Melacak Model Bahasa Besar (LLM) dengan MLflow: Panduan Lengkap

pip install mlflow>=2.8.1
pip install openai
pip install chromadb==0.4.15
pip install langchain==0.0.348
pip install tiktoken
pip install 'mlflow[genai]'
pip install databricks-sdk --upgrade

import mlflow
import chromadb

print(f"MLflow version: {mlflow.__version__}")
print(f"ChromaDB version: {chromadb.__version__}")

import mlflow
import openai

def query_llm(prompt, max_tokens=100):
    response = openai.Completion.create(
        engine="text-davinci-002",
        prompt=prompt,
        max_tokens=max_tokens
    )
    return response.choices[0].text.strip()

with mlflow.start_run():
    prompt = "Explain the concept of machine learning in simple terms."
    
    # Log parameters
    mlflow.log_param("model", "text-davinci-002")
    mlflow.log_param("max_tokens", 100)
    
    # Query the LLM and log the result
    result = query_llm(prompt)
    mlflow.log_metric("response_length", len(result))
    
    # Log the prompt and response
    mlflow.log_table("prompt_responses", {"prompt": [prompt], "response": [result]})
    
    print(f"Response: {result}")

import mlflow
from mlflow.deployments import get_deploy_client

# Initialize the deployment client
client = get_deploy_client("databricks")

# Define the endpoint configuration
endpoint_name = "llm-endpoint"
endpoint_config = {
    "served_entities": [{
        "name": "gpt-model",
        "external_model": {
            "name": "gpt-3.5-turbo",
            "provider": "openai",
            "task": "llm/v1/completions",
            "openai_config": {
                "openai_api_type": "azure",
                "openai_api_key": "{{secrets/scope/openai_api_key}}",
                "openai_api_base": "{{secrets/scope/openai_api_base}}",
                "openai_deployment_name": "gpt-35-turbo",
                "openai_api_version": "2023-05-15",
            },
        },
    }],
}

# Create the endpoint
client.create_endpoint(name=endpoint_name, config=endpoint_config)

<div class="relative flex flex-col rounded-lg">

response = client.predict(
endpoint=endpoint_name,
inputs={"prompt": "Explain the concept of neural networks briefly.","max_tokens": 100,},)

print(response)

Ini akan mengirimkan prompt ke model yang kami terapkan dan mengembalikan respons yang dihasilkan.

Mengevaluasi LLM dengan MLflow

Evaluasi sangat penting untuk memahami kinerja dan perilaku LLM Anda. MLflow menyediakan alat komprehensif untuk mengevaluasi LLM, termasuk metrik bawaan dan khusus.

Mempersiapkan LLM Anda untuk Evaluasi

Untuk mengevaluasi LLM Anda dengan mlflow.evaluate(), model Anda harus dalam salah satu bentuk berikut:

1. An mlflow.pyfunc.PyFuncModel instance atau URI yang menunjuk ke model MLflow yang dicatat.
2. Fungsi Python yang mengambil input string dan menghasilkan string tunggal.
3. URI titik akhir Penerapan MLflow.
4. set model=None dan memasukkan keluaran model dalam data evaluasi.

Mari kita lihat contoh menggunakan model MLflow yang dicatat:

import mlflow
import openai

with mlflow.start_run():
    system_prompt = "Answer the following question concisely."
    logged_model_info = mlflow.openai.log_model(
        model="gpt-3.5-turbo",
        task=openai.chat.completions,
        artifact_path="model",
        messages=[
            {"role": "system", "content": system_prompt},
            {"role": "user", "content": "{question}"},
        ],
    )

# Prepare evaluation data
eval_data = pd.DataFrame({
    "question": ["What is machine learning?", "Explain neural networks."],
    "ground_truth": [
        "Machine learning is a subset of AI that enables systems to learn and improve from experience without explicit programming.",
        "Neural networks are computing systems inspired by biological neural networks, consisting of interconnected nodes that process and transmit information."
    ]
})

# Evaluate the model
results = mlflow.evaluate(
    logged_model_info.model_uri,
    eval_data,
    targets="ground_truth",
    model_type="question-answering",
)

print(f"Evaluation metrics: {results.metrics}")

Contoh ini mencatat model OpenAI, menyiapkan data evaluasi, lalu mengevaluasi model menggunakan metrik bawaan MLflow untuk tugas menjawab pertanyaan.

Metrik Evaluasi Khusus

MLflow memungkinkan Anda menentukan metrik khusus untuk evaluasi LLM. Berikut contoh pembuatan metrik khusus untuk mengevaluasi profesionalisme respons:

from mlflow.metrics.genai import EvaluationExample, make_genai_metric

professionalism = make_genai_metric(
    name="professionalism",
    definition="Measure of formal and appropriate communication style.",
    grading_prompt=(
        "Score the professionalism of the answer on a scale of 0-4:\n"
        "0: Extremely casual or inappropriate\n"
        "1: Casual but respectful\n"
        "2: Moderately formal\n"
        "3: Professional and appropriate\n"
        "4: Highly formal and expertly crafted"
    ),
    examples=[
        EvaluationExample(
            input="What is MLflow?",
            output="MLflow is like your friendly neighborhood toolkit for managing ML projects. It's super cool!",
            score=1,
            justification="The response is casual and uses informal language."
        ),
        EvaluationExample(
            input="What is MLflow?",
            output="MLflow is an open-source platform for the machine learning lifecycle, including experimentation, reproducibility, and deployment.",
            score=4,
            justification="The response is formal, concise, and professionally worded."
        )
    ],
    model="openai:/gpt-3.5-turbo-16k",
    parameters={"temperature": 0.0},
    aggregations=["mean", "variance"],
    greater_is_better=True,
)

# Use the custom metric in evaluation
results = mlflow.evaluate(
    logged_model_info.model_uri,
    eval_data,
    targets="ground_truth",
    model_type="question-answering",
    extra_metrics=[professionalism]
)

print(f"Professionalism score: {results.metrics['professionalism_mean']}")

Metrik khusus ini menggunakan GPT-3.5-turbo untuk menilai profesionalisme respons, yang menunjukkan bagaimana Anda dapat memanfaatkan LLM itu sendiri untuk evaluasi.

Teknik Evaluasi LLM Tingkat Lanjut

Seiring dengan semakin canggihnya LLM, teknik evaluasinya pun semakin canggih. Mari kita jelajahi beberapa metode evaluasi lanjutan menggunakan MLflow.

Evaluasi Retrieval-Augmented Generation (RAG).

Sistem RAG menggabungkan kekuatan model berbasis pengambilan dan model generatif. Mengevaluasi sistem RAG memerlukan penilaian komponen pengambilan dan pembangkitan. Berikut cara Anda dapat menyiapkan sistem RAG dan mengevaluasinya menggunakan MLflow:

from langchain.document_loaders import WebBaseLoader
from langchain.text_splitter import CharacterTextSplitter
from langchain.embeddings import OpenAIEmbeddings
from langchain.vectorstores import Chroma
from langchain.chains import RetrievalQA
from langchain.llms import OpenAI

# Load and preprocess documents
loader = WebBaseLoader(["https://mlflow.org/docs/latest/index.html"])
documents = loader.load()
text_splitter = CharacterTextSplitter(chunk_size=1000, chunk_overlap=0)
texts = text_splitter.split_documents(documents)

# Create vector store
embeddings = OpenAIEmbeddings()
vectorstore = Chroma.from_documents(texts, embeddings)

# Create RAG chain
llm = OpenAI(temperature=0)
qa_chain = RetrievalQA.from_chain_type(
    llm=llm,
    chain_type="stuff",
    retriever=vectorstore.as_retriever(),
    return_source_documents=True
)

# Evaluation function
def evaluate_rag(question):
    result = qa_chain({"query": question})
    return result["result"], [doc.page_content for doc in result["source_documents"]]

# Prepare evaluation data
eval_questions = [
    "What is MLflow?",
    "How does MLflow handle experiment tracking?",
    "What are the main components of MLflow?"
]

# Evaluate using MLflow
with mlflow.start_run():
    for question in eval_questions:
        answer, sources = evaluate_rag(question)
        
        mlflow.log_param(f"question", question)
        mlflow.log_metric("num_sources", len(sources))
        mlflow.log_text(answer, f"answer_{question}.txt")
        
        for i, source in enumerate(sources):
            mlflow.log_text(source, f"source_{question}_{i}.txt")

    # Log custom metrics
    mlflow.log_metric("avg_sources_per_question", sum(len(evaluate_rag(q)[1]) for q in eval_questions) / len(eval_questions))