Dear Apache Pulsar community members,
In Pulsar, when a partitioned topic is deleted, the relevant authorization
information in ZooKeeper remains. Specifically, if I1. Create a partitioned
topic "persistent://lbw-tenant/lbw-test-ns1/my.topic.5" with 5 partitions.2.
Grant it with consume and produce permissions.3. delete the topic using
`pulsar-admin topics delete-partitioned-topic
persistent://lbw-tenant/lbw-test-ns1/my.topic.5`Then the authorization
information still remains in ZooKeeper, like```
[zk: localhost:2181(CONNECTED) 8] get /admin/policies/lbw-tenant/lbw-test-ns1
{"auth_policies":{"namespace_auth":{},"destination_auth":{"persistent://lbw-tenant/lbw-test-ns1/my.topic.5-partition-0":{"test-user":["consume"]},"persistent://lbw-tenant/lbw-test-ns1/my.topic.5-partition-1":{"test-user":["consume"]},"persistent://lbw-tenant/lbw-test-ns1/my.topic.5-partition-2":{"test-user":["consume"]},"persistent://lbw-tenant/lbw-test-ns1/my.topic.5-partition-3":{"test-user":["produce","consume"]},"persistent://lbw-tenant/lbw-test-ns1/my.topic.5-partition-4":{"test-user":["produce","consume"]},"persistent://lbw-tenant/lbw-test-ns1/my.topic.5":{"test-user":["consume"]}},"subscription_auth_roles":{}},"replication_clusters":["standalone"],"bundles":{"boundaries":["0x00000000","0x40000000","0x80000000","0xc0000000","0xffffffff"],"numBundles":4},"backlog_quota_map":{},"clusterDispatchRate":{},"topicDispatchRate":{},"subscriptionDispatchRate":{},"replicatorDispatchRate":{},"clusterSubscribeRate":{},"publishMaxMessageRate":{},"latency_stats_sample_rate":{},"deleted":false,"encryption_required":false,"subscription_auth_mode":"None","offload_threshold":-1,"schema_auto_update_compatibility_strategy":"Full","schema_compatibility_strategy":"UNDEFINED","is_allow_auto_update_schema":true,"schema_validation_enforced":false,"subscription_types_enabled":[],"properties":{}}
```
If the number of topics is large, this is obviously a waste of storage. So
maybe we need to consider to delete the relevant authorization information when
the topic is deleted.But on the other hand, we have some configuration like
"brokerDeleteInactiveTopicsEnabled" and "allowAutoTopicCreation" which will
automatically create and delete the topic at some time, so we need to be
cautious to delete the relevant authorization information.In conclude, maybe we
need to discuss whether the authorization information of a topic should be
deleted when the topic is deleted. What's your opinion?
