Merge pull request #1 from leo79901/leo79901-patch-1

add check befor fencing

Author: leo79901

plugins/hypervisors/kvm/src/main/java/org/apache/cloudstack/kvm/ha/KVMHAProvider.java

@@ -84,18 +84,24 @@ public boolean recover(Host r) throws HARecoveryException {
 
     @Override
     public boolean fence(Host r) throws HAFenceException {
-
         try {
-            if (outOfBandManagementService.isOutOfBandManagementEnabled(r)){
-                final OutOfBandManagementResponse resp = outOfBandManagementService.executePowerOperation(r, PowerOperation.OFF, null);
-                return resp.getSuccess();
+            // host exists and is managed OOB
+            if (r != null && outOfBandManagementService.isOutOfBandManagementEnabled(r)) {
+                // check host status
+                if (Host.Status.DOWN.equals(r.getStatus())) {
+                    LOG.info("Host " + r.getName() + " is already down. Returning success.");
+                    return true;
+                } else {
+                    final OutOfBandManagementResponse resp = outOfBandManagementService.executePowerOperation(r, PowerOperation.OFF, null);
+                    return resp.getSuccess();
+                }
             } else {
-                logger.warn("OOBM fence operation failed for this host " + r.getName());
+                LOG.warn("OOBM fence operation failed for this host " + r.getName());
                 return false;
             }
-        } catch (Exception e){
-            logger.warn("OOBM service is not configured or enabled for this host " + r.getName() + " error is " + e.getMessage());
-            throw new HAFenceException("OBM service is not configured or enabled for this host " + r.getName() , e);
+        } catch (Exception e) {
+            LOG.warn("OOBM service is not configured or enabled for this host " + r.getName() + " error is " + e.getMessage());
+            throw new HAFenceException("OBM service is not configured or enabled for this host " + r.getName(), e);
         }
     }