Hi All, I have drafted a propoal to enhance topic observability by adding topicCreationTimeStamp and lastPublishTimeStamp to the topic stats API.
*Motivation:* Currently, it is difficult to programmatically determine a topic's age or its most recent message activity. This hinders essential operational tasks such as identifying and cleaning up stale topics, performing compliance audits, and gaining quick troubleshooting insights. Existing metrics like lastLedgerCreatedTimestamp or rate-based metrics are not suitable for these lifecycle management use cases. *Proposed Solution:* This PIP proposes adding two new fields to the TopicStats object: 1. *topicCreationTimeStamp*: This value will be retrieved directly from the ctime attribute of the topic's underlying metadata node ( org.apache.pulsar.metadata.api.Stat). This approach is efficient and provides an accurate creation timestamp for all topics, including those created before this feature's deployment. 2. *lastPublishTimeStamp*: This will be maintained as a high-performance, in-memory long value on the owning broker, updated on every successful message publish. To ensure durability across broker restarts or topic reloads, the value will be recovered from the last entry in the managed ledger when the user gets topic internal stats. These changes are designed to be fully backward-compatible and have a negligible performance impact on the message-publishing path. The full proposal is available for review here: https://github.com/apache/pulsar/pull/24469 I welcome any feedback, questions, or suggestions you may have. Thanks, Penghui
