runtime_context: record the publishing process role (#33012)

python/sglang/srt/disaggregation/encode_server.py

@@ -63,10 +63,10 @@ from sglang.srt.observability.trace import (
     process_tracing_init,
     trace_set_thread_info,
 )
+from sglang.srt.runtime_context import publish
 from sglang.srt.server_args import (
     PortArgs,
     ServerArgs,
-    set_global_server_args_for_scheduler,
 )
 from sglang.srt.utils import (
     CLIENT_MEDIA_EXCEPTIONS,
@@ -265,7 +265,7 @@ class MMEncoder:
     ):
         logger.info(f"init MMEncoder {rank}/{server_args.tp_size}")
         self.server_args = server_args
-        set_global_server_args_for_scheduler(server_args)
+        publish(server_args, role="encoder")
         self.rank = rank
         # DP rank for metric labels; overridden by run_dp_worker in DP mode.
         # 0 in the single-instance (non-DP) path.

python/sglang/srt/elastic_ep/expert_backup_manager.py

@@ -17,10 +17,10 @@ from sglang.srt.managers.io_struct import (
 )
 from sglang.srt.model_loader.loader import DefaultModelLoader, get_model_loader
 from sglang.srt.model_loader.utils import set_default_torch_dtype
+from sglang.srt.runtime_context import publish
 from sglang.srt.server_args import (
     PortArgs,
     ServerArgs,
-    set_global_server_args_for_scheduler,
 )
 from sglang.srt.utils.network import get_local_ip_auto
 
@@ -159,7 +159,7 @@ def run_expert_backup_manager_process(
     server_args: ServerArgs,
     port_args: PortArgs,
 ):
-    set_global_server_args_for_scheduler(server_args)
+    publish(server_args, role="expert_backup")
     from sglang.srt.distributed.device_communicators.mooncake_transfer_engine import (
         init_mooncake_transfer_engine,
     )

python/sglang/srt/managers/data_parallel_controller.py

@@ -48,6 +48,7 @@ from sglang.srt.managers.scheduler import run_scheduler_process
 from sglang.srt.observability.cpu_monitor import start_cpu_monitor_thread
 from sglang.srt.observability.req_time_stats import DPControllerReqTimeStats
 from sglang.srt.observability.trace import process_tracing_init, trace_set_thread_info
+from sglang.srt.runtime_context import publish
 from sglang.srt.server_args import (
     DP_ATTENTION_HANDSHAKE_PORT_DELTA,
     PortArgs,
@@ -815,6 +816,8 @@ def run_data_parallel_controller_process(
     kill_itself_when_parent_died()
     parent_process = psutil.Process().parent()
 
+    # This process reads the config namespaces before spawning schedulers.
+    publish(server_args, role="dp_controller")
     configure_logger(server_args)
     if server_args.enable_trace:
         process_tracing_init(

python/sglang/srt/managers/scheduler.py

@@ -250,7 +250,7 @@ from sglang.srt.observability.trace import process_tracing_init, trace_set_threa
 from sglang.srt.parser.reasoning_parser import ReasoningParser
 from sglang.srt.platforms import current_platform
 from sglang.srt.plugins import load_plugins
-from sglang.srt.runtime_context import get_context, get_parallel
+from sglang.srt.runtime_context import get_context, get_parallel, publish
 from sglang.srt.sampling.sampling_batch_info import SamplingBatchInfo
 from sglang.srt.sampling.sampling_params import TOP_K_ALL
 from sglang.srt.server_args import PortArgs, ServerArgs
@@ -4765,6 +4765,9 @@ def run_scheduler_process(
         display_dp_rank=display_dp_rank,
         display_moe_ep_rank=display_moe_ep_rank,
     )
+    # Scheduler.__init__ reads the config namespaces before the model
+    # worker's own publish.
+    publish(server_args, role="scheduler")
     parent_process = psutil.Process().parent()
 
     # Set up tracing

python/sglang/srt/ray/scheduler_actor.py

@@ -16,13 +16,12 @@
 from __future__ import annotations
 
 import logging
-from typing import TYPE_CHECKING, Any, Dict, Optional
+from typing import Any, Dict, Optional
 
 import ray
 
-if TYPE_CHECKING:
+from sglang.srt.runtime_context import publish
-    from sglang.srt.server_args import PortArgs, ServerArgs
+from sglang.srt.server_args import PortArgs, ServerArgs
-
 
 logger = logging.getLogger(__name__)
 
@@ -100,6 +99,10 @@ class SchedulerActor:
                     f"[TP{tp_rank}] Bound to NUMA node {numa_node} for GPU {actual_gpu_id}"
                 )
 
+        # This actor constructs Scheduler directly (no run_scheduler_process),
+        # which reads the config namespaces before the model worker's publish.
+        publish(server_args, role="scheduler")
+
         # Create scheduler (loads model into GPU, initializes NCCL)
         self.scheduler = Scheduler(
             server_args=server_args,

python/sglang/srt/runtime_context.py

@@ -574,9 +574,17 @@ class _ConfigBag:
     writers are ``get_context().override(source, ...)`` (permanent) and
     the scoped ``.override(**kw)`` context manager (tests). Sub-namespaces
     (e.g. ``exec.moe``) are nested ``_ConfigBag`` instances reached by attribute.
-    """
 
-    __slots__ = ("_path", "_fields", "_subs")
+    Leaves and sub-bags are stored as **real instance attributes** (in
+    ``__dict__``), so ``bag.leaf`` / ``bag.sub`` is a plain attribute load that
+    ``torch.compile`` / dynamo can trace — config reads inside a compiled model
+    forward (e.g. ``get_exec().comm.enable_symm_mem`` in the embedding layer)
+    must not graph-break. ``_fields`` / ``_subs`` keep the authoritative
+    name→value maps used for override routing, membership, and scoped restore;
+    ``__getattr__`` is only a fallback for genuinely absent names. (Deliberately
+    no ``__slots__``: leaves are dynamic, and the ``__dict__`` is what makes the
+    reads traceable.)
+    """
 
     def __init__(self, path: str):
         object.__setattr__(self, "_path", path)
@@ -584,7 +592,9 @@ class _ConfigBag:
         object.__setattr__(self, "_subs", {})  # {subname: _ConfigBag}
 
     def __getattr__(self, name: str) -> Any:
-        # Reached only when ``name`` is not a real attribute (slot).
+        # Fallback only: real leaves/sub-bags resolve via __dict__ before this
+        # runs. Uses object.__getattribute__ (not self._fields) to stay safe if
+        # invoked before __init__ populates the bookkeeping dicts.
         fields = object.__getattribute__(self, "_fields")
         if name in fields:
             return fields[name]
@@ -601,8 +611,16 @@ class _ConfigBag:
         )
 
     def _set(self, name: str, value: Any) -> None:
-        """Internal write (publish + override) that bypasses the read-only guard."""
+        """Internal write (publish + override) that bypasses the read-only guard.
+        Updates both the bookkeeping map and the real attribute (traceable read)."""
         object.__getattribute__(self, "_fields")[name] = value
+        object.__setattr__(self, name, value)
+
+    def _set_sub(self, name: str, sub: _ConfigBag) -> None:
+        """Register a nested bag as both a bookkeeping entry and a real
+        attribute (so ``bag.sub`` is a plain, traceable attribute load)."""
+        object.__getattribute__(self, "_subs")[name] = sub
+        object.__setattr__(self, name, sub)
 
     def __contains__(self, name: str) -> bool:
         return name in object.__getattribute__(self, "_fields")
@@ -617,11 +635,13 @@ class _ConfigBag:
             path = object.__getattribute__(self, "_path")
             raise ValueError(f"unknown config leaf for {path!r}: {sorted(unknown)}")
         saved = {name: fields[name] for name in kwargs}
-        fields.update(kwargs)
+        for name, value in kwargs.items():
+            self._set(name, value)
         try:
             yield self
         finally:
-            fields.update(saved)
+            for name, value in saved.items():
+                self._set(name, value)
 
 
 def _build_config_bags(server_args: Any) -> dict:
@@ -660,7 +680,8 @@ def _build_config_bags(server_args: Any) -> dict:
             subs = object.__getattribute__(bag, "_subs")
             child = subs.get(name)
             if child is None:
-                child = subs[name] = _ConfigBag(".".join(parts[: depth + 1]))
+                child = _ConfigBag(".".join(parts[: depth + 1]))
+                bag._set_sub(name, child)
             bag = child
         if field in object.__getattribute__(bag, "_subs"):
             raise ValueError(
@@ -709,6 +730,7 @@ class RuntimeContext:
         "_server_args",
         "_config_bags",
         "_overrides_log",
+        "_publish_role",
         "flags",
         "resources",
         "forward",
@@ -719,6 +741,7 @@ class RuntimeContext:
         self._server_args: ServerArgs | None = None
         self._config_bags: dict | None = None
         self._overrides_log: list = []
+        self._publish_role: str | None = None
         self.flags = Flags()
         self.resources = Resources()
         self.forward = ForwardFlags()
@@ -784,8 +807,9 @@ class RuntimeContext:
         # leaves like pp_max_micro_batch_size are served via ParallelContext
         # __getattr__; live topology properties still win by name).
         self.parallel._config = self._config_bags.get("parallel")
-        # Fresh config lifecycle: prior override provenance no longer applies.
+        # A direct install is roleless; ``publish`` assigns the role afterwards.
         self._overrides_log = []
+        self._publish_role = None
 
     def config_bag(self, name: str) -> _ConfigBag:
         """Return the top-level config namespace bag (``device`` / ``model`` /
@@ -843,8 +867,11 @@ class RuntimeContext:
         self._overrides_log.append((source, dict(fields)))
 
     def overrides_log(self) -> list:
-        """Provenance of post-publish ``override`` calls: ``[(source, {field: value})]``."""
+        """Provenance of post-publish ``override`` calls: ``[(source, {field: value})]``.
-        return list(self._overrides_log)
+
+        Returns deep-ish copies (source, dict(fields)) so callers inspecting the
+        log cannot mutate the recorded provenance in place."""
+        return [(source, dict(fields)) for source, fields in self._overrides_log]
 
     def resolved_server_args_dict(self, base: dict | None = None) -> dict:
         """Serialize the *resolved* config: the pristine ``server_args`` fields
@@ -898,6 +925,7 @@ class RuntimeContext:
         prev_bags = self._config_bags
         prev_bag_values = _snapshot_bag_values(prev_bags)
         prev_overrides_log = list(self._overrides_log)
+        prev_publish_role = self._publish_role
         prev_parallel_config = self.parallel._config
         prev_capture = self.flags.capture.enable_torch_compile
         try:
@@ -908,6 +936,7 @@ class RuntimeContext:
             if prev_bags is not None:
                 _restore_bag_values(prev_bags, prev_bag_values)
             self._overrides_log = prev_overrides_log
+            self._publish_role = prev_publish_role
             self.parallel._config = prev_parallel_config
             self.flags.capture.enable_torch_compile = prev_capture
 
@@ -922,13 +951,21 @@ class _ServerArgsOverride:
     nondeterministic point.
     """
 
-    __slots__ = ("_context", "_fields", "_previous", "_previous_capture", "_installed")
+    __slots__ = (
+        "_context",
+        "_fields",
+        "_prev_server_args",
+        "_prev_bags",
+        "_prev_overrides_log",
+        "_prev_publish_role",
+        "_prev_parallel_config",
+        "_prev_capture",
+        "_installed",
+    )
 
     def __init__(self, context: RuntimeContext, fields: dict):
         self._context = context
         self._fields = fields
-        self._previous: ServerArgs | None = None
-        self._previous_capture = False
         self._installed = False
 
     def install(self) -> ServerArgs:
@@ -938,8 +975,13 @@ class _ServerArgsOverride:
         from sglang.srt.server_args import ServerArgs
 
         assert not self._installed, "override_server_args already installed"
-        self._previous = self._context._server_args
+        ctx = self._context
-        self._previous_capture = self._context.flags.capture.enable_torch_compile
+        self._prev_server_args = ctx._server_args
+        self._prev_bags = ctx._config_bags
+        self._prev_overrides_log = ctx._overrides_log
+        self._prev_publish_role = ctx._publish_role
+        self._prev_parallel_config = ctx.parallel._config
+        self._prev_capture = ctx.flags.capture.enable_torch_compile
         server_args = ServerArgs(model_path="dummy")
         if self._fields:
             server_args.override(source="test-override", **self._fields)
@@ -948,24 +990,26 @@ class _ServerArgsOverride:
         # materialized so bare post-publish writes raise like they do on a
         # fully resolved config.
         object.__setattr__(server_args, "_declarations_materialized", True)
-        self._context.set_server_args(server_args)
+        ctx.set_server_args(server_args)
         self._installed = True
         return server_args
 
     def restore(self) -> None:
-        """Reinstate the previously published config (or the empty slot)."""
+        """Reinstate the exact pre-install lifecycle state (or the empty slot)."""
         if not self._installed:
             return
         self._installed = False
-        previous, self._previous = self._previous, None
+        ctx = self._context
-        if previous is None:
+        ctx._server_args = self._prev_server_args
-            self._context._server_args = None
+        ctx._config_bags = self._prev_bags
-        else:
+        ctx._overrides_log = self._prev_overrides_log
-            self._context.set_server_args(previous)
+        ctx._publish_role = self._prev_publish_role
-        # set_server_args reseeds the capture tier from the published object
+        ctx.parallel._config = self._prev_parallel_config
-        # (and the empty-slot path does not touch it at all); the snapshot
+        ctx.flags.capture.enable_torch_compile = self._prev_capture
-        # puts back the exact pre-install runtime state either way.
+        self._prev_server_args = None
-        self._context.flags.capture.enable_torch_compile = self._previous_capture
+        self._prev_bags = None
+        self._prev_overrides_log = None
+        self._prev_parallel_config = None
 
     def __enter__(self) -> ServerArgs:
         return self.install()
@@ -1051,6 +1095,36 @@ def get_observability() -> _ConfigBag:
     return _CONTEXT.config_bag("observability")
 
 
+def publish(server_args, *, role: str, hf_config: Any = None) -> RuntimeContext:
+    """Install process-wide config for this OS process.
+
+    Records the process ``role`` (``tokenizer`` / ``scheduler`` /
+    ``dp_controller`` / ``encoder`` / ``expert_backup`` /
+    ``weight_cache_daemon`` / ``launcher`` / ``test``) and
+    projects the config bags. Draft workers skip publish (they must not clobber
+    the target). ``role`` is provenance today — per-role namespace projection
+    and fail-closed enforcement is a later unit. ``hf_config`` is accepted for
+    forward-compat and currently unused.
+
+    Normally one call per process, but re-publish is allowed and is
+    **last-publish-wins** (bags re-projected, provenance reset, role
+    overwritten). Two sanctioned multi-publish shapes exist: the in-process
+    Engine builds its ``TokenizerManager`` inside the launcher process (the
+    process ends up with the tokenizer publish), and multiple Engines in one
+    process publish in sequence — which is exactly why per-instance managers
+    must read ``self.server_args`` for anything engine-specific rather than
+    the process-global bags.
+    """
+    _CONTEXT.set_server_args(server_args)
+    _CONTEXT._publish_role = role
+    return _CONTEXT
+
+
+def publish_role() -> str | None:
+    """The role recorded by the last ``publish`` (None for a legacy set)."""
+    return _CONTEXT._publish_role
+
+
 def get_stream(name: str) -> Any:
     return _CONTEXT.get_stream(name)
 
@@ -1084,6 +1158,7 @@ def reset_context() -> None:
     _CONTEXT._server_args = None
     _CONTEXT._config_bags = None
     _CONTEXT._overrides_log = []
+    _CONTEXT._publish_role = None
     _CONTEXT.parallel._config = None
     _CONTEXT.flags = Flags()
     _CONTEXT.resources = Resources()

python/sglang/srt/server_args.py

@@ -9007,14 +9007,19 @@ class ServerArgs:
 # (decrease-only) by test/registered/unit/test_legacy_global_ratchet.py.
 # Imports are in-function so the two modules stay cycle-free at import time.
 def set_global_server_args_for_scheduler(server_args: ServerArgs):
-    """Legacy publish shim — prefer ``get_context().set_server_args()`` from
+    """Legacy publish shim (role=scheduler) — prefer
-    ``sglang.srt.runtime_context`` in new code."""
+    ``runtime_context.publish(server_args, role=...)`` in new code."""
-    from sglang.srt.runtime_context import get_context
+    from sglang.srt.runtime_context import publish
 
-    get_context().set_server_args(server_args)
+    publish(server_args, role="scheduler")
 
 
-set_global_server_args_for_tokenizer = set_global_server_args_for_scheduler
+def set_global_server_args_for_tokenizer(server_args: ServerArgs):
+    """Legacy publish shim (role=tokenizer). Not aliased to the scheduler shim:
+    the process role differs."""
+    from sglang.srt.runtime_context import publish
+
+    publish(server_args, role="tokenizer")
 
 
 def get_global_server_args() -> ServerArgs:

python/sglang/srt/speculative/draft_worker_common.py

@@ -97,7 +97,9 @@ def build_draft_tp_worker(
         context_length=target_model_config.context_len,
     )
 
+    # The draft's layers must resolve config from the draft's own bags.
     with get_context().preserve_config():
+        get_context().set_server_args(draft_server_args)
         draft_worker = TpModelWorker(
             server_args=draft_server_args,
             gpu_id=gpu_id,

python/sglang/srt/weight_cache/daemon.py

@@ -46,6 +46,7 @@ import torch.distributed as dist
 
 from sglang.srt.configs.load_config import LoadConfig
 from sglang.srt.platforms import current_platform
+from sglang.srt.runtime_context import publish
 from sglang.srt.utils import MultiprocessingSerializer
 
 from .protocol import (
@@ -208,7 +209,6 @@ class WeightCacheDaemon:
         from sglang.srt.configs.device_config import DeviceConfig
         from sglang.srt.configs.model_config import ModelConfig
         from sglang.srt.model_loader.loader import get_model_loader
-        from sglang.srt.runtime_context import get_context
         from sglang.srt.server_args import ServerArgs
 
         server_args = ServerArgs(
@@ -223,7 +223,7 @@ class WeightCacheDaemon:
             load_format=self.load_format,
             model_loader_extra_config=self.model_loader_extra_config,
         )
-        get_context().set_server_args(server_args)
+        publish(server_args, role="weight_cache_daemon")
 
         # Initialize distributed backend for model loading
         # (must be done after server_args and model_config are available)

test/registered/unit/test_legacy_global_ratchet.py

@@ -31,7 +31,7 @@ _RATCHETS = [
     (
         "set_global_server_args_for_*",
         r"\bset_global_server_args_for_(?:scheduler|tokenizer)\s*\(",
-        5,
+        4,
     ),
 ]
 

test/registered/unit/test_runtime_context.py

@@ -215,8 +215,10 @@ class TestServerArgsOwnership(_IsolatedServerArgs):
         self.assertIs(get_server_args(), sentinel)
         self.assertIs(get_context().server_args, sentinel)
 
-    def test_tokenizer_alias_is_same_function(self):
+    def test_tokenizer_alias_is_distinct_role_shim(self):
-        self.assertIs(
+        # Deliberately NOT an alias: the two legacy setters publish with
+        # different process roles (scheduler vs tokenizer).
+        self.assertIsNot(
             server_args_module.set_global_server_args_for_tokenizer,
             server_args_module.set_global_server_args_for_scheduler,
         )

test/registered/unit/test_runtime_context_override.py

@@ -164,6 +164,34 @@ class TestContextOverride(CustomTestCase):
         self.assertIs(rc.get_context().server_args, target)
         self.assertEqual(rc.get_schedule().page_size, 16)
 
+    def test_publish_records_role(self):
+        rc.publish(ServerArgs(model_path="dummy"), role="scheduler")
+        self.assertEqual(rc.publish_role(), "scheduler")
+
+    def test_legacy_shims_record_roles(self):
+        # Unit 2a: the legacy setters publish with their process role.
+        from sglang.srt.server_args import (
+            set_global_server_args_for_scheduler,
+            set_global_server_args_for_tokenizer,
+        )
+
+        set_global_server_args_for_scheduler(ServerArgs(model_path="dummy"))
+        self.assertEqual(rc.publish_role(), "scheduler")
+        set_global_server_args_for_tokenizer(ServerArgs(model_path="dummy"))
+        self.assertEqual(rc.publish_role(), "tokenizer")
+
+    def test_reset_clears_role(self):
+        rc.publish(ServerArgs(model_path="dummy"), role="test")
+        rc.reset_context()
+        self.assertIsNone(rc.publish_role())
+
+    def test_direct_install_clears_role(self):
+        # A role-less set_server_args (test overrides, draft-worker builds)
+        # must not inherit the previous lifecycle's role.
+        rc.publish(ServerArgs(model_path="dummy"), role="scheduler")
+        rc.get_context().set_server_args(ServerArgs(model_path="dummy"))
+        self.assertIsNone(rc.publish_role())
+
 
 if __name__ == "__main__":
     unittest.main()