feat(sglang): aggregated support (#937)

Co-authored-by: ishandhanani <ishandhananai@gmail.com>

examples/sglang/README.md

+<!--
+SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+SPDX-License-Identifier: Apache-2.0
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+# LLM Deployment Examples using SGLang
+
+This directory contains examples and reference implementations for deploying Large Language Models (LLMs) in various configurations using SGLang. SGLang internally uses ZMQ to communicate between the ingress and the engine processes. For Dynamo, we leverage the runtime to communicate directly with the engine processes and handle ingress and pre/post processing on our end.
+
+## Deployment Architectures
+
+See [deployment architectures](../llm/README.md#deployment-architectures) to learn about the general idea of the architecture. SGLang currently support only aggregated serving but routing and disaggregation support are coming very soon!
+
+## Getting Started
+
+1. Choose a deployment architecture based on your requirements
+2. Configure the components as needed
+3. Deploy using the provided scripts
+
+### Prerequisites
+
+Start required services (etcd and NATS) using [Docker Compose](../../deploy/docker-compose.yml)
+```bash
+docker compose -f deploy/docker-compose.yml up -d
+```
+
+### Build docker
+
+```bash
+# On an x86 machine - sglang does not support ARM yet
+./container/build.sh
+```
+
+### Run container
+
+```bash
+./container/run.sh -it
+```
+
+### Example architectures
+
+#### Aggregated
+
+```bash
+cd /workspace/examples/sglang
+dynamo serve graphs.agg:Frontend -f ./configs/agg.yaml
+```
+

examples/sglang/components/frontend.py

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+import subprocess
+from pathlib import Path
+
+from components.worker import SGLangWorker
+from fastapi import FastAPI
+from pydantic import BaseModel
+
+import dynamo.sdk as sdk
+from dynamo.sdk import depends, service
+from dynamo.sdk.lib.config import ServiceConfig
+from dynamo.sdk.lib.image import DYNAMO_IMAGE
+
+logger = logging.getLogger(__name__)
+
+
+def get_dynamo_run_binary():
+    """Find the dynamo-run binary path in SDK or fallback to 'dynamo-run' command."""
+    sdk_path = Path(sdk.__file__)
+    binary_path = sdk_path.parent / "cli/bin/dynamo-run"
+    if not binary_path.exists():
+        return "dynamo-run"
+    else:
+        return str(binary_path)
+
+
+class FrontendConfig(BaseModel):
+    """Configuration for the Frontend service including model and HTTP server settings."""
+
+    served_model_name: str
+    endpoint: str
+    port: int = 8080
+
+
+@service(
+    dynamo={
+        "enabled": True,
+        "namespace": "dynamo",
+    },
+    workers=1,
+    image=DYNAMO_IMAGE,
+    app=FastAPI(title="LLM Example"),
+)
+class Frontend:
+    worker = depends(SGLangWorker)
+
+    def __init__(self):
+        """Initialize Frontend service with HTTP server and model configuration."""
+        config = ServiceConfig.get_instance()
+        frontend_config = FrontendConfig(**config.get("Frontend", {}))
+        self.frontend_config = frontend_config
+        self.process = None
+
+        self.start_ingress_and_processor()
+
+    def start_ingress_and_processor(self):
+        """Starting dynamo-run based ingress and processor"""
+        logger.info(
+            f"Starting HTTP server and processor on port {self.frontend_config.port}"
+        )
+        dynamo_run_binary = get_dynamo_run_binary()
+        endpoint = f"dyn://{self.frontend_config.endpoint}"
+
+        self.process = subprocess.Popen(
+            [
+                dynamo_run_binary,
+                "in=http",
+                f"out={endpoint}",
+                "--http-port",
+                str(self.frontend_config.port),
+            ],
+            stdout=None,
+            stderr=None,
+        )

examples/sglang/components/worker.py

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""
+SGLang disaggregated serving flow is
+
+Processor -> PrefillWorker -> DecodeWorker
+
+This is different from how we've implemented the vLLM disaggregated flow.
+
+For now - the SGLangWorker will be responsible for aggreagted and prefill and we will
+have a separate DecodeWorker.
+"""
+
+import logging
+import signal
+
+import sglang as sgl
+from utils.protocol import PreprocessedRequest
+from utils.sglang import parse_sglang_args
+
+from dynamo.llm import ModelType, register_llm
+from dynamo.sdk import async_on_start, dynamo_context, dynamo_endpoint, service
+
+logger = logging.getLogger(__name__)
+
+
+@service(
+    dynamo={
+        "enabled": True,
+        "namespace": "dynamo",
+    },
+    resources={"gpu": 1},
+    workers=1,
+)
+class SGLangWorker:
+    def __init__(self):
+        class_name = self.__class__.__name__
+        self.engine_args = parse_sglang_args(class_name, "")
+        self.engine = sgl.Engine(server_args=self.engine_args)
+
+        for sig in [signal.SIGINT, signal.SIGTERM]:
+            signal.signal(sig, self.shutdown_sglang_engine)
+
+        logger.info("SGLangWorker initialized")
+
+    @async_on_start
+    async def async_init(self):
+        runtime = dynamo_context["runtime"]
+        logger.info("Registering LLM for discovery")
+        comp_ns, comp_name = SGLangWorker.dynamo_address()  # type: ignore
+        endpoint = runtime.namespace(comp_ns).component(comp_name).endpoint("generate")
+        await register_llm(
+            ModelType.Backend,
+            endpoint,
+            self.engine_args.model_path,
+            self.engine_args.served_model_name,
+        )
+
+    def shutdown_sglang_engine(self, signum, frame):
+        self.engine.shutdown()
+        logger.info("SGLang engine shutdown")
+
+    def _build_sampling_params(self, request: PreprocessedRequest) -> dict:
+        # TODO: maintain a full mapping from PreprocessedRequest to SGLang's SamplingParams
+        sampling_params = {}
+        if request.sampling_options.temperature:
+            sampling_params["temperature"] = request.sampling_options.temperature
+        if request.sampling_options.top_p:
+            sampling_params["top_p"] = request.sampling_options.top_p
+        if request.sampling_options.top_k:
+            sampling_params["top_k"] = request.sampling_options.top_k
+        sampling_params["max_new_tokens"] = request.stop_conditions.max_tokens
+        if request.stop_conditions.ignore_eos:
+            sampling_params["ignore_eos"] = request.stop_conditions.ignore_eos
+        return sampling_params
+
+    @dynamo_endpoint()
+    async def generate(self, request: PreprocessedRequest):
+        # TODO: maintain a mapping from SGLang's Ouput struct to LLMEngineOuput
+        sampling_params = self._build_sampling_params(request)
+        g = await self.engine.async_generate(
+            input_ids=request.token_ids,
+            sampling_params=sampling_params,
+            stream=True,
+        )
+        num_output_tokens_so_far = 0
+        async for res in g:
+            finish_reason = res["meta_info"]["finish_reason"]
+            if finish_reason:
+                # Don't forward the stop token
+                out = {"token_ids": [], "finish_reason": finish_reason["type"]}
+            else:
+                next_total_toks = len(res["output_ids"])
+                out = {"token_ids": res["output_ids"][num_output_tokens_so_far:]}
+            yield out
+            num_output_tokens_so_far = next_total_toks

examples/sglang/configs/agg.yaml

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+Frontend:
+  served_model_name: deepseek-ai/DeepSeek-R1-Distill-Llama-8B
+  endpoint: dynamo.SGLangWorker.generate
+  port: 8000
+
+SGLangWorker:
+  model-path: deepseek-ai/DeepSeek-R1-Distill-Llama-8B
+  served-model-name: deepseek-ai/DeepSeek-R1-Distill-Llama-8B
+  tp: 1
+  trust-remote-code: true
+  skip-tokenizer-init: true
+  ServiceArgs:
+    workers: 1
+    resources:
+      gpu: 1
\ No newline at end of file

examples/sglang/graphs/agg.py

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from components.frontend import Frontend
+from components.worker import SGLangWorker
+
+Frontend.link(SGLangWorker)

examples/sglang/utils/protocol.py

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import List, Optional
+
+from pydantic import BaseModel, Field
+
+TokenIdType = int
+
+
+# TODO: move these to common for all LLMs once we adopt dynamo-run
+# derived from lib/llm/src/protocols/common/preprocessor.rs
+class StopConditions(BaseModel):
+    max_tokens: Optional[int] = None
+    stop: Optional[List[str]] = None
+    stop_token_ids_hidden: Optional[List[TokenIdType]] = None
+    min_tokens: Optional[int] = None
+    ignore_eos: Optional[bool] = None
+
+
+class SamplingOptions(BaseModel):
+    n: Optional[int] = None
+    best_of: Optional[int] = None
+    presence_penalty: Optional[float] = None
+    frequency_penalty: Optional[float] = None
+    repetition_penalty: Optional[float] = None
+    temperature: Optional[float] = None
+    top_p: Optional[float] = None
+    top_k: Optional[int] = None
+    min_p: Optional[float] = None
+    use_beam_search: Optional[bool] = None
+    length_penalty: Optional[float] = None
+    seed: Optional[int] = None
+
+
+class PreprocessedRequest(BaseModel):
+    token_ids: List[TokenIdType]
+    stop_conditions: StopConditions
+    sampling_options: SamplingOptions
+    eos_token_ids: List[TokenIdType] = Field(default_factory=list)
+    mdc_sum: Optional[str] = None
+    annotations: List[str] = Field(default_factory=list)

examples/sglang/utils/sglang.py

+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import argparse
+
+from sglang.srt.server_args import ServerArgs
+
+from dynamo.sdk.lib.config import ServiceConfig
+
+
+def parse_sglang_args(service_name, prefix) -> ServerArgs:
+    config = ServiceConfig.get_instance()
+    sglang_args = config.as_args(service_name, prefix=prefix)
+    parser = argparse.ArgumentParser()
+
+    # add future dynamo arguments here
+
+    ServerArgs.add_cli_args(parser)
+    args = parser.parse_args(sglang_args)
+    return ServerArgs.from_cli_args(args)

launch/dynamo-run/src/subprocess/sglang_inc.py

@@ -60,16 +60,12 @@ class RequestHandler:
 
     async def generate(self, request):
         sampling_params = {}
-        for key, value in request["sampling_options"].items():
-            if value:
-                # TODO: Do these always match? Maybe allow-list the fields that do match
-                sampling_params[key] = value
-
+        if request["sampling_options"]["temperature"] is not None:
+            sampling_params["temperature"] = request["sampling_options"]["temperature"]
+        sampling_params = {
             # sglang defaults this to 128
-        max_new_tokens = request["stop_conditions"]["max_tokens"]
-        if max_new_tokens:
-            sampling_params["max_new_tokens"] = max_new_tokens
-
+            "max_new_tokens": request["stop_conditions"]["max_tokens"],
+        }
         num_output_tokens_so_far = 0
         gen = await self.engine_client.async_generate(
             input_ids=request["token_ids"], sampling_params=sampling_params, stream=True

lib/bindings/python/src/dynamo/runtime/logging.py

@@ -92,7 +92,9 @@ def configure_dynamo_logging(
     dyn_var = os.environ.get("DYN_LOG", "info")
     dyn_level = log_level_mapping(dyn_var)
 
+    # configure inference engine loggers
     configure_vllm_logging(dyn_level)
+    configure_sglang_logging(dyn_level)
 
     # loggers that should be configured to ERROR
     error_loggers = ["bentoml", "tag"]
@@ -125,6 +127,38 @@ def log_level_mapping(level: str) -> int:
         return logging.INFO
 
 
+def configure_sglang_logging(dyn_level: int):
+    """
+    SGLang allows us to create a custom logging config file
+    """
+
+    sglang_level = logging.getLevelName(dyn_level)
+
+    sglang_config = {
+        "formatters": {"simple": {"format": "%(message)s"}},
+        "handlers": {
+            "dynamo": {
+                "class": "dynamo.runtime.logging.LogHandler",
+                "formatter": "simple",
+                "level": sglang_level,
+            }
+        },
+        "loggers": {
+            "sglang": {
+                "handlers": ["dynamo"],
+                "level": sglang_level,
+                "propagate": False,
+            }
+        },
+        "version": 1,
+        "disable_existing_loggers": False,
+    }
+
+    with tempfile.NamedTemporaryFile(mode="w", suffix=".json", delete=False) as f:
+        json.dump(sglang_config, f)
+        os.environ["SGLANG_LOGGING_CONFIG_PATH"] = f.name
+
+
 def configure_vllm_logging(dyn_level: int):
     """
     vLLM requires a logging config file to be set in the environment.

pyproject.toml

@@ -34,6 +34,7 @@ dependencies = [
     "distro",
     "typer",
     "circus>=0.17.0",
+    "sglang[all]==0.4.6.post2"
 ]
 
 classifiers = [