def METHOD_NAME(benchmark_spec):
  """Spawn YCSB and gather the results.
  Args:
    benchmark_spec: The benchmark specification. Contains all data that is
        required to run the benchmark.
  Returns:
    A list of sample.Sample instances.
  """
  logging.info('Start benchmarking memcached service, scenario is %s.',
               FLAGS.memcached_scenario)
  clients = benchmark_spec.vm_groups['clients']
  samples = list(benchmark_spec.executor.LoadAndRun(clients))
  for sample in samples:
    sample.metadata.update(benchmark_spec.metadata)
  return samples