如果在配置gmond.conf时，没有使用多播，那么必须把自己的ip加入到send_channel里面，否则 gmond不会感知本机的数据！
udp_send_channel {
#bind_hostname = yes # Highly recommended, soon to be default.
# This option tells gmond to use a source address
# that resolves to the machine’s hostname. Without
# this, the metrics may appear to come from any
# interface and the DNS names associated with
# those IPs will be used to create the RRDs.
#mcast_join = 239.2.11.71
host = 192.168.1.1
port = 28649
ttl = 1
}