Hello, I am looking for help regarding topologies and tasks in KS. Mostly where this information is stored outside of KS app.
My case is upgrading the KS topology from v1 to v2, the topology is different (f.e adding peek node in v2). I made a change in code, prepared a jar and deployed. The issue that I observed was when old and new versions of app are up and running (by mistake). The task for peek node is missing in old nodes hence deployment crashes. My next steps were shutting down all nodes and deployment without old nodes. But this did not help. New deployment crashed too and I was not able to figure out why. The topology just stopped ingestion from the source topic. No error in logs. My hypothesis is that the former deployment of (KS topology v1 and v2 at once) leaves some sort of ephemeral state in the kafka cluster itself. And here is my question. what kind of state except messages in repartition and changelog topics, consumer offsets are stored by KS in kafka cluster ? What can be the root cause from your point of view ? Thank you Peter
