firestore times out when using default DNS resolver

[sergiocampama]

import asyncio
import firebase_admin
from firebase_admin import credentials
from firebase_admin import firestore_async
import sys

async def main():
  user_id = sys.argv[1]

  cred = credentials.Certificate("credentials.json")
  firebase_admin.initialize_app(cred)

  db = firestore_async.client()

  user_ref = db.collection("users").document(user_id)
  user = await user_ref.get()
  print(user)

if __name__ == "__main__":
  asyncio.run(main())

This code, using a firebase service account credential, and a database with a users table, will hang for 60 seconds and will fail with a DNS error, this one:

D0408 14:38:20.114377000 7971737600 grpc_ares_wrapper.cc:723]          (c-ares resolver) request:0x60000318e4e0 on_hostbyname_done_locked: C-ares status is not ARES_SUCCESS qtype=AAAA name=firestore.googleapis.com is_balancer=0: DNS query cancelled
D0408 14:38:20.114381000 7971737600 grpc_ares_wrapper.cc:723]          (c-ares resolver) request:0x60000318e4e0 on_hostbyname_done_locked: C-ares status is not ARES_SUCCESS qtype=A name=firestore.googleapis.com is_balancer=0: DNS query cancelled
...
D0408 14:38:20.114467000 7971737600 dns_resolver_ares.cc:328]          (c-ares resolver) resolver:0x600003f8d4a0 dns resolution failed: UNKNOWN:C-ares status is not ARES_SUCCESS qtype=A name=firestore.googleapis.com is_balancer=0: DNS query cancelled {created_time:"2024-04-08T14:38:20.114389-04:00", children:[UNKNOWN:C-ares status is not ARES_SUCCESS qtype=AAAA name=firestore.googleapis.com is_balancer=0: DNS query cancelled {created_time:"2024-04-08T14:38:20.114379-04:00"}]}

This is with firebase-admin 6.5.0 and python 3.12.2

Workaround

Call the python script with this environment variable:

GRPC_DNS_RESOLVER=native

works around the issue.

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.

[shrijitsingh99]

I had the same issue and using GRPC_DNS_RESOLVER=native as @sergiocampama suggested resolved it.
I noticed this only happened when I have two interfaces on my machine enable together i.e. WiFi and Cellular.
Disabling any one of them would fix the issue. Also the timeout is erratic, sometimes it succeeds though take more time then usual.