fastapi: After executing first request, rest of the request got stuck till the first one is executed


##  IN MY app/repository/connector.py  

import os
import sys
import psutil


async def get_all_lines(loc="xyz.log"):
    try:
        with open(loc) as read_file:
            all_lines = read_file.readlines()
            all_lines = list(map(lambda s: s.strip(), all_lines))
            all_lines = [s for s in all_lines if s]
        return all_lines[-1].split("-")[0].split(",")[0]
    except Exception as e:
        return "[ERROR] Unable to process file {}".format(loc)


async def checkIfProcessRunning(processName):
    for proc in psutil.process_iter():
        try:
            if processName.lower() in proc.name().lower():
                return True
        except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess):
            pass
    return False

async def get_running_status(processes=['ABC', 'chrome.exe', "java"]):
    status = ""
    for process in processes:
        if await checkIfProcessRunning(process):
            status += "{} is in running state\n".format(process)
        else:
            status += "{} is NOT in running state\n".format(process)
    return status


##  IN MY app/router/connection.py  

from fastapi import APIRouter, Depends, status, HTTPException
from .. import schemas, oauth2
from typing import List
from .. repository import connector

router = APIRouter(
    tags=['connector'],
    prefix="/connector"
)


@router.get('/', status_code=200)
async def show(current_user = Depends(oauth2.get_current_user)):
    status = await connector.get_all_lines()
    return {"last_connected_at": status}

@router.get('/process_running_status', status_code=200)
async def show(current_user = Depends(oauth2.get_current_user)):
    status = await connector.get_running_status()
    return {"process_status": status}

Description

Open the browser and I call the endpoint /process_running_status.
It returns a { “process_status”: "ABC is NOT in running state\nchrome.exe is in running state\njava is in running state }` but takes sometime to respond
But when this is executing, my all other requests to the API are on hold till it gets completed. Am i doing this right way?
I want if this request /process_running_status is running, it should not hold the other request.

Environment

OS: Windows:
FastAPI Version: 0.63.0
Python version: Python3.9

About this issue

Original URL
State: closed
Created 3 years ago
Comments: 15 (1 by maintainers)

Most upvoted comments

Also, any help is much appreciated. @tiangolo or anyone from this community. I request all of you to Please look into this on priority

vik03 on May 14, 2021

you need to understand asyncio

your question is same as https://github.com/tiangolo/fastapi/issues/2574#issuecomment-751784508

and this https://github.com/tiangolo/fastapi/issues/3091#issuecomment-824193131

raphaelauv on May 16, 2021

an example

import time
import concurrent.futures


def func(num: int):
    time.sleep(1)
    print(num)


nums = [1, 2, 3]


with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:

    executor.map(func, nums)

panla on May 16, 2021

Ok, but any idea how I can code with the help of multithreading to achieve the goal in fastapi here. Can you please paste the code. I will be extremely grateful to you

vik03 on May 15, 2021

if still the same is After executing first request, rest of the request got stuck till the first one is executed: this is not a question, because you do not use async and you can use thead or process. elif the error is ValueError: [TypeError("'coroutine' object is not iterable"): i do not know

panla on May 15, 2021

@panla still the same.

vik03 on May 14, 2021

IN MY app/repository/connector.py

import os
import sys
import psutil


def get_all_lines(loc="xyz.log"):
    try:
        with open(loc) as read_file:
            all_lines = read_file.readlines()
            all_lines = list(map(lambda s: s.strip(), all_lines))
            all_lines = [s for s in all_lines if s]
        return all_lines[-1].split("-")[0].split(",")[0]
    except Exception as e:
        return "[ERROR] Unable to process file {}".format(loc)


def checkIfProcessRunning(processName):
    for proc in psutil.process_iter():
        try:
            if processName.lower() in proc.name().lower():
                return True
        except (psutil.NoSuchProcess, psutil.AccessDenied, psutil.ZombieProcess):
            pass
    return False

def get_running_status(processes=['ABC', 'chrome.exe', "java"]):
    status = ""
    for process in processes:
        if checkIfProcessRunning(process):
            status += "{} is in running state\n".format(process)
        else:
            status += "{} is NOT in running state\n".format(process)
    return status

IN MY app/router/connection.py

from fastapi import APIRouter, Depends, status, HTTPException
from .. import schemas, oauth2
from typing import List
from .. repository import connector

router = APIRouter(
    tags=['connector'],
    prefix="/connector"
)


@router.get('/', status_code=200)
async def show(current_user = Depends(oauth2.get_current_user)):
    status = connector.get_all_lines()
    return {"last_connected_at": status}

@router.get('/process_running_status', status_code=200)
async def show(current_user = Depends(oauth2.get_current_user)):
    status = connector.get_running_status()
    return {"process_status": status}

you can try it, andI haven’t tested, ha ha ha ha.

panla on May 14, 2021