CMS has a higher risk of a long stop-the-world full GC that will cause a burst of timeouts, but if you're not getting that or don't mind if it happens now and then CMS is probably the way to go. It's generally lower-overhead than G1. If you really don't care about latency it might even be worth testing the Parallel collector, but at 16GB there might be timeouts.
On Wed, Nov 17, 2021 at 6:25 AM onmstester onmstester <onmstes...@zoho.com> wrote: > Thank You > I'm going to achieve the most possible (write) throughput with Cassandra > and care less about latency, recommendations from community suggests that > better to use G1GC with 16GB heap, but when i already got 92% throughput > with CMS, should i consider changing it? > > Sent using Zoho Mail <https://www.zoho.com/mail/> > > > ---- On Tue, 16 Nov 2021 16:52:29 +0330 *Bowen Song <bo...@bso.ng > <bo...@bso.ng>>* wrote ---- > > Do you have any performance issues? such as long STW GC pauses or high > p99.9 latency? If not, then you shouldn't tune the GC for the sake of it. > However, if you do have performance issues related to GC, regardless what > is the GC metric you are looking at saying, you will need to address the > issue and that probably will involve some GC tunings. > On 15/11/2021 06:00, onmstester onmstester wrote: > > Hi, > We are using Apache Cassandra 3.11.2 with its default gc configuration > (CMS and ...) on a 16GB heap, i inspected gc logs using gcviewer and it > reported 92% of throughput, is that means not necessary to do any further > tuning for gc? and everything is ok with gc of Cassandra? > > > Sent using Zoho Mail <https://www.zoho.com/mail/> > > > > >
