Client's auth token times out (StackOverflow)

@dhermes Seems like you have the best grasp on our oauthclient story.

http://stackoverflow.com/questions/37982336/unauthenticated-error-using-gcloud-python-to-connect-to-google-bigtable

/cc @sduskis

[herbertrlee]

@dhermes - Using gcloud 0.18.0 (previously 0.17.0), oauthclient 3.0.0 (previously 2.2.0), and grpcio 1.0.0rc1 (previously 0.15.0), I no longer seem to be able to reproduce this issue. I do still occasionally get auth errors, but I recover from them on subsequent attempts without needing to redeploy my app, which I can handle on my side. Thanks for your help and patience!

[dr3x]

Strange - based on the log - looks like it failed at an hour, even though the expiry showed it had more time?

Timeline: Start 00:00 Refresh 00:45 Auth Error 00:60 (which is 15 minutes after successfully invoking refresh)

… Inserting batch: 1337671, Table: Some_Table, Expiration: 0:45:01.936000 Inserting batch: 1338172, Table: Some_Table, Expiration: 0:45:00.733000

Traceback (most recent call last):
  File "quick_table_load.py", line 124, in <module>
    load_table(table_name)
  File "quick_table_load.py", line 110, in load_table
    insert_batch(table_name,col_names,chgs,tsv_arr)
  File "quick_table_load.py", line 80, in insert_batch
    values=tsv_arr)
  File "C:\src\github\python-docs-samples\env\lib\site-packages\google\cloud\spanner\database.py", line 462, in __exit__
    self._batch.commit()
  File "C:\src\github\python-docs-samples\env\lib\site-packages\google\cloud\spanner\batch.py", line 156, in commit
    options=options)
  File "C:\src\github\python-docs-samples\env\lib\site-packages\google\cloud\gapic\spanner\v1\spanner_client.py", line 832, in commit
    return self._commit(request, options)
  File "C:\src\github\python-docs-samples\env\lib\site-packages\google\gax\api_callable.py", line 428, in inner
    return api_caller(api_call, this_settings, request)
  File "C:\src\github\python-docs-samples\env\lib\site-packages\google\gax\api_callable.py", line 416, in base_caller
    return api_call(*args)
  File "C:\src\github\python-docs-samples\env\lib\site-packages\google\gax\api_callable.py", line 376, in inner
    return a_func(*args, **kwargs)
  File "C:\src\github\python-docs-samples\env\lib\site-packages\google\gax\retry.py", line 127, in inner
    ' classified as transient', exception)
google.gax.errors.RetryError: GaxError(Exception occurred in retry method that was not classified as transient, caused by <_Rendezvous of RPC that terminated with (StatusCode.UNAUTHENTICATED, Request
had invalid authentication credentials. Expected OAuth 2 access token, login cookie or other valid authentication credential. See https://developers.google.com/identity/sign-in/web/devconsole-project.
)>)

(env) C:\src\github\python-docs-samples>