if the nodes are almost the same, except the disk space, then giving them more may make siltation worse - they will get more requests than other nodes, and won't have resources to process them. In Cassandra the disk size isn't the main "success" factor - it's a memory, CPU, disk type (SSD), etc.
On Sat, Mar 20, 2021 at 5:26 PM Lapo Luchini <l...@lapo.it> wrote: > Hi, thanks for suggestions! > I'll definitely migrate to 4.0 after all this is done, then. > > Old prod DC I fear can't suffer losing a node right now (a few nodes > have the disk 70% full), but I can maybe find a third node for the new > DC right away. > > BTW the new nodes have got 3× the disk space, but are not so much > different regarding CPU and RAM: does it make any sense giving them a > bit more num_tokens (maybe 20-30 instead of 16) than the rest of the old > DC hosts or "asymmetrical" clusters lead to problems? > > No real need to do that anyways, moving from 6 nodes to (eventually) 8 > should be enough lessen the load on the disks, and before more space is > needed I will probably have more nodes. > > Lapo > > On 2021-03-20 16:23, Alex Ott wrote: > > I personally maybe would go following way (need to calculate how many > > joins/decommissions will be at the end): > > > > * Decommission one node from prod DC > > * Form new DC from two new machines and decommissioned one. > > * Rebuild DC from existing one, make sure that repair finished, etc. > > * Switch traffic > > * Remove old DC > > * Add nodes from old DC one by one into new DC > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: user-unsubscr...@cassandra.apache.org > For additional commands, e-mail: user-h...@cassandra.apache.org > > -- With best wishes, Alex Ott http://alexott.net/ Twitter: alexott_en (English), alexott (Russian)
