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
An elephant’s trunk 🐘 is an amazing example of evolutionary development 🧬. It is a combined nose and upper lip that lengthened as the elephant’s ancestors became taller and their tusks grew bigger. With its heavy head, it needed an easy way to reach the ground.
@googlefactss#evolution
Автопортреты Joni Mitchell, которые стали обложками её релизов
• Clouds
• Ladies Of The Canyon
• Wild Things Run Fast
• Turbulent Indigo
• Taming The Tiger
• Both Sides Now
• Travelogue
• Dreamland
• The Reprise Albums (1968-1971)
Митчелл часто говорила, что она «художник, который выпускает песни».
Нельзя не заметить очевидную отсылку на другого художника, который за жизнь нарисовал с десяток автопортретов, — Винсента Ван Гога с отрезанным ухом на обложке «Turbulent Indigo».
#evolution
🌍 The island of New Caledonia is a biodiversity hotspot where ancient plants like the rare Amborella tree represent some of Earth’s oldest surviving flowering lineages, found nowhere else. ✨
#biodiversity⚡#islands⚡#evolution⚡#geography⚡#nature⚡#earth
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🌎 The star-nosed mole detects prey in total darkness using its unique nose, covered in 22 finger-like tentacles packed with touch sensors. This extraordinary adaptation lets it identify and eat tiny insects and worms faster than any other mammal, even underwater. ✨
#animals⚡#adaptation⚡#evolution
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🌎 The saiga antelope’s enlarged, drooping nose acts as a built-in air filter and cooler on the Central Asian steppes. When alarmed, herds can stampede at speeds up to 80 kilometers per hour. ✨
#animals⚡#evolution⚡#biodiversity
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🌎 The shoebill stork stands over 1.2 meters tall and has a massive, shoe-shaped bill up to 24 centimeters long. Native to East African swamps, this solitary bird hunts lungfish, frogs, and even baby crocodiles. ✨
#animals⚡#biodiversity⚡#evolution
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🌎 The platypus baffles scientists as it lays eggs like a reptile but produces milk and has fur like a mammal—a rare mix found in no other living animal. This odd, Australian creature even senses prey underwater using electroreceptors in its bill. ✨
#animals⚡#evolution⚡#Australia
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🌎 Horseshoe crabs have remained virtually unchanged for about 450 million years. Despite their name, they are more closely related to spiders than to true crabs. Modern horseshoe crabs can be found along the Atlantic coast of North America and in Southeast Asia. ✨
#animals⚡#evolution⚡#fossils
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🌎 Living fossils like the chambered nautilus and horseshoe crab have changed little for hundreds of millions of years. The nautilus dates back over 500 million years, and its closest extinct relatives include ammonites, which died out with the dinosaurs. ✨
#evolution⚡#fossils⚡#animals
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🌎 Living fossils like the giant freshwater stingray and the Australian lungfish have remained almost unchanged for over 100 million years, surviving dramatic changes in Earth’s environment. The horseshoe crab’s body plan is so ancient, it first appeared 450 million years ago. ✨
#evolution⚡#fossils⚡#animals
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🌎 Some ancient animals have survived unchanged for millions of years. The coelacanth, once thought extinct, first appeared 400 million years ago and still swims deep ocean waters today. The horseshoe crab dates back over 450 million years, predating dinosaurs and even trees. ✨
#evolution⚡#fossils⚡#animals
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