vllm.py

# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
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# Licensed under the Apache License, Version 2.0 (the "License");
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# http://www.apache.org/licenses/LICENSE-2.0
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# TODO: rename to avoid ambiguity with vllm package
from vllm.engine.arg_utils import AsyncEngineArgs
from vllm.utils import FlexibleArgumentParser

from dynamo.sdk.lib.config import ServiceConfig


def parse_vllm_args(service_name, prefix) -> AsyncEngineArgs:
    config = ServiceConfig.get_instance()
    vllm_args = config.as_args(service_name, prefix=prefix)
    parser = FlexibleArgumentParser()
    parser.add_argument(
        "--router",
        type=str,
        choices=["random", "round-robin", "kv"],
        default="random",
        help="Router type to use for scheduling requests to workers",
    )
    parser.add_argument(
        "--remote-prefill", action="store_true", help="Enable remote prefill"
    )
    parser.add_argument(
        "--conditional-disagg",
        action="store_true",
        help="Use disaggregated router to decide whether to prefill locally or remotely",
    )
    parser.add_argument(
        "--max-local-prefill-length",
        type=int,
        default=1000,
        help="Maximum length of local prefill",
    )
    parser = AsyncEngineArgs.add_cli_args(parser)
    args = parser.parse_args(vllm_args)
    engine_args = AsyncEngineArgs.from_cli_args(args)
    engine_args.router = args.router
    engine_args.remote_prefill = args.remote_prefill
    engine_args.conditional_disagg = args.conditional_disagg
    engine_args.max_local_prefill_length = args.max_local_prefill_length
    return engine_args