FastAPI: Cross Requests freeze my microservices when they are too frequent - python-3.x

Question

I discover FastAPI for the first time with which I try to discuss 2 services.
When a service asks "how are you?" the other service replies "Good!", and vice versa. The same requests are therefore made in both directions, they are crossed.... And this is repeated after a certain delay.
Here is my code for a service (it's the same code for the 2 services).
It works well, except when the delay is too short!
from fastapi import FastAPI
import requests
import uvicorn
import asyncio
app = FastAPI()
def get(url, headers, json_data=False):
if json_data:
r = requests.get(url, headers=headers, json=json_data)
else:
r = requests.get(url, headers=headers)
return r
#app.get("/")
async def how_are_you():
message = f"{service_name}: Good!"
print(message)
return message
async def toc_toc(message):
await asyncio.sleep(5)
url = f"http://{remote_host}:{remote_port}/"
headers = {
'accept': 'application/json',
}
count = 0
while True:
await asyncio.sleep(waiting)
print(f"{count}\t{service_name}: {message}!")
get(url, headers)
count += 1
async def run_webserver():
config = uvicorn.Config(app, host=host, port=port)
server = uvicorn.Server(config)
await server.serve()
async def main():
await asyncio.gather(
toc_toc("How are you"),
run_webserver()
)
Here are the input variables
of my first serve:
if __name__ == "__main__":
waiting = 0.1
service_name = "service_1"
host = "0.0.0.0"
port = 82
remote_host = "0.0.0.0"
remote_port = 83
loop = asyncio.get_event_loop()
tasks = main()
loop.run_until_complete(tasks)
And those of my second service:
if __name__ == "__main__":
waiting = 0.1
service_name = "service_2"
host = "0.0.0.0"
port = 83
remote_host = "0.0.0.0"
remote_port = 82
loop = asyncio.get_event_loop()
tasks = main()
loop.run_until_complete(tasks)
If I set this delay "waiting" to 1 second (between 2 requests "how are you?"), I have no problem. Everything works perfectly for minutes at least.
On the other hand, if I reduce this variable to 0.1 seconds (or even lower), the services send each other requests and respond to each other a hundred times and then the applications seem to freeze.
So I don't have any error message that could help me to debug.
I need to be able to lower this delay to 0.001 seconds to simulate a production load peak that my services will have to be able to support.
I have the impression that the problem comes from the fact that the requests are crossed between my 2 services. Because in the case where only one service can send requests to the other (by commenting out the get(url, headers) line for service 2), it works very well even with a delay of 0.001 seconds.
Do you have any ideas ?
Thanks in advance
PS: I run my services directly on my Mac M1 but also on my local Kubernets cluster, and I have the same result.