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
Our #Measles situation report for weeks 45, 2024 has been published.
The weekly report provides a summary of the #Measles epidemiological situation as at November 2024 and response activities in Nigeria.
🔗 Download, read, and share via: https://ncdc.gov.ng/ncdc.gov.ng/themes/common/files/sitreps/ac1f0718b5d4964c70a2de687309f94d.pdf
#Measles is highly infectious.
Early symptoms are high-grade fever, cough, runny nose, red eyes & tiny white spots in the mouth.
Please report immediately to a health facility when these symptoms are observed.
Read more via:
https://ncdc.gov.ng/diseases/info/M
REDNESS OF THE EYE is an early indication of #Measles when observed with symptoms like high-grade fever, running nose, dry cough & tiny spots in the mouth.
Please report immediately to a health facility when these symptoms are observed.
Visit https://ncdc.gov.ng/diseases/info/M for more information.
#Measles is highly infectious.
Early symptoms are high-grade fever, cough, runny nose, red eyes & tiny white spots in the mouth.
Please report immediately to a health facility when these symptoms are observed.
Read more via:
https://ncdc.gov.ng/diseases/info/M
Runny nose, red eyes, cough, high fever and tiny white spots in the mouth are early symptoms of #measles infection.
Seek immediate medical attention if you experience these symptoms or notice them in your loved ones.
Visit https://ncdc.gov.ng/diseases/info/M to read more
#Measles is highly contagious.
Take all persons showing symptoms of the disease to the nearest healthcare centre for accurate diagnosis and treatment.
Read more via https://ncdc.gov.ng/diseases/info/M
#Measles is an acute, highly infectious disease with initial symptoms of high-grade fever, cough, runny nose, red eyes & tiny white spots in the mouth.
Please report to a health facility immediately if you experience these symptoms.
RUNNING NOSE is an early indication of #Measles when observed with symptoms like high fever, red eyes, dry cough & tiny spots in the mouth.
Please report immediately to a health facility when these symptoms are observed.
Visit https://ncdc.gov.ng/diseases/info/M for more.
REDNESS OF THE EYE is an early indication of #Measles when observed with symptoms like high-grade fever, running nose, dry cough & tiny spots in the mouth.
Please report immediately to a health facility when these symptoms are observed.
Visit https://ncdc.gov.ng/diseases/info/M for more.
#Measles is highly contagious.
Isolate all suspected cases of the disease and take them to the nearest healthcare facility immediately.
Read more via https://ncdc.gov.ng/diseases/info/M
#Measles is an acute, highly infectious disease with initial symptoms of high fever, cough, runny nose, red eyes & tiny white spots in the mouth.
Please immediately report to a health facility if you experience these symptoms.
Read more: https://ncdc.gov.ng/diseases/info/M
#Measles is not just a rash.
Routine immunisation must remain a priority for parents and caregivers.
#TakeResponsibility to prevent the spread of such as #Measles.