title: How to force cleanup/compaction in Cassandra
body: <p>I'm using Cassandra 2.1.8 for managing various assets, mostly images.
  The cluster is setup with RF=3 on 3 nodes for the main CF, using Leveled Compaction.  I deleted a large portion of the data from the cluster (using a CQL script with lots of deletes), but the space has not yet been reclaimed.
  Furthermore, one node experienced corruption on SSTables and I chose to wipe out its data and run repair to re-create it.
  Now, the repaired node now uses 250GB in 100 SSTables, while the other 2 use 750GB in 300 SSTables.  "nodetool cfstats" shows 4.5M keys on one node, and 17M in the other two.</p>
  
  <p>Is there a way to force a cleanup on these 2 nodes?  Running "nodetool compact" did not seem to have much effect on the 2 nodes - and it finishes rather quick.</p>