Redis Vector Store¶
In this notebook we are going to show a quick demo of using the RedisVectorStore.
If you're opening this Notebook on colab, you will probably need to install LlamaIndex 🦙.
%pip install -U llama-index llama-index-vector-stores-redis llama-index-embeddings-cohere llama-index-embeddings-openai
import os
import getpass
import sys
import logging
import textwrap
import warnings
warnings.filterwarnings("ignore")
# Uncomment to see debug logs
logging.basicConfig(stream=sys.stdout, level=logging.INFO)
from llama_index.core import VectorStoreIndex, SimpleDirectoryReader
from llama_index.vector_stores.redis import RedisVectorStore
Start Redis¶
The easiest way to start Redis is using the Redis Stack docker image or quickly signing up for a FREE Redis Cloud instance.
To follow every step of this tutorial, launch the image as follows:
docker run --name redis-vecdb -d -p 6379:6379 -p 8001:8001 redis/redis-stack:latest
This will also launch the RedisInsight UI on port 8001 which you can view at http://localhost:8001.
Setup OpenAI¶
Lets first begin by adding the openai api key. This will allow us to access openai for embeddings and to use chatgpt.
oai_api_key = getpass.getpass("OpenAI API Key:")
os.environ["OPENAI_API_KEY"] = oai_api_key
Download Data
!mkdir -p 'data/paul_graham/'
!wget 'https://raw.githubusercontent.com/run-llama/llama_index/main/docs/docs/examples/data/paul_graham/paul_graham_essay.txt' -O 'data/paul_graham/paul_graham_essay.txt'
--2024-04-10 19:35:33-- https://raw.githubusercontent.com/run-llama/llama_index/main/docs/docs/examples/data/paul_graham/paul_graham_essay.txt Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 2606:50c0:8003::154, 2606:50c0:8000::154, 2606:50c0:8002::154, ... Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|2606:50c0:8003::154|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 75042 (73K) [text/plain] Saving to: ‘data/paul_graham/paul_graham_essay.txt’ data/paul_graham/pa 100%[===================>] 73.28K --.-KB/s in 0.03s 2024-04-10 19:35:33 (2.15 MB/s) - ‘data/paul_graham/paul_graham_essay.txt’ saved [75042/75042]
Read in a dataset¶
Here we will use a set of Paul Graham essays to provide the text to turn into embeddings, store in a RedisVectorStore
and query to find context for our LLM QnA loop.
# load documents
documents = SimpleDirectoryReader("./data/paul_graham").load_data()
print(
"Document ID:",
documents[0].id_,
"Document Filename:",
documents[0].metadata["file_name"],
)
Document ID: 7056f7ba-3513-4ef4-9792-2bd28040aaed Document Filename: paul_graham_essay.txt
Initialize the default Redis Vector Store¶
Now we have our documents prepared, we can initialize the Redis Vector Store with default settings. This will allow us to store our vectors in Redis and create an index for real-time search.
from llama_index.core import StorageContext
from redis import Redis
# create a Redis client connection
redis_client = Redis.from_url("redis://localhost:6379")
# create the vector store wrapper
vector_store = RedisVectorStore(redis_client=redis_client, overwrite=True)
# load storage context
storage_context = StorageContext.from_defaults(vector_store=vector_store)
# build and load index from documents and storage context
index = VectorStoreIndex.from_documents(
documents, storage_context=storage_context
)
# index = VectorStoreIndex.from_vector_store(vector_store=vector_store)
19:39:17 llama_index.vector_stores.redis.base INFO Using default RedisVectorStore schema. 19:39:19 httpx INFO HTTP Request: POST https://api.openai.com/v1/embeddings "HTTP/1.1 200 OK" 19:39:19 llama_index.vector_stores.redis.base INFO Added 22 documents to index llama_index
Query the default vector store¶
Now that we have our data stored in the index, we can ask questions against the index.
The index will use the data as the knowledge base for an LLM. The default setting for as_query_engine() utilizes OpenAI embeddings and GPT as the language model. Therefore, an OpenAI key is required unless you opt for a customized or local language model.
Below we will test searches against out index and then full RAG with an LLM.
query_engine = index.as_query_engine()
retriever = index.as_retriever()
result_nodes = retriever.retrieve("What did the author learn?")
for node in result_nodes:
print(node)
19:39:22 httpx INFO HTTP Request: POST https://api.openai.com/v1/embeddings "HTTP/1.1 200 OK" 19:39:22 llama_index.vector_stores.redis.base INFO Querying index llama_index with filters * 19:39:22 llama_index.vector_stores.redis.base INFO Found 2 results for query with id ['llama_index/vector_adb6b7ce-49bb-4961-8506-37082c02a389', 'llama_index/vector_e39be1fe-32d0-456e-b211-4efabd191108'] Node ID: adb6b7ce-49bb-4961-8506-37082c02a389 Text: What I Worked On February 2021 Before college the two main things I worked on, outside of school, were writing and programming. I didn't write essays. I wrote what beginning writers were supposed to write then, and probably still are: short stories. My stories were awful. They had hardly any plot, just characters with strong feelings, which I ... Score: 0.820 Node ID: e39be1fe-32d0-456e-b211-4efabd191108 Text: Except for a few officially anointed thinkers who went to the right parties in New York, the only people allowed to publish essays were specialists writing about their specialties. There were so many essays that had never been written, because there had been no way to publish them. Now they could be, and I was going to write them. [12] I've wor... Score: 0.819
response = query_engine.query("What did the author learn?")
print(textwrap.fill(str(response), 100))
19:39:25 httpx INFO HTTP Request: POST https://api.openai.com/v1/embeddings "HTTP/1.1 200 OK" 19:39:25 llama_index.vector_stores.redis.base INFO Querying index llama_index with filters * 19:39:25 llama_index.vector_stores.redis.base INFO Found 2 results for query with id ['llama_index/vector_adb6b7ce-49bb-4961-8506-37082c02a389', 'llama_index/vector_e39be1fe-32d0-456e-b211-4efabd191108'] 19:39:27 httpx INFO HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK" The author learned that working on things that weren't prestigious often led to valuable discoveries and indicated the right kind of motives. Despite the lack of initial prestige, pursuing such work could be a sign of genuine potential and appropriate motivations, steering clear of the common pitfall of being driven solely by the desire to impress others.
result_nodes = retriever.retrieve("What was a hard moment for the author?")
for node in result_nodes:
print(node)
19:39:27 httpx INFO HTTP Request: POST https://api.openai.com/v1/embeddings "HTTP/1.1 200 OK" 19:39:27 llama_index.vector_stores.redis.base INFO Querying index llama_index with filters * 19:39:27 llama_index.vector_stores.redis.base INFO Found 2 results for query with id ['llama_index/vector_adb6b7ce-49bb-4961-8506-37082c02a389', 'llama_index/vector_e39be1fe-32d0-456e-b211-4efabd191108'] Node ID: adb6b7ce-49bb-4961-8506-37082c02a389 Text: What I Worked On February 2021 Before college the two main things I worked on, outside of school, were writing and programming. I didn't write essays. I wrote what beginning writers were supposed to write then, and probably still are: short stories. My stories were awful. They had hardly any plot, just characters with strong feelings, which I ... Score: 0.802 Node ID: e39be1fe-32d0-456e-b211-4efabd191108 Text: Except for a few officially anointed thinkers who went to the right parties in New York, the only people allowed to publish essays were specialists writing about their specialties. There were so many essays that had never been written, because there had been no way to publish them. Now they could be, and I was going to write them. [12] I've wor... Score: 0.799
response = query_engine.query("What was a hard moment for the author?")
print(textwrap.fill(str(response), 100))
19:39:29 httpx INFO HTTP Request: POST https://api.openai.com/v1/embeddings "HTTP/1.1 200 OK" 19:39:29 llama_index.vector_stores.redis.base INFO Querying index llama_index with filters * 19:39:29 llama_index.vector_stores.redis.base INFO Found 2 results for query with id ['llama_index/vector_adb6b7ce-49bb-4961-8506-37082c02a389', 'llama_index/vector_e39be1fe-32d0-456e-b211-4efabd191108'] 19:39:31 httpx INFO HTTP Request: POST https://api.openai.com/v1/chat/completions "HTTP/1.1 200 OK" A hard moment for the author was when one of his programs on the IBM 1401 mainframe didn't terminate, leading to a technical error and an uncomfortable situation with the data center manager.
index.vector_store.delete_index()
19:39:34 llama_index.vector_stores.redis.base INFO Deleting index llama_index
Use a custom index schema¶
In most use cases, you need the ability to customize the underling index configuration and specification. For example, this is handy in order to define specific metadata filters you wish to enable.
With Redis, this is as simple as defining an index schema object (from file or dict) and passing it through to the vector store client wrapper.
For this example, we will:
- switch the embedding model to Cohere
- add an additional metadata field for the document
updated_at
timestamp - index the existing
file_name
metadata field
from llama_index.core.settings import Settings
from llama_index.embeddings.cohere import CohereEmbedding
# set up Cohere Key
co_api_key = getpass.getpass("Cohere API Key:")
os.environ["CO_API_KEY"] = co_api_key
# set llamaindex to use Cohere embeddings
Settings.embed_model = CohereEmbedding()
from redisvl.schema import IndexSchema
custom_schema = IndexSchema.from_dict(
{
# customize basic index specs
"index": {
"name": "paul_graham",
"prefix": "essay",
"key_separator": ":",
},
# customize fields that are indexed
"fields": [
# required fields for llamaindex
{"type": "tag", "name": "id"},
{"type": "tag", "name": "doc_id"},
{"type": "text", "name": "text"},
# custom metadata fields
{"type": "numeric", "name": "updated_at"},
{"type": "tag", "name": "file_name"},
# custom vector field definition for cohere embeddings
{
"type": "vector",
"name": "vector",
"attrs": {
"dims": 1024,
"algorithm": "hnsw",
"distance_metric": "cosine",
},
},
],
}
)
custom_schema.index
IndexInfo(name='paul_graham', prefix='essay', key_separator=':', storage_type=<StorageType.HASH: 'hash'>)
custom_schema.fields
{'id': TagField(name='id', type='tag', path=None, attrs=TagFieldAttributes(sortable=False, separator=',', case_sensitive=False, withsuffixtrie=False)), 'doc_id': TagField(name='doc_id', type='tag', path=None, attrs=TagFieldAttributes(sortable=False, separator=',', case_sensitive=False, withsuffixtrie=False)), 'text': TextField(name='text', type='text', path=None, attrs=TextFieldAttributes(sortable=False, weight=1, no_stem=False, withsuffixtrie=False, phonetic_matcher=None)), 'updated_at': NumericField(name='updated_at', type='numeric', path=None, attrs=NumericFieldAttributes(sortable=False)), 'file_name': TagField(name='file_name', type='tag', path=None, attrs=TagFieldAttributes(sortable=False, separator=',', case_sensitive=False, withsuffixtrie=False)), 'vector': HNSWVectorField(name='vector', type='vector', path=None, attrs=HNSWVectorFieldAttributes(dims=1024, algorithm=<VectorIndexAlgorithm.HNSW: 'HNSW'>, datatype=<VectorDataType.FLOAT32: 'FLOAT32'>, distance_metric=<VectorDistanceMetric.COSINE: 'COSINE'>, initial_cap=None, m=16, ef_construction=200, ef_runtime=10, epsilon=0.01))}
Learn more about schema and index design with redis.
from datetime import datetime
def date_to_timestamp(date_string: str) -> int:
date_format: str = "%Y-%m-%d"
return int(datetime.strptime(date_string, date_format).timestamp())
# iterate through documents and add new field
for document in documents:
document.metadata["updated_at"] = date_to_timestamp(
document.metadata["last_modified_date"]
)
vector_store = RedisVectorStore(
schema=custom_schema, # provide customized schema
redis_client=redis_client,
overwrite=True,
)
storage_context = StorageContext.from_defaults(vector_store=vector_store)
# build and load index from documents and storage context
index = VectorStoreIndex.from_documents(
documents, storage_context=storage_context
)
19:40:05 httpx INFO HTTP Request: POST https://api.cohere.ai/v1/embed "HTTP/1.1 200 OK" 19:40:06 httpx INFO HTTP Request: POST https://api.cohere.ai/v1/embed "HTTP/1.1 200 OK" 19:40:06 httpx INFO HTTP Request: POST https://api.cohere.ai/v1/embed "HTTP/1.1 200 OK" 19:40:06 llama_index.vector_stores.redis.base INFO Added 22 documents to index paul_graham
Query the vector store and filter on metadata¶
Now that we have additional metadata indexed in Redis, let's try some queries with filters.
from llama_index.core.vector_stores import (
MetadataFilters,
MetadataFilter,
ExactMatchFilter,
)
retriever = index.as_retriever(
similarity_top_k=3,
filters=MetadataFilters(
filters=[
ExactMatchFilter(key="file_name", value="paul_graham_essay.txt"),
MetadataFilter(
key="updated_at",
value=date_to_timestamp("2023-01-01"),
operator=">=",
),
MetadataFilter(
key="text",
value="learn",
operator="text_match",
),
],
condition="and",
),
)
result_nodes = retriever.retrieve("What did the author learn?")
for node in result_nodes:
print(node)
19:40:22 httpx INFO HTTP Request: POST https://api.cohere.ai/v1/embed "HTTP/1.1 200 OK"
19:40:22 llama_index.vector_stores.redis.base INFO Querying index paul_graham with filters ((@file_name:{paul_graham_essay\.txt} @updated_at:[1672549200 +inf]) @text:(learn)) 19:40:22 llama_index.vector_stores.redis.base INFO Found 3 results for query with id ['essay:0df3b734-ecdb-438e-8c90-f21a8c80f552', 'essay:01108c0d-140b-4dcc-b581-c38b7df9251e', 'essay:ced36463-ac36-46b0-b2d7-935c1b38b781'] Node ID: 0df3b734-ecdb-438e-8c90-f21a8c80f552 Text: All that seemed left for philosophy were edge cases that people in other fields felt could safely be ignored. I couldn't have put this into words when I was 18. All I knew at the time was that I kept taking philosophy courses and they kept being boring. So I decided to switch to AI. AI was in the air in the mid 1980s, but there were two things... Score: 0.410 Node ID: 01108c0d-140b-4dcc-b581-c38b7df9251e Text: It was not, in fact, simply a matter of teaching SHRDLU more words. That whole way of doing AI, with explicit data structures representing concepts, was not going to work. Its brokenness did, as so often happens, generate a lot of opportunities to write papers about various band-aids that could be applied to it, but it was never going to get us ... Score: 0.390 Node ID: ced36463-ac36-46b0-b2d7-935c1b38b781 Text: Grad students could take classes in any department, and my advisor, Tom Cheatham, was very easy going. If he even knew about the strange classes I was taking, he never said anything. So now I was in a PhD program in computer science, yet planning to be an artist, yet also genuinely in love with Lisp hacking and working away at On Lisp. In other... Score: 0.389
Restoring from an existing index in Redis¶
Restoring from an index requires a Redis connection client (or URL), overwrite=False
, and passing in the same schema object used before. (This can be offloaded to a YAML file for convenience using .to_yaml()
)
custom_schema.to_yaml("paul_graham.yaml")
vector_store = RedisVectorStore(
schema=IndexSchema.from_yaml("paul_graham.yaml"),
redis_client=redis_client,
)
index = VectorStoreIndex.from_vector_store(vector_store=vector_store)
19:40:28 redisvl.index.index INFO Index already exists, not overwriting.
In the near future -- we will implement a convenience method to load just using an index name:
RedisVectorStore.from_existing_index(index_name="paul_graham", redis_client=redis_client)
Deleting documents or index completely¶
Sometimes it may be useful to delete documents or the entire index. This can be done using the delete
and delete_index
methods.
document_id = documents[0].doc_id
document_id
'7056f7ba-3513-4ef4-9792-2bd28040aaed'
print("Number of documents before deleting", redis_client.dbsize())
vector_store.delete(document_id)
print("Number of documents after deleting", redis_client.dbsize())
Number of documents before deleting 22 19:40:32 llama_index.vector_stores.redis.base INFO Deleted 22 documents from index paul_graham Number of documents after deleting 0
However, the Redis index still exists (with no associated documents) for continuous upsert.
vector_store.index_exists()
True
# now lets delete the index entirely
# this will delete all the documents and the index
vector_store.delete_index()
19:40:37 llama_index.vector_stores.redis.base INFO Deleting index paul_graham
print("Number of documents after deleting", redis_client.dbsize())
Number of documents after deleting 0
Troubleshooting¶
If you get an empty query result, there a couple of issues to check:
Schema¶
Unlike other vector stores, Redis expects users to explicitly define the schema for the index. This is for a few reasons:
- Redis is used for many use cases, including real-time vector search, but also for standard document storage/retrieval, caching, messaging, pub/sub, session mangement, and more. Not all attributes on records need to be indexed for search. This is partially an efficiency thing, and partially an attempt to minimize user foot guns.
- All index schemas, when using Redis & LlamaIndex, must include the following fields
id
,doc_id
,text
, andvector
, at a minimum.
Instantiate your RedisVectorStore
with the default schema (assumes OpenAI embeddings), or with a custom schema (see above).
Prefix issues¶
Redis expects all records to have a key prefix that segments the keyspace into "partitions" for potentially different applications, use cases, and clients.
Make sure that the chosen prefix
, as part of the index schema, is consistent across your code (tied to a specific index).
To see what prefix your index was created with, you can run FT.INFO <name of your index>
in the Redis CLI and look under index_definition
=> prefixes
.
Data vs Index¶
Redis treats the records in the dataset and the index as different entities. This allows you more flexibility in performing updates, upserts, and index schema migrations.
If you have an existing index and want to make sure it's dropped, you can run FT.DROPINDEX <name of your index>
in the Redis CLI. Note that this will not drop your actual data unless you pass DD
Empty queries when using metadata¶
If you add metadata to the index after it has already been created and then try to query over that metadata, your queries will come back empty.
Redis indexes fields upon index creation only (similar to how it indexes the prefixes, above).