def METHOD_NAME():
    if hasattr(signal, 'SIGUSR1'):
        # Windows doesn't support SIGUSR1
        logger.info('Send SIGUSR1 signal to pid %i to start the checker', os.getpid())
        signal.signal(signal.SIGUSR1, _signal_handler)
    # special case when debug is activate
    if searx_debug and settings['checker']['off_when_debug']:
        logger.info('debug mode: checker is disabled')
        return
    # check value of checker.scheduling.every now
    scheduling = settings['checker']['scheduling']
    if scheduling is None or not scheduling:
        logger.info('Checker scheduler is disabled')
        return
    # make sure there is a Redis connection
    if get_redis_client() is None:
        logger.error('The checker requires Redis')
        return
    # start the background scheduler
    every_range = _get_interval(scheduling.get('every', (300, 1800)), 'checker.scheduling.every is not a int or list')
    start_after_range = _get_interval(
        scheduling.get('start_after', (300, 1800)), 'checker.scheduling.start_after is not a int or list'
    )
    t = threading.Thread(
        target=scheduler_function,
        args=(start_after_range[0], start_after_range[1], every_range[0], every_range[1], run),
        name='checker_scheduler',
    )
    t.daemon = True
    t.start()