Our single-source replicas work well with checksums configured through recursion-method=dsn=D=percona,t=dsns and with dsn values like h=some-fqdn. How might I check a specific mariadb connection_name? I see --channel listed in the docs with master references, but not how to control a multi-channel slave.
If a replica has multiple sources, you would need to run pt-table-checksum on each source. Normally, you don’t run pt-t-c from a replica, you run it from the source.