Hello,
I am trying to migrate a statefulset of Cassandra from one cluster to another. I am running into issues that I believe are more related to the statefulset applications than Kasten but, could be wrong.
One key aspect is the namespace and K8s cluster domain change on the destination side. I think this is where having different NS and domains between clusters can be problematic. Since the application uses DNS to find pods & services, this breaks things when the migration occurs. So when the restored pod starts up, it is looking for the old DNS name of the pod/svc. It seems the only real way to modify a statefulset is to perform an update (rolling, canary, etc...) or delete, modify, redeploy.
So I tried (on the destination system) to restore only the PV, modify the statefulset [change NS, PVC template, and value for seeds DNS], then deploy the app.
- Pods attached to the existing PV
- But then Cassandra could not find any seed nodes and decided to reinitialize the DB (as brand new)
So I am trying to find out if anyone has done this in the past or if possible via Kasten that I am missing.
Application:
- statefulset
- Cassandra
- Image: 3.11.13
- nodes: 5
- storage: RBD on Rook-Ceph
- Cassandra
Environment:
- K8 on-prem
- source: v1.21.1
- destination: v1.24.2
- K10 v5.0.4 (both)
- Shared S3 bucket between both K10 just for migrations
