Hi Alexander, after re-reading this https://issues.apache.org/jira/browse/CASSANDRA-13418 it seems you would recommend leaving dclocal_read_repair at maybe 10% is that true?
Also, has this been patched to 2.1? https://github.com/thelastpickle/cassandra/commit/58440e707cd6490847a37dc8d76c150d3eb27aab#diff-e8e282423dcbf34d30a3578c8dec15cdR176 Cheers, -B On Sat, Jan 20, 2018 at 10:49 AM Brian Spindler <brian.spind...@gmail.com> wrote: > Hi Alexander, Thanks for your response! I'll give it a shot. > > On Sat, Jan 20, 2018 at 10:22 AM Alexander Dejanovski < > a...@thelastpickle.com> wrote: > >> Hi Brian, >> >> You should definitely set unchecked_tombstone_compaction to true and set >> the interval to the default of 1 day. Use a tombstone_threshold of 0.6 for >> example and see how that works. >> Tombstones will get purged depending on your partitioning as their >> partition needs to be fully contained within a single sstable. >> >> Deleting the sstables by hand is theoretically possible but should be >> kept as a last resort option if you're running out of space. >> >> Cheers, >> >> Le sam. 20 janv. 2018 à 15:41, Brian Spindler <brian.spind...@gmail.com> >> a écrit : >> >>> I probably should have mentioned our setup: we’re on Cassandra version >>> 2.1.15. >>> >>> >>> On Sat, Jan 20, 2018 at 9:33 AM Brian Spindler <brian.spind...@gmail.com> >>> wrote: >>> >>>> Hi, I have several column families using TWCS and it’s great. >>>> Unfortunately we seem to have missed the great advice in Alex’s article >>>> here: http://thelastpickle.com/blog/2016/12/08/TWCS-part1.html about >>>> setting the appropriate aggressive tombstone settings and now we have lots >>>> of timestamp overlaps and disk space to reclaim. >>>> >>>> >>>> >>>> I am trying to figure the best way out of this. Lots of the SSTables >>>> with overlapping timestamps in newer SSTables have droppable tombstones at >>>> like 0.895143957 or something similar, very close to 0.90 where the full >>>> sstable will drop afaik. >>>> >>>> >>>> >>>> I’m thinking to do the following immediately: >>>> >>>> >>>> >>>> Set *unchecked_tombstone_compaction = true* >>>> >>>> Set* tombstone_compaction_interval == TTL + gc_grace_seconds* >>>> >>>> Set* dclocal_read_repair_chance = 0.0 (currently 0.1)* >>>> >>>> >>>> >>>> If I do this, can I expect TWCS/C* to reclaim the space from those >>>> SSTables with 0.89* droppable tombstones? Or do I (can I?) manually >>>> delete these files and will c* just ignore the overlapping data and treat >>>> as tombstoned? >>>> >>>> >>>> >>>> What else should/could be done? >>>> >>>> >>>> >>>> Thank you in advance for your advice, >>>> >>>> >>>> >>>> *__________________________________________________* >>>> >>>> *Brian Spindler * >>>> >>>> >>>> >>>> >>>> >>> -- >> ----------------- >> Alexander Dejanovski >> France >> @alexanderdeja >> >> Consultant >> Apache Cassandra Consulting >> http://www.thelastpickle.com >> >
