GCS Connection Error

[Saurav-D]

Describe the bug
Got ConnectionError while training after looking at the traceback it seems when event_file_writer do flush() and if there's a connection error it hangs that thread as well as training.

Expected behavior
Training to complete without any errors.

Traceback

Exception in thread Thread-65:
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/dist-packages/urllib3/connectionpool.py", line 677, in urlopen
    chunked=chunked,
  File "/usr/local/lib/python3.7/dist-packages/urllib3/connectionpool.py", line 426, in _make_request
    six.raise_from(e, None)
  File "<string>", line 3, in raise_from
  File "/usr/local/lib/python3.7/dist-packages/urllib3/connectionpool.py", line 421, in _make_request
    httplib_response = conn.getresponse()
  File "/usr/lib/python3.7/http/client.py", line 1344, in getresponse
    response.begin()
  File "/usr/lib/python3.7/http/client.py", line 306, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python3.7/http/client.py", line 275, in _read_status
    raise RemoteDisconnected("Remote end closed connection without"
http.client.RemoteDisconnected: Remote end closed connection without response
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/dist-packages/requests/adapters.py", line 449, in send
    timeout=timeout
  File "/usr/local/lib/python3.7/dist-packages/urllib3/connectionpool.py", line 727, in urlopen
    method, url, error=e, _pool=self, _stacktrace=sys.exc_info()[2]
  File "/usr/local/lib/python3.7/dist-packages/urllib3/util/retry.py", line 403, in increment
    raise six.reraise(type(error), error, _stacktrace)
  File "/usr/local/lib/python3.7/dist-packages/urllib3/packages/six.py", line 734, in reraise
    raise value.with_traceback(tb)
  File "/usr/local/lib/python3.7/dist-packages/urllib3/connectionpool.py", line 677, in urlopen
    chunked=chunked,
  File "/usr/local/lib/python3.7/dist-packages/urllib3/connectionpool.py", line 426, in _make_request
    six.raise_from(e, None)
  File "<string>", line 3, in raise_from
  File "/usr/local/lib/python3.7/dist-packages/urllib3/connectionpool.py", line 421, in _make_request
    httplib_response = conn.getresponse()
  File "/usr/lib/python3.7/http/client.py", line 1344, in getresponse
    response.begin()
  File "/usr/lib/python3.7/http/client.py", line 306, in begin
    version, status, reason = self._read_status()
  File "/usr/lib/python3.7/http/client.py", line 275, in _read_status
    raise RemoteDisconnected("Remote end closed connection without"
urllib3.exceptions.ProtocolError: ('Connection aborted.', RemoteDisconnected('Remote end closed connection without response'))
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
  File "/usr/lib/python3.7/threading.py", line 926, in _bootstrap_inner
    self.run()
  File "/usr/local/lib/python3.7/dist-packages/tensorboardX/event_file_writer.py", line 219, in run
    self._record_writer.flush()
  File "/usr/local/lib/python3.7/dist-packages/tensorboardX/event_file_writer.py", line 69, in flush
    self._py_recordio_writer.flush()
  File "/usr/local/lib/python3.7/dist-packages/tensorboardX/record_writer.py", line 187, in flush
    self._writer.flush()
  File "/usr/local/lib/python3.7/dist-packages/tensorboardX/record_writer.py", line 149, in flush
    self.blob.upload_from_string(upload_buffer.getvalue())
  File "/usr/local/lib/python3.7/dist-packages/google/cloud/storage/blob.py", line 1733, in upload_from_string
    if_metageneration_not_match=if_metageneration_not_match,
  File "/usr/local/lib/python3.7/dist-packages/google/cloud/storage/blob.py", line 1567, in upload_from_file
    if_metageneration_not_match,
  File "/usr/local/lib/python3.7/dist-packages/google/cloud/storage/blob.py", line 1420, in _do_upload
    if_metageneration_not_match,
  File "/usr/local/lib/python3.7/dist-packages/google/cloud/storage/blob.py", line 1098, in _do_multipart_upload
    response = upload.transmit(transport, data, object_metadata, content_type)
  File "/usr/local/lib/python3.7/dist-packages/google/resumable_media/requests/upload.py", line 106, in transmit
    retry_strategy=self._retry_strategy,
  File "/usr/local/lib/python3.7/dist-packages/google/resumable_media/requests/_helpers.py", line 136, in http_request
    return _helpers.wait_and_retry(func, RequestsMixin._get_status_code, retry_strategy)
  File "/usr/local/lib/python3.7/dist-packages/google/resumable_media/_helpers.py", line 150, in wait_and_retry
    response = func()
  File "/usr/local/lib/python3.7/dist-packages/google/auth/transport/requests.py", line 470, in request
    **kwargs
  File "/usr/local/lib/python3.7/dist-packages/requests/sessions.py", line 530, in request
    resp = self.send(prep, **send_kwargs)
  File "/usr/local/lib/python3.7/dist-packages/requests/sessions.py", line 643, in send
    r = adapter.send(request, **kwargs)
  File "/usr/local/lib/python3.7/dist-packages/requests/adapters.py", line 498, in send
    raise ConnectionError(err, request=request)
requests.exceptions.ConnectionError: ('Connection aborted.', RemoteDisconnected('Remote end closed connection without response'))

Seems like there's already a PR that handle connection error for S3: #555