This. We recently had to upgrade to a c4 instance in AWS because the single core on a c3 couldn't take what we were sending. We needed something like Brubeck because eventually the c4 will run out of headroom too.

To clarify, statsite does spawn threads to do some of the aggregation and flushing at the end of the collection interval, but yes it is possible to saturate the main loop at a very high ingest rate.