disagg_router.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 dynamo.llm import DisaggregatedRouter


class PyDisaggregatedRouter:
    def __init__(
        self,
        runtime,
        served_model_name,
        custom_disagg_router=False,
        max_local_prefill_length=1000,
        max_remote_prefill_cache_hit_ratio=0.5,
    ):
        self.runtime = runtime
        self.served_model_name = served_model_name
        self.max_local_prefill_length = max_local_prefill_length
        self.max_remote_prefill_cache_hit_ratio = max_remote_prefill_cache_hit_ratio
        self.custom_disagg_router = custom_disagg_router

        if not self.custom_disagg_router:
            # TODO: add max_remote_prefill_cache_hit_ratio to rust router
            self.disagg_router = DisaggregatedRouter(
                runtime,
                served_model_name,
                max_local_prefill_length,
            )

    def prefill_remote(self, prompt_length, cache_hit_length=0):
        if self.custom_disagg_router:
            # TODO: add max_remote_prefill_cache_hit_ratio to python router
            return prompt_length > self.max_local_prefill_length
        else:
            return self.disagg_router.prefill_remote(prompt_length, cache_hit_length)