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
🌍 Some rainforest insects mimic leaves so perfectly they even show “bite marks” or rot spots on their bodies, hiding from predators in the dense, shadowy understory. ✨
#rainforest⚡#biodiversity⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography
👉more Channels
🌍 Terraced vineyards on Portugal's Douro River show how people reshape steep hillsides for farming. Ancient stone walls protect soil from erosion while letting grape vines thrive in harsh terrain. ✨
#agriculture⚡#landscape⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography
👉more Channels
🌍 Terraced rice fields in Southeast Asia transform steep hillsides into farmable land, reducing soil erosion and creating unique landscapes shaped by both nature and human ingenuity. ✨
#agriculture⚡#landscape⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography🌍
🌎 The male seahorse is the only animal where the male becomes pregnant, carrying fertilized eggs in a special pouch until they hatch. Seahorses can give birth to hundreds of fully formed young at a time—up to 2,000 in a single brood. ✨
#adaptation⚡#animals⚡#ocean
👉subscribe Interesting Planet
👉more Channels
🌍 In tundra landscapes, some mosses and lichens can survive temperatures below –50°C and continue to photosynthesize under snow, making them some of the Earth’s hardiest plants. ✨
#tundra⚡#permafrost⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography
👉more Channels
🌍 The Galápagos Islands are home to the only marine iguanas on Earth. These unique lizards swim and dive in the Pacific Ocean, making them the world’s only sea-going reptiles. ✨
#islands⚡#wildlife⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography
👉more Channels
🌍 Urban green roofs, where buildings are topped with plants, help cities manage rainwater, reduce heat, and provide habitats for birds and insects, blending urban life with nature. ✨
#cities⚡#environment⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography🌍
🌍 In tropical rainforests, some plant leaves grow waxy surfaces and pointed tips called "drip tips." These features help water run off quickly, stopping mold and fungi in the damp climate. ✨
#rainforest⚡#tropics⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography
👉more Channels
🌍 Earth’s climate zones are not just about temperature—they also shape which plants and animals can survive. Some cacti thrive in deserts, while rainforests burst with life in tropical zones. ✨
#climate⚡#vegetation⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography🌍
🌎 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
👉subscribe Interesting Planet
🌍 Tropical savannas can burn naturally every 1–3 years, yet some species, like the baobab tree, thrive by storing water in thick trunks to survive both drought and fire. ✨
#savanna⚡#grassland⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography
👉more Channels
🌍 In Chile's Atacama Desert, rare fog called "camanchaca" drifts inland from the Pacific. Some plants here survive by absorbing water directly from this fog, not from rainfall. ✨
#desert⚡#arid⚡#adaptation⚡#geography⚡#nature⚡#earth
👉subscribe Amazing Geography
👉more Channels