With a large number of requests, Guzzle gets an empty response -> 504, why?

Question

API

Good afternoon.
In a Laravel project, we connected Guzzle, we use it to access different Services, starting with a login and ending with widgets (graphs).
The project hangs in the docker from 3 containers (web, app, db).
I noticed the following: as soon as two or more computers log in at the same time, the service completely freezes (restarting the app container helps) -> in the lara logs:

production.ERROR: GuzzleHttp\Exception\ConnectException: cURL error 52: Empty reply from server (see curl.haxx.se/libcurl/c/libcurl-errors.html) in /var/www/vendor/guzzlehttp/guzzle/src/ Handler/CurlFactory.php:186

When logging in, there are about 20 requests in 1-2 seconds.
Tell me how to treat?
I searched about system limits, php, docker'a .. but did not find a solution.
Thanks a lot.

Answer 1

The problem was that one of the services was throwing an Exception, and Guzzle was waiting for a response.

Answer 2

When logging in, there are about 20 requests in 1-2 seconds.
Tell me how to treat?

treat encoders who need to do this IMHO.
the server does not pull, apparently, except for debugging, no one will tell you anything about your system.