hi this ticket is about to records partition metrics rather than topic metrics. It helps us to observe more precis metrics for specify partition. The downside is that broker needs more space to keep metrics and the origin metrics interface (tags) is broken since this ticket adds new tag "partition=xxx" to it. The alternative is an new config flag used to enable new metrics (of course, it is false by default). Also, we ought to provide enough document to explain benefit and cost of new metrics.
KIP-581 (https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=148642648) JIRA (https://issues.apache.org/jira/browse/KAFKA-9730) Please take a look :) Best Regards, Chia-Ping