Great catch. It's for sure a tricky one.
We have the incorrect tags for two releases already... Good thing: the
docs are correct, not mentioning the incorrect tag.
For sure not ideal, but I tend to prefer to remove the tag for the
affected metrics, and follow what the KIP proposes -- we might also want
to backport the removal to 4.0 and 4.1 -- there will be for sure a 4.1.2
release; so maybe only 4.0 would be affected.
It just seems cleaner to me this way. Curious to hear what others think.
-Matthias
On 11/4/25 6:55 PM, Bill Bejeck wrote:
Hi All,
When working on KIP-1091
<https://cwiki.apache.org/confluence/display/KAFKA/KIP-1091%3A+Improved+Kafka+Streams+operator+metrics>,
we mistakenly applied the `process-id` tag to all client-level metrics,
rather than just the `client-state`, `thread-state`, and `recording-level`
metrics as specified in the KIP. This issue came to light while working on
KIP-1221
<https://cwiki.apache.org/confluence/display/KAFKA/KIP-1221%3A+Add+application-id+tag+to+Kafka+Streams+state+metric>,
which aimed to add the `application-id` as a tag to the `client-state`
metric introduced by KIP-1091.
To address the issue, we could remove the `process-id` from the metrics
that are not intended to have the tag. However, we'd like to initiate a
conversation with the community about the best approach to resolving this
issue.
I'm looking forward to your feedback.
Thanks,
Bill Bejeck
