The ancestors were used primarily to clean up leftovers in the case that cassandra was killed right as compaction finished, where the source/origin/ancestors were still on the disk at the same time as the compaction result.
It's not timestamp based, though - that compaction process has moved to using a transaction log, which tracks the source/results on a per compaction basis, and cassandra uses those logs/journals rather than inspecting the ancestors. - Jeff On Thu, Mar 23, 2017 at 4:35 PM, Rajath Subramanyam <rajat...@gmail.com> wrote: > Thanks, Jeff. Did all the internal tasks and the compaction tasks move to a > timestamp-based approach? > > Regards, > Rajath > > ------------------------ > Rajath Subramanyam > > > On Thu, Mar 23, 2017 at 2:12 PM, Jeff Jirsa <jji...@gmail.com> wrote: > > > That information was removed, because it was really meant to be used for > a > > handful of internal tasks, most of which were no longer used. The > remaining > > use was cleaning up compaction leftovers, and the compaction leftover > code > > was rewritten in 3.0 / CASSANDRA-7066 (note, though, that it's somewhat > > incomplete in the upgrade case , so CASSANDRA-13313 may be interesting to > > people who are very very very very very very very sensitive to data > > consistency) > > > > > > On Thu, Mar 23, 2017 at 2:00 PM, Rajath Subramanyam <rajat...@gmail.com> > > wrote: > > > > > Hello Cassandra-Users and Cassandra-dev, > > > > > > One of the handy features in sstablemetadata that was part of Cassandra > > > 2.1.15 was that it displayed Ancestor information of an SSTable. Here > is > > a > > > sample output of the sstablemetadata tool with the ancestors > information > > in > > > C* 2.1.15: > > > [centos@chen-datos test1-b83746000fef11e7bdfc8bb2d6662df7]$ > > > sstablemetadata > > > ks3-test1-ka-2-Statistics.db | grep "Ancestors" > > > Ancestors: [1] > > > [centos@chen-datos test1-b83746000fef11e7bdfc8bb2d6662df7]$ > > > > > > However, the same tool in Cassandra 3.0.x no longer gives us that > > > information. Here is a sample output of the sstablemetadata grepping > for > > > Ancestors information in C* 3.0 (the output is empty since it is no > > longer > > > available): > > > [centos@rj-cassandra-1 elsevier1-ab7389f0fafb11e6ac23e7ccf62f494b]$ > > > sstablemetadata mc-5-big-Statistics.db | grep "Ancestors" > > > [centos@rj-cassandra-1 elsevier1-ab7389f0fafb11e6ac23e7ccf62f494b]$ > > > > > > My question, how can I get this information in C* 3.0.x ? > > > > > > Thank you ! > > > > > > Regards, > > > Rajath > > > > > > ------------------------ > > > Rajath Subramanyam > > > > > >