Resize replicas (volume) together with primary

When resizing volume for an instance which is the primary of a
replication, cluster, Trove also resizes the volume for all the replicas
automatically.

Change-Id: I2e719772fe7abc719255ea2a705d9ec342aced2a

api-ref/source/instance-actions.inc

@@ -82,6 +82,9 @@ size. A valid volume size is an integer value in gigabytes (GB).
 You cannot increase the volume to a size that is larger than the
 API volume size limit.
 
+For replication cluster, resizing volume of the primary will also resize
+replicas automatically.
+
 Normal response codes: 202
 
 Request

releasenotes/notes/victoria-resize-vollume-for-replication.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - When resizing volume for an instance which is the primary of a replication
+    cluster, Trove also resizes the volume for all the replicas automatically.

trove/instance/models.py

@@ -1353,28 +1353,41 @@ class Instance(BuiltInstance):
                                                  new_flavor)
 
     def resize_volume(self, new_size):
-        def _resize_resources():
-            self.validate_can_perform_action()
-            LOG.info("Resizing volume of instance %s.", self.id)
-            if self.db_info.cluster_id is not None:
-                raise exception.ClusterInstanceOperationNotSupported()
-            old_size = self.volume_size
-            if int(new_size) <= old_size:
-                raise exception.BadRequest(_("The new volume 'size' must be "
-                                             "larger than the current volume "
-                                             "size of '%s'.") % old_size)
-            # Set the task to Resizing before sending off to the taskmanager
-            self.update_db(task_status=InstanceTasks.RESIZING)
-            task_api.API(self.context).resize_volume(new_size, self.id)
+        """Resize instance volume.
 
+        If the instance is primary in a replication cluster, volumes of all the
+        replicas are also resized.
+        """
+
+        def _resize_resources(instance):
+            LOG.info("Resizing volume of instance %s.", instance.id)
+            instance.update_db(task_status=InstanceTasks.RESIZING)
+            task_api.API(self.context).resize_volume(new_size, instance.id)
+
+        new_size_l = int(new_size)
+
+        if self.db_info.cluster_id is not None:
+            raise exception.ClusterInstanceOperationNotSupported()
         if not self.volume_size:
             raise exception.BadRequest(_("Instance %s has no volume.")
                                        % self.id)
-        new_size_l = int(new_size)
+        if new_size_l <= self.volume_size:
+            raise exception.BadRequest(_("The new volume 'size' must be "
+                                         "larger than the current volume "
+                                         "size of '%s'.") % self.volume_size)
         validate_volume_size(new_size_l)
-        return run_with_quotas(self.tenant_id,
-                               {'volumes': new_size_l - self.volume_size},
-                               _resize_resources)
+        self.validate_can_perform_action()
+
+        instances = [self]
+        for dbinfo in self.slaves:
+            replica = Instance.load(self.context, dbinfo.id, needs_server=True)
+            replica.validate_can_perform_action()
+            instances.append(replica)
+
+        for instance in instances:
+            run_with_quotas(
+                self.tenant_id, {'volumes': new_size_l - self.volume_size},
+                _resize_resources, instance)
 
     def reboot(self):
         LOG.info("Rebooting instance %s.", self.id)

trove/quota/quota.py

@@ -356,13 +356,13 @@ resources = [Resource(Resource.INSTANCES, 'max_instances_per_tenant'),
 QUOTAS.register_resources(resources)
 
 
-def run_with_quotas(tenant_id, deltas, f):
+def run_with_quotas(tenant_id, deltas, f, *args, **kwargs):
     """Quota wrapper."""
 
     reservations = QUOTAS.reserve(tenant_id, **deltas)
     result = None
     try:
-        result = f()
+        result = f(*args, **kwargs)
     except Exception:
         QUOTAS.rollback(reservations)
         raise