Storage: Flaky 503 on list_blobs

[bencaine1]

Environment details

OS: Linux dc32b7e8763a 4.9.0-6-amd64 #1 SMP Debian 4.9.82-1+deb9u3 (2018-03-02) x86_64 x86_64 x86_64 GNU/Linux
Python version: Python 2.7.6
google-cloud-storage: 1.13.1

Code example

from google.cloud import storage
gs_client = storage.Client('my-project')
bucket = storage.bucket.Bucket(gs_client, 'my-bucket')
blobs = self.gs_bucket.list_blobs(prefix='my-folder')  # flaky failure from this line

Stack trace

  File "/opt/conda/lib/python2.7/site-packages/google/api_core/page_iterator.py", line 204, in _items_iter
    for page in self._page_iter(increment=False):
  File "/opt/conda/lib/python2.7/site-packages/google/api_core/page_iterator.py", line 235, in _page_iter
    page = self._next_page()
  File "/opt/conda/lib/python2.7/site-packages/google/api_core/page_iterator.py", line 361, in _next_page
    response = self._get_next_page_response()
  File "/opt/conda/lib/python2.7/site-packages/google/api_core/page_iterator.py", line 411, in _get_next_page_response
    method=self._HTTP_METHOD, path=self.path, query_params=params
  File "/opt/conda/lib/python2.7/site-packages/google/cloud/_http.py", line 319, in api_request
    raise exceptions.from_http_response(response)
google.api_core.exceptions.ServiceUnavailable: 503 GET https://www.googleapis.com/storage/v1/b/pm-results-prod/o?prefix=temp%2FInbound%2FCMS-Prod-20190617135540%2F4000192377%2F4000192377-Prod-export_result-31115705099441&projection=noAcl: Backend Error

This is a flaky error. It would be great if the library could retry when this happens!

[agraubert]

👍 Also experiencing intermittent 503's

[tseaver]

Duplicates #7907.