Productionizing a RAG App with Prefect, Weave, and RAGAS | by Ed Izaguirre | Aug, 2024

Including analysis, automated information pulling, and different enhancements.

12 min learn

·

10 hours in the past

Desk of Contents

1. Introduction
2. Offline Analysis
3. On-line Analysis
4. Automated Knowledge Pulling with Prefect
5. Abstract

Related Hyperlinks

A couple of months in the past, I launched the Movie Search app, a Retrieval-Augmented Technology (RAG) software designed to advocate movies primarily based on person queries. For instance, a person could ask: “Discover me drama films in English which can be lower than 2 hours lengthy and have canines.” and obtain a suggestion like:

Title of Movie: Hachi: A Canine’s Story

Runtime: 93 minutes
Launch 12 months: 2009
Streaming: Not out there for streaming
This movie tells the poignant true story of Hachiko, an Akita canine identified for his exceptional loyalty to his proprietor. The emotional depth and the themes of friendship and loyalty resonate strongly, making it a touching drama that showcases the profound bond between people and canines. It’s excellent for anybody searching for a heartfelt story that highlights the significance of companionship.

…

This was not only a easy RAG app, nonetheless. It included what is named self-querying retrieval. Which means that the bot takes the person’s question and transforms it by including metadata filters. This ensures any paperwork pulled into the chat mannequin’s context respects the constraints set by the person’s question. For extra info, I like to recommend trying out my earlier article linked above.

Sadly, there have been some points with the app:

• There was no offline analysis finished, moreover passing the ‘eye take a look at’. This take a look at is critical, however not enough.
• Observability was non-existent. If a question went poorly, you needed to manually pull up the undertaking and run some ad-hoc scripts in an try and see what went flawed.
• The Pinecone vector database needed to be pulled manually. This meant the paperwork would shortly be old-fashioned if, say, a movie bought pulled from a streaming service.

On this article, I’ll briefly cowl among the enhancements made to the Movie Search app. This may cowl:

• Offline Analysis utilizing RAGAS and Weave
• On-line Analysis and Observability
• Automated Knowledge Pulling utilizing Prefect

One factor earlier than we leap in: I discovered the title Movie Search to be a bit generic, so I rebranded the app as Rosebud 🌹, therefore the picture proven above. Actual movie geeks will perceive the reference.

You will need to be capable to decide if a change made to your LLM software improves or degrades its efficiency. Sadly, analysis of LLM apps is a tough and novel house. There’s merely not a lot settlement on what constitutes a superb analysis.

For Rosebud 🌹, I made a decision to sort out what is named the RAG triad. This method is promoted by TruLens, a platform to judge and monitor LLM purposes.

The triad covers three features of a RAG app:

• Context Relevancy: When a question is made by the person, paperwork fill the context of the chat mannequin. Is the retrieved context really helpful? If not, you might have to tweak issues like doc embedding, chunking, or metadata filtering.
• Faithfulness: Is the mannequin’s response really grounded within the retrieved paperwork? You don’t need the mannequin making up information; the entire level of RAG is to assist scale back hallucinations through the use of retrieved paperwork.
• Reply Relevancy: Does the mannequin’s response really reply the person’s question? If the person asks for “Comedy movies made within the Nineteen Nineties?”, the mannequin’s reply higher comprise solely comedy movies made within the Nineteen Nineties.

There are a number of methods to aim to evaluate these three capabilities of a RAG app. A technique can be to make use of human knowledgeable evaluators. Sadly, this might be costly and wouldn’t scale. For Rosebud 🌹 I made a decision to make use of LLMs-as-a-judges. This implies utilizing a chat mannequin to have a look at every of the three standards above and assigning a rating of 0 to 1 for every. This technique has the benefit of being low-cost and scaling properly. To perform this, I used RAGAS, a well-liked framework that helps you consider your RAG purposes. The RAGAS framework consists of the three metrics talked about above and makes it pretty simple to make use of them to judge your apps. Under is a code snippet demonstrating how I performed this offline analysis:

from ragas import consider
from ragas.metrics import AnswerRelevancy, ContextRelevancy, Faithfulness
import weave
@weave.op()
def evaluate_with_ragas(question, model_output):
# Put information right into a Dataset object
information = {
"query": [query],
"contexts": [[model_output['context']]],
"reply": [model_output['answer']]
}
dataset = Dataset.from_dict(information)
# Outline metrics to evaluate
metrics = [
AnswerRelevancy(),
ContextRelevancy(),
Faithfulness(),
]
judge_model = ChatOpenAI(mannequin=config['JUDGE_MODEL_NAME'])
embeddings_model = OpenAIEmbeddings(mannequin=config['EMBEDDING_MODEL_NAME'])
analysis = consider(dataset=dataset, metrics=metrics, llm=judge_model, embeddings=embeddings_model)
return {
"answer_relevancy": float(analysis['answer_relevancy']),
"context_relevancy": float(analysis['context_relevancy']),
"faithfulness": float(analysis['faithfulness']),
}
def run_evaluation():
# Initialize chat mannequin
mannequin = rosebud_chat_model()
# Outline analysis questions
questions = [
{"query": "Suggest a good movie based on a book."},  # Adaptations
{"query": "Suggest a film for a cozy night in."},  # Mood-Based
{"query": "What are some must-watch horror movies?"},  # Genre-Specific
...
# Total of 20 questions
]
# Create Weave Analysis object
analysis = weave.Analysis(dataset=questions, scorers=[evaluate_with_ragas])
# Run the analysis
asyncio.run(analysis.consider(mannequin))
if __name__ == "__main__":
weave.init('film-search')
run_evaluation()

A couple of notes:

• With twenty questions and three standards to evaluate throughout, you’re taking a look at sixty LLM requires a single analysis! It will get even worse although; with the rosebud_chat_model , there are two calls for each question: one to assemble the metadata filter and one other to offer the reply, so actually that is 120 requires a single eval! All fashions used my analysis are the brand new gpt-4o-mini , which I strongly advocate. In my expertise the calls value $0.05 per analysis.
• Notice that we’re utilizing asyncio.run to run the evals. It’s very best to make use of asynchronous calls since you don’t need to consider every query sequentially one after the opposite. As a substitute, with asyncio we will start evaluating different questions as we await earlier I/O operations to complete.
• There are a complete of twenty questions for a single analysis. These span quite a lot of typical movie queries a person could ask. I largely got here up with these myself, however in observe it could be higher to make use of queries really requested by customers in manufacturing.
• Discover the weave.init and the @weave.op decorator which can be getting used. These are a part of the brand new Weave library from Weights & Biases (W&B). Weave is a complement to the standard W&B library, with a deal with LLM purposes. It lets you seize inputs and outputs of LLMs through the use of a the straightforward @weave.op decorator. It additionally lets you seize the outcomes of evaluations utilizing weave.Analysis(…) . By integrating RAGAS to carry out evaluations and Weave to seize and log them, we get a strong duo that helps GenAI builders iteratively enhance their purposes. You additionally get to log the mannequin latency, value, and extra.

In idea, one can now tweak a hyperparameter (e.g. temperature), re-run the analysis, and see if the adjustment has a constructive or adverse affect. Sadly, in observe I discovered the LLM judging to be finicky, and I’m not the one one. LLM judges appear to be pretty unhealthy at utilizing a floating level worth to evaluate these metrics. As a substitute, it seems they appear to do higher at classification e.g. a thumbs up/thumbs down. RAGAS doesn’t but assist LLM judges performing classification. Writing it by hand doesn’t appear too tough, and maybe in a future replace I’ll try this myself.

Offline analysis is sweet for seeing how tweaking hyperparameters impacts efficiency, however in my view on-line analysis is way extra helpful. In Rosebud 🌹 I’ve now included using 👍/👎 buttons on the backside of each response to offer suggestions.

When a person clicks on both button they’re instructed that their suggestions was logged. Under is a snippet of how this was completed within the Streamlit interface:

def start_log_feedback(suggestions):
print("Logging suggestions.")
st.session_state.feedback_given = True
st.session_state.sentiment = suggestions
thread = threading.Thread(goal=log_feedback, args=(st.session_state.sentiment,
st.session_state.question,
st.session_state.query_constructor,
st.session_state.context,
st.session_state.response))
thread.begin()
def log_feedback(sentiment, question, query_constructor, context, response):
ct = datetime.datetime.now()
wandb.init(undertaking="film-search",
title=f"question: {ct}")
desk = wandb.Desk(columns=["sentiment", "query", "query_constructor", "context", "response"])
desk.add_data(sentiment,
question,
query_constructor,
context,
response
)
wandb.log({"Question Log": desk})
wandb.end()

Notice that the method of sending the suggestions to W&B runs on a separate thread moderately than on the primary thread. That is to forestall the person from getting caught for a number of seconds ready for the logging to finish.

A W&B desk is used to retailer the suggestions. 5 portions are logged within the desk:

• Sentiment: Whether or not the person clicked thumbs up or thumbs down
• Question: The person’s question, e.g. Discover me drama films in English which can be lower than 2 hours lengthy and have canines.
• Query_Constructor: The outcomes of the question constructor, which rewrites the person’s question and consists of metadata filtering if mandatory, e.g.

{
"question": "drama English canines", 
"filter": {
"operator": "and", 
"arguments": [
{
"comparator": "eq", "attribute": "Genre", "value": "Drama"
}, 
{
"comparator": "eq", "attribute": "Language", "value": "English"
}, 
{
"comparator": "lt", "attribute": "Runtime (minutes)", "value": 120
}
]
},
}

• Context: The retrieved context primarily based on the reconstructed question, e.g. Title: Hachi: A Canine’s Story. Overview: A drama primarily based on the true story of a school professor’s…
• Response: The mannequin’s response

All of that is logged conveniently in the identical undertaking because the Weave evaluations proven earlier. Now, when a question goes south it is so simple as hitting the thumbs down button to see precisely what occurred. This may enable a lot sooner iteration and enchancment of the Rosebud 🌹 suggestion software.

To make sure suggestions from Rosebud 🌹 proceed to remain correct it was necessary to automate the method of pulling information and importing them to Pinecone. For this process, I selected Prefect. Prefect is a well-liked workflow orchestration device. I used to be searching for one thing light-weight, simple to study, and Pythonic. I discovered all of this in Prefect.

Prefect provides quite a lot of methods to schedule your workflows. I made a decision to make use of the push work swimming pools with automated infrastructure provisioning. I discovered that this setup balances simplicity with configurability. It permits the person to process Prefect with mechanically provisioning all the infrastructure wanted to run your movement in your cloud supplier of selection. I selected to deploy on Azure, however deploying on GCP or AWS solely requires altering a number of strains of code. Confer with the pinecone_flow.py file for extra particulars. A simplified movement is offered beneath:

@process
def begin():
"""
Begin-up: examine every thing works or fail quick!
"""
# Print out some debug information
print("Beginning movement!")
# Guarantee person has set the suitable env variables
assert os.environ['LANGCHAIN_API_KEY']
assert os.environ['OPENAI_API_KEY']
...
@process(retries=3, retry_delay_seconds=[1, 10, 100])
def pull_data_to_csv(config):
TMBD_API_KEY = os.getenv('TMBD_API_KEY')
YEARS = vary(config["years"][0], config["years"][-1] + 1)
CSV_HEADER = ['Title', 'Runtime (minutes)', 'Language', 'Overview', ...]
for yr in YEARS:
# Seize record of ids for all movies made in {YEAR}
movie_list = record(set(get_id_list(TMBD_API_KEY, yr)))
FILE_NAME = f'./information/{yr}_movie_collection_data.csv'
# Creating file
with open(FILE_NAME, 'w') as f:
author = csv.author(f)
author.writerow(CSV_HEADER)
...
print("Efficiently pulled information from TMDB and created csv information in information/")
@process
def convert_csv_to_docs():
# Loading in information from all csv information
loader = DirectoryLoader(
...
show_progress=True)
docs = loader.load()
metadata_field_info = [
AttributeInfo(name="Title",
description="The title of the movie", type="string"),
AttributeInfo(name="Runtime (minutes)",
description="The runtime of the movie in minutes", type="integer"),
...
]
def convert_to_list(doc, subject):
if subject in doc.metadata and doc.metadata[field] is just not None:
doc.metadata[field] = [item.strip()
for item in doc.metadata[field].cut up(',')]
...
fields_to_convert_list = ['Genre', 'Actors', 'Directors',
'Production Companies', 'Stream', 'Buy', 'Rent']
...
# Set 'overview' and 'key phrases' as 'page_content' and different fields as 'metadata'
for doc in docs:
# Parse the page_content string right into a dictionary
page_content_dict = dict(line.cut up(": ", 1)
for line in doc.page_content.cut up("n") if ": " in line)
doc.page_content = (
'Title: ' + page_content_dict.get('Title') +
'. Overview: ' + page_content_dict.get('Overview') +
...
)
...
print("Efficiently took csv information and created docs")
return docs
@process
def upload_docs_to_pinecone(docs, config):
# Create empty index
PINECONE_KEY, PINECONE_INDEX_NAME = os.getenv(
'PINECONE_API_KEY'), os.getenv('PINECONE_INDEX_NAME')
laptop = Pinecone(api_key=PINECONE_KEY)
# Goal index and examine standing
pc_index = laptop.Index(PINECONE_INDEX_NAME)
print(pc_index.describe_index_stats())
embeddings = OpenAIEmbeddings(mannequin=config['EMBEDDING_MODEL_NAME'])
namespace = "film_search_prod"
PineconeVectorStore.from_documents(
docs,
...
)
print("Efficiently uploaded docs to Pinecone vector retailer")
@process
def publish_dataset_to_weave(docs):
# Initialize Weave
weave.init('film-search')
rows = []
for doc in docs:
row = {
'Title': doc.metadata.get('Title'),
'Runtime (minutes)': doc.metadata.get('Runtime (minutes)'),
...
}
rows.append(row)
dataset = Dataset(title='Film Assortment', rows=rows)
weave.publish(dataset)
print("Efficiently revealed dataset to Weave")
@movement(log_prints=True)
def pinecone_flow():
with open('./config.json') as f:
config = json.load(f)
begin()
pull_data_to_csv(config)
docs = convert_csv_to_docs()
upload_docs_to_pinecone(docs, config)
publish_dataset_to_weave(docs)
if __name__ == "__main__":
pinecone_flow.deploy(
title="pinecone-flow-deployment",
work_pool_name="my-aci-pool",
cron="0 0 * * 0",
picture=DeploymentImage(
title="prefect-flows:newest",
platform="linux/amd64",
)
)

Discover how easy it’s to show Python capabilities right into a Prefect movement. All you want are some sub-functions styled with @process decorators and a @movement decorator on the primary perform. Additionally observe that after importing the paperwork to Pinecone, the final step of our movement publishes the dataset to Weave. That is necessary for reproducibility functions.

On the backside of the script we see how deployment is completed in Prefect.

• We have to present a title for the deployment. That is arbitrary.
• We additionally have to specify a work_pool_name . Push work swimming pools in Prefect mechanically ship duties to serverless computer systems while not having a intermediary. This title must match the title used to create the pool, which we’ll see beneath.
• You additionally have to specify a cron , which is brief for chronograph. This lets you specify how usually to repeat a workflow. The worth “0 0 * * 0” means repeat this workflow each week. Try this web site for particulars on how the cron syntax works.
• Lastly, you might want to specify a DeploymentImage . Right here you specify each a title and a platform . The title is unfair, however the platform is just not. Since I need to deploy to Azure compute situations, and these situations run Linux, it’s necessary I specify that within the DeploymentImage .

To deploy this movement on Azure utilizing the CLI, run the next instructions:

prefect work-pool create --type azure-container-instance:push --provision-infra my-aci-pool
prefect deployment run 'get_repo_info/my-deployment'

These instructions will mechanically provision all the mandatory infrastructure on Azure. This consists of an Azure Container Registry (ACR) that may maintain a Docker picture containing all information in your listing in addition to any mandatory libraries listed in a necessities.txt . It would additionally embody an Azure Container Occasion (ACI) Id that may have permissions essential to deploy a container with the aforementioned Docker picture. Lastly, the deployment run command will schedule the code to be run each week. You may examine the Prefect dashboard to see your movement get run:

By updating my Pinecone vector retailer weekly, I can make sure that the suggestions from Rosebud 🌹 stay correct.

On this article, I mentioned my expertise enhancing the Rosebud 🌹 app. This included the method of incorporating offline and on-line analysis, in addition to automating the replace of my Pinecone vector retailer.

Another enhancements not talked about on this article:

• Together with rankings from The Film Database within the movie information. Now you can ask for “extremely rated movies” and the chat mannequin will filter for movies above a 7/10.
• Upgraded chat fashions. Now the question and abstract fashions are utilizing gpt-4o-mini . Recall that the LLM decide mannequin can be utilizing gpt-4o-mini .
• Embedding mannequin upgraded to text-embedding-3-small from text-embedding-ada-002 .
• Years now span 1950–2023, as an alternative of beginning at 1920. Movie information from 1920–1950 was not prime quality, and solely tousled suggestions.
• UI is cleaner, with all particulars concerning the undertaking relegated to a sidebar.
• Vastly improved documentation on GitHub.
• Bug fixes.

As talked about on the high of the article, the app is now 100% free to make use of! I’ll foot the invoice for queries for the foreseeable future (therefore the selection of gpt-4o-mini as an alternative of the costlier gpt-4o). I actually need to get the expertise of working an app in manufacturing, and having my readers take a look at out Rosebud 🌹 is a good way to do that. Within the unlikely occasion that the app actually blows up, I must provide you with another mannequin of funding. However that will an important drawback to have.

Get pleasure from discovering superior movies! 🎥