Local Llama2 + VectorStoreIndex#

This notebook walks through the proper setup to use llama-2 with LlamaIndex locally. Note that you need a decent GPU to run this notebook, ideally an A100 with at least 40GB of memory.

Specifically, we look at using a vector store index.

Setup#

%pip install llama-index-llms-huggingface
%pip install llama-index-embeddings-huggingface

!pip install llama-index ipywidgets

Set Up#

IMPORTANT: Please sign in to HF hub with an account that has access to the llama2 models, using huggingface-cli login in your console. For more details, please see: https://ai.meta.com/resources/models-and-libraries/llama-downloads/.

import logging
import sys

logging.basicConfig(stream=sys.stdout, level=logging.INFO)
logging.getLogger().addHandler(logging.StreamHandler(stream=sys.stdout))


from IPython.display import Markdown, display

import torch
from llama_index.llms.huggingface import HuggingFaceLLM
from llama_index.core import PromptTemplate

# Model names (make sure you have access on HF)
LLAMA2_7B = "meta-llama/Llama-2-7b-hf"
LLAMA2_7B_CHAT = "meta-llama/Llama-2-7b-chat-hf"
LLAMA2_13B = "meta-llama/Llama-2-13b-hf"
LLAMA2_13B_CHAT = "meta-llama/Llama-2-13b-chat-hf"
LLAMA2_70B = "meta-llama/Llama-2-70b-hf"
LLAMA2_70B_CHAT = "meta-llama/Llama-2-70b-chat-hf"

selected_model = LLAMA2_13B_CHAT

SYSTEM_PROMPT = """You are an AI assistant that answers questions in a friendly manner, based on the given source documents. Here are some rules you always follow:
- Generate human readable output, avoid creating output with gibberish text.
- Generate only the requested output, don't include any other language before or after the requested output.
- Never say thank you, that you are happy to help, that you are an AI agent, etc. Just answer directly.
- Generate professional language typically used in business documents in North America.
- Never generate offensive or foul language.
"""

query_wrapper_prompt = PromptTemplate(
    "[INST]<<SYS>>\n" + SYSTEM_PROMPT + "<</SYS>>\n\n{query_str}[/INST] "
)

llm = HuggingFaceLLM(
    context_window=4096,
    max_new_tokens=2048,
    generate_kwargs={"temperature": 0.0, "do_sample": False},
    query_wrapper_prompt=query_wrapper_prompt,
    tokenizer_name=selected_model,
    model_name=selected_model,
    device_map="auto",
    # change these settings below depending on your GPU
    model_kwargs={"torch_dtype": torch.float16, "load_in_8bit": True},
)

from llama_index.embeddings.huggingface import HuggingFaceEmbedding

embed_model = HuggingFaceEmbedding(model_name="BAAI/bge-small-en-v1.5")

from llama_index.core import Settings

Settings.llm = llm
Settings.embed_model = embed_model

Download Data

!mkdir -p 'data/paul_graham/'
!wget 'https://raw.githubusercontent.com/run-llama/llama_index/main/docs/examples/data/paul_graham/paul_graham_essay.txt' -O 'data/paul_graham/paul_graham_essay.txt'

from llama_index.core import SimpleDirectoryReader

# load documents
documents = SimpleDirectoryReader("./data/paul_graham/").load_data()

from llama_index.core import VectorStoreIndex

index = VectorStoreIndex.from_documents(documents)

Querying#

# set Logging to DEBUG for more detailed outputs
query_engine = index.as_query_engine()

response = query_engine.query("What did the author do growing up?")
display(Markdown(f"<b>{response}</b>"))

Growing up, the author wrote short stories, programmed on an IBM 1401, and eventually convinced his father to buy him a TRS-80 microcomputer. He wrote simple games, a program to predict how high his model rockets would fly, and a word processor. He studied philosophy in college, but eventually switched to AI. He wrote essays and published them online, and worked on spam filters and painting. He also hosted dinners for a group of friends every Thursday night and bought a building in Cambridge.

Streaming Support#

import time

query_engine = index.as_query_engine(streaming=True)
response = query_engine.query("What happened at interleaf?")

start_time = time.time()

token_count = 0
for token in response.response_gen:
    print(token, end="")
    token_count += 1

time_elapsed = time.time() - start_time
tokens_per_second = token_count / time_elapsed

print(f"\n\nStreamed output at {tokens_per_second} tokens/s")

At Interleaf, a group of people worked on projects for customers. One of the employees told the narrator about a new thing called HTML, which was a derivative of SGML. The narrator left Interleaf to pursue art school at RISD, but continued to do freelance work for the group. Eventually, the narrator and two of his friends, Robert and Trevor, started a new company called Viaweb to create a web app that allowed users to build stores through the browser. They opened for business in January 1996 with 6 stores. The software had three main parts: the editor, the shopping cart, and the manager.

Streamed output at 26.923490295496002 tokens/s