[Bugfix] Validate lora adapters to avoid crashing server (#11727)

Signed-off-by: Joe Runde <Joseph.Runde@ibm.com>
Co-authored-by: Jee Jee Li <pandaleefree@gmail.com>

tests/entrypoints/openai/test_lora_adapters.py

+import asyncio
+import json
+import shutil
+from contextlib import suppress
+
+import openai  # use the official client for correctness check
+import pytest
+import pytest_asyncio
+# downloading lora to test lora requests
+from huggingface_hub import snapshot_download
+
+from ...utils import RemoteOpenAIServer
+
+# any model with a chat template should work here
+MODEL_NAME = "HuggingFaceH4/zephyr-7b-beta"
+# technically this needs Mistral-7B-v0.1 as base, but we're not testing
+# generation quality here
+LORA_NAME = "typeof/zephyr-7b-beta-lora"
+
+
+@pytest.fixture(scope="module")
+def zephyr_lora_files():
+    return snapshot_download(repo_id=LORA_NAME)
+
+
+@pytest.fixture(scope="module")
+def server_with_lora_modules_json(zephyr_lora_files):
+    # Define the json format LoRA module configurations
+    lora_module_1 = {
+        "name": "zephyr-lora",
+        "path": zephyr_lora_files,
+        "base_model_name": MODEL_NAME
+    }
+
+    lora_module_2 = {
+        "name": "zephyr-lora2",
+        "path": zephyr_lora_files,
+        "base_model_name": MODEL_NAME
+    }
+
+    args = [
+        # use half precision for speed and memory savings in CI environment
+        "--dtype",
+        "bfloat16",
+        "--max-model-len",
+        "8192",
+        "--enforce-eager",
+        # lora config below
+        "--enable-lora",
+        "--lora-modules",
+        json.dumps(lora_module_1),
+        json.dumps(lora_module_2),
+        "--max-lora-rank",
+        "64",
+        "--max-cpu-loras",
+        "2",
+        "--max-num-seqs",
+        "64",
+    ]
+
+    # Enable the /v1/load_lora_adapter endpoint
+    envs = {"VLLM_ALLOW_RUNTIME_LORA_UPDATING": "True"}
+
+    with RemoteOpenAIServer(MODEL_NAME, args, env_dict=envs) as remote_server:
+        yield remote_server
+
+
+@pytest_asyncio.fixture
+async def client(server_with_lora_modules_json):
+    async with server_with_lora_modules_json.get_async_client(
+    ) as async_client:
+        yield async_client
+
+
+@pytest.mark.asyncio
+async def test_static_lora_lineage(client: openai.AsyncOpenAI,
+                                   zephyr_lora_files):
+    models = await client.models.list()
+    models = models.data
+    served_model = models[0]
+    lora_models = models[1:]
+    assert served_model.id == MODEL_NAME
+    assert served_model.root == MODEL_NAME
+    assert served_model.parent is None
+    assert all(lora_model.root == zephyr_lora_files
+               for lora_model in lora_models)
+    assert all(lora_model.parent == MODEL_NAME for lora_model in lora_models)
+    assert lora_models[0].id == "zephyr-lora"
+    assert lora_models[1].id == "zephyr-lora2"
+
+
+@pytest.mark.asyncio
+async def test_dynamic_lora_lineage(client: openai.AsyncOpenAI,
+                                    zephyr_lora_files):
+
+    response = await client.post("load_lora_adapter",
+                                 cast_to=str,
+                                 body={
+                                     "lora_name": "zephyr-lora-3",
+                                     "lora_path": zephyr_lora_files
+                                 })
+    # Ensure adapter loads before querying /models
+    assert "success" in response
+
+    models = await client.models.list()
+    models = models.data
+    dynamic_lora_model = models[-1]
+    assert dynamic_lora_model.root == zephyr_lora_files
+    assert dynamic_lora_model.parent == MODEL_NAME
+    assert dynamic_lora_model.id == "zephyr-lora-3"
+
+
+@pytest.mark.asyncio
+async def test_dynamic_lora_not_found(client: openai.AsyncOpenAI):
+    with pytest.raises(openai.NotFoundError):
+        await client.post("load_lora_adapter",
+                          cast_to=str,
+                          body={
+                              "lora_name": "notfound",
+                              "lora_path": "/not/an/adapter"
+                          })
+
+
+@pytest.mark.asyncio
+async def test_dynamic_lora_invalid_files(client: openai.AsyncOpenAI,
+                                          tmp_path):
+    invalid_files = tmp_path / "invalid_files"
+    invalid_files.mkdir()
+    (invalid_files / "adapter_config.json").write_text("this is not json")
+
+    with pytest.raises(openai.BadRequestError):
+        await client.post("load_lora_adapter",
+                          cast_to=str,
+                          body={
+                              "lora_name": "invalid-json",
+                              "lora_path": str(invalid_files)
+                          })
+
+
+@pytest.mark.asyncio
+async def test_dynamic_lora_invalid_lora_rank(client: openai.AsyncOpenAI,
+                                              tmp_path, zephyr_lora_files):
+    invalid_rank = tmp_path / "invalid_rank"
+
+    # Copy adapter from zephyr_lora_files to invalid_rank
+    shutil.copytree(zephyr_lora_files, invalid_rank)
+
+    with open(invalid_rank / "adapter_config.json") as f:
+        adapter_config = json.load(f)
+
+    print(adapter_config)
+
+    # assert False
+
+    # Change rank to invalid value
+    adapter_config["r"] = 1024
+    with open(invalid_rank / "adapter_config.json", "w") as f:
+        json.dump(adapter_config, f)
+
+    with pytest.raises(openai.BadRequestError,
+                       match="is greater than max_lora_rank"):
+        await client.post("load_lora_adapter",
+                          cast_to=str,
+                          body={
+                              "lora_name": "invalid-json",
+                              "lora_path": str(invalid_rank)
+                          })
+
+
+@pytest.mark.asyncio
+async def test_multiple_lora_adapters(client: openai.AsyncOpenAI, tmp_path,
+                                      zephyr_lora_files):
+    """Validate that many loras can be dynamically registered and inferenced 
+    with concurrently"""
+
+    # This test file configures the server with --max-cpu-loras=2 and this test
+    # will concurrently load 10 adapters, so it should flex the LRU cache
+    async def load_and_run_adapter(adapter_name: str):
+        await client.post("load_lora_adapter",
+                          cast_to=str,
+                          body={
+                              "lora_name": adapter_name,
+                              "lora_path": str(zephyr_lora_files)
+                          })
+        for _ in range(3):
+            await client.completions.create(
+                model=adapter_name,
+                prompt=["Hello there", "Foo bar bazz buzz"],
+                max_tokens=5,
+            )
+
+    lora_tasks = []
+    for i in range(10):
+        lora_tasks.append(
+            asyncio.create_task(load_and_run_adapter(f"adapter_{i}")))
+
+    results, _ = await asyncio.wait(lora_tasks)
+
+    for r in results:
+        assert not isinstance(r, Exception), f"Got exception {r}"
+
+
+@pytest.mark.asyncio
+async def test_loading_invalid_adapters_does_not_break_others(
+        client: openai.AsyncOpenAI, tmp_path, zephyr_lora_files):
+
+    invalid_files = tmp_path / "invalid_files"
+    invalid_files.mkdir()
+    (invalid_files / "adapter_config.json").write_text("this is not json")
+
+    stop_good_requests_event = asyncio.Event()
+
+    async def run_good_requests(client):
+        # Run chat completions requests until event set
+
+        results = []
+
+        while not stop_good_requests_event.is_set():
+            try:
+                batch = await client.completions.create(
+                    model="zephyr-lora",
+                    prompt=["Hello there", "Foo bar bazz buzz"],
+                    max_tokens=5,
+                )
+                results.append(batch)
+            except Exception as e:
+                results.append(e)
+
+        return results
+
+    # Create task to run good requests
+    good_task = asyncio.create_task(run_good_requests(client))
+
+    # Run a bunch of bad adapter loads
+    for _ in range(25):
+        with suppress(openai.NotFoundError):
+            await client.post("load_lora_adapter",
+                              cast_to=str,
+                              body={
+                                  "lora_name": "notfound",
+                                  "lora_path": "/not/an/adapter"
+                              })
+    for _ in range(25):
+        with suppress(openai.BadRequestError):
+            await client.post("load_lora_adapter",
+                              cast_to=str,
+                              body={
+                                  "lora_name": "invalid",
+                                  "lora_path": str(invalid_files)
+                              })
+
+    # Ensure all the running requests with lora adapters succeeded
+    stop_good_requests_event.set()
+    results = await good_task
+    for r in results:
+        assert not isinstance(r, Exception), f"Got exception {r}"
+
+    # Ensure we can load another adapter and run it
+    await client.post("load_lora_adapter",
+                      cast_to=str,
+                      body={
+                          "lora_name": "valid",
+                          "lora_path": zephyr_lora_files
+                      })
+    await client.completions.create(
+        model="valid",
+        prompt=["Hello there", "Foo bar bazz buzz"],
+        max_tokens=5,
+    )

tests/entrypoints/openai/test_lora_lineage.py

-import json
-
-import openai  # use the official client for correctness check
-import pytest
-import pytest_asyncio
-# downloading lora to test lora requests
-from huggingface_hub import snapshot_download
-
-from ...utils import RemoteOpenAIServer
-
-# any model with a chat template should work here
-MODEL_NAME = "HuggingFaceH4/zephyr-7b-beta"
-# technically this needs Mistral-7B-v0.1 as base, but we're not testing
-# generation quality here
-LORA_NAME = "typeof/zephyr-7b-beta-lora"
-
-
-@pytest.fixture(scope="module")
-def zephyr_lora_files():
-    return snapshot_download(repo_id=LORA_NAME)
-
-
-@pytest.fixture(scope="module")
-def server_with_lora_modules_json(zephyr_lora_files):
-    # Define the json format LoRA module configurations
-    lora_module_1 = {
-        "name": "zephyr-lora",
-        "path": zephyr_lora_files,
-        "base_model_name": MODEL_NAME
-    }
-
-    lora_module_2 = {
-        "name": "zephyr-lora2",
-        "path": zephyr_lora_files,
-        "base_model_name": MODEL_NAME
-    }
-
-    args = [
-        # use half precision for speed and memory savings in CI environment
-        "--dtype",
-        "bfloat16",
-        "--max-model-len",
-        "8192",
-        "--enforce-eager",
-        # lora config below
-        "--enable-lora",
-        "--lora-modules",
-        json.dumps(lora_module_1),
-        json.dumps(lora_module_2),
-        "--max-lora-rank",
-        "64",
-        "--max-cpu-loras",
-        "2",
-        "--max-num-seqs",
-        "64",
-    ]
-
-    # Enable the /v1/load_lora_adapter endpoint
-    envs = {"VLLM_ALLOW_RUNTIME_LORA_UPDATING": "True"}
-
-    with RemoteOpenAIServer(MODEL_NAME, args, env_dict=envs) as remote_server:
-        yield remote_server
-
-
-@pytest_asyncio.fixture
-async def client_for_lora_lineage(server_with_lora_modules_json):
-    async with server_with_lora_modules_json.get_async_client(
-    ) as async_client:
-        yield async_client
-
-
-@pytest.mark.asyncio
-async def test_static_lora_lineage(client_for_lora_lineage: openai.AsyncOpenAI,
-                                   zephyr_lora_files):
-    models = await client_for_lora_lineage.models.list()
-    models = models.data
-    served_model = models[0]
-    lora_models = models[1:]
-    assert served_model.id == MODEL_NAME
-    assert served_model.root == MODEL_NAME
-    assert served_model.parent is None
-    assert all(lora_model.root == zephyr_lora_files
-               for lora_model in lora_models)
-    assert all(lora_model.parent == MODEL_NAME for lora_model in lora_models)
-    assert lora_models[0].id == "zephyr-lora"
-    assert lora_models[1].id == "zephyr-lora2"
-
-
-@pytest.mark.asyncio
-async def test_dynamic_lora_lineage(
-        client_for_lora_lineage: openai.AsyncOpenAI, zephyr_lora_files):
-
-    response = await client_for_lora_lineage.post("load_lora_adapter",
-                                                  cast_to=str,
-                                                  body={
-                                                      "lora_name":
-                                                      "zephyr-lora-3",
-                                                      "lora_path":
-                                                      zephyr_lora_files
-                                                  })
-    # Ensure adapter loads before querying /models
-    assert "success" in response
-
-    models = await client_for_lora_lineage.models.list()
-    models = models.data
-    dynamic_lora_model = models[-1]
-    assert dynamic_lora_model.root == zephyr_lora_files
-    assert dynamic_lora_model.parent == MODEL_NAME
-    assert dynamic_lora_model.id == "zephyr-lora-3"

tests/entrypoints/openai/test_serving_chat.py

@@ -52,7 +52,7 @@ async def _async_serving_chat_init():
     engine = MockEngine()
     model_config = await engine.get_model_config()
 
-    models = OpenAIServingModels(model_config, BASE_MODEL_PATHS)
+    models = OpenAIServingModels(engine, model_config, BASE_MODEL_PATHS)
     serving_completion = OpenAIServingChat(engine,
                                            model_config,
                                            models,
@@ -73,7 +73,8 @@ def test_serving_chat_should_set_correct_max_tokens():
     mock_engine.get_tokenizer.return_value = get_tokenizer(MODEL_NAME)
     mock_engine.errored = False
 
-    models = OpenAIServingModels(base_model_paths=BASE_MODEL_PATHS,
+    models = OpenAIServingModels(engine_client=mock_engine,
+                                 base_model_paths=BASE_MODEL_PATHS,
                                  model_config=MockModelConfig())
     serving_chat = OpenAIServingChat(mock_engine,
                                      MockModelConfig(),
@@ -116,7 +117,8 @@ def test_serving_chat_could_load_correct_generation_config():
     mock_engine.errored = False
 
     # Initialize the serving chat
-    models = OpenAIServingModels(base_model_paths=BASE_MODEL_PATHS,
+    models = OpenAIServingModels(engine_client=mock_engine,
+                                 base_model_paths=BASE_MODEL_PATHS,
                                  model_config=mock_model_config)
     serving_chat = OpenAIServingChat(mock_engine,
                                      mock_model_config,

tests/entrypoints/openai/test_serving_models.py

@@ -4,6 +4,7 @@ from unittest.mock import MagicMock
 import pytest
 
 from vllm.config import ModelConfig
+from vllm.engine.protocol import EngineClient
 from vllm.entrypoints.openai.protocol import (ErrorResponse,
                                               LoadLoraAdapterRequest,
                                               UnloadLoraAdapterRequest)
@@ -21,13 +22,16 @@ LORA_UNLOADING_SUCCESS_MESSAGE = (
 
 async def _async_serving_models_init() -> OpenAIServingModels:
     mock_model_config = MagicMock(spec=ModelConfig)
+    mock_engine_client = MagicMock(spec=EngineClient)
     # Set the max_model_len attribute to avoid missing attribute
     mock_model_config.max_model_len = 2048
 
-    serving_models = OpenAIServingModels(base_model_paths=BASE_MODEL_PATHS,
+    serving_models = OpenAIServingModels(engine_client=mock_engine_client,
+                                         base_model_paths=BASE_MODEL_PATHS,
                                          model_config=mock_model_config,
                                          lora_modules=None,
                                          prompt_adapters=None)
+    await serving_models.init_static_loras()
 
     return serving_models
 
@@ -113,5 +117,5 @@ async def test_unload_lora_adapter_not_found():
     request = UnloadLoraAdapterRequest(lora_name="nonexistent_adapter")
     response = await serving_models.unload_lora_adapter(request)
     assert isinstance(response, ErrorResponse)
-    assert response.type == "InvalidUserInput"
-    assert response.code == HTTPStatus.BAD_REQUEST
+    assert response.type == "NotFoundError"
+    assert response.code == HTTPStatus.NOT_FOUND

tests/entrypoints/openai/test_shutdown.py

-import json
-import os
-
 import openai
 import pytest
 
@@ -10,16 +7,7 @@ MODEL_NAME = "meta-llama/Llama-3.2-1B"
 
 
 @pytest.mark.asyncio
-async def test_shutdown_on_engine_failure(tmp_path):
-    # Use a bad adapter to crash the engine
-    # (This test will fail when that bug is fixed)
-    adapter_path = tmp_path / "bad_adapter"
-    os.mkdir(adapter_path)
-    with open(adapter_path / "adapter_model_config.json", "w") as f:
-        json.dump({"not": "real"}, f)
-    with open(adapter_path / "adapter_model.safetensors", "wb") as f:
-        f.write(b"this is fake")
-
+async def test_shutdown_on_engine_failure():
     # dtype, max-len etc set so that this can run in CI
     args = [
         "--dtype",
@@ -29,9 +17,6 @@ async def test_shutdown_on_engine_failure(tmp_path):
         "--enforce-eager",
         "--max-num-seqs",
         "128",
-        "--enable-lora",
-        "--lora-modules",
-        f"bad-adapter={tmp_path / 'bad_adapter'}",
     ]
 
     with RemoteOpenAIServer(MODEL_NAME, args) as remote_server:
@@ -39,9 +24,13 @@ async def test_shutdown_on_engine_failure(tmp_path):
 
             with pytest.raises(
                 (openai.APIConnectionError, openai.InternalServerError)):
-                # This crashes the engine
-                await client.completions.create(model="bad-adapter",
-                                                prompt="Hello, my name is")
+                # Asking for lots of prompt logprobs will currently crash the
+                # engine. This may change in the future when that bug is fixed
+                prompt = "Hello " * 4000
+                await client.completions.create(
+                    model=MODEL_NAME,
+                    prompt=prompt,
+                    extra_body={"prompt_logprobs": 10})
 
             # Now the server should shut down
             return_code = remote_server.proc.wait(timeout=8)

vllm/engine/async_llm_engine.py

@@ -1257,6 +1257,10 @@ class AsyncLLMEngine(EngineClient):
         else:
             self.engine.model_executor._run_workers("stop_profile")
 
+    async def add_lora(self, lora_request: LoRARequest) -> None:
+        """Load a new LoRA adapter into the engine for future requests."""
+        self.engine.add_lora(lora_request)
+
 
 # TODO(v1): Remove this class proxy when V1 goes default.
 if envs.VLLM_USE_V1:

vllm/engine/multiprocessing/__init__.py

-from dataclasses import dataclass
+import uuid
+from dataclasses import dataclass, field
 from enum import Enum
 from typing import List, Mapping, Optional, Union, overload
 
@@ -120,10 +121,23 @@ class RPCUProfileRequest(Enum):
     STOP_PROFILE = 2
 
 
+@dataclass
+class RPCLoadAdapterRequest:
+    lora_request: LoRARequest
+    # Set the default value of request_id to a new UUID
+    request_id: str = field(default_factory=lambda: str(uuid.uuid4()))
+
+
+@dataclass
+class RPCAdapterLoadedResponse:
+    request_id: str
+
+
 RPC_REQUEST_T = Union[RPCProcessRequest, RPCAbortRequest, RPCStartupRequest,
-                      RPCUProfileRequest]
+                      RPCUProfileRequest, RPCLoadAdapterRequest]
 
-REQUEST_OUTPUTS_T = Union[List[RequestOutput], RPCError]
+REQUEST_OUTPUTS_T = Union[List[RequestOutput], RPCAdapterLoadedResponse,
+                          RPCError]
 
 
 def ENGINE_DEAD_ERROR(

vllm/engine/multiprocessing/client.py

@@ -25,8 +25,10 @@ from vllm.engine.multiprocessing import (ENGINE_DEAD_ERROR, IPC_DATA_EXT,
                                          IPC_HEALTH_EXT, IPC_INPUT_EXT,
                                          IPC_OUTPUT_EXT, RPC_REQUEST_T,
                                          VLLM_RPC_SUCCESS_STR, RPCAbortRequest,
-                                         RPCError, RPCProcessRequest,
-                                         RPCStartupRequest, RPCStartupResponse,
+                                         RPCAdapterLoadedResponse, RPCError,
+                                         RPCLoadAdapterRequest,
+                                         RPCProcessRequest, RPCStartupRequest,
+                                         RPCStartupResponse,
                                          RPCUProfileRequest)
 from vllm.engine.protocol import EngineClient
 # yapf: enable
@@ -240,17 +242,22 @@ class MQLLMEngineClient(EngineClient):
                         queue = self.output_queues.get(request_id)
                         if queue is not None:
                             queue.put_nowait(exception)
+                # Put each output into the appropriate queue.
+                elif isinstance(request_outputs, RPCAdapterLoadedResponse):
+                    self._add_output(request_outputs)
                 else:
-                    # Put each output into the appropriate steam.
                     for request_output in request_outputs:
-                        queue = self.output_queues.get(
-                            request_output.request_id)
-                        if queue is not None:
-                            queue.put_nowait(request_output)
+                        self._add_output(request_output)
 
         except asyncio.CancelledError:
             logger.debug("Shutting down MQLLMEngineClient output handler.")
 
+    def _add_output(self, request_output: Union[RequestOutput,
+                                                RPCAdapterLoadedResponse]):
+        queue = self.output_queues.get(request_output.request_id)
+        if queue is not None:
+            queue.put_nowait(request_output)
+
     async def setup(self):
         """Setup the client before it starts sending server requests."""
 
@@ -659,3 +666,24 @@ class MQLLMEngineClient(EngineClient):
 
         await self._send_one_way_rpc_request(
             request=RPCUProfileRequest.STOP_PROFILE, socket=self.input_socket)
+
+    async def add_lora(self, lora_request: LoRARequest) -> None:
+        """Load a new LoRA adapter into the engine for future requests."""
+        # Uses the same I/O as generate requests
+        request = RPCLoadAdapterRequest(lora_request)
+
+        # Create output queue for this requests.
+        queue: asyncio.Queue[Union[None, BaseException]] = asyncio.Queue()
+        self.output_queues[request.request_id] = queue
+
+        # Send the request
+        request_bytes = pickle.dumps(request)
+        await self.input_socket.send_multipart((request_bytes, ), copy=False)
+
+        # Wait for the response
+        request_output = await queue.get()
+        self.output_queues.pop(request.request_id)
+
+        # Raise on error, otherwise happily return None
+        if isinstance(request_output, BaseException):
+            raise request_output

vllm/engine/multiprocessing/engine.py

@@ -14,8 +14,10 @@ from vllm.engine.multiprocessing import (ENGINE_DEAD_ERROR, IPC_DATA_EXT,
                                          IPC_HEALTH_EXT, IPC_INPUT_EXT,
                                          IPC_OUTPUT_EXT, REQUEST_OUTPUTS_T,
                                          VLLM_RPC_SUCCESS_STR, RPCAbortRequest,
-                                         RPCError, RPCProcessRequest,
-                                         RPCStartupRequest, RPCStartupResponse,
+                                         RPCAdapterLoadedResponse, RPCError,
+                                         RPCLoadAdapterRequest,
+                                         RPCProcessRequest, RPCStartupRequest,
+                                         RPCStartupResponse,
                                          RPCUProfileRequest)
 # yapf: enable
 from vllm.executor.gpu_executor import GPUExecutor
@@ -234,6 +236,8 @@ class MQLLMEngine:
                         self.start_profile()
                     else:
                         self.stop_profile()
+                elif isinstance(request, RPCLoadAdapterRequest):
+                    self._handle_load_adapter_request(request)
                 else:
                     raise ValueError("Unknown RPCRequest Type: "
                                      f"{type(request)}")
@@ -284,6 +288,19 @@ class MQLLMEngine:
         if self.log_requests:
             logger.info("Aborted request %s.", request.request_id)
 
+    def _handle_load_adapter_request(self, request: RPCLoadAdapterRequest):
+        try:
+            self.engine.add_lora(request.lora_request)
+        except BaseException as e:
+            # Send back an error if the adater fails to load
+            rpc_err = RPCError(request_id=request.request_id,
+                               is_engine_errored=False,
+                               exception=e)
+            self._send_outputs(rpc_err)
+        # Otherwise, send back the successful load message
+        self._send_outputs(
+            RPCAdapterLoadedResponse(request_id=request.request_id))
+
     def _health_check(self):
         # Send unhealthy if engine has already errored
         if self._errored_with is not None:
@@ -296,7 +313,11 @@ class MQLLMEngine:
             self._send_unhealthy(e)
 
     def _send_outputs(self, outputs: REQUEST_OUTPUTS_T):
-        """Send List of RequestOutput to RPCClient."""
+        """Send outputs back to the engine client. These can be:
+        - Exceptions
+        - A list of generation outputs
+        - A response from loading a lora adapter
+        """
         if outputs:
             try:
                 from ray.exceptions import RayTaskError

vllm/engine/protocol.py

@@ -270,3 +270,8 @@ class EngineClient(ABC):
     async def stop_profile(self) -> None:
         """Start profiling the engine"""
         ...
+
+    @abstractmethod
+    async def add_lora(self, lora_request: LoRARequest) -> None:
+        """Load a new LoRA adapter into the engine for future requests."""
+        ...

vllm/entrypoints/openai/api_server.py

@@ -662,7 +662,7 @@ def build_app(args: Namespace) -> FastAPI:
     return app
 
 
-def init_app_state(
+async def init_app_state(
     engine_client: EngineClient,
     model_config: ModelConfig,
     state: State,
@@ -690,12 +690,13 @@ def init_app_state(
     logger.info("Using supplied chat template:\n%s", resolved_chat_template)
 
     state.openai_serving_models = OpenAIServingModels(
+        engine_client=engine_client,
         model_config=model_config,
         base_model_paths=base_model_paths,
         lora_modules=args.lora_modules,
         prompt_adapters=args.prompt_adapters,
     )
-    # TODO: The chat template is now broken for lora adapters :(
+    await state.openai_serving_models.init_static_loras()
     state.openai_serving_chat = OpenAIServingChat(
         engine_client,
         model_config,
@@ -794,7 +795,7 @@ async def run_server(args, **uvicorn_kwargs) -> None:
         app = build_app(args)
 
         model_config = await engine_client.get_model_config()
-        init_app_state(engine_client, model_config, app.state, args)
+        await init_app_state(engine_client, model_config, app.state, args)
 
         shutdown_task = await serve_http(
             app,

vllm/entrypoints/openai/run_batch.py

@@ -215,6 +215,7 @@ async def main(args):
 
     # Create the openai serving objects.
     openai_serving_models = OpenAIServingModels(
+        engine_client=engine,
         model_config=model_config,
         base_model_paths=base_model_paths,
         lora_modules=None,

vllm/entrypoints/openai/serving_models.py

@@ -5,15 +5,19 @@ from http import HTTPStatus
 from typing import List, Optional, Union
 
 from vllm.config import ModelConfig
+from vllm.engine.protocol import EngineClient
 from vllm.entrypoints.openai.protocol import (ErrorResponse,
                                               LoadLoraAdapterRequest,
                                               ModelCard, ModelList,
                                               ModelPermission,
                                               UnloadLoraAdapterRequest)
+from vllm.logger import init_logger
 from vllm.lora.request import LoRARequest
 from vllm.prompt_adapter.request import PromptAdapterRequest
 from vllm.utils import AtomicCounter
 
+logger = init_logger(__name__)
+
 
 @dataclass
 class BaseModelPath:
@@ -45,6 +49,7 @@ class OpenAIServingModels:
 
     def __init__(
         self,
+        engine_client: EngineClient,
         model_config: ModelConfig,
         base_model_paths: List[BaseModelPath],
         *,
@@ -55,20 +60,11 @@ class OpenAIServingModels:
 
         self.base_model_paths = base_model_paths
         self.max_model_len = model_config.max_model_len
+        self.engine_client = engine_client
 
+        self.static_lora_modules = lora_modules
+        self.lora_requests: List[LoRARequest] = []
         self.lora_id_counter = AtomicCounter(0)
-        self.lora_requests = []
-        if lora_modules is not None:
-            self.lora_requests = [
-                LoRARequest(lora_name=lora.name,
-                            lora_int_id=i,
-                            lora_path=lora.path,
-                            base_model_name=lora.base_model_name
-                            if lora.base_model_name
-                            and self.is_base_model(lora.base_model_name) else
-                            self.base_model_paths[0].name)
-                for i, lora in enumerate(lora_modules, start=1)
-            ]
 
         self.prompt_adapter_requests = []
         if prompt_adapters is not None:
@@ -84,6 +80,19 @@ class OpenAIServingModels:
                         prompt_adapter_local_path=prompt_adapter.local_path,
                         prompt_adapter_num_virtual_tokens=num_virtual_tokens))
 
+    async def init_static_loras(self):
+        """Loads all static LoRA modules.
+        Raises if any fail to load"""
+        if self.static_lora_modules is None:
+            return
+        for lora in self.static_lora_modules:
+            load_request = LoadLoraAdapterRequest(lora_path=lora.path,
+                                                  lora_name=lora.name)
+            load_result = await self.load_lora_adapter(
+                request=load_request, base_model_name=lora.base_model_name)
+            if isinstance(load_result, ErrorResponse):
+                raise ValueError(load_result.message)
+
     def is_base_model(self, model_name):
         return any(model.name == model_name for model in self.base_model_paths)
 
@@ -129,17 +138,47 @@ class OpenAIServingModels:
 
     async def load_lora_adapter(
             self,
-            request: LoadLoraAdapterRequest) -> Union[ErrorResponse, str]:
+            request: LoadLoraAdapterRequest,
+            base_model_name: Optional[str] = None
+    ) -> Union[ErrorResponse, str]:
         error_check_ret = await self._check_load_lora_adapter_request(request)
         if error_check_ret is not None:
             return error_check_ret
 
         lora_name, lora_path = request.lora_name, request.lora_path
         unique_id = self.lora_id_counter.inc(1)
-        self.lora_requests.append(
-            LoRARequest(lora_name=lora_name,
+        lora_request = LoRARequest(lora_name=lora_name,
                                    lora_int_id=unique_id,
-                        lora_path=lora_path))
+                                   lora_path=lora_path)
+        if base_model_name is not None and self.is_base_model(base_model_name):
+            lora_request.base_model_name = base_model_name
+
+        # Validate that the adapter can be loaded into the engine
+        # This will also pre-load it for incoming requests
+        try:
+            await self.engine_client.add_lora(lora_request)
+        except ValueError as e:
+            # Adapter not found or lora configuration errors
+            if "No adapter found" in str(e):
+                return create_error_response(message=str(e),
+                                             err_type="NotFoundError",
+                                             status_code=HTTPStatus.NOT_FOUND)
+            else:
+                return create_error_response(
+                    message=str(e),
+                    err_type="BadRequestError",
+                    status_code=HTTPStatus.BAD_REQUEST)
+        except BaseException as e:
+            # Some other unexpected problem loading the adapter, e.g. malformed
+            # input files.
+            # More detailed error messages for the user would be nicer here
+            return create_error_response(message=str(e),
+                                         err_type="BadRequestError",
+                                         status_code=HTTPStatus.BAD_REQUEST)
+
+        self.lora_requests.append(lora_request)
+        logger.info("Loaded new LoRA adapter: name '%s', path '%s'", lora_name,
+                    lora_path)
         return f"Success: LoRA adapter '{lora_name}' added successfully."
 
     async def unload_lora_adapter(
@@ -155,6 +194,7 @@ class OpenAIServingModels:
             lora_request for lora_request in self.lora_requests
             if lora_request.lora_name != lora_name
         ]
+        logger.info("Removed LoRA adapter: name '%s'", lora_name)
         return f"Success: LoRA adapter '{lora_name}' removed successfully."
 
     async def _check_load_lora_adapter_request(
@@ -195,8 +235,8 @@ class OpenAIServingModels:
             return create_error_response(
                 message=
                 f"The lora adapter '{request.lora_name}' cannot be found.",
-                err_type="InvalidUserInput",
-                status_code=HTTPStatus.BAD_REQUEST)
+                err_type="NotFoundError",
+                status_code=HTTPStatus.NOT_FOUND)
 
         return None
 

vllm/lora/worker_manager.py

@@ -115,6 +115,14 @@ class WorkerLoRAManager(AbstractWorkerManager):
                 embedding_padding_modules=self.embedding_padding_modules,
                 weights_mapper=hf_to_vllm_mapper)
 
+        except FileNotFoundError as e:
+            # FileNotFoundError should be raised if both
+            # - No adapter found to download from huggingface (or in
+            #       offline mode)
+            # - No local adapter files found at `lora_request.lora_path`
+            raise ValueError(
+                f"Loading lora {lora_request.lora_name} failed: No adapter "
+                f"found for {lora_path}") from e
         except Exception as e:
             raise RuntimeError(f"Loading lora {lora_path} failed") from e
         if lora.rank > self.lora_config.max_lora_rank:
@@ -209,12 +217,19 @@ class LRUCacheWorkerLoRAManager(WorkerLoRAManager):
 
     def add_adapter(self, lora_request: LoRARequest) -> bool:
         if lora_request.lora_int_id not in self.list_adapters():
-            # Remove before we load the new lora to save memory
+            # Load the new adapter first to ensure it is actually valid, before
+            # evicting any existing adapters.
+            # This may cause the # of loaded lora adapters to very temporarily
+            # exceed `--max-cpu-loras`.
+            lora = self._load_adapter(lora_request)
+
+            # Loading succeeded, now check if we will exceed cache capacity and
+            # evict if the oldest adapter if so
             if len(self._adapter_manager) + 1 > self._adapter_manager.capacity:
                 assert isinstance(self._adapter_manager,
                                   LRUCacheLoRAModelManager)
                 self._adapter_manager.remove_oldest_adapter()
-            lora = self._load_adapter(lora_request)
+            # Then add the new adapter to the cache
             loaded = self._adapter_manager.add_adapter(lora)
         else:
             # If the lora is already loaded, just touch it to

vllm/v1/engine/async_llm.py

@@ -339,3 +339,7 @@ class AsyncLLM(EngineClient):
     @property
     def dead_error(self) -> BaseException:
         return Exception()  # TODO: implement
+
+    async def add_lora(self, lora_request: LoRARequest) -> None:
+        """Load a new LoRA adapter into the engine for future requests."""
+        raise NotImplementedError("LoRA not yet supported in V1")