If you want to have all of your systems in one cluster it should work with one central gmond.
You should have everywhere the same clustername in gmond.conf and use the central system as host in the udp_send_channel configuration.

In gmetad.conf you should use the same clustername (e.g. "Production") and the central gmond server for collecting data.

I use this actually to collect the data of all systems in cluster "Standalone"

If you want to have separated clusters I guess there are two options (where I'm not sure if the 2nd option really works):
1) In every cluster define at least one head node and use that for communication with gmetad (I use this for all of the partitioned System P machines in my environment)
2) You have to define an private udp port for every cluster. The central gmond is configured with matching udp receive channels. Gmetad collects the data from the central gmond with different ports for each cluster.

From:        solarflow99 <solarflow99@gmail.com>
To:        ganglia-general@lists.sourceforge.net,
Date:        15.12.2011 16:47
Subject:        [Ganglia-general] multiple cluster directives

Is it possible to have multiple cluster directives in gmond?  I am
trying to have all different cluster nodes send to 1 gmond receiver in
unicast.  Can this be done, or do I have to have multiple gmond
daemons running each with their own config file?

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