def METHOD_NAME(duthost):
    """ Test to replace ntp server
    """
    json_patch = [
        {
            "op": "remove",
            "path": "/NTP_SERVER/{}".format(NTP_SERVER_INIT)
        },
        {
            "op": "add",
            "path": "/NTP_SERVER/{}".format(NTP_SERVER_DUMMY),
            "value": {}
        }
    ]
    tmpfile = generate_tmpfile(duthost)
    logger.info("tmpfile {}".format(tmpfile))
    try:
        start_time = datetime.datetime.now()
        output = apply_patch(duthost, json_data=json_patch, dest_file=tmpfile)
        expect_op_success(duthost, output)
        pytest_assert(
            ntp_service_restarted(duthost, start_time),
            "ntp.service is not restarted after change"
        )
        pytest_assert(
            not server_exist_in_conf(duthost, NTP_SERVER_RE.format(NTP_SERVER_INIT)) and
            server_exist_in_conf(duthost, NTP_SERVER_RE.format(NTP_SERVER_DUMMY)),
            "Failed to replace ntp server."
        )
    finally:
        delete_tmpfile(duthost, tmpfile)