title: Using Prometheus with Connexion - ValueError: Duplicated timeseries in CollectorRegistry
body: <p>I get the following error message when using prometheus with connexion using python3.6/3.7:</p>
  
  <blockquote>
    <p>ValueError: Duplicated timeseries in CollectorRegistry: {'app_request_processing_seconds_sum', 'app_request_processing_seconds_count', 'app_request_processing_seconds_created', 'app_request_processing_seconds'}</p>
  </blockquote>
  
  <pre><code>#!/usr/bin/env python3
  from gevent import monkey  # noqa
  
  # monkey.patch_all()  # noqa
  
  import json
  import os
  import connexion
  import datetime
  import logging
  
  from connexion import NoContent
  from prometheus_client import Summary, Counter
  
  logger = logging.getLogger(__name__)
  
  REQUEST_TIME = Summary('app_request_processing_seconds', 'time spent processing')
  REQUEST_COUNTER = Counter('app_request_count', 'number of requests')
  
  @REQUEST_TIME.time()
  def get_health():
      try:
          'Hello'
      except Exception:
          return connexion.problem(503, "Service Unavailable", "Unhealthy")
      else:
          return "Healthy"
  
  
  logging.basicConfig(level=logging.INFO)
  app = connexion.App(__name__)
  app.add_api("swagger.yaml")
  
  if __name__ == "__main__":
      # run our standalone gevent server
      app.run(port=8080, server="gevent")
  </code></pre>
  
  <p>There is a swagger.yaml that is identical to:
  <a href="https://github.com/hjacobs/connexion-example-redis-kubernetes/blob/master/swagger.yaml" rel="nofollow noreferrer">https://github.com/hjacobs/connexion-example-redis-kubernetes/blob/master/swagger.yaml</a></p>
  
  <p>Any help would be great</p>