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Activeloop 深度记忆

Activeloop Deep Memory 是一套工具,使您能够根据您的使用场景优化您的向量存储,并在您的LLM应用中实现更高的准确性。

Retrieval-Augmented Generatation (RAG) 最近获得了显著的关注。随着先进的RAG技术和代理的出现,它们扩展了RAG所能实现的潜力。然而,一些挑战可能会限制RAG在生产中的集成。在生产环境中实施RAG时,主要考虑的因素是准确性(召回率)、成本和延迟。对于基本用例,OpenAI的Ada模型与简单的相似性搜索结合可以产生令人满意的结果。然而,为了在搜索中获得更高的准确性或召回率,可能需要采用高级的检索技术。这些方法可能涉及不同的数据块大小、多次重写查询等,可能会增加延迟和成本。Activeloop的Deep MemoryActiveloop Deep Lake用户可用的一个功能,通过引入一个微小的神经网络层来解决这些问题,该层经过训练以将用户查询与语料库中的相关数据匹配。虽然这种增加在搜索过程中会产生最小的延迟,但它可以将检索准确性提高多达27%,并且仍然具有成本效益且易于使用,无需任何额外的高级RAG技术。

在本教程中,我们将解析DeepLake文档,并创建一个RAG系统,该系统可以回答文档中的问题。

1. 数据集创建

我们将使用BeautifulSoup库和LangChain的文档解析器如Html2TextTransformerAsyncHtmlLoader来解析本教程中的activeloop文档。因此,我们需要安装以下库:

%pip install --upgrade --quiet  tiktoken langchain-openai python-dotenv datasets langchain deeplake beautifulsoup4 html2text ragas

此外,您还需要创建一个Activeloop账户。

ORG_ID = "..."
from langchain.chains import RetrievalQA
from langchain_community.vectorstores import DeepLake
from langchain_openai import ChatOpenAI, OpenAIEmbeddings
import getpass
import os

if "OPENAI_API_KEY" not in os.environ:
os.environ["OPENAI_API_KEY"] = getpass.getpass("Enter your OpenAI API token: ")
# # activeloop token is needed if you are not signed in using CLI: `activeloop login -u <USERNAME> -p <PASSWORD>`
if "ACTIVELOOP_TOKEN" not in os.environ:
os.environ["ACTIVELOOP_TOKEN"] = getpass.getpass(
"Enter your ActiveLoop API token: "
) # Get your API token from https://app.activeloop.ai, click on your profile picture in the top right corner, and select "API Tokens"

token = os.getenv("ACTIVELOOP_TOKEN")
openai_embeddings = OpenAIEmbeddings()
db = DeepLake(
dataset_path=f"hub://{ORG_ID}/deeplake-docs-deepmemory", # org_id stands for your username or organization from activeloop
embedding=openai_embeddings,
runtime={"tensor_db": True},
token=token,
# overwrite=True, # user overwrite flag if you want to overwrite the full dataset
read_only=False,
)

使用BeautifulSoup解析网页中的所有链接

from urllib.parse import urljoin

import requests
from bs4 import BeautifulSoup


def get_all_links(url):
response = requests.get(url)
if response.status_code != 200:
print(f"Failed to retrieve the page: {url}")
return []

soup = BeautifulSoup(response.content, "html.parser")

# Finding all 'a' tags which typically contain href attribute for links
links = [
urljoin(url, a["href"]) for a in soup.find_all("a", href=True) if a["href"]
]

return links


base_url = "https://docs.deeplake.ai/en/latest/"
all_links = get_all_links(base_url)

加载数据:

from langchain_community.document_loaders.async_html import AsyncHtmlLoader

loader = AsyncHtmlLoader(all_links)
docs = loader.load()
API Reference:AsyncHtmlLoader

将数据转换为用户可读的格式:

from langchain_community.document_transformers import Html2TextTransformer

html2text = Html2TextTransformer()
docs_transformed = html2text.transform_documents(docs)
API Reference:Html2TextTransformer

现在,让我们进一步分块文档,因为其中一些包含太多文本:

from langchain_text_splitters import RecursiveCharacterTextSplitter

chunk_size = 4096
docs_new = []

text_splitter = RecursiveCharacterTextSplitter(
chunk_size=chunk_size,
)

for doc in docs_transformed:
if len(doc.page_content) < chunk_size:
docs_new.append(doc)
else:
docs = text_splitter.create_documents([doc.page_content])
docs_new.extend(docs)

填充向量存储:

docs = db.add_documents(docs_new)

2. 生成合成查询并训练深度记忆

下一步将是训练一个deep_memory模型,该模型将把用户的查询与您已有的数据集对齐。如果您还没有任何用户查询,不用担心,我们将使用LLM生成它们!

待办事项:添加图片

上面我们展示了deep_memory的整体工作原理。如你所见,为了训练它,你需要相关性、查询以及语料库数据(我们想要查询的数据)。语料库数据已经在上一节中填充完毕,这里我们将生成问题和相关性。

  1. questions - 是一个字符串文本,其中每个字符串代表一个查询
  2. relevance - 包含每个问题的真实答案的链接。可能有多个文档包含给定问题的答案。因此,相关性是List[List[tuple[str, float]]],其中外部列表表示查询,内部列表表示相关文档。元组包含str, float对,其中字符串表示源文档的id(对应于数据集中的id张量),而浮点数表示当前文档与问题的相关程度。

现在,让我们生成合成问题和相关性:

from typing import List

from langchain.chains.openai_functions import (
create_structured_output_chain,
)
from langchain_core.messages import HumanMessage, SystemMessage
from langchain_core.prompts import ChatPromptTemplate, HumanMessagePromptTemplate
from langchain_openai import ChatOpenAI
from pydantic import BaseModel, Field
# fetch dataset docs and ids if they exist (optional you can also ingest)
docs = db.vectorstore.dataset.text.data(fetch_chunks=True, aslist=True)["value"]
ids = db.vectorstore.dataset.id.data(fetch_chunks=True, aslist=True)["value"]
# If we pass in a model explicitly, we need to make sure it supports the OpenAI function-calling API.
llm = ChatOpenAI(model="gpt-3.5-turbo", temperature=0)


class Questions(BaseModel):
"""Identifying information about a person."""

question: str = Field(..., description="Questions about text")


prompt_msgs = [
SystemMessage(
content="You are a world class expert for generating questions based on provided context. \
You make sure the question can be answered by the text."
),
HumanMessagePromptTemplate.from_template(
"Use the given text to generate a question from the following input: {input}"
),
HumanMessage(content="Tips: Make sure to answer in the correct format"),
]
prompt = ChatPromptTemplate(messages=prompt_msgs)
chain = create_structured_output_chain(Questions, llm, prompt, verbose=True)

text = "# Understanding Hallucinations and Bias ## **Introduction** In this lesson, we'll cover the concept of **hallucinations** in LLMs, highlighting their influence on AI applications and demonstrating how to mitigate them using techniques like the retriever's architectures. We'll also explore **bias** within LLMs with examples."
questions = chain.run(input=text)
print(questions)
import random

from langchain_openai import OpenAIEmbeddings
from tqdm import tqdm


def generate_queries(docs: List[str], ids: List[str], n: int = 100):
questions = []
relevances = []
pbar = tqdm(total=n)
while len(questions) < n:
# 1. randomly draw a piece of text and relevance id
r = random.randint(0, len(docs) - 1)
text, label = docs[r], ids[r]

# 2. generate queries and assign and relevance id
generated_qs = [chain.run(input=text).question]
questions.extend(generated_qs)
relevances.extend([[(label, 1)] for _ in generated_qs])
pbar.update(len(generated_qs))
if len(questions) % 10 == 0:
print(f"q: {len(questions)}")
return questions[:n], relevances[:n]


chain = create_structured_output_chain(Questions, llm, prompt, verbose=False)
questions, relevances = generate_queries(docs, ids, n=200)

train_questions, train_relevances = questions[:100], relevances[:100]
test_questions, test_relevances = questions[100:], relevances[100:]
API Reference:OpenAIEmbeddings

现在我们创建了100个训练查询以及100个测试查询。现在让我们训练deep_memory:

job_id = db.vectorstore.deep_memory.train(
queries=train_questions,
relevance=train_relevances,
)

让我们跟踪训练进度:

db.vectorstore.deep_memory.status("6538939ca0b69a9ca45c528c")

--------------------------------------------------------------
| 6538e02ecda4691033a51c5b |
--------------------------------------------------------------
| status | completed |
--------------------------------------------------------------
| progress | eta: 1.4 seconds |
| | recall@10: 79.00% (+34.00%) |
--------------------------------------------------------------
| results | recall@10: 79.00% (+34.00%) |
--------------------------------------------------------------

3. 评估深度记忆性能

太好了,我们已经训练了模型!它在召回率上显示出了一些显著的改进,但我们如何现在使用它并在未见过的数据上进行评估呢?在本节中,我们将深入探讨模型评估和推理部分,并看看如何与LangChain一起使用以提高检索准确性。

3.1 深度记忆评估

首先,我们可以使用 deep_memory 的内置评估方法。 它计算了几个 recall 指标。 只需几行代码即可轻松完成。

recall = db.vectorstore.deep_memory.evaluate(
queries=test_questions,
relevance=test_relevances,
)

Embedding queries took 0.81 seconds
---- Evaluating without model ----
Recall@1: 9.0%
Recall@3: 19.0%
Recall@5: 24.0%
Recall@10: 42.0%
Recall@50: 93.0%
Recall@100: 98.0%
---- Evaluating with model ----
Recall@1: 19.0%
Recall@3: 42.0%
Recall@5: 49.0%
Recall@10: 69.0%
Recall@50: 97.0%
Recall@100: 97.0%

它在未见过的测试数据集上也显示出相当大的改进!!!

3.2 深度记忆 + RAGas

from ragas.langchain import RagasEvaluatorChain
from ragas.metrics import (
context_recall,
)

让我们将召回率转换为真实值:

def convert_relevance_to_ground_truth(docs, relevance):
ground_truths = []

for rel in relevance:
ground_truth = []
for doc_id, _ in rel:
ground_truth.append(docs[doc_id])
ground_truths.append(ground_truth)
return ground_truths
ground_truths = convert_relevance_to_ground_truth(docs, test_relevances)

for deep_memory in [False, True]:
print("\nEvaluating with deep_memory =", deep_memory)
print("===================================")

retriever = db.as_retriever()
retriever.search_kwargs["deep_memory"] = deep_memory

qa_chain = RetrievalQA.from_chain_type(
llm=ChatOpenAI(model="gpt-3.5-turbo"),
chain_type="stuff",
retriever=retriever,
return_source_documents=True,
)

metrics = {
"context_recall_score": 0,
}

eval_chains = {m.name: RagasEvaluatorChain(metric=m) for m in [context_recall]}

for question, ground_truth in zip(test_questions, ground_truths):
result = qa_chain({"query": question})
result["ground_truths"] = ground_truth
for name, eval_chain in eval_chains.items():
score_name = f"{name}_score"
metrics[score_name] += eval_chain(result)[score_name]

for metric in metrics:
metrics[metric] /= len(test_questions)
print(f"{metric}: {metrics[metric]}")
print("===================================")

Evaluating with deep_memory = False
===================================
context_recall_score = 0.3763423145
===================================

Evaluating with deep_memory = True
===================================
context_recall_score = 0.5634545323
===================================

3.3 深度记忆推理

待办事项:添加图片

使用深度记忆

retriever = db.as_retriever()
retriever.search_kwargs["deep_memory"] = True
retriever.search_kwargs["k"] = 10

query = "Deamination of cytidine to uridine on the minus strand of viral DNA results in catastrophic G-to-A mutations in the viral genome."
qa = RetrievalQA.from_chain_type(
llm=ChatOpenAI(model="gpt-4"), chain_type="stuff", retriever=retriever
)
print(qa.run(query))
The base htype of the 'video_seq' tensor is 'video'.

没有 deep_memory

retriever = db.as_retriever()
retriever.search_kwargs["deep_memory"] = False
retriever.search_kwargs["k"] = 10

query = "Deamination of cytidine to uridine on the minus strand of viral DNA results in catastrophic G-to-A mutations in the viral genome."
qa = RetrievalQA.from_chain_type(
llm=ChatOpenAI(model="gpt-4"), chain_type="stuff", retriever=retriever
)
qa.run(query)
The text does not provide information on the base htype of the 'video_seq' tensor.

3.4 深度内存成本节省

深度记忆提高了检索准确性,而无需改变您现有的工作流程。此外,通过减少输入到LLM的top_k,您可以显著降低推理成本,因为使用的令牌数量减少了。


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