Running an Inference Job

This guide will walk you through the process of running an inference job using the Lumigator SDK and a model downloaded from the Hugging Face Hub. The model will generate summaries for a given set of text data.

This tutorial will show you how to perform inference as a single job. If you would like to do this as a part of an experiment and workflow (which includes evaluation of the results), see the quickstart.

Note

You can also use the OpenAI GPT family of models or the Mistral API to run an inference job. To do so, you need to set the appropriate environment variables: OPENAI_API_KEY or MISTRAL_API_KEY. Refer to the troubleshooting section for more details.

What You’ll Need

• A running instance of Lumigator.

Procedure

1. Install the Lumigator SDK:

   user@host:~/lumigator$ uv pip install -e lumigator/sdk
   

2. Create a new Python file:

   user@host:~/lumigator$ touch inference.py
   

3. Add the following code to inference.py:

   import json
   import requests
   
   from lumigator_sdk.lumigator import LumigatorClient
   from lumigator_schemas import jobs, datasets
   
   
   BUCKET = "lumigator-storage"
   HOST = "localhost"
   LUMIGATOR_PORT = 8000
   RAY_PORT = 8265
   
   
   # Instantiate the Lumigator client
   lm_client = LumigatorClient(f"{HOST}:{LUMIGATOR_PORT}")
   
   # Upload a dataset
   dataset_path = "lumigator/sample_data/dialogsum_exc.csv"
   dataset = lm_client.datasets.create_dataset(
       dataset=open(dataset_path, 'rb'),
       format=datasets.DatasetFormat.JOB
   )
   
   # Create and submit an inference job
   name = "bart-summarization-run"
   model = "facebook/bart-large-cnn"
   provider = "hf"
   task = "summarization"
   
   job_args = jobs.JobInferenceCreate(
       name=name,
       model=model,
       provider=provider,
       dataset=dataset.id,
       task=task,
   )
   
   job = lm_client.jobs.create_job(
       type=jobs.JobType.INFERENCE, request=job_args)
   
   # Wait for the job to complete
   lm_client.jobs.wait_for_job(job.id, poll_wait=10)
   
   # Retrieve the job results
   url = f"http://{HOST}:{RAY_PORT}/{BUCKET}/jobs/results/{name}/{job.id}/results.json"
   response = requests.get(url=url)
   
   if response.status_code != 200:
       raise Exception(f"Failed to retrieve job results: {response.text}")
   results = response.json()
   
   # Write the JSON results to a file
   with open("results.json", "w") as f:
       json.dump(results, f, indent=4)
   

4. Run the script:

   user@host:~/lumigator$ uv run python inference.py
   

Model Specification

Different models can be chosen for summarization. The information about those models can be retrieved via the http://<lumigator-host>:8000/api/v1/models/summarization endpoint. It contains the following information for each model:

• display_name: an identification name for the model

• model: The model to use, e.g. facebook/bart-large-cnn

• provider: a URI specifying how and where to use the model. The following protocols are supported:

  • hf: direct model usage in an HF pipeline

  • Any protocol supported by LiteLLM. For example, openai/, mistral/, deepseek/, etc. You will need to have set the correct API keys for them, e.g. OPENAI_API_KEY, or MISTRAL_API_KEY, or DEEPSEEK_API_KEY

• base_url: this field can be filled out if running a custom model that uses the openai protocol. For example, llamafile is generally hosted on your computer at http://localhost:8080/v1.

• website_url: a link to a web page with more information about the model

• description: a short description about the model

• info: a map containing information about the model like parameter count or model size

• tasks: a list of supported tasks, with parameters and capabilities appropriate to the task and their default or set values

Verify

Review the contents of the results.json file to ensure that the inference job ran successfully:

user@host:~/lumigator$ cat results.json | jq
{
"predictions": [
    "A man has trouble breathing. He is sent to see a pulmonary specialist. The doctor tests him for asthma. He does not have any allergies that he knows of. He also has a heavy feeling in his chest when he tries to breathe. This happens a lot when he works out, he says.",
...

Next Steps

Congratulations! You have successfully run an inference job using the Lumigator SDK. You can now use the results to evaluate your model’s performance.