title: ServiceUnavailable: 503 failed to connect to all addresses during attempt to recognize audio
body: <p>I'm trying to run a following code to recognize an audio file. The code is just a compilation from different official examples. But it doesn't work.</p>
  
  <pre><code>import os
  from google.cloud import speech
  from google.cloud.speech import enums
  from google.cloud.speech import types
  from google.oauth2 import service_account
  import io
  
  def transcribe_file(speech_file):
      client = speech.SpeechClient(credentials=credentials)
  
      with io.open(speech_file, 'rb') as audio_file:
          content = audio_file.read()
  
      audio = types.RecognitionAudio(content=content)
      config = types.RecognitionConfig(
          encoding=enums.RecognitionConfig.AudioEncoding.LINEAR16,
          sample_rate_hertz=16000,
          language_code='ru-RU')
  
      response = client.long_running_recognize(config, audio)
      for result in response.results:
          print(u'Transcript: {}'.format(result.alternatives[0].transcript))
  
  audio_folder_path = 'data_wav'
  all_audios = os.listdir(audio_folder_path)
  
  file_name = os.path.join(audio_folder_path, all_audios[0])
  
  credentials = service_account.Credentials.from_service_account_file("google_aut.json")
  
  transcribe_file(file_name)
  </code></pre>
  
  <p>I use Anaconda 4.7.12 for Python 3.7 under Windows 10, google-cloud-speech v 1.2.0, google-auth v 1.6.3</p>
  
  <p>The error I get every time is</p>
  
  <blockquote>
    <p>_Rendezvous                               Traceback (most recent call last)
    ~\AppData\Local\Continuum\anaconda3\lib\site-packages\google\api_core\grpc_helpers.py
    in error_remapped_callable(*args, **kwargs)
         56         try:
    ---> 57             return callable_(*args, **kwargs)
         58         except grpc.RpcError as exc:</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\grpc_channel.py
    in <strong>call</strong>(self, request, timeout, metadata, credentials,
    wait_for_ready, compression)
        564                                       wait_for_ready, compression)
    --> 565         return _end_unary_response_blocking(state, call, False, None)
        566</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\grpc_channel.py
    in _end_unary_response_blocking(state, call, with_call, deadline)
        466     else:
    --> 467         raise _Rendezvous(state, None, None, deadline)
        468</p>
    
    <p>_Rendezvous: &lt;_Rendezvous of RPC that terminated with:
            status = StatusCode.UNAVAILABLE
            details = "failed to connect to all addresses"
            debug_error_string = "{"created":"@1569838382.864000000","description":"Failed to pick
    subchannel","file":"src/core/ext/filters/client_channel/client_channel.cc","file_line":3818,"referenced_errors":[{"created":"@1569838382.863000000","description":"failed
    to connect to all
    addresses","file":"src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc","file_line":395,"grpc_status":14}]}"
    ></p>
    
    <p>The above exception was the direct cause of the following exception:</p>
    
    <p>ServiceUnavailable                        Traceback (most recent call
    last)  in 
    ----> 1 transcribe_file(file_name)</p>
    
    <p> in transcribe_file(speech_file)
         20
         21     # [START speech_python_migration_sync_response]
    ---> 22     response = client.long_running_recognize(config, audio)
         23     # [END speech_python_migration_sync_request]
         24     # Each result is for a consecutive portion of the audio. Iterate through</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\google\cloud\speech_v1\gapic\speech_client.py
    in long_running_recognize(self, config, audio, retry, timeout,
    metadata)
        339         )
        340         operation = self._inner_api_calls["long_running_recognize"](
    --> 341             request, retry=retry, timeout=timeout, metadata=metadata
        342         )
        343         return google.api_core.operation.from_gapic(</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\google\api_core\gapic_v1\method.py
    in <strong>call</strong>(self, *args, **kwargs)
        141             kwargs["metadata"] = metadata
        142
    --> 143         return wrapped_func(*args, **kwargs)
        144
        145</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\google\api_core\retry.py
    in retry_wrapped_func(*args, **kwargs)
        271                 sleep_generator,
        272                 self._deadline,
    --> 273                 on_error=on_error,
        274             )
        275</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\google\api_core\retry.py
    in retry_target(target, predicate, sleep_generator, deadline,
    on_error)
        180     for sleep in sleep_generator:
        181         try:
    --> 182             return target()
        183
        184         # pylint: disable=broad-except</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\google\api_core\timeout.py
    in func_with_timeout(*args, **kwargs)
        212             """Wrapped function that adds timeout."""
        213             kwargs["timeout"] = next(timeouts)
    --> 214             return func(*args, **kwargs)
        215
        216         return func_with_timeout</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\google\api_core\grpc_helpers.py
    in error_remapped_callable(*args, **kwargs)
         57             return callable_(*args, **kwargs)
         58         except grpc.RpcError as exc:
    ---> 59             six.raise_from(exceptions.from_grpc_error(exc), exc)
         60
         61     return error_remapped_callable</p>
    
    <p>~\AppData\Local\Continuum\anaconda3\lib\site-packages\six.py in
    raise_from(value, from_value)</p>
  </blockquote>
  
  <p>ServiceUnavailable: 503 failed to connect to all addresses</p>
  
  <p>How can I fix it?</p>