Недавно делал быстрый прототип асинхронного приложения в котором требовалось вызывать много синхронного кода. Да, я знаю, что это не лучший дизайн, но нужно было быстрое решение на один процесс и без очередей. Поэтому я выполнял код в потоках.
Выглядело это примерно так:
from fastapi.concurrency import run_in_threadpool
async def execute(data: DataRequest) -> DataResponse:
try:
result = await run_in_threadpool(sync_function, data)
return DataResponse(data=result)
except Exception as e:
return DataResponse(
error=str(e),
success=False,
)
В общем работает нормально. Для всех вызовов под капотом используется общий тредпул, всё работает предсказуемо.
Но потребовалось изменить количество запускаемых в пуле потоков (по умолчанию создается 40 воркеров).
Так как дело происходит с FastAPI, делается это через lifespan используя настройки anyio:
import anyio
@asynccontextmanager
async def lifespan(app: FastAPI):
limiter = anyio.to_thread.current_default_thread_limiter()
limiter.total_tokens = 100
yield
# если вдруг нужно вернуть обратно
limiter.total_tokens = 40
Зачем менять количество воркеров?
- уменьшить, если оперативки мало (один тред занимает ~8мб)
- увеличить чтобы выдержать нагрузку
Если есть предложения получше при тех же вводных - предлагайте😉
#async
Really Good One to Watch
The daughter takes a step forward with each question.
The father stands there. The daughter, who starts off playfully laughing.... is shocked to see her father standing there despite her progress.
When the father steps forward for the final question, she hugs him. Father - Daughter ❤️
Children can be raised without knowing hardship.
But it is important to make them know that nothing they get comes so easily ❤️
#Inspiring
@InspiringThoughts
Really Good One to Watch
The daughter takes a step forward with each question.
The father stands there. The daughter, who starts off playfully laughing.... is shocked to see her father standing there despite her progress.
When the father steps forward for the final question, she hugs him. Father - Daughter ❤️
Children can be raised without knowing hardship.
But it is important to make them know that nothing they get comes so easily ❤️
#Inspiring
@InspiringThoughts
Really Good One to Watch
The daughter takes a step forward with each question.
The father stands there. The daughter, who starts off playfully laughing.... is shocked to see her father standing there despite her progress.
When the father steps forward for the final question, she hugs him. Father - Daughter ❤️
Children can be raised without knowing hardship.
But it is important to make them know that nothing they get comes so easily ❤️
#Inspiring
@InspiringThoughts
Really Good One to Watch
The daughter takes a step forward with each question.
The father stands there. The daughter, who starts off playfully laughing.... is shocked to see her father standing there despite her progress.
When the father steps forward for the final question, she hugs him. Father - Daughter ❤️
Children can be raised without knowing hardship.
But it is important to make them know that nothing they get comes so easily ❤️
#Inspiring
@InspiringThoughts
Really Good One to Watch
The daughter takes a step forward with each question.
The father stands there. The daughter, who starts off playfully laughing.... is shocked to see her father standing there despite her progress.
When the father steps forward for the final question, she hugs him. Father - Daughter ❤️
Children can be raised without knowing hardship.
But it is important to make them know that nothing they get comes so easily ❤️
#Inspiring
@InspiringThoughts