'Retrieve all the clients for the AbstractClientStatsCollectors.'

@flow.StateHandler()
def Start(self):

    self.stats = aff4.FACTORY.Create(self.FILESTORE_STATS_URN, aff4_stats.FilestoreStats, mode='w', token=self.token)
    self._CreateConsumers()
    hashes = aff4.FACTORY.Open(self.HASH_PATH, token=self.token).ListChildren(limit=(10 ** 8))
    try:
        for urns in utils.Grouper(hashes, self.OPEN_FILES_LIMIT):
            for fd in aff4.FACTORY.MultiOpen(urns, mode='r', token=self.token, age=aff4.NEWEST_TIME):
                for consumer in self.consumers:
                    consumer.ProcessFile(fd)
            self.HeartBeat()
    finally:
        for consumer in self.consumers:
            consumer.Save(self.stats)
        self.stats.Close()
