I want use ganglia's data to analyze our cluster, But I don't know where is the ganglia's database.
Anyone had do this before?
It is rrd files that stores metrics data on gmetad. usually the default path is /var/lib/ganglia/rrds/<cluster-name>/<node-name>/
where each metric is stored in a single rrd file like bytes_in.rrd
Please refer to command rrdfetch or this question to see how to fetch data from rrd file (this is pure rrdtool question which is out of ganglia technology)