Compaction memory usage is too high with no limit #4636
Description
We are trying a single instance pyroscope with a bunch of machines reporting to it, backed by Cloudflare R2. We have observed quite high memory usage after a while.
Zoomed into a single recent profile I see 120GiB+ of memory used, pretty much exclusively in compactor:
That tracks with cadvisor metrics for the service:
There doesn't seem to be a way to set the limit. There should be both a limit and a reasonable default here.