CLOUDSTACK-8910: The reserved_capacity field increases suddenly after a vmware host failure

In case of vmware host failure, all the VMs including stopped VMs migrate
to the new host. For the Stopped Vms powerhost gets updated. This was
triggering HandlePowerStateReport which finally calls updatePowerState
updating update_time for the VM. This cause the capacity being reserved
for stopped VMs.

(cherry picked from commit 9d268c8cd5)
Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

engine/schema/src/com/cloud/vm/dao/VMInstanceDaoImpl.java

@@ -456,6 +456,9 @@ public class VMInstanceDaoImpl extends GenericDaoBase<VMInstanceVO, Long> implem
             // state is same, don't need to update
             return true;
         }
+        if(ifStateUnchanged(oldState,newState, oldHostId, newHostId)) {
+            return true;
+        }
 
         // lock the target row at beginning to avoid lock-promotion caused deadlock
         lockRow(vm.getId(), true);
@@ -503,6 +506,14 @@ public class VMInstanceDaoImpl extends GenericDaoBase<VMInstanceVO, Long> implem
         return result > 0;
     }
 
+    boolean ifStateUnchanged(State oldState, State newState, Long oldHostId, Long newHostId ) {
+        if (oldState == State.Stopped && newState == State.Stopped && newHostId == null && oldHostId == null) {
+            // No change , no need to update
+            return true;
+        }
+        return false;
+    }
+
     @Override
     public List<VMInstanceVO> listByLastHostId(Long hostId) {
         SearchCriteria<VMInstanceVO> sc = AllFieldsSearch.create();

engine/schema/test/com/cloud/vm/dao/VMInstanceDaoImplTest.java

@@ -0,0 +1,70 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package com.cloud.vm.dao;
+
+import com.cloud.utils.Pair;
+import com.cloud.vm.VirtualMachine;
+import org.joda.time.DateTime;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.Assert;
+import org.mockito.Mock;
+
+import static com.cloud.vm.VirtualMachine.State.Running;
+import static com.cloud.vm.VirtualMachine.State.Stopped;
+
+import static org.mockito.Mockito.when;
+import com.cloud.vm.VMInstanceVO;
+import org.mockito.MockitoAnnotations;
+import org.mockito.Spy;
+
+/**
+ * Created by sudharma_jain on 3/2/17.
+ */
+
+public class VMInstanceDaoImplTest {
+
+    @Spy
+    VMInstanceDaoImpl vmInstanceDao = new VMInstanceDaoImpl();
+
+    @Mock
+    VMInstanceVO vm;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        Long hostId = null;
+        when(vm.getHostId()).thenReturn(hostId);
+        when(vm.getUpdated()).thenReturn(5L);
+        when(vm.getUpdateTime()).thenReturn(DateTime.now().toDate());
+    }
+
+    @Test
+    public void testUpdateState() throws Exception {
+        Long destHostId = null;
+        Pair<Long, Long> opaqueMock = new Pair<Long, Long>(new Long(1), destHostId);
+        vmInstanceDao.updateState(Stopped, VirtualMachine.Event.FollowAgentPowerOffReport, Stopped, vm , opaqueMock);
+    }
+
+    @Test
+    public void testIfStateAndHostUnchanged() throws Exception {
+        Assert.assertEquals(vmInstanceDao.ifStateUnchanged(Stopped, Stopped, null, null), true);
+        Assert.assertEquals(vmInstanceDao.ifStateUnchanged(Stopped, Running, null, null), false);
+    }
+
+}