Allow HostState to handle empty capabilities

In some cases, where the capabilities reported from driver is
emtpy, scheduler would raise exception thus unable to correctly
handle scheduling request even when other backend candidates are
able to fulfill the request.  This change does some modifications
to HostState so that it is able to handle empty capabilities.

Change-Id: Icb6522852d427dea3fbd1ec4b4cc94a184d3669d
Fixes-bug: #1398875

diff --git a/cinder/scheduler/host_manager.py b/cinder/scheduler/host_manager.py
index 9563ea1721695fdb18ddbbcd5978c825f4dbb6e8..ace38eb043df6e2f3569a25423dc5e5c74d2f9f6 100644 (file)
--- a/cinder/scheduler/host_manager.py
+++ b/cinder/scheduler/host_manager.py
@@ -300,12 +300,12 @@ class PoolState(HostState):
                 return
             self.update_backend(capability)
 
-            self.total_capacity_gb = capability['total_capacity_gb']
-            self.free_capacity_gb = capability['free_capacity_gb']
+            self.total_capacity_gb = capability.get('total_capacity_gb', 0)
+            self.free_capacity_gb = capability.get('free_capacity_gb', 0)
             self.allocated_capacity_gb = capability.get(
                 'allocated_capacity_gb', 0)
             self.QoS_support = capability.get('QoS_support', False)
-            self.reserved_percentage = capability['reserved_percentage']
+            self.reserved_percentage = capability.get('reserved_percentage', 0)
 
     def update_pools(self, capability):
         # Do nothing, since we don't have pools within pool, yet

diff --git a/cinder/tests/scheduler/test_host_manager.py b/cinder/tests/scheduler/test_host_manager.py
index 3f51d4bbd96b634924fd8ad3cfd166bbcfb18744..aaa4bf54987e9608c60579f85452b38445ada599 100644 (file)
--- a/cinder/tests/scheduler/test_host_manager.py
+++ b/cinder/tests/scheduler/test_host_manager.py
@@ -427,6 +427,20 @@ class HostStateTestCase(test.TestCase):
         self.assertEqual(fake_host.pools['_pool0'].free_capacity_gb,
                          'unknown')
 
+    def test_update_from_empty_volume_capability(self):
+        fake_host = host_manager.HostState('host1')
+
+        vol_cap = {'timestamp': None}
+
+        fake_host.update_from_volume_capability(vol_cap)
+        self.assertEqual(fake_host.total_capacity_gb, 0)
+        self.assertEqual(fake_host.free_capacity_gb, None)
+        # Pool stats has been updated
+        self.assertEqual(fake_host.pools['_pool0'].total_capacity_gb,
+                         0)
+        self.assertEqual(fake_host.pools['_pool0'].free_capacity_gb,
+                         0)
+
 
 class PoolStateTestCase(test.TestCase):
     """Test case for HostState class."""