Simple query times out 4 out of 5 times

[MeLight]

from google.cloud import datastore
import datetime
from datetime import timedelta

client = datastore.Client()
result = client.query(kind='Shop').add_filter('plan_expiry', '>', datetime.datetime.today()-timedelta(days=3)).fetch(3)

for entity in result:
	print(entity.get('owner_email'))

Running this from the command line mostly produces a timeout. Running similar query on other entities in the Datastore produces less timeouts but still does very often.

Traceback (most recent call last):
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/grpc_helpers.py", line 72, in error_remapped_callable
    return callable_(*args, **kwargs)
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/grpc/_channel.py", line 946, in __call__
    return _end_unary_response_blocking(state, call, False, None)
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/grpc/_channel.py", line 849, in _end_unary_response_blocking
    raise _InactiveRpcError(state)
grpc._channel._InactiveRpcError: <_InactiveRpcError of RPC that terminated with:
        status = StatusCode.DEADLINE_EXCEEDED
        details = "Deadline Exceeded"
        debug_error_string = "UNKNOWN:Deadline Exceeded {created_time:"2023-01-16T22:24:12.003883865+02:00", grpc_status:4}"
>

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/retry.py", line 191, in retry_target
    return target()
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/timeout.py", line 120, in func_with_timeout
    return func(*args, **kwargs)
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/grpc_helpers.py", line 74, in error_remapped_callable
    raise exceptions.from_grpc_error(exc) from exc
google.api_core.exceptions.DeadlineExceeded: 504 Deadline Exceeded

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/user/stuff/myproject/stores.py", line 8, in <module>
    for entity in result:
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/page_iterator.py", line 208, in _items_iter
    for page in self._page_iter(increment=False):
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/page_iterator.py", line 244, in _page_iter
    page = self._next_page()
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/cloud/datastore/query.py", line 627, in _next_page
    response_pb = self.client._datastore_api.run_query(
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/cloud/datastore_v1/services/datastore/client.py", line 625, in run_query
    response = rpc(
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/gapic_v1/method.py", line 113, in __call__
    return wrapped_func(*args, **kwargs)
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/retry.py", line 349, in retry_wrapped_func
    return retry_target(
  File "/home/user/stuff/myproject/venv/lib/python3.9/site-packages/google/api_core/retry.py", line 207, in retry_target
    raise exceptions.RetryError(
google.api_core.exceptions.RetryError: Deadline of 60.0s exceeded while calling target function, last exception: 504 Deadline Exceeded

Please advise

[Mariatta]

Thanks for filing an issue. The Deadline Exceeded error is an error from the backend, and not an issue with the client library.
Can you please file a support ticket with Datastore? There's information about it here: https://cloud.google.com/datastore/docs/getting-support

Another thing you can do is to increase the timeout. The fetch function accepts a timeout parameter. By default it is 60 seconds, but you can adjust it from your side.

Hope this helps.