Author here and a few other M3ers around too, please do ask any questions. Ultimately we'd just like to make the project useful to others, so any and all feedback is appreciated, thank you!
Edit: I was interested in M3 for this instead of just a time series DB because I’d also like to aggregate the metrics at lower resolutions and higher resolutions.
It’s mainly just disk space that is the primary bottleneck.
Basically though when you set retention mapping rules, metrics are downsampled to whatever resolution you choose (10s, 1min, 10min, etc) and then stored for whatever time the retention the namespace you have setup for that policy.
And with respect to my comment about disk space being the bottleneck - unless you have a huge dataset you actually might not be bottlenecked by disk, it’s just we’ve encountered that at times with our really high cardinality data sets.
What does that mean? What kind of compaction?