issue monitoring hadoop response

I am using ganglia to monitor Hadoop. gmond and gmetad are running fine. When I telnet on gmond port (8649) and when I telnet gmetad on its xml answer port, I get no hadoop data. How can it be ?

cluster {
  name = "my cluster"
  owner = "Master"
  latlong = "unspecified"
  url = "unspecified"
}

host {
  location = localhost
}

udp_send_channel {
  #bind_hostname = yes 
  #mcast_join = 239.2.11.71
  host = localhost
  port = 8649
  ttl = 1
}

udp_recv_channel {
  #mcast_join = 239.2.11.71
  port = 8649
  retry_bind = true
  # Size of the UDP buffer. If you are handling lots of metrics you really
  # should bump it up to e.g. 10MB or even higher.
  # buffer = 10485760
}

tcp_accept_channel {
  port = 8649
  # If you want to gzip XML output
  gzip_output = no
}

I find out the issue. It was related to the hadoop metrics properties. I set up ganglia in the hadoop-metrics.properties but I had to set up hadoop-metrics.properties config file. Now ganglia throws correct metrics.