diff --git a/zaza/openstack/charm_tests/hacluster/tests.py b/zaza/openstack/charm_tests/hacluster/tests.py
index fb9d8e2..ebffb84 100644
--- a/zaza/openstack/charm_tests/hacluster/tests.py
+++ b/zaza/openstack/charm_tests/hacluster/tests.py
@@ -49,6 +49,10 @@ class HaclusterTest(test_utils.OpenStackBaseTest):
 
         if primary_status["units"][leader].get("subordinates"):
             for subordinate in primary_status["units"][leader]["subordinates"]:
+                # mysql-router is a subordinate from focal onwards
+                _app = subordinate.split('/')[0]
+                if _app != 'hacluster':
+                    continue
                 logging.info("Cleaning {}".format(subordinate))
                 _action = "cleanup"
                 action_id = zaza.model.run_action(subordinate, "cleanup")
@@ -84,6 +88,10 @@ class HaclusterTest(test_utils.OpenStackBaseTest):
 
         if primary_status["units"][leader].get("subordinates"):
             for subordinate in primary_status["units"][leader]["subordinates"]:
+                # mysql-router is a subordinate from focal onwards
+                _app = subordinate.split('/')[0]
+                if _app != 'hacluster':
+                    continue
                 logging.info("Pausing {}".format(subordinate))
                 zaza.model.run_action(subordinate, "pause")
                 zaza.model.block_until_unit_wl_status(
diff --git a/zaza/openstack/charm_tests/test_utils.py b/zaza/openstack/charm_tests/test_utils.py
index 137f096..ae431c1 100644
--- a/zaza/openstack/charm_tests/test_utils.py
+++ b/zaza/openstack/charm_tests/test_utils.py
@@ -254,6 +254,44 @@ class BaseCharmTest(unittest.TestCase):
         # TODO: Optimize with a block on a specific application until idle.
         model.block_until_all_units_idle()
 
+    def restart_on_changed_debug_oslo_config_file(self, config_file, services,
+                                                  config_section='DEFAULT'):
+        """Check restart happens on config change by flipping debug mode.
+
+        Change debug mode and assert that change propagates to the correct
+        file and that services are restarted as a result. config_file must be
+        an oslo config file and debug option must be set in the
+        `config_section` section.
+
+        :param config_file: OSLO Config file to check for settings
+        :type config_file: str
+        :param services: Services expected to be restarted when config_file is
+                         changed.
+        :type services: list
+        """
+        # Expected default and alternate values
+        current_value = model.get_application_config(
+            self.application_name)['debug']['value']
+        new_value = str(not bool(current_value)).title()
+        current_value = str(current_value).title()
+
+        set_default = {'debug': current_value}
+        set_alternate = {'debug': new_value}
+        default_entry = {config_section: {'debug': [current_value]}}
+        alternate_entry = {config_section: {'debug': [new_value]}}
+
+        # Make config change, check for service restarts
+        logging.info(
+            'Changing settings on {} to {}'.format(
+                self.application_name, set_alternate))
+        self.restart_on_changed(
+            config_file,
+            set_default,
+            set_alternate,
+            default_entry,
+            alternate_entry,
+            services)
+
     def restart_on_changed(self, config_file, default_config, alternate_config,
                            default_entry, alternate_entry, services,
                            pgrep_full=False):