Does MSK cluster configuration update will affect existing topic configuration?

Hi there, please find the answers inline

1. For example, if I change partition num in my cluster configuration and apply to the cluster, will it also help me update the existing topic partition number?

• Partition number (num.partitions), replication factor (default.replication.factor) etc which can be set in cluster level configuration only applies to the 'auto created topics'(auto.create.topics.enable=true).

• And when you change this configuration it applies only to the auto created topics after the update was made, it doesn't update the existing topics configuration.

2. If not, is there a list of configuration that will not be overridden by cluster configuration change after the resource has been initialized?

• We do not currently have a list but parameters that can be applied on both topic level and cluster level are mostly only retention related parameters, segment related parameters and min.insync.replicas. The retention and segment related parameters set at topic level takes precedence over retention set at cluster level. Same applies to min.insync.replicas which by default is 2 at cluster level. But you can set it at topic level which takes precedence. So for above parameters topic level configurations takes precedence and cluster level settings won't override it.