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

Including analysis, automated knowledge pulling, and different enhancements.

12 min learn

·

15 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 Era (RAG) utility designed to suggest movies primarily based on person queries. For instance, a person might ask: “Discover me drama motion pictures in English which might be lower than 2 hours lengthy and have canine.” and obtain a suggestion like:

Title of Movie: Hachi: A Canine’s Story

Runtime: 93 minutes
Launch 12 months: 2009
Streaming: Not accessible for streaming
This movie tells the poignant true story of Hachiko, an Akita canine identified for his outstanding 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 canine. It’s excellent for anybody in search of 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 data, I like to recommend testing my earlier article linked above.

Sadly, there have been some points with the app:

• There was no offline analysis accomplished, apart from passing the ‘eye take a look at’. This take a look at is important, however not ample.
• 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 improper.
• The Pinecone vector database needed to be pulled manually. This meant the paperwork would rapidly be old-fashioned if, say, a movie obtained pulled from a streaming service.

On this article, I’ll briefly cowl a number of the enhancements made to the Movie Search app. This can cowl:

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

One factor earlier than we bounce in: I discovered the identify 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.

It is very important have the ability to choose if a change made to your LLM utility improves or degrades its efficiency. Sadly, analysis of LLM apps is a troublesome and novel house. There may be merely not a lot settlement on what constitutes a very good analysis.

For Rosebud 🌹, I made a decision to deal with what is named the RAG triad. This strategy is promoted by TruLens, a platform to guage and monitor LLM functions.

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 truly helpful? If not, it’s possible you’ll have to tweak issues like doc embedding, chunking, or metadata filtering.
• Faithfulness: Is the mannequin’s response truly grounded within the retrieved paperwork? You don’t need the mannequin making up info; the entire level of RAG is to assist cut back hallucinations by utilizing retrieved paperwork.
• Reply Relevancy: Does the mannequin’s response truly 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 just a few methods to try to evaluate these three features of a RAG app. A technique could be to make use of human knowledgeable evaluators. Sadly, this could 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 methodology has the benefit of being low-cost and scaling nicely. To perform this, I used RAGAS, a well-liked framework that helps you consider your RAG functions. The RAGAS framework consists of the three metrics talked about above and makes it pretty straightforward to make use of them to guage your apps. Under is a code snippet demonstrating how I carried out 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 knowledge right into a Dataset object
knowledge = {
"query": [query],
"contexts": [[model_output['context']]],
"reply": [model_output['answer']]
}
dataset = Dataset.from_dict(knowledge)
# 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 suggest. In my expertise the calls price $0.05 per analysis.
• Be aware that we’re utilizing asyncio.run to run the evals. It’s splendid to make use of asynchronous calls since you don’t need to consider every query sequentially one after the opposite. As an alternative, with asyncio we will start evaluating different questions as we look ahead to earlier I/O operations to complete.
• There are a complete of twenty questions for a single analysis. These span a wide range of typical movie queries a person might ask. I largely got here up with these myself, however in apply it will be higher to make use of queries truly requested by customers in manufacturing.
• Discover the weave.init and the @weave.op decorator which might be getting used. These are a part of the brand new Weave library from Weights & Biases (W&B). Weave is a complement to the normal W&B library, with a concentrate on LLM functions. It permits you to seize inputs and outputs of LLMs by utilizing a the easy @weave.op decorator. It additionally permits you to 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 robust duo that helps GenAI builders iteratively enhance their functions. You additionally get to log the mannequin latency, price, and extra.

In concept, one can now tweak a hyperparameter (e.g. temperature), re-run the analysis, and see if the adjustment has a optimistic or unfavorable affect. Sadly, in apply I discovered the LLM judging to be finicky, and I’m not the one one. LLM judges appear to be pretty dangerous at utilizing a floating level worth to evaluate these metrics. As an alternative, 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 troublesome, and maybe in a future replace I’ll try this myself.

Offline analysis is nice for seeing how tweaking hyperparameters impacts efficiency, however for my part on-line analysis is much extra helpful. In Rosebud 🌹 I’ve now integrated 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 achieved 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",
identify=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()

Be aware that the method of sending the suggestions to W&B runs on a separate thread reasonably than on the primary thread. That is to stop the person from getting caught for just a few 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 motion pictures in English which might be lower than 2 hours lengthy and have canine.
• Query_Constructor: The outcomes of the question constructor, which rewrites the person’s question and consists of metadata filtering if essential, e.g.

{
"question": "drama English canine", 
"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 faculty 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 can permit a lot quicker iteration and enchancment of the Rosebud 🌹 suggestion utility.

To make sure suggestions from Rosebud 🌹 proceed to remain correct it was essential to automate the method of pulling knowledge and importing them to Pinecone. For this activity, I selected Prefect. Prefect is a well-liked workflow orchestration device. I used to be in search of one thing light-weight, straightforward to be taught, and Pythonic. I discovered all of this in Prefect.

Prefect gives a wide range of methods to schedule your workflows. I made a decision to make use of the push work swimming pools with computerized infrastructure provisioning. I discovered that this setup balances simplicity with configurability. It permits the person to activity Prefect with robotically provisioning all the infrastructure wanted to run your move in your cloud supplier of alternative. I selected to deploy on Azure, however deploying on GCP or AWS solely requires altering just a few traces of code. Discuss with the pinecone_flow.py file for extra particulars. A simplified move is supplied beneath:

@activity
def begin():
"""
Begin-up: verify all the pieces works or fail quick!
"""
# Print out some debug data
print("Beginning move!")
# Guarantee person has set the suitable env variables
assert os.environ['LANGCHAIN_API_KEY']
assert os.environ['OPENAI_API_KEY']
...
@activity(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 12 months in YEARS:
# Seize checklist of ids for all movies made in {YEAR}
movie_list = checklist(set(get_id_list(TMBD_API_KEY, 12 months)))
FILE_NAME = f'./knowledge/{12 months}_movie_collection_data.csv'
# Creating file
with open(FILE_NAME, 'w') as f:
author = csv.author(f)
author.writerow(CSV_HEADER)
...
print("Efficiently pulled knowledge from TMDB and created csv recordsdata in knowledge/")
@activity
def convert_csv_to_docs():
# Loading in knowledge from all csv recordsdata
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, discipline):
if discipline in doc.metadata and doc.metadata[field] shouldn't be None:
doc.metadata[field] = [item.strip()
for item in doc.metadata[field].break 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.break up(": ", 1)
for line in doc.page_content.break up("n") if ": " in line)
doc.page_content = (
'Title: ' + page_content_dict.get('Title') +
'. Overview: ' + page_content_dict.get('Overview') +
...
)
...
print("Efficiently took csv recordsdata and created docs")
return docs
@activity
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 verify 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")
@activity
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(identify='Film Assortment', rows=rows)
weave.publish(dataset)
print("Efficiently printed dataset to Weave")
@move(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(
identify="pinecone-flow-deployment",
work_pool_name="my-aci-pool",
cron="0 0 * * 0",
picture=DeploymentImage(
identify="prefect-flows:newest",
platform="linux/amd64",
)
)

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

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

• We have to present a identify for the deployment. That is arbitrary.
• We additionally have to specify a work_pool_name . Push work swimming pools in Prefect robotically ship duties to serverless computer systems without having a intermediary. This identify must match the identify 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 typically 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 should specify a DeploymentImage . Right here you specify each a identify and a platform . The identify is bigoted, however the platform shouldn’t be. Since I need to deploy to Azure compute cases, and these cases run Linux, it’s essential I specify that within the DeploymentImage .

To deploy this move 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 robotically provision all the essential infrastructure on Azure. This consists of an Azure Container Registry (ACR) that can maintain a Docker picture containing all recordsdata in your listing in addition to any essential libraries listed in a necessities.txt . It’ll additionally embody an Azure Container Occasion (ACI) Identification that can 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’ll be able to verify the Prefect dashboard to see your move 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 bettering 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 scores from The Film Database within the movie knowledge. 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 choose 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 knowledge from 1920–1950 was not top quality, and solely tousled suggestions.
• UI is cleaner, with all particulars relating to 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 operating 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 should give you another mannequin of funding. However that might an incredible downside to have.

Take pleasure in discovering superior movies! 🎥