Prepare Model

To prepare a model version to be served in ⚗️ Instill Model, please follow these steps on your local system:

  1. Install the latest Python 📦 Instill SDK:

pip install instill-sdk

  1. Create an empty folder for your custom model and run the init command to generate required files, with sample codes and comments that describe their function

instill init

  1. Modify the model config file (instill.yaml) to describe your model's dependencies.
  2. Modify the model.py file which defines the model class that will be decorated into a servable model with the Python 📦 Instill SDK.
  3. Organize the repository files into a valid model layout.

#Model Configuration

Model configuration is handled within the instill.yaml file that accompanies the model. It describes the models necessary dependency information and is crucial for reproducibility, sharing and discoverability.

In the instill.yaml file, you are can specify the following details:

  • build:
    • gpu:
      • Required: boolean
      • Description: Specifies if the model needs GPU support.
    • python_version:
      • Required: string
      • Supported Versions: 3.11
    • cuda_version:
      • Optional: string
      • Supported Versions: 11.5, 11.6, 11.7, 11.8, 12.1
      • Default: Defaults to 11.8 if not specified or empty.
    • python_packages:
      • Optional: list
      • Description: Lists packages to be installed with pip.
    • system_packages:
      • Optional: list
      • Description: Lists packages to be installed from the apt package manager. The model image is based on Ubuntu 20.04 LTS.

Below is an example for the TinyLlama model:

instill.yaml

build:
gpu: true
python_version: "3.11" # support only 3.11
cuda_version: "12.1"
python_packages:
- torch==2.2.1
- transformers==4.36.2
- accelerate==0.25.0

#Model Layout

To deploy a model in ⚗️ Instill Model, we suggest you prepare the model files similar to the following layout:


.
├── instill.yaml
├── model.py
├── <additional_modules>
└── <weights>
├── <weight_file_1>
├── <weight_file_2>
├── ...
└── <weight_file_n>

The above layout displays a typical model in ⚗️ Instill Model consisting of

  • instill.yaml - model config file that describe the model dependencies
  • model.py - a decorated model class that contains custom inference logic
  • <additional_modules> - a directory that holds supporting python modules if necessary
  • <weights> - a directory that holds the weight files if necessary

You can name the <weights> and <additional_modules> folders freely provided that they can be properly loaded and used by the model.py file.

#Prepare Model Code

To implement a custom model that can be deployed and served in ⚗️ Instill Model, you only need to construct a simple model class within the model.py file.

The custom model class is required to contain three methods:

  1. __init__ This is where the model loading process is defined, allowing the weights to be stored in memory and yielding faster auto-scaling behavior.
  2. ModelMetadata This method tells the backend service the expected input/output shape that the model is expecting. If you are using one of our predefined AI Tasks, you can simply import construct_{task}_metadata_response and use it as return.
  3. __call__ This is the inference request entrypoint, and is where you implement your model inference logic.

Below is a simple example implementation of the TinyLlama model with explanations:


# import necessary packages
import torch
from transformers import pipeline
# import SDK helper functions
# const package hosts the standard Datatypes and Input class for each standard Instill AI Task
from instill.helpers.const import TextGenerationChatInput
# ray_io package hosts the parsers to easily convert request payload into input parameters, and model outputs to response
from instill.helpers.ray_io import StandardTaskIO
# ray_config package hosts the decorators and deployment object for the model class
from instill.helpers.ray_config import instill_deployment, InstillDeployable
from instill.helpers import (
construct_text_generation_chat_infer_response,
construct_text_generation_chat_metadata_response,
)
# use instill_deployment decorator to convert the model class to a servable model
@instill_deployment
class TinyLlama:
# within the __init__ function, setup the model instance with the desired framework, in this
# case it is a transformers pipeline
def __init__(self):
self.pipeline = pipeline(
"text-generation",
model="TinyLlama/TinyLlama-1.1B-Chat-v1.0",
torch_dtype=torch.bfloat16,
)
# ModelMetadata tells the server what input and output shapes the model is expecting
def ModelMetadata(self, req):
return construct_text_generation_chat_metadata_response(req=req)
# __call__ handles the trigger request from Instill Model
async def __call__(self, request):
# use StandardTaskIO package to parse the request and get the corresponding input
# for text-generation-chat task
task_text_generation_chat_input: TextGenerationChatInput = (
StandardTaskIO.parse_task_text_generation_chat_input(request=request)
)
# prepare prompt with chat template
conv = [
{
"role": "system",
"content": "You are a friendly chatbot",
},
{
"role": "user",
"content": task_text_generation_chat_input.prompt,
},
]
prompt = self.pipeline.tokenizer.apply_chat_template(
conv,
tokenize=False,
add_generation_prompt=True,
)
# inference
sequences = self.pipeline(
prompt,
max_new_tokens=task_text_generation_chat_input.max_new_tokens,
do_sample=True,
temperature=task_text_generation_chat_input.temperature,
top_k=task_text_generation_chat_input.top_k,
top_p=0.95,
)
# convert the model output into response output using StandardTaskIO
task_text_generation_chat_output = (
StandardTaskIO.parse_task_text_generation_chat_output(sequences=sequences)
)
return construct_text_generation_chat_infer_response(
req=request,
# specify the output dimension
shape=[1, len(sequences)],
raw_outputs=[task_text_generation_chat_output],
)
# now simply declare a global entrypoint for deployment
entrypoint = InstillDeployable(TinyLlama).get_deployment_handle()

Once all the required model files are prepared, please refer to the Build Model Image and Push Model Image pages for futher information about creating and pushing your custom model image to ⚗️ Instill Model in 🔮 Instil Core or on ☁️ Instill Cloud.

Last updated: 7/19/2024, 2:19:08 PM