llama-stack-mirror/llama_stack/providers/adapters/memory/chroma/chroma.py
Ashwin Bharambe 6bb57e72a7
Remove "routing_table" and "routing_key" concepts for the user (#201)
This PR makes several core changes to the developer experience surrounding Llama Stack.

Background: PR #92 introduced the notion of "routing" to the Llama Stack. It introduces three object types: (1) models, (2) shields and (3) memory banks. Each of these objects can be associated with a distinct provider. So you can get model A to be inferenced locally while model B, C can be inference remotely (e.g.)

However, this had a few drawbacks:

you could not address the provider instances -- i.e., if you configured "meta-reference" with a given model, you could not assign an identifier to this instance which you could re-use later.
the above meant that you could not register a "routing_key" (e.g. model) dynamically and say "please use this existing provider I have already configured" for a new model.
the terms "routing_table" and "routing_key" were exposed directly to the user. in my view, this is way too much overhead for a new user (which almost everyone is.) people come to the stack wanting to do ML and encounter a completely unexpected term.
What this PR does: This PR structures the run config with only a single prominent key:

- providers
Providers are instances of configured provider types. Here's an example which shows two instances of the remote::tgi provider which are serving two different models.

providers:
  inference:
  - provider_id: foo
    provider_type: remote::tgi
    config: { ... }
  - provider_id: bar
    provider_type: remote::tgi
    config: { ... }
Secondly, the PR adds dynamic registration of { models | shields | memory_banks } to the API surface. The distribution still acts like a "routing table" (as previously) except that it asks the backing providers for a listing of these objects. For example it asks a TGI or Ollama inference adapter what models it is serving. Only the models that are being actually served can be requested by the user for inference. Otherwise, the Stack server will throw an error.

When dynamically registering these objects, you can use the provider IDs shown above. Info about providers can be obtained using the Api.inspect set of endpoints (/providers, /routes, etc.)

The above examples shows the correspondence between inference providers and models registry items. Things work similarly for the safety <=> shields and memory <=> memory_banks pairs.

Registry: This PR also makes it so that Providers need to implement additional methods for registering and listing objects. For example, each Inference provider is now expected to implement the ModelsProtocolPrivate protocol (naming is not great!) which consists of two methods

register_model
list_models
The goal is to inform the provider that a certain model needs to be supported so the provider can make any relevant backend changes if needed (or throw an error if the model cannot be supported.)

There are many other cleanups included some of which are detailed in a follow-up comment.
2024-10-10 10:24:13 -07:00

157 lines
4.9 KiB
Python

# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.
import json
from typing import List
from urllib.parse import urlparse
import chromadb
from numpy.typing import NDArray
from pydantic import parse_obj_as
from llama_stack.apis.memory import * # noqa: F403
from llama_stack.providers.datatypes import MemoryBanksProtocolPrivate
from llama_stack.providers.utils.memory.vector_store import (
BankWithIndex,
EmbeddingIndex,
)
class ChromaIndex(EmbeddingIndex):
def __init__(self, client: chromadb.AsyncHttpClient, collection):
self.client = client
self.collection = collection
async def add_chunks(self, chunks: List[Chunk], embeddings: NDArray):
assert len(chunks) == len(
embeddings
), f"Chunk length {len(chunks)} does not match embedding length {len(embeddings)}"
await self.collection.add(
documents=[chunk.json() for chunk in chunks],
embeddings=embeddings,
ids=[f"{c.document_id}:chunk-{i}" for i, c in enumerate(chunks)],
)
async def query(self, embedding: NDArray, k: int) -> QueryDocumentsResponse:
results = await self.collection.query(
query_embeddings=[embedding.tolist()],
n_results=k,
include=["documents", "distances"],
)
distances = results["distances"][0]
documents = results["documents"][0]
chunks = []
scores = []
for dist, doc in zip(distances, documents):
try:
doc = json.loads(doc)
chunk = Chunk(**doc)
except Exception:
import traceback
traceback.print_exc()
print(f"Failed to parse document: {doc}")
continue
chunks.append(chunk)
scores.append(1.0 / float(dist))
return QueryDocumentsResponse(chunks=chunks, scores=scores)
class ChromaMemoryAdapter(Memory, MemoryBanksProtocolPrivate):
def __init__(self, url: str) -> None:
print(f"Initializing ChromaMemoryAdapter with url: {url}")
url = url.rstrip("/")
parsed = urlparse(url)
if parsed.path and parsed.path != "/":
raise ValueError("URL should not contain a path")
self.host = parsed.hostname
self.port = parsed.port
self.client = None
self.cache = {}
async def initialize(self) -> None:
try:
print(f"Connecting to Chroma server at: {self.host}:{self.port}")
self.client = await chromadb.AsyncHttpClient(host=self.host, port=self.port)
except Exception as e:
import traceback
traceback.print_exc()
raise RuntimeError("Could not connect to Chroma server") from e
async def shutdown(self) -> None:
pass
async def register_memory_bank(
self,
memory_bank: MemoryBankDef,
) -> None:
assert (
memory_bank.type == MemoryBankType.vector.value
), f"Only vector banks are supported {memory_bank.type}"
collection = await self.client.get_or_create_collection(
name=memory_bank.identifier,
metadata={"bank": memory_bank.json()},
)
bank_index = BankWithIndex(
bank=memory_bank, index=ChromaIndex(self.client, collection)
)
self.cache[memory_bank.identifier] = bank_index
async def list_memory_banks(self) -> List[MemoryBankDef]:
collections = await self.client.list_collections()
for collection in collections:
try:
data = json.loads(collection.metadata["bank"])
bank = parse_obj_as(MemoryBankDef, data)
except Exception:
import traceback
traceback.print_exc()
print(f"Failed to parse bank: {collection.metadata}")
continue
index = BankWithIndex(
bank=bank,
index=ChromaIndex(self.client, collection),
)
self.cache[bank.identifier] = index
return [i.bank for i in self.cache.values()]
async def insert_documents(
self,
bank_id: str,
documents: List[MemoryBankDocument],
ttl_seconds: Optional[int] = None,
) -> None:
index = self.cache.get(bank_id, None)
if not index:
raise ValueError(f"Bank {bank_id} not found")
await index.insert_documents(documents)
async def query_documents(
self,
bank_id: str,
query: InterleavedTextMedia,
params: Optional[Dict[str, Any]] = None,
) -> QueryDocumentsResponse:
index = self.cache.get(bank_id, None)
if not index:
raise ValueError(f"Bank {bank_id} not found")
return await index.query_documents(query, params)