conf: Remove deprecated 'compute_stats_class' opt

Change-Id: I9efbd7ba066705d5fa2353587237d197015a4f25
Blueprint centralize-config-options-ocata

nova/compute/resource_tracker.py

@@ -22,10 +22,10 @@ import copy
 
 from oslo_log import log as logging
 from oslo_serialization import jsonutils
-from oslo_utils import importutils
 
 from nova.compute import claims
 from nova.compute import monitors
+from nova.compute import stats
 from nova.compute import task_states
 from nova.compute import vm_states
 import nova.conf
@@ -87,7 +87,7 @@ class ResourceTracker(object):
         self.pci_tracker = None
         self.nodename = nodename
         self.compute_node = None
-        self.stats = importutils.import_object(CONF.compute_stats_class)
+        self.stats = stats.Stats()
         self.tracked_instances = {}
         self.tracked_migrations = {}
         monitor_handler = monitors.MonitorHandler(self)

nova/conf/compute.py

@@ -168,20 +168,6 @@ Possible values:
 
   * Any positive integer representing amount of memory in MB to reserve
     for the host.
-"""),
-    cfg.StrOpt('compute_stats_class',
-        default='nova.compute.stats.Stats',
-        deprecated_for_removal=True,
-        deprecated_since='13.0.0',
-        help="""
-Abstracts out managing compute host stats to pluggable class. This class
-manages and updates stats for the local compute host after an instance
-is changed. These configurable compute stats may be useful for a
-particular scheduler implementation.
-
-Possible values
-
-  * A string representing fully qualified class name.
 """),
 ]
 

nova/db/sqlalchemy/models.py

@@ -539,6 +539,8 @@ class Reservation(BASE, NovaBase, models.SoftDeleteMixin):
                          'QuotaUsage.deleted == 0)')
 
 
+# TODO(macsz) This class can be removed. It might need a DB migration to drop
+# this.
 class Snapshot(BASE, NovaBase, models.SoftDeleteMixin):
     """Represents a block storage device that can be attached to a VM."""
     __tablename__ = 'snapshots'

releasenotes/notes/remove-deprecated-compute-options-dbf2be75d6bdbcc8.yaml

@@ -0,0 +1,5 @@
+---
+upgrade:
+  - |
+    The ``compute_stats_class`` options is deprecated and have been removed
+    from the ``default`` group of nova.conf.