Grafana/Graphite Complex query

Hi,

I’m searching to graph something like this:

$prefix.$server.memory.memory-used - ($prefix.$server.processes-spark.ps_rss + $prefix.$server.processes-impalad.ps_rss)

On the graph I want one line per server when $server represent multiple servers. I’m not able to write the query, and I don’t even know if it’s possible.

Could someone help me on that?

Regards

Tried any of the graphite subtract functions

I’m just able to do this:

groupByNode($prefix.$server.{processes-impalad,processes-spark}.ps_rss, 1, ‘sum’)

If I add a diffSeries I’m not able to keep the information per servers.