Ironic Scheduler Performance patch

ironic-scheduler-performance.patch

commit 76b2a790a65690812c69ae72ed9edbf6208a33c6
Author: Mathieu Gagné <mgagne@iweb.com>
Date:   Mon Jul 25 18:37:28 2016 -0400

    Only load empty compute nodes in Ironic HostManager
    
    There is no way to schedule more than one instance on an Ironic node.
    Optimize nova-scheduler when Ironic is used to only load empty compute nodes.
    
    Change-Id: I476c9372ad7d9a693217fd250b37508daf83d02d

diff --git a/nova/db/api.py b/nova/db/api.py
index 39e3fe5..d4971d9 100644
--- a/nova/db/api.py
+++ b/nova/db/api.py
@@ -209,6 +209,16 @@ def compute_node_get_all(context):
     return IMPL.compute_node_get_all(context)
 
 
+def compute_node_get_all_empty(context):
+    """Get all empty computeNodes.
+
+    :param context: The security context
+
+    :returns: List of dictionaries each containing compute node properties
+    """
+    return IMPL.compute_node_get_all_empty(context)
+
+
 def compute_node_get_all_by_host(context, host, use_slave=False):
     """Get compute nodes by host name
 
diff --git a/nova/db/sqlalchemy/api.py b/nova/db/sqlalchemy/api.py
index cdc6363..4d13be0 100644
--- a/nova/db/sqlalchemy/api.py
+++ b/nova/db/sqlalchemy/api.py
@@ -618,6 +618,13 @@ def compute_node_get_all(context):
 
 
 @require_admin_context
+def compute_node_get_all_empty(context):
+    return model_query(context, models.ComputeNode, read_deleted='no').\
+        filter_by(running_vms=0).\
+        all()
+
+
+@require_admin_context
 def compute_node_search_by_hypervisor(context, hypervisor_match):
     field = models.ComputeNode.hypervisor_hostname
     return model_query(context, models.ComputeNode).\
diff --git a/nova/objects/compute_node.py b/nova/objects/compute_node.py
index e11ca57..e517d60 100644
--- a/nova/objects/compute_node.py
+++ b/nova/objects/compute_node.py
@@ -312,6 +312,12 @@ class ComputeNodeList(base.ObjectListBase, base.NovaObject):
                                   db_computes)
 
     @base.remotable_classmethod
+    def get_all_empty(cls, context):
+        db_computes = db.compute_node_get_all_empty(context)
+        return base.obj_make_list(context, cls(context), objects.ComputeNode,
+                                  db_computes)
+
+    @base.remotable_classmethod
     def get_by_hypervisor(cls, context, hypervisor_match):
         db_computes = db.compute_node_search_by_hypervisor(context,
                                                            hypervisor_match)
diff --git a/nova/scheduler/host_manager.py b/nova/scheduler/host_manager.py
index 0dcf23f..4d808bc 100644
--- a/nova/scheduler/host_manager.py
+++ b/nova/scheduler/host_manager.py
@@ -532,7 +532,7 @@ class HostManager(object):
                         for service in objects.ServiceList.get_by_binary(
                             context, 'nova-compute')}
         # Get resource usage across the available compute nodes:
-        compute_nodes = objects.ComputeNodeList.get_all(context)
+        compute_nodes = self._get_compute_node_list(context)
         seen_nodes = set()
         for compute in compute_nodes:
             service = service_refs.get(compute.host)
@@ -571,6 +571,9 @@ class HostManager(object):
 
         return self.host_state_map.itervalues()
 
+    def _get_compute_node_list(self, context):
+        return objects.ComputeNodeList.get_all(context)
+
     def _add_instance_info(self, context, compute, host_state):
         """Adds the host instance info to the host_state object.
 
diff --git a/nova/scheduler/ironic_host_manager.py b/nova/scheduler/ironic_host_manager.py
index 664ecbf..f9b9774 100644
--- a/nova/scheduler/ironic_host_manager.py
+++ b/nova/scheduler/ironic_host_manager.py
@@ -27,6 +27,7 @@ from oslo_log import log as logging
 from oslo_utils import timeutils
 
 from nova.compute import hv_type
+from nova import objects
 from nova.scheduler import host_manager
 
 host_manager_opts = [
@@ -99,6 +100,9 @@ class IronicNodeState(host_manager.HostState):
 class IronicHostManager(host_manager.HostManager):
     """Ironic HostManager class."""
 
+    def _get_compute_node_list(self, context):
+        return objects.ComputeNodeList.get_all_empty(context)
+
     def _load_filters(self):
         if CONF.scheduler_use_baremetal_filters:
             return CONF.baremetal_scheduler_default_filters