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
#Tourist
The Great Wall of China :
is a huge chain of defensive fortifications stretching across northern China, it is a symbol of China and one of the Seven Wonders of the new world, known for its enormous length exceeding 21 thousand kilometers, it was built over centuries, especially during the Ming dynasty, it features watchtowers and strategic corridors, it is a UNESCO World Heritage Site and an outstanding world tourist destination.
📝
Construction history:
the first construction work began more than 2000 years ago, during the spring and autumn reign and the Warring States, and it was significantly expanded and renovated by later dynasties, especially the Ming Dynasty (1369-1644).
#Nature
#Tourist
Socotra:
is a Yemeni archipelago belonging to the Hadramaut region consisting of six islands on the Indian Ocean off the coast of the Horn of Africa near the Gulf of Aden, located about 240 kilometers (150 Mi) east of the coast of Somalia and 380 kilometers (240 Mi) south of the Arabian Peninsula.
The island was classified as a World Heritage Site in 2008, and the New York Times ranked it as the most beautiful island in the world in 2010 due to the unique biodiversity and environmental importance of this island and its reflection on the world. In October of 2013, the Socotra archipelago governorate became an independent governorate from Hadramaut governorate.
#History
#Tourist
The Great Sphinx:
is a huge stone sculpture carved from limestone, embodying a mythical creature with a human head and the body of a lion in a reclining position.
Facing directly from West to East, the statue is located on the Giza plateau on the West Bank of the Nile in Giza, Egypt.
It is believed that the facial features of the statue belong to Pharaoh Khafre.
The original figure of the Sphinx was carved from the Adim Rock, later it was restored with limestone layers. The statue is 73 M (240 ft) long from claw to tail, 20 M (66 ft) high from the base to the top of the head, and 19 m (62 ft) wide at its hind feet