Telegraf: invert / negate measurement

Hi!

Right now we are looking into telegraf replacing our crappy collect librato agent. All of our existing alarms inside librato require some special names (which i can rename without a hassle) and metrics. One of those is sending an alert if the free disk space in percent is crossing a threshold. telegraf disk plugin reports used disk space in percent. Is there a way to negate / invert the value without patching the plugin itself? I’ve looked into processors, enum ,aggregators and so on and could not find any possibility to do so.

Thanks!

Hi @morph027 I don’t think that is possible ,
in kapacitor it is a piece of cake but I guess you are not planning to use kapacitor ?

best regards ,

Currently, the plan is to use telegraf as drop-in replacement for the old stuff so it still needs to report to librato and have the same tags and so on to support the already existing alarms. Long-term plan is to switch to another backend (e.g. Influx itself or Prometheus or whatever).

I have seen in other post that you can open an issue
here if you want : https://github.com/influxdata/telegraf