Determine if a batch should be processed and if not, pop off all of
    the pending metrics for that batch.

    :rtype: bool

def _sample_batch():
    """Determine if a batch should be processed and if not, pop off all of
    the pending metrics for that batch.

    :rtype: bool

    """
    if _sample_probability == 1.0 or random.random() < _sample_probability:
        return True

    # Pop off all the metrics for the batch
    for database in _measurements:
        _measurements[database] = _measurements[database][_max_batch_size:]
    return False