I have a deployment involving Grafana and StatsD. I’ve enabled StatsD’s deleteIdleStats option, so 0s are not automatically flushed for metrics. My Carbon’s retention policy saves metrics in 10-second intervals for data less than 24 hours old. Therefore, for example, if I want to send a particular metric once every minute (rather than every 10 seconds), carbon/whisper will save several null datapoints for the metric. That’s all fine, but the problem then is that I cannot produce a line of graph of that metric, because there are null points in between.
Without changing Carbon’s retention policy, what is the simplest way to get Grafana to effectively ignore those null points and produce a proper line graph? I’m guessing there’s a function I can apply to the metric query to accomplish this by, for example, taking groups of 6 data points each representing 10-seconds, and making that grouped data point represent a minute, and therefore there wouldn’t be any null data points preventing a line graph from being created.