diff --git a/octavia/amphorae/drivers/haproxy/rest_api_driver.py b/octavia/amphorae/drivers/haproxy/rest_api_driver.py
index 7738502787..4b81b92018 100644
--- a/octavia/amphorae/drivers/haproxy/rest_api_driver.py
+++ b/octavia/amphorae/drivers/haproxy/rest_api_driver.py
@@ -284,8 +284,10 @@ class AmphoraAPIClient(object):
                 # amphora is not yet up, in which case retry.
                 # Otherwise return the response quickly.
                 if r.status_code == 404:
-                    LOG.debug('Got a 404 (content-type: %s) -- connection '
-                              'data: %s' % (content_type, r.content))
+                    LOG.debug('Got a 404 (content-type: %(content_type)s) -- '
+                              'connection data: %(content)s',
+                              {'content_type': content_type,
+                               'content': r.content})
                     if content_type.find("application/json") == -1:
                         LOG.debug("Amphora agent not ready.")
                         raise requests.ConnectionError
diff --git a/octavia/controller/housekeeping/house_keeping.py b/octavia/controller/housekeeping/house_keeping.py
index 6a46be56aa..46a4f9b145 100644
--- a/octavia/controller/housekeeping/house_keeping.py
+++ b/octavia/controller/housekeeping/house_keeping.py
@@ -47,7 +47,7 @@ class SpareAmphora(object):
 
         # When the current spare amphora is less than required
         if diff_count > 0:
-            LOG.info("Initiating creation of %d spare amphora." % diff_count)
+            LOG.info("Initiating creation of %d spare amphora.", diff_count)
 
             # Call Amphora Create Flow diff_count times
             for i in range(1, diff_count + 1):
@@ -81,7 +81,7 @@ class DatabaseCleanup(object):
                     self.amp_health_repo.delete(session, amphora_id=amp.id)
                 except sqlalchemy_exceptions.NoResultFound:
                     pass  # Best effort delete, this record might not exist
-                LOG.info('Deleted Amphora id : %s' % amp.id)
+                LOG.info('Deleted Amphora id : %s', amp.id)
 
     def cleanup_load_balancers(self):
         """Checks the DB for old load balancers and triggers their removal."""
@@ -97,7 +97,7 @@ class DatabaseCleanup(object):
                                                         exp_age):
                 LOG.info('Attempting to delete load balancer id : %s', lb.id)
                 self.lb_repo.delete(session, id=lb.id)
-                LOG.info('Deleted load balancer id : %s' % lb.id)
+                LOG.info('Deleted load balancer id : %s', lb.id)
 
 
 class CertRotation(object):
@@ -120,5 +120,4 @@ class CertRotation(object):
                 LOG.debug("Cert expired amphora's id is: %s", amp.id)
                 executor.submit(self.cw.amphora_cert_rotation, amp.id)
             if rotation_count > 0:
-                LOG.info("Rotated certificates for %s amphora" %
-                         rotation_count)
+                LOG.info("Rotated certificates for %s amphora", rotation_count)
diff --git a/octavia/controller/queue/endpoint.py b/octavia/controller/queue/endpoint.py
index 0f736a3c79..07956a586c 100644
--- a/octavia/controller/queue/endpoint.py
+++ b/octavia/controller/queue/endpoint.py
@@ -92,37 +92,37 @@ class Endpoint(object):
         self.worker.delete_health_monitor(health_monitor_id)
 
     def create_member(self, context, member_id):
-        LOG.info('Creating member \'%s\'...' % member_id)
+        LOG.info('Creating member \'%s\'...', member_id)
         self.worker.create_member(member_id)
 
     def update_member(self, context, member_id, member_updates):
-        LOG.info('Updating member \'%s\'...' % member_id)
+        LOG.info('Updating member \'%s\'...', member_id)
         self.worker.update_member(member_id, member_updates)
 
     def delete_member(self, context, member_id):
-        LOG.info('Deleting member \'%s\'...' % member_id)
+        LOG.info('Deleting member \'%s\'...', member_id)
         self.worker.delete_member(member_id)
 
     def create_l7policy(self, context, l7policy_id):
-        LOG.info('Creating l7policy \'%s\'...' % l7policy_id)
+        LOG.info('Creating l7policy \'%s\'...', l7policy_id)
         self.worker.create_l7policy(l7policy_id)
 
     def update_l7policy(self, context, l7policy_id, l7policy_updates):
-        LOG.info('Updating l7policy \'%s\'...' % l7policy_id)
+        LOG.info('Updating l7policy \'%s\'...', l7policy_id)
         self.worker.update_l7policy(l7policy_id, l7policy_updates)
 
     def delete_l7policy(self, context, l7policy_id):
-        LOG.info('Deleting l7policy \'%s\'...' % l7policy_id)
+        LOG.info('Deleting l7policy \'%s\'...', l7policy_id)
         self.worker.delete_l7policy(l7policy_id)
 
     def create_l7rule(self, context, l7rule_id):
-        LOG.info('Creating l7rule \'%s\'...' % l7rule_id)
+        LOG.info('Creating l7rule \'%s\'...', l7rule_id)
         self.worker.create_l7rule(l7rule_id)
 
     def update_l7rule(self, context, l7rule_id, l7rule_updates):
-        LOG.info('Updating l7rule \'%s\'...' % l7rule_id)
+        LOG.info('Updating l7rule \'%s\'...', l7rule_id)
         self.worker.update_l7rule(l7rule_id, l7rule_updates)
 
     def delete_l7rule(self, context, l7rule_id):
-        LOG.info('Deleting l7rule \'%s\'...' % l7rule_id)
+        LOG.info('Deleting l7rule \'%s\'...', l7rule_id)
         self.worker.delete_l7rule(l7rule_id)
diff --git a/octavia/controller/worker/controller_worker.py b/octavia/controller/worker/controller_worker.py
index 09640a742d..113ceac6a1 100644
--- a/octavia/controller/worker/controller_worker.py
+++ b/octavia/controller/worker/controller_worker.py
@@ -651,7 +651,7 @@ class ControllerWorker(base_taskflow.BaseTaskFlowEngine):
 
         except Exception as e:
             with excutils.save_and_reraise_exception():
-                LOG.error("Failover exception: %s" % e)
+                LOG.error("Failover exception: %s", e)
 
     def amphora_cert_rotation(self, amphora_id):
         """Perform cert rotation for an amphora.
@@ -663,7 +663,7 @@ class ControllerWorker(base_taskflow.BaseTaskFlowEngine):
 
         amp = self._amphora_repo.get(db_apis.get_session(),
                                      id=amphora_id)
-        LOG.info("Start amphora cert rotation, amphora's id is: %s" % amp.id)
+        LOG.info("Start amphora cert rotation, amphora's id is: %s", amp.id)
 
         certrotation_amphora_tf = self._taskflow_load(
             self._amphora_flows.cert_rotate_amphora_flow(),
diff --git a/octavia/network/drivers/neutron/allowed_address_pairs.py b/octavia/network/drivers/neutron/allowed_address_pairs.py
index 8a66ad35b7..e9263fd858 100644
--- a/octavia/network/drivers/neutron/allowed_address_pairs.py
+++ b/octavia/network/drivers/neutron/allowed_address_pairs.py
@@ -500,7 +500,7 @@ class AllowedAddressPairsDriver(neutron_base.BaseNeutronDriver):
                 raise base.PlugNetworkException(e.message)
         except nova_client_exceptions.Conflict:
             LOG.info('Port %(portid)s is already plugged, '
-                     'skipping' % {'portid': port.id})
+                     'skipping', {'portid': port.id})
             plugged_interface = n_data_models.Interface(
                 compute_id=amphora.compute_id,
                 network_id=port.network_id,
diff --git a/tox.ini b/tox.ini
index 09c70935fa..4a571cc3cd 100644
--- a/tox.ini
+++ b/tox.ini
@@ -116,6 +116,8 @@ ignore =
 show-source = true
 builtins = _
 exclude = .venv,.git,.tox,dist,doc,*lib/python*,*egg,build
+# [H904] Delay string interpolations at logging calls.
+enable-extensions=H904
 
 [hacking]
 import_exceptions = octavia.i18n