Fix Version/s: None
This is a highly frustration-driven ticket. Apologize for roughness in tone
Background: I happen to have a partition key with lots of tombstones. Sadly, I happen to run LeveledCompactionStrategy (LCS). Yes, it's probably my mistake to have put them there but running into tombstone issues seem to be common for Cassandra, so I don't think this ticket can be discarded as simply user error. In fact, I believe this could happen to the best of us. And when it does, there should be a quick way of correcting this.
Problem: How does one handle this? Well, for DTCS one could issue a compaction using `nodetool compact`, or one could use the forceUserDefinedCompaction MBean. Neither of these work for LCS (shall I also say DTCS?).
Workaround: The only options AFAIK are
1. to lower "gc_grace_seconds" and "wait it out" until the Cassandra node(s) has garbage collected the sstables. This can take days.
2. possibly lower `tombstone_threshold` to something tiny, optionally lowering `tombstone_compaction_interval ` (for recent deletes). This has the implication that nodes might start garbage collecting a ton of unrelated stuff.
3. variations of "delete some or all your sstables" and run a full repair. Takes ages.
Proposed solution: Either
- Make forceUserDefinedCompaction support LCS, or create a similar endpoint that does something similar.
- make something similar to `nodetool compact` work with LCS.
Additional comments: I read somewhere where someone proposed making LCS default compaction strategy. Before this ticket is fixed, I don't see that as an option.
Let me know what you think (or close if not relevant).