llama-stack-mirror/llama_stack/apis/batch_inference/batch_inference.py
Ashwin Bharambe f34f22f8c7
feat: add batch inference API to llama stack inference (#1945)
# What does this PR do?

This PR adds two methods to the Inference API:
- `batch_completion`
- `batch_chat_completion`

The motivation is for evaluations targeting a local inference engine
(like meta-reference or vllm) where batch APIs provide for a substantial
amount of acceleration.

Why did I not add this to `Api.batch_inference` though? That just
resulted in a _lot_ more book-keeping given the structure of Llama
Stack. Had I done that, I would have needed to create a notion of a
"batch model" resource, setup routing based on that, etc. This does not
sound ideal.

So what's the future of the batch inference API? I am not sure. Maybe we
can keep it for true _asynchronous_ execution. So you can submit
requests, and it can return a Job instance, etc.

## Test Plan

Run meta-reference-gpu using:
```bash
export INFERENCE_MODEL=meta-llama/Llama-4-Scout-17B-16E-Instruct
export INFERENCE_CHECKPOINT_DIR=../checkpoints/Llama-4-Scout-17B-16E-Instruct-20250331210000
export MODEL_PARALLEL_SIZE=4
export MAX_BATCH_SIZE=32
export MAX_SEQ_LEN=6144

LLAMA_MODELS_DEBUG=1 llama stack run meta-reference-gpu
```

Then run the batch inference test case.
2025-04-12 11:41:12 -07:00

55 lines
1.9 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
from typing import List, Optional, Protocol, runtime_checkable
from llama_stack.apis.common.job_types import Job
from llama_stack.apis.inference import (
InterleavedContent,
LogProbConfig,
Message,
ResponseFormat,
SamplingParams,
ToolChoice,
ToolDefinition,
ToolPromptFormat,
)
from llama_stack.schema_utils import webmethod
@runtime_checkable
class BatchInference(Protocol):
"""Batch inference API for generating completions and chat completions.
This is an asynchronous API. If the request is successful, the response will be a job which can be polled for completion.
NOTE: This API is not yet implemented and is subject to change in concert with other asynchronous APIs
including (post-training, evals, etc).
"""
@webmethod(route="/batch-inference/completion", method="POST")
async def completion(
self,
model: str,
content_batch: List[InterleavedContent],
sampling_params: Optional[SamplingParams] = None,
response_format: Optional[ResponseFormat] = None,
logprobs: Optional[LogProbConfig] = None,
) -> Job: ...
@webmethod(route="/batch-inference/chat-completion", method="POST")
async def chat_completion(
self,
model: str,
messages_batch: List[List[Message]],
sampling_params: Optional[SamplingParams] = None,
# zero-shot tool definitions as input to the model
tools: Optional[List[ToolDefinition]] = None,
tool_choice: Optional[ToolChoice] = ToolChoice.auto,
tool_prompt_format: Optional[ToolPromptFormat] = None,
response_format: Optional[ResponseFormat] = None,
logprobs: Optional[LogProbConfig] = None,
) -> Job: ...