Can I make clean old tombstones?

Question

I recently omitted gc_grace_seconds for a CQL table. I am running LeveledCompactionStrategy . Can I get my old SSTables to be cleaned from old tombstones?

Answer 1

TL DR

Your tombstones will disappear on their own through a bit of compaction, make sure that you are repairing, or they may return from the dead.

http://www.datastax.com/documentation/cassandra/2.0/cassandra/dml/dml_about_deletes_c.html

Adding additional information:

Graves are not accessible for removal until both:

1) gc_grace_seconds has expired

2) they meet the requirements configured in the sub-properties of tombstone compaction

I need to free the disk with outdated tombstones, how can I do this quickly?

1) Start the repair to make sure your tombstones are matched.

2) Reduce gc_grace_seconds for your table ( change table statement )

3) Set additional properties to speed up the removal of tombstones:

Decrease tombstone_compaction_interval and decrease tombstone_threshold or set unchecked_tombstone_compaction to true to ignore both conditions and collect based solely on gc grace.

Does he work?

You can see tombstone statistics in nodetool cfstats and with the sstable metatdata utility found in your sstablemetadata <sstable filenames> tool directory.