If you set a different num_tokens value for new hosts (the value should never be changed on an existing host), the amount of data moved to that host will be proportional to the num_tokens value. So, if the new hosts are set to 32 when they're added to the cluster, those hosts will get twice as much data as the initial 16-token hosts.
I think it's generally advised to keep a Cassandra cluster identical in terms of hardware and num_tokens, at least within a DC. I suspect having a lot of different values would slow down Reaper significantly, but I've had decent results so far adding a few hosts with beefier hardware and num_tokens=32 to an existing 16-token cluster. On Wed, Jun 15, 2022 at 1:33 AM Marc Hoppins <marc.hopp...@eset.com> wrote: > Hi all, > > Say we have 2 datacentres with 12 nodes in each. All hardware is the same. > > 4-core, 2 x HDD (eg, 4TiB) > > num_tokens = 16 as a start point > > If a plan is to gradually increase the nodes per DC, and new hardware will > have more of everything, especially storage, I assume I increase the > num_tokens value. Should I have started with a lower value? > > What would be considered as a good adjustment for: > > Any increase in number of HDD for any node? > > Any increase in capacity per HDD for any node? > > Is there any direct correlation between new token count and the > proportional increase in either quantity of devices or total capacity, or > is any adjustment purely arbitrary just to differentiate between varied > nodes? > > Thanks > > M > -- This email, including its contents and any attachment(s), may contain confidential and/or proprietary information and is solely for the review and use of the intended recipient(s). If you have received this email in error, please notify the sender and permanently delete this email, its content, and any attachment(s). Any disclosure, copying, or taking of any action in reliance on an email received in error is strictly prohibited.
