Hi, In v2.11.0, the system topic enables by default [1]. This causes the `GET_TOPICS_OF_NAMESPACE ` command to redundantly return the system topic.
This causes some incompatibility issues: If consumers use pattern subscribe and the pattern is `/tenant/namespace/.*`, it will subscribe `__change_events` topic. I suggest that GET_TOPICS_OF_NAMESPACE should filter out system topics(or add include-system-topic param, like the HTTP interface[2]) to maintain consistent behavior with versions before 2.11.0 Refer: - [1] https://github.com/apache/pulsar/pull/15619 - [2] https://github.com/apache/pulsar/pull/15410 Thanks, Baodi Shi