need to reclaim space with TWCS

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

Re: need to reclaim space with TWCS

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 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://thelastpi

Re: need to reclaim space with TWCS

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 wit

Re: need to reclaim space with TWCS

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_th

Re: need to reclaim space with TWCS

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/58440e707cd6490847a37dc8d76c150d3eb27

Re: need to reclaim space with TWCS

I would turn background read repair off on the table to improve the overlap issue, but you'll still have foreground read repair if you use quorum reads anyway. So put dclocal_... to 0.0. The commit you're referring to has been merged in 3.11.1 as 2.1 doesn't patched anymore. Le sam. 20 janv. 201

Re: need to reclaim space with TWCS

Got it. Thanks again. > On Jan 20, 2018, at 11:17 AM, Alexander Dejanovski > wrote: > > I would turn background read repair off on the table to improve the overlap > issue, but you'll still have foreground read repair if you use quorum reads > anyway. > > So put dclocal_... to 0.0. > > Th