High inter-dc latency could make writes more likely not to land, which would make repair do more work.
Also true for read and writes - waiting for the cross-dc request will keep threads around longer, so more concurrent work, so more GC. May be that the GC is coming from the read/write path, and you're only noticing it when repair tips you over the edge. On Wed, Aug 4, 2021 at 6:54 AM manish khandelwal < manishkhandelwa...@gmail.com> wrote: > Can inter dc latency cause high gc pauses? Other clusters working fine > with same configuration? Only this particular cluster is giving long GC > pauses during repair. > > Regards > Manish > > On Tue, Aug 3, 2021 at 6:42 PM Jim Shaw <jxys...@gmail.com> wrote: > >> CMS heap too large will have long GC. you may try reduce heap on 1 node >> to see. or go GC1 if it is easy way. >> >> Thanks, >> Jim >> >> On Tue, Aug 3, 2021 at 3:33 AM manish khandelwal < >> manishkhandelwa...@gmail.com> wrote: >> >>> Long GC (1 seconds /2 seconds) pauses seen during repair on the >>> coordinator. Running full repair with partition range option. GC collector >>> is CMS and heap is 14G. Cluster is 7+7. Cassandra version is 3.11.2. Not >>> much traffic when repair is running. What could be the probable cause of >>> long gc pauses? What things should I look into? >>> >>> Regards >>> Manish >>> >>
