Build RAG Chatbot with LangChain, Faiss, Groq llama3-70b-8192, and Cohere embed-english-v2.0

Introduction to RAG

Retrieval-Augmented Generation (RAG) is a game-changer for GenAI applications, especially in conversational AI. It combines the power of pre-trained large language models (LLMs) like OpenAI’s GPT with external knowledge sources stored in vector databases such as Milvus and Zilliz Cloud, allowing for more accurate, contextually relevant, and up-to-date response generation. A RAG pipeline usually consists of four basic components: a vector database, an embedding model, an LLM, and a framework.

Key Components We'll Use for This RAG Chatbot

This tutorial shows you how to build a simple RAG chatbot in Python using the following components:

LangChain: An open-source framework that helps you orchestrate the interaction between LLMs, vector stores, embedding models, etc, making it easier to integrate a RAG pipeline.
Faiss: also known as Facebook AI Similarity Search, is an open-source vector search library that allows developers to quickly search for semantically similar multimedia data within a massive dataset of unstructured data. (If you want a much more scalable solution or hate to manage your own infrastructure, we recommend using Zilliz Cloud, which is a fully managed vector database service built on the open-source Milvus and offers a free tier supporting up to 1 million vectors.)
Groq llama3-70b-8192: The llama3-70b-8192 model is a large language model developed by Meta, featuring 70 billion parameters and an 8,192-token context window. This model is designed for general-purpose language tasks, including text generation, summarization, and translation. Groq, a company specializing in AI hardware and software solutions, offers the llama3-70b-8192 model through its API. This integration allows developers to leverage Groq's high-performance Language Processing Unit (LPU) for efficient inference. Groq's LPU is known for its deterministic, single-core streaming architecture, which provides predictable and repeatable performance for AI workloads.
Cohere embed-english-v2.0: This model specializes in generating high-quality embeddings for English text, enhancing semantic understanding in various applications. Its strengths lie in capturing nuanced meanings and context, making it ideal for tasks like semantic search, recommendation systems, and clustering. Efficient and scalable, it's perfect for developers looking to integrate advanced text analysis into their applications.

By the end of this tutorial, you’ll have a functional chatbot capable of answering questions based on a custom knowledge base.

Note: Since we may use proprietary models in our tutorials, make sure you have the required API key beforehand.

Step 1: Install and Set Up LangChain

%pip install --quiet --upgrade langchain-text-splitters langchain-community langgraph

Step 2: Install and Set Up Groq llama3-70b-8192

pip install -qU "langchain[groq]"

import getpass
import os

if not os.environ.get("GROQ_API_KEY"):
  os.environ["GROQ_API_KEY"] = getpass.getpass("Enter API key for Groq: ")

from langchain.chat_models import init_chat_model

llm = init_chat_model("llama3-8b-8192", model_provider="groq")

Step 3: Install and Set Up Cohere embed-english-v2.0

pip install -qU langchain-cohere

import getpass
import os

if not os.environ.get("COHERE_API_KEY"):
  os.environ["COHERE_API_KEY"] = getpass.getpass("Enter API key for Cohere: ")

from langchain_cohere import CohereEmbeddings

embeddings = CohereEmbeddings(model="embed-english-v2.0")

Step 4: Install and Set Up Faiss

pip install -qU langchain-community

from langchain_community.vectorstores import FAISS

vector_store = FAISS(embedding_function=embeddings)

Step 5: Build a RAG Chatbot

Now that you’ve set up all components, let’s start to build a simple chatbot. We’ll use the Milvus introduction doc as a private knowledge base. You can replace it with your own dataset to customize your RAG chatbot.

import bs4
from langchain import hub
from langchain_community.document_loaders import WebBaseLoader
from langchain_core.documents import Document
from langchain_text_splitters import RecursiveCharacterTextSplitter
from langgraph.graph import START, StateGraph
from typing_extensions import List, TypedDict

# Load and chunk contents of the blog
loader = WebBaseLoader(
    web_paths=("https://milvus.io/docs/overview.md",),
    bs_kwargs=dict(
        parse_only=bs4.SoupStrainer(
            class_=("doc-style doc-post-content")
        )
    ),
)

docs = loader.load()

text_splitter = RecursiveCharacterTextSplitter(chunk_size=1000, chunk_overlap=200)
all_splits = text_splitter.split_documents(docs)

# Index chunks
_ = vector_store.add_documents(documents=all_splits)

# Define prompt for question-answering
prompt = hub.pull("rlm/rag-prompt")


# Define state for application
class State(TypedDict):
    question: str
    context: List[Document]
    answer: str


# Define application steps
def retrieve(state: State):
    retrieved_docs = vector_store.similarity_search(state["question"])
    return {"context": retrieved_docs}


def generate(state: State):
    docs_content = "\n\n".join(doc.page_content for doc in state["context"])
    messages = prompt.invoke({"question": state["question"], "context": docs_content})
    response = llm.invoke(messages)
    return {"answer": response.content}


# Compile application and test
graph_builder = StateGraph(State).add_sequence([retrieve, generate])
graph_builder.add_edge(START, "retrieve")
graph = graph_builder.compile()

Test the Chatbot

Yeah! You've built your own chatbot. Let's ask the chatbot a question.

response = graph.invoke({"question": "What data types does Milvus support?"})
print(response["answer"])

Example Output

Milvus supports various data types including sparse vectors, binary vectors, JSON, and arrays. Additionally, it handles common numerical and character types, making it versatile for different data modeling needs. This allows users to manage unstructured or multi-modal data efficiently.

Optimization Tips

As you build your RAG system, optimization is key to ensuring peak performance and efficiency. While setting up the components is an essential first step, fine-tuning each one will help you create a solution that works even better and scales seamlessly. In this section, we’ll share some practical tips for optimizing all these components, giving you the edge to build smarter, faster, and more responsive RAG applications.

LangChain optimization tips

To optimize LangChain, focus on minimizing redundant operations in your workflow by structuring your chains and agents efficiently. Use caching to avoid repeated computations, speeding up your system, and experiment with modular design to ensure that components like models or databases can be easily swapped out. This will provide both flexibility and efficiency, allowing you to quickly scale your system without unnecessary delays or complications.

Faiss Optimization Tips

To enhance the performance of the Faiss library in a Retrieval-Augmented Generation (RAG) system, begin by selecting the appropriate index type based on your data volume and query speed requirements; for example, using an IVF (Inverted File) index can significantly speed up queries on large datasets by reducing the search space. Optimize your indexing process by using the nlist parameter to partition data into smaller clusters and set an appropriate number of probes (nprobe) during retrieval to balance between speed and accuracy. Ensure the vectors are properly normalized and consider using 16-bit or 8-bit quantization during indexing to reduce memory footprints for large datasets while maintaining reasonable retrieval accuracy. Additionally, consider leveraging GPU acceleration if available, as Faiss highly benefits from parallel processing, leading to faster nearest neighbor searches. Continuous fine-tuning and benchmarking with varying parameters and configurations can guide you in finding the most efficient setup specific to your data characteristics and retrieval requirements.

Groq llama3-70b-8192 optimization tips

To optimize Groq llama3-70b-8192 in a Retrieval-Augmented Generation (RAG) system, focus on efficient batch processing to maximize throughput by grouping multiple requests together. Utilize mixed precision for faster computation while maintaining model accuracy, and adjust input sequence length to strike a balance between context richness and computational efficiency. Leverage model parallelism to distribute workloads across multiple processing units, ensuring scalability. Regularly monitor GPU utilization and ensure that memory is efficiently managed by freeing unused tensors to prevent bottlenecks. Fine-tune the model on specific tasks or domains to improve accuracy and reduce inference time. Additionally, consider pruning or quantizing certain layers to optimize performance for production-level tasks without compromising too much on model output quality.

Cohere embed-english-v2.0 optimization tips

Cohere embed-english-v2.0 is a robust English-language embedding model, ideal for fast and accurate semantic retrieval in RAG systems. To optimize performance, preprocess input text by removing redundant information and normalizing formatting. Apply techniques like stemming or lemmatization to reduce the dimensionality of the input without losing meaning. Use high-performance indexing algorithms like HNSW for efficient vector search. When working with large-scale systems, batch embeddings for faster processing and minimize API latency. Consider implementing dimensionality reduction techniques to compress embeddings and reduce storage costs while retaining sufficient accuracy. For large document collections, periodically refresh the embeddings to ensure that they stay relevant to evolving data.

By implementing these tips across your components, you'll be able to enhance the performance and functionality of your RAG system, ensuring it’s optimized for both speed and accuracy. Keep testing, iterating, and refining your setup to stay ahead in the ever-evolving world of AI development.

RAG Cost Calculator: A Free Tool to Calculate Your Cost in Seconds

Estimating the cost of a Retrieval-Augmented Generation (RAG) pipeline involves analyzing expenses across vector storage, compute resources, and API usage. Key cost drivers include vector database queries, embedding generation, and LLM inference.

RAG Cost Calculator is a free tool that quickly estimates the cost of building a RAG pipeline, including chunking, embedding, vector storage/search, and LLM generation. It also helps you identify cost-saving opportunities and achieve up to 10x cost reduction on vector databases with the serverless option.

Calculate your RAG cost now.

Calculate your RAG cost

What Have You Learned?

By now, you’ve unlocked the magic of building a modern RAG system from the ground up! You’ve seen how LangChain acts as the glue, elegantly orchestrating the entire pipeline—tying together data retrieval, processing, and generation into a seamless workflow. With Faiss as your vector database, you’ve learned to store and query embeddings at lightning speed, turning unstructured data into searchable knowledge. The Cohere embed-english-v2.0 model became your trusty tool for transforming text into rich, semantic embeddings, capturing meaning in ways keyword searches never could. And then came the star of the show: Groq’s blazing-fast Llama3-70B-8192 model, which transformed retrieved context into coherent, human-like responses, proving just how powerful (and efficient) cutting-edge LLMs can be.

But this wasn’t just about connecting components—you also picked up pro tips for optimization, like tuning chunk sizes for better retrieval or balancing cost and performance. And let’s not forget the free RAG cost calculator you explored, a game-changer for budgeting your AI projects wisely. Now, armed with this toolkit, you’re ready to tackle real-world challenges—whether building smarter chatbots, dynamic Q&A systems, or domain-specific assistants. The possibilities are endless, and the best part? You’ve got everything you need to start experimenting, iterating, and innovating. So go ahead—dive into your next project, tweak those parameters, and watch your ideas come to life. The future of intelligent applications is in your hands, and it’s going to be awesome. Let’s build! 🚀

Further Resources

🌟 In addition to this RAG tutorial, unleash your full potential with these incredible resources to level up your RAG skills.

How to Build a Multimodal RAG | Documentation
How to Enhance the Performance of Your RAG Pipeline
Graph RAG with Milvus | Documentation
How to Evaluate RAG Applications - Zilliz Learn
Generative AI Resource Hub | Zilliz

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