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
Let's work together to prevent the spread of #Lassafever.
Be a guardian of proper sanitation in your community and promote frequent #Handwashing with soap and running water.
Read our latest #LassaFever situation report:
https://ncdc.gov.ng/diseases/sitreps/?cat=5&name=An%20update%20of%20Lassa%20fever%20outbreak%20in%20Nigeria
Let's work together to prevent the spread of #Lassafever.
Be a guardian of proper sanitation in your community and promote frequent #Handwashing with soap and running water.
Read our latest #LassaFever situation report:
https://ncdc.gov.ng/diseases/sitreps/?cat=5&name=An%20update%20of%20Lassa%20fever%20outbreak%20in%20Nigeria
#Lassafever is preventable.
Be a guardian of proper hand hygiene in your community
Promote frequent #handwashing with soap and running water.
#LassaFeverInfo
#Handwashing with soap under clean, running water is very vital to the prevention of #cholera.
Important #handwashing moments⬇️
✅While caring for the ill
✅After using the toilet
✅Before food preparation
✅Before and after eating
✅After touching high-contact surfaces
#STOPcholera
#Handwashing is a basic and effective tool against infections.
If we do not become sick, we would not need to use #antimicrobials.
Encourage your loved ones to practice frequent #handwashing with soap under running water.
Do your part to prevent #AntimicrobialResistance
#HandHygiene with clean, running water is very vital to the prevention of #cholera.
Important #handwashing moments⬇️
✅While caring for the ill
✅After using the toilet
✅Before food preparation
✅Before and after eating
✅After touching high contact surfaces
#TakeResponsibility
#HandHygiene with soap under clean, running water is very vital to the prevention of #cholera.
Important #handwashing moments⬇️
✅While caring for the ill
✅After using the toilet
✅Before food preparation
✅Before and after eating
✅After touching high contact surfaces
#TakeResponsibility
#HandHygiene with clean, running water is very vital to the prevention of #cholera.
Important #handwashing moments⬇️
✅While caring for the ill
✅After using the toilet
✅Before food preparation
✅Before and after eating
✅After touching high contact surfaces
#TakeResponsibility
#HandWashing remains the most basic and effective means to prevent the spread of infections.
Frequent #handwashing with soap under running water at home, work, health facilities, gatherings, and public spaces is highly important to stay healthy.
Let us all make #cleanhands a regular habit. It protects us all.
#TakeResponsibility
#HandWashing is a basic &effective tool against infections.
If we don't become sick, we would not need to use #antibiotics.
Let us promote the practice of #handwashing in our homes & communities to prevent #AntimicrobialResistance together.
#WorldAntimicrobialAwarenessWeek2022