Hi Robert, What has happened is that you have now two datacenters in your cluster. The way they replicate information will depend on your keyspace settings.
Regarding your process I don't think it is safe to do it that way. I'd start off by decommissioning nodes 4 and 5 so that your cluster is back to 1 datacenter with 3 nodes and then add them sequentially again making sure the configuration in the Snitch is the proper one. Regards. Carlos Alonso | Software Engineer | @calonso <https://twitter.com/calonso> On 28 October 2016 at 10:06, Robert Sicoie <robert.sic...@gmail.com> wrote: > Hi guys, > > I have a cluster with 5 nodes, cassandra 3.0.5, RF=2, PropertyFileSnitch. > Three of the nodes were added initially, DC=PRD. The other two were added > more recently. > > The default for unknown nodes default=DC1:r1 (which is bad in my case, as > it would have been nice to have PRD as default) > > As the three initial do not have the information about the later two in > the properties file, they see node4 and node5 as in DC1:r1. > > I assume that: > > - 1-2-3 have mode data than 4 and 5 because all writes that come to > 1-2-3 are replicated only on 1-2-3 (as there is no schema for DC1) and this > is why 1,2,3 have more data and the cluster is unbalanced. > - all writes that come to 4 and 5 are replicated on 1,2,3,4 and 5 as > the property file snitch config has info about the entire cluster on 4 and > 5. > > Is it save if I just update the network topology file on 1, 2, 3 and add > lines about node 4 and 5, and then roll restart 4 and 5? Will the cluster > balance itself? Currently 1, 2, 3 have about 16GB each and 4,5 about 6 GB > each. > > Thanks, > > Robert >
