Hi Jeff, Thanks for your reply.
I am using version 3.0.14. I did run the nodetool repair -pr --full 1_TB_keyspace I notice the 'anti-compaction after repair' were run after I ran the above command. I am still puzzled with the questions above. Thanks Regards Martin On Sun, Aug 4, 2019 at 10:29 AM Jeff Jirsa <jji...@gmail.com> wrote: > > > On Aug 3, 2019, at 5:03 PM, Martin Xue <martin...@gmail.com> wrote: > > > > Hi Cassandra community, > > > > I am using Cassandra 3.0.14, 1 cluster, node a,b,c in DC1, node d,e,f in > DC2. > > > > Keyspace_m is 1TB > > > > When I run repair -pr a full keyspace_m on node a, what I noticed are: > > 1. Repair process is running on node a > > 2. Anti compaction after repair are running on other nodes at least node > b,d,e,f > > > > I want to know > > 1. why there are anti compactions running after repair? > > > They should run before repair - they split data you’re going to repair > from data you’re not going to repair > > If they’re running after, either there’s another repair command on > adjacent nodes or you’re repairing multiple key spaces and lost track > > > 2. Why it needs to run on other nodes? (I only run primary range repair > on node a) > > Every host involved in the repair will anticompact to split data in the > range you’re repairing from other data. That means RF number of hosts will > run anticompaction for each range you repair > > 3. What's the purpose of anti compaction after repair? > > Answered above , but reminder it’s before > > > 4. Can I disable the anti compaction? If so any damage will cause? (It > takes more than 2 days to run on 1TB keyspace_m, and filled up disk > quickly, too time and resources consuming) > > > You can run full repair instead of incremental by passing -full > > But he cost of anticompaction should go down after the first successful > incremental repair > > > > > Any suggestions would be appreciated. > > > > Thanks > > Regards > > Martin > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org > >
