Hi all I noticed that the PIP-145 made a break change that caused clients to not subscribe to partitioned topics with a suffix-matched regexp.
### Background PIP-145(https://github.com/apache/pulsar/issues/14505) moved the logic of regexp compare from client-side to the broker-side. After PIP-145, Pulsar uses the partition name(E.g., "topic-partition-0") to match the Regexp. But the original behavior is to use a partitioned topic name(E.g., "topic") to match the Regexp. ### The behavior change 1 - start a consumer with `topicPattern`: `persistent://my-property/my-ns/pattern-.*-1` - create a partitioned topic `persistent://my-tenant/my-ns/pattern-topic-x` with `4` partitions `3.0.2`: the consumer will automatically add `4` internal consumers for the `4` partitions. `2.10.5`: No internal consumers added. ### The behavior change 2 - start a consumer with regexp `persistent://public/default/tp$` - create a partitioned topic persistent://public/default/tp` with `4` partitions `3.0.2`: the pattern consumer has no internal consumers. `2.10.5`: the consumer will automatically add `4` internal consumers for the `4` partitions. ### Summary After PIP-145, there are two behaviors are confused: - You can not use a suffix-regexp to subscribe to the partitioned topics. - You will get all partitions if you just want one partition with a suffix-regexp `-partition-0`. And before PIP-145, you will get no topics. This behavior is not supported on all versions, but the behavior is not the same. ### Fix I pushed a PR to revert the behavior to the original(before PIP-145). See: https://github.com/apache/pulsar/pull/21885. Thanks Yubiao Femg
