There are operational advantages to having #racks == RF, however it's by no means mandatory. Having more racks than RF doesn't cause any availability/health/balance problems, it is only disadvantageous in that it makes some cluster maintenance tasks more expensive/unwieldy like repairs and DC migrations. Note that you can re-use racks across your physical servers assuming you have more physical servers than RF, it's not necessary to have a separate rack per physical server, as long as there are at least RF physical servers (ideally these physical servers should also be in the same rack/AZ in the datacenter to protect against physical rack/datacenter outage).
FYI this went to spam on GMail. I suspect google is flexing their monopoly muscles against zoho. On Mon, Feb 15, 2021 at 5:26 PM onmstester onmstester <onmstes...@zoho.com.invalid> wrote: > Hi, > In a article by thelastpickle [1], i noticed: > > The key here is to configure the cluster so that for a given datacenter > the number of racks is the same as the replication factor. > > > When using virtual machines as Cassandra nodes we have to set up the > cluster in a way that number of racks is the same as physical servers, so > by losing one physical server just one copy of any data would be lost, > right? which could be much greater than RF, would this cause any harm on > cluster health/balance/availability? > > [1]: > https://thelastpickle.com/blog/2021/01/29/impacts-of-changing-the-number-of-vnodes.html > > Sent using Zoho Mail <https://www.zoho.com/mail/> > > >
