https://cwiki.apache.org/confluence/display/KAFKA/KIP-164-+Add+UnderMinIsrPartitionCount+and+per-partition+UnderMinIsr+metrics
the JIRA shows it was shipped in 1.0, but the wiki page lists it as "Discussion" -- *Jeff Widman* jeffwidman.com <http://www.jeffwidman.com/> | 740-WIDMAN-J (943-6265) <><
