sglang.srt.debug_utils.tensor_dump_forward_hook import (
     register_forward_hook_for_model,
 )
@@ -1055,6 +1056,9 @@ class ModelRunner(ModelRunnerKVCacheMixin):
                 self.pp_rank,
             )
 
+        if dumper.may_enable:
+            dumper.register_non_intrusive_dumper(self.model)
+
         # Pre-expand RoPE cache before CUDA Graph capture
         reserve_rope_cache_for_long_sequences(
             self.model,
@@ -2438,6 +2442,9 @@ class ModelRunner(ModelRunnerKVCacheMixin):
         if self.eplb_manager is not None:
             self.eplb_manager.on_forward_pass_end()
 
+        if dumper.may_enable:
+            dumper.step()
+
         return output
 
     def _forward_raw(

test/registered/debug_utils/test_dumper.py

@@ -102,6 +102,21 @@ class TestDumperConfig:
         d.configure_default(filter="from_code")
         assert d._config.filter == "from_code"
 
+    def test_may_enable_default_false(self):
+        d = _Dumper(config=_DumperConfig())
+        assert d.may_enable is False
+
+    def test_may_enable_true_when_enabled(self):
+        d = _Dumper(config=_DumperConfig(enable=True))
+        assert d.may_enable is True
+
+    def test_may_enable_true_when_server_port_set(self):
+        d = _Dumper(config=_DumperConfig(server_port="40000"))
+        assert d.may_enable is True
+
+        d2 = _Dumper(config=_DumperConfig(server_port="reuse"))
+        assert d2.may_enable is True
+
 
 class TestDumperPureFunctions:
     def test_get_truncated_value(self):
@@ -1548,5 +1563,81 @@ class TestNonIntrusiveLayerIdCtx(_NonIntrusiveTestBase):
         assert len(layer1_keys) == 0, f"layer 1 dumps should be filtered: {layer1_keys}"
 
 
+class TestDumperE2E:
+    def test_step_and_non_intrusive_hooks(self, tmp_path):
+        base_url = DEFAULT_URL_FOR_TEST
+        dump_dir = str(tmp_path)
+        env = {
+            **os.environ,
+            "DUMPER_SERVER_PORT": "reuse",
+        }
+        proc = popen_launch_server(
+            "Qwen/Qwen3-0.6B",
+            base_url,
+            timeout=DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
+            other_args=["--tp", "2", "--max-total-tokens", "128"],
+            env=env,
+        )
+        try:
+            states = requests.post(f"{base_url}/dumper/get_state", json={}).json()
+            assert len(states) == 2, f"Expected 2 ranks (tp=2), got {len(states)}"
+            for state in states:
+                assert state["config"]["enable"] is False
+                assert state["step"] == 0
+
+            requests.post(
+                f"{base_url}/dumper/configure",
+                json={"enable": True, "dir": dump_dir},
+            ).raise_for_status()
+
+            states = requests.post(f"{base_url}/dumper/get_state", json={}).json()
+            assert len(states) == 2
+            for rank, state in enumerate(states):
+                assert (
+                    state["config"]["enable"] is True
+                ), f"rank {rank}: enable should be True after configure"
+                assert state["config"]["dir"] == dump_dir
+
+            resp = requests.post(
+                f"{base_url}/generate",
+                json={"text": "Hello", "sampling_params": {"max_new_tokens": 8}},
+            )
+            assert resp.status_code == 200, f"Generate failed: {resp.text}"
+
+            states = requests.post(f"{base_url}/dumper/get_state", json={}).json()
+            assert len(states) == 2
+            steps = [s["step"] for s in states]
+            for rank, step in enumerate(steps):
+                assert step > 0, f"rank {rank}: step should be > 0, got {step}"
+            assert steps[0] == steps[1], f"step mismatch across ranks: {steps}"
+
+            dump_files = list(Path(dump_dir).glob("dump_*/*.pt"))
+            assert len(dump_files) > 0, f"No dump files in {dump_dir}"
+            filenames = {f.name for f in dump_files}
+
+            for field in ("input_ids", "positions"):
+                assert any(f"name={field}" in f for f in filenames), (
+                    f"Missing {field} dump from non-intrusive hooks, "
+                    f"got: {sorted(filenames)[:10]}"
+                )
+
+            for rank in range(2):
+                assert any(
+                    f"rank={rank}" in f for f in filenames
+                ), f"No dump files for rank {rank}"
+
+            sample_file = dump_files[0]
+            loaded = torch.load(sample_file, map_location="cpu", weights_only=False)
+            assert isinstance(loaded, dict), f"Expected dict, got {type(loaded)}"
+            assert (
+                "value" in loaded and "meta" in loaded
+            ), f"Missing value/meta keys: {loaded.keys()}"
+            assert "name" in loaded["meta"]
+            assert "rank" in loaded["meta"]
+            assert "step" in loaded["meta"]
+        finally:
+            kill_process_tree(proc.pid)
+
+
 if __name__ == "__main__":
     sys.exit(pytest.main([__file__]))