Make resource tracker uses faster DB query

Fixes bug 1060363

db.instance_get_all_by_filters() uses a regex when filtering on host,
which will do a full table scan. A regex isn't needed and instead,
db.instance_get_all_by_host() can be used which does not impact the
performance so much.

Change-Id: I812e1d5320763e5c65232351e1e21285e04e6a4b

3 files changed, 19 insertions, 15 deletions

diff --git a/nova/compute/resource_tracker.py b/nova/compute/resource_tracker.py
index eb0d302b0..e5e1194a5 100644
--- a/nova/compute/resource_tracker.py
+++ b/nova/compute/resource_tracker.py
@@ -379,8 +379,7 @@ class ResourceTracker(object):
         self._purge_expired_claims()
 
         # Grab all instances assigned to this host:
-        filters = {'host': self.host, 'deleted': False}
-        instances = db.instance_get_all_by_filters(context, filters)
+        instances = db.instance_get_all_by_host(context, self.host)
 
         # Now calculate usage based on instance utilization:
         self._update_usage_from_instances(resources, instances)
diff --git a/nova/tests/compute/test_compute.py b/nova/tests/compute/test_compute.py
index bb7a9a637..048c8414b 100644
--- a/nova/tests/compute/test_compute.py
+++ b/nova/tests/compute/test_compute.py
@@ -279,7 +279,8 @@ class ComputeTestCase(BaseTestCase):
     def test_create_instance_unlimited_memory(self):
         """Default of memory limit=None is unlimited"""
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
         params = {"memory_mb": 999999999999}
         filter_properties = {'limits': {'memory_mb': None}}
         instance = self._create_fake_instance(params)
@@ -290,7 +291,8 @@ class ComputeTestCase(BaseTestCase):
 
     def test_create_instance_unlimited_disk(self):
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
         params = {"root_gb": 999999999999,
                   "ephemeral_gb": 99999999999}
         filter_properties = {'limits': {'disk_gb': None}}
@@ -300,7 +302,8 @@ class ComputeTestCase(BaseTestCase):
 
     def test_create_multiple_instances_then_starve(self):
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
         filter_properties = {'limits': {'memory_mb': 4096, 'disk_gb': 1000}}
         params = {"memory_mb": 1024, "root_gb": 128, "ephemeral_gb": 128}
         instance = self._create_fake_instance(params)
@@ -330,7 +333,8 @@ class ComputeTestCase(BaseTestCase):
         """Test passing of oversubscribed ram policy from the scheduler."""
 
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
 
         # get total memory as reported by virt driver:
         resources = self.compute.driver.get_available_resource()
@@ -358,7 +362,8 @@ class ComputeTestCase(BaseTestCase):
         with insufficient memory.
         """
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
 
         # get total memory as reported by virt driver:
         resources = self.compute.driver.get_available_resource()
@@ -383,7 +388,8 @@ class ComputeTestCase(BaseTestCase):
         """Test passing of oversubscribed cpu policy from the scheduler."""
 
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
         limits = {'vcpu': 3}
         filter_properties = {'limits': limits}
 
@@ -435,7 +441,8 @@ class ComputeTestCase(BaseTestCase):
         """Test passing of oversubscribed disk policy from the scheduler."""
 
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
 
         # get total memory as reported by virt driver:
         resources = self.compute.driver.get_available_resource()
@@ -462,7 +469,8 @@ class ComputeTestCase(BaseTestCase):
         with insufficient disk.
         """
         self.flags(reserved_host_disk_mb=0, reserved_host_memory_mb=0)
-        self.compute.resource_tracker.update_available_resource(self.context)
+        self.compute.resource_tracker.update_available_resource(
+                self.context.elevated())
 
         # get total memory as reported by virt driver:
         resources = self.compute.driver.get_available_resource()
diff --git a/nova/tests/compute/test_resource_tracker.py b/nova/tests/compute/test_resource_tracker.py
index 81b2be130..04b2dfdba 100644
--- a/nova/tests/compute/test_resource_tracker.py
+++ b/nova/tests/compute/test_resource_tracker.py
@@ -84,8 +84,8 @@ class BaseTestCase(test.TestCase):
         self.context = FakeContext()
 
         self._instances = []
-        self.stubs.Set(db, 'instance_get_all_by_filters',
-                self._fake_instance_get_all_by_filters)
+        self.stubs.Set(db, 'instance_get_all_by_host',
+                       lambda c, h: self._instances)
 
     def _create_compute_node(self, values=None):
         compute = {
@@ -139,9 +139,6 @@ class BaseTestCase(test.TestCase):
         self._instances.append(instance)
         return instance
 
-    def _fake_instance_get_all_by_filters(self, ctx, filters, **kwargs):
-        return self._instances
-
     def _tracker(self, unsupported=False):
         host = "fakehost"