docs: def index(
          config, date=None, directory=None, concurrency=5, accounts=None,
          tag=None, verbose=False):
      """index traildbs directly from s3 for multiple accounts.
  
      context: assumes a daily traildb file in s3 with dated key path
      """
  
      logging.basicConfig(level=(verbose and logging.DEBUG or logging.INFO))
      logging.getLogger('botocore').setLevel(logging.WARNING)
      logging.getLogger('elasticsearch').setLevel(logging.WARNING)
      logging.getLogger('urllib3').setLevel(logging.WARNING)
      logging.getLogger('requests').setLevel(logging.WARNING)
      logging.getLogger('c7n.worker').setLevel(logging.INFO)
  
      with open(config) as fh:
          config = yaml.safe_load(fh.read())
      jsonschema.validate(config, CONFIG_SCHEMA)
  
      date = get_date_path(date, delta=24)
      directory = directory or "/tmp"
  
      with ProcessPoolExecutor(max_workers=concurrency) as w:
          futures = {}
          jobs = []
  
          for account in config.get('accounts'):
              if accounts and account['name'] not in accounts:
                  continue
              if tag:
                  found = False
                  for t in account['tags'].values():
                      if tag == t:
                          found = True
                          break
                  if not found:
                      continue
              for region in account.get('regions'):
                  p = (config, account, region, date, directory)
                  jobs.append(p)
  
          for j in jobs:
              log.debug("submit account:{} region:{} date:{}".format(
                  j[1]['name'], j[2], j[3]))
              futures[w.submit(index_account_trails, *j)] = j
  
          # Process completed
          for f in as_completed(futures):
              config, account, region, date, directory = futures[f]
              if f.exception():
                  log.warning("error account:{} region:{} error:{}".format(
                      account['name'], region, f.exception()))
                  continue
              log.info("complete account:{} region:{}".format(
                  account['name'], region))