We have deployed the mysql probe to a Linux 8 server with MySQL 8.x installed on it, and have enabled the re_slave_running, and it shows as green in status, but there is no value populated.
Release: Any
Component: UIM MYSQL
This value has been deprecated in MySQL 8.x, per:
https://dev.mysql.com/doc/refman/5.7/en/server-status-variables.html#statvar_Slave_running