So I looked at the code and the compaction seems to concentrate / find
"most interesting" the newer buckets for compaction.
Our problem is that we have a huge fragmented number of sstables in buckets
that are a few days old. (not yet expired, our expiration is 7 days), so
the sstable selection
The existing 15 node cluster had about 450-500GB/node, most in one TWCS
table. Data is applied with a 7-day TTL. Our cluster couldn't be expanded
due to a bit of political foot dragging and new load of about 2x-3x started
up around the time we started expanding.
about 500 sstables per node, with
