Is it safe to do a rolling restart to rename a datacenter in xdr? During the rolling restart, nodes in the cluster will have different names for the datacenter in their config. Would this pose an issue at all?
That is correct. The name is superficial and is mainly for user’s convenience in the current version. More important thing is that the order of DC configuration should be maintained across nodes. So, when the DC is renamed in the config file, please do not change its position in the config file.
We will be moving to a name-centric model in the near future and become order independent. Just something to be kept in mind for future. When we go to this model, we will allow dynamic addition/removal of DCs. Then you do not need to rename an existing DC. You can just remove the existing one and add a new one.
@sunil I have a followup question regarding the ordering. Does that mean when adding new datacenters (consisting of new nodes) in a rolling restart, you need to add them at the end? Would adding a new DC stanza in the middle of 2 existing stanzas cause issues?
Yes, if you had to add new DCs they should be added at the end of the list. Adding it in the middle will cause issues.
- Is there documentation depicting what sorts of issues can happen?
- Would I be able to add a DC in the middle if I take some extra steps beforehand, such as disable XDR/shipping? Or a full restart?