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worker-vllm/src/engine.py
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2026-02-13 03:16:43 -06:00

345 lines
17 KiB
Python

import asyncio
import json
import logging
import os
import time
from typing import AsyncGenerator, Optional
from dotenv import load_dotenv
from vllm import AsyncLLMEngine
from vllm.entrypoints.logger import RequestLogger
from vllm.entrypoints.openai.chat_completion.protocol import ChatCompletionRequest
from vllm.entrypoints.openai.chat_completion.serving import OpenAIServingChat
from vllm.entrypoints.openai.completion.protocol import CompletionRequest
from vllm.entrypoints.openai.completion.serving import OpenAIServingCompletion
from vllm.entrypoints.openai.engine.protocol import ErrorResponse
from vllm.entrypoints.openai.models.protocol import BaseModelPath, LoRAModulePath
from vllm.entrypoints.openai.models.serving import OpenAIServingModels
from constants import DEFAULT_BATCH_SIZE, DEFAULT_BATCH_SIZE_GROWTH_FACTOR, DEFAULT_MAX_CONCURRENCY, DEFAULT_MIN_BATCH_SIZE
from engine_args import get_engine_args
from tokenizer import TokenizerWrapper
from utils import BatchSize, DummyRequest, JobInput, create_error_response
class vLLMEngine:
def __init__(self, engine = None):
load_dotenv() # For local development
self.engine_args = get_engine_args()
logging.info(f"Engine args: {self.engine_args}")
# Initialize vLLM engine first
self.llm = self._initialize_llm() if engine is None else engine.llm
# Only create custom tokenizer wrapper if not using mistral tokenizer mode
# For mistral models, let vLLM handle tokenizer initialization
if self.engine_args.tokenizer_mode != 'mistral':
self.tokenizer = TokenizerWrapper(self.engine_args.tokenizer or self.engine_args.model,
self.engine_args.tokenizer_revision,
self.engine_args.trust_remote_code)
else:
# For mistral models, we'll get the tokenizer from vLLM later
self.tokenizer = None
self.max_concurrency = int(os.getenv("MAX_CONCURRENCY", DEFAULT_MAX_CONCURRENCY))
self.default_batch_size = int(os.getenv("DEFAULT_BATCH_SIZE", DEFAULT_BATCH_SIZE))
self.batch_size_growth_factor = int(os.getenv("BATCH_SIZE_GROWTH_FACTOR", DEFAULT_BATCH_SIZE_GROWTH_FACTOR))
self.min_batch_size = int(os.getenv("MIN_BATCH_SIZE", DEFAULT_MIN_BATCH_SIZE))
def _get_tokenizer_for_chat_template(self):
"""Get tokenizer for chat template application"""
if self.tokenizer is not None:
return self.tokenizer
else:
# For mistral models, get tokenizer from vLLM engine
# This is a fallback - ideally chat templates should be handled by vLLM directly
try:
from transformers import AutoTokenizer
tokenizer = AutoTokenizer.from_pretrained(
self.engine_args.tokenizer or self.engine_args.model,
revision=self.engine_args.tokenizer_revision or "main",
trust_remote_code=self.engine_args.trust_remote_code
)
# Create a minimal wrapper
class MinimalTokenizerWrapper:
def __init__(self, tokenizer):
self.tokenizer = tokenizer
self.custom_chat_template = os.getenv("CUSTOM_CHAT_TEMPLATE")
self.has_chat_template = bool(self.tokenizer.chat_template) or bool(self.custom_chat_template)
if self.custom_chat_template and isinstance(self.custom_chat_template, str):
self.tokenizer.chat_template = self.custom_chat_template
def apply_chat_template(self, input):
if isinstance(input, list):
if not self.has_chat_template:
raise ValueError(
"Chat template does not exist for this model, you must provide a single string input instead of a list of messages"
)
elif isinstance(input, str):
input = [{"role": "user", "content": input}]
else:
raise ValueError("Input must be a string or a list of messages")
return self.tokenizer.apply_chat_template(
input, tokenize=False, add_generation_prompt=True
)
return MinimalTokenizerWrapper(tokenizer)
except Exception as e:
logging.error(f"Failed to create fallback tokenizer: {e}")
raise e
def dynamic_batch_size(self, current_batch_size, batch_size_growth_factor):
return min(current_batch_size*batch_size_growth_factor, self.default_batch_size)
async def generate(self, job_input: JobInput):
try:
async for batch in self._generate_vllm(
llm_input=job_input.llm_input,
validated_sampling_params=job_input.sampling_params,
batch_size=job_input.max_batch_size,
stream=job_input.stream,
apply_chat_template=job_input.apply_chat_template,
request_id=job_input.request_id,
batch_size_growth_factor=job_input.batch_size_growth_factor,
min_batch_size=job_input.min_batch_size
):
yield batch
except Exception as e:
yield {"error": create_error_response(str(e)).model_dump()}
async def _generate_vllm(self, llm_input, validated_sampling_params, batch_size, stream, apply_chat_template, request_id, batch_size_growth_factor, min_batch_size: str) -> AsyncGenerator[dict, None]:
if apply_chat_template or isinstance(llm_input, list):
tokenizer_wrapper = self._get_tokenizer_for_chat_template()
llm_input = tokenizer_wrapper.apply_chat_template(llm_input)
results_generator = self.llm.generate(llm_input, validated_sampling_params, request_id)
n_responses, n_input_tokens, is_first_output = validated_sampling_params.n, 0, True
last_output_texts, token_counters = ["" for _ in range(n_responses)], {"batch": 0, "total": 0}
batch = {
"choices": [{"tokens": []} for _ in range(n_responses)],
}
max_batch_size = batch_size or self.default_batch_size
batch_size_growth_factor, min_batch_size = batch_size_growth_factor or self.batch_size_growth_factor, min_batch_size or self.min_batch_size
batch_size = BatchSize(max_batch_size, min_batch_size, batch_size_growth_factor)
async for request_output in results_generator:
if is_first_output: # Count input tokens only once
n_input_tokens = len(request_output.prompt_token_ids)
is_first_output = False
for output in request_output.outputs:
output_index = output.index
token_counters["total"] += 1
if stream:
new_output = output.text[len(last_output_texts[output_index]):]
batch["choices"][output_index]["tokens"].append(new_output)
token_counters["batch"] += 1
if token_counters["batch"] >= batch_size.current_batch_size:
batch["usage"] = {
"input": n_input_tokens,
"output": token_counters["total"],
}
yield batch
batch = {
"choices": [{"tokens": []} for _ in range(n_responses)],
}
token_counters["batch"] = 0
batch_size.update()
last_output_texts[output_index] = output.text
if not stream:
for output_index, output in enumerate(last_output_texts):
batch["choices"][output_index]["tokens"] = [output]
token_counters["batch"] += 1
if token_counters["batch"] > 0:
batch["usage"] = {"input": n_input_tokens, "output": token_counters["total"]}
yield batch
def _initialize_llm(self):
try:
start = time.time()
engine = AsyncLLMEngine.from_engine_args(self.engine_args)
end = time.time()
logging.info(f"Initialized vLLM engine in {end - start:.2f}s")
return engine
except Exception as e:
logging.error("Error initializing vLLM engine: %s", e)
raise e
class OpenAIvLLMEngine(vLLMEngine):
def __init__(self, vllm_engine):
super().__init__(vllm_engine)
self.served_model_name = os.getenv("OPENAI_SERVED_MODEL_NAME_OVERRIDE") or self.engine_args.served_model_name or self.engine_args.model
self.response_role = os.getenv("OPENAI_RESPONSE_ROLE") or "assistant"
self.lora_adapters = self._load_lora_adapters()
# Always defer OpenAI engine initialization to the first request.
# asyncio.run() creates a temporary event loop that gets closed, but async
# components (tokenizer pool, serving engines) bind futures to that loop.
# When Runpod's serverless handler runs in its own event loop, those futures
# are "attached to a different loop" causing RuntimeError.
# This affects all configurations, not just LoRA.
self._engines_initialized = False
if self.lora_adapters:
logging.info(f"LoRA mode: {len(self.lora_adapters)} adapter(s) will load on first request")
for adapter in self.lora_adapters:
logging.info(f" - {adapter.name}: {adapter.path}")
else:
logging.info("OpenAI engines will initialize on first request")
# Handle both integer and boolean string values for RAW_OPENAI_OUTPUT
raw_output_env = os.getenv("RAW_OPENAI_OUTPUT", "1")
if raw_output_env.lower() in ('true', 'false'):
self.raw_openai_output = raw_output_env.lower() == 'true'
else:
self.raw_openai_output = bool(int(raw_output_env))
def _load_lora_adapters(self):
adapters = []
try:
adapters = json.loads(os.getenv("LORA_MODULES", '[]'))
except Exception as e:
logging.info(f"---Initialized adapter json load error: {e}")
for i, adapter in enumerate(adapters):
try:
adapters[i] = LoRAModulePath(**adapter)
logging.info(f"---Initialized adapter: {adapter}")
except Exception as e:
logging.info(f"---Initialized adapter not worked: {e}")
continue
return adapters
async def _ensure_engines_initialized(self):
"""Initialize engines on first request to avoid event loop mismatch.
In Runpod Serverless, the startup code runs outside the handler's event
loop. Deferring initialization to the first request ensures all async
components (tokenizer pool, serving engines, LoRA state) are created in
the correct event loop context.
"""
if not self._engines_initialized:
logging.info("Initializing OpenAI serving engines...")
await self._initialize_engines()
self._engines_initialized = True
logging.info("OpenAI serving engines initialized successfully")
async def _initialize_engines(self):
self.model_config = self.llm.model_config
self.base_model_paths = [
BaseModelPath(name=self.served_model_name, model_path=self.engine_args.model)
]
self.serving_models = OpenAIServingModels(
engine_client=self.llm,
base_model_paths=self.base_model_paths,
lora_modules=self.lora_adapters,
)
await self.serving_models.init_static_loras()
# Get chat template from vLLM tokenizer if available
chat_template = None
if self.tokenizer and hasattr(self.tokenizer, 'tokenizer'):
chat_template = self.tokenizer.tokenizer.chat_template
self.chat_engine = OpenAIServingChat(
engine_client=self.llm,
models=self.serving_models,
response_role=self.response_role,
request_logger=None,
chat_template=chat_template,
chat_template_content_format="auto",
trust_request_chat_template=os.getenv('TRUST_REQUEST_CHAT_TEMPLATE', 'false').lower() == 'true',
return_tokens_as_token_ids=os.getenv('RETURN_TOKENS_AS_TOKEN_IDS', 'false').lower() == 'true',
reasoning_parser=os.getenv('REASONING_PARSER', "") or "",
enable_auto_tools=os.getenv('ENABLE_AUTO_TOOL_CHOICE', 'false').lower() == 'true',
exclude_tools_when_tool_choice_none=os.getenv('EXCLUDE_TOOLS_WHEN_TOOL_CHOICE_NONE', 'false').lower() == 'true',
tool_parser=os.getenv('TOOL_CALL_PARSER', "") or None,
enable_prompt_tokens_details=os.getenv('ENABLE_PROMPT_TOKENS_DETAILS', 'false').lower() == 'true',
enable_force_include_usage=os.getenv('ENABLE_FORCE_INCLUDE_USAGE', 'false').lower() == 'true',
enable_log_outputs=os.getenv('ENABLE_LOG_OUTPUTS', 'false').lower() == 'true',
log_error_stack=os.getenv('LOG_ERROR_STACK', 'false').lower() == 'true',
)
self.completion_engine = OpenAIServingCompletion(
engine_client=self.llm,
models=self.serving_models,
request_logger=None,
return_tokens_as_token_ids=os.getenv('RETURN_TOKENS_AS_TOKEN_IDS', 'false').lower() == 'true',
enable_prompt_tokens_details=os.getenv('ENABLE_PROMPT_TOKENS_DETAILS', 'false').lower() == 'true',
enable_force_include_usage=os.getenv('ENABLE_FORCE_INCLUDE_USAGE', 'false').lower() == 'true',
log_error_stack=os.getenv('LOG_ERROR_STACK', 'false').lower() == 'true',
)
if hasattr(self.chat_engine, 'warmup'):
await self.chat_engine.warmup()
async def generate(self, openai_request: JobInput):
# Ensure engines are ready (no-op if already initialized at startup)
await self._ensure_engines_initialized()
if openai_request.openai_route == "/v1/models":
yield await self._handle_model_request()
elif openai_request.openai_route in ["/v1/chat/completions", "/v1/completions"]:
async for response in self._handle_chat_or_completion_request(openai_request):
yield response
else:
yield create_error_response("Invalid route").model_dump()
async def _handle_model_request(self):
models = await self.serving_models.show_available_models()
return models.model_dump()
async def _handle_chat_or_completion_request(self, openai_request: JobInput):
if openai_request.openai_route == "/v1/chat/completions":
request_class = ChatCompletionRequest
generator_function = self.chat_engine.create_chat_completion
elif openai_request.openai_route == "/v1/completions":
request_class = CompletionRequest
generator_function = self.completion_engine.create_completion
try:
request = request_class(
**openai_request.openai_input
)
except Exception as e:
yield create_error_response(str(e)).model_dump()
return
dummy_request = DummyRequest()
response_generator = await generator_function(request, raw_request=dummy_request)
if not openai_request.openai_input.get("stream") or isinstance(response_generator, ErrorResponse):
yield response_generator.model_dump()
else:
batch = []
batch_token_counter = 0
batch_size = BatchSize(self.default_batch_size, self.min_batch_size, self.batch_size_growth_factor)
async for chunk_str in response_generator:
if "data" in chunk_str:
if self.raw_openai_output:
data = chunk_str
elif "[DONE]" in chunk_str:
continue
else:
data = json.loads(chunk_str.removeprefix("data: ").rstrip("\n\n")) if not self.raw_openai_output else chunk_str
batch.append(data)
batch_token_counter += 1
if batch_token_counter >= batch_size.current_batch_size:
if self.raw_openai_output:
batch = "".join(batch)
yield batch
batch = []
batch_token_counter = 0
batch_size.update()
if batch:
if self.raw_openai_output:
batch = "".join(batch)
yield batch