Comment 29 for bug 1879798

designate/3 was created at 2023-07-13 09:33:51,

$ juju ssh designate/3 -- sudo grep -r 'designate\/3' /var/log/juju/ |grep started
/var/log/juju/unit-designate-3.log:2023-07-13 09:33:51 INFO juju.worker.uniter uniter.go:326 unit "designate/3" started

modzone was triggered at 2023-07-13 09:55:04.419

ubuntu@juju-5abc40-jammy-designate-1:~$ sudo grep -r 'modzone' /var/log/designate/designate-* |tail -n1
/var/log/designate/designate-worker.log:2023-07-13 09:55:04.419 53020 DEBUG oslo_concurrency.processutils [req-3a99b88c-7e95-4a44-9132-e1383cb7e375 - - - - -] CMD "sudo designate-rootwrap /etc/designate/rootwrap.conf rndc -s 10.5.2.44 -p 953 -k /etc/designate/rndc.key modzone extdns.example { type slave; masters { 10.5.3.135 port 5354; 10.5.3.71 port 5354;}; file "slave.extdns.example.aba56bfb-50c8-4e5c-8447-01666d2012a7"; };" returned: 0 in 6.484s execute /usr/lib/python3/dist-packages/oslo_concurrency/processutils.py:422

So it seems target.get("masters", []) in the code [1] doesn't have an updated master list.

[1] https://review.opendev.org/c/openstack/designate/+/731603/8/designate/manage/pool.py#53