diff --git a/server/src/com/cloud/network/lb/LoadBalancingRulesManagerImpl.java b/server/src/com/cloud/network/lb/LoadBalancingRulesManagerImpl.java
index bd58e398473..b830910eba1 100755
--- a/server/src/com/cloud/network/lb/LoadBalancingRulesManagerImpl.java
+++ b/server/src/com/cloud/network/lb/LoadBalancingRulesManagerImpl.java
@@ -1405,7 +1405,8 @@ public class LoadBalancingRulesManagerImpl<Type> extends ManagerBase implements
         
                 if (generateUsageEvent) {
                     // Generate usage event right after all rules were marked for revoke
-                    UsageEventUtils.publishUsageEvent(EventTypes.EVENT_LOAD_BALANCER_DELETE, lb.getAccountId(), 0, lb.getId(),
+                    Network network = _networkModel.getNetwork(lb.getNetworkId());
+                    UsageEventUtils.publishUsageEvent(EventTypes.EVENT_LOAD_BALANCER_DELETE, lb.getAccountId(), network.getDataCenterId(), lb.getId(),
                             null, LoadBalancingRule.class.getName(), lb.getUuid());
                 }
                 
@@ -2052,6 +2053,11 @@ public class LoadBalancingRulesManagerImpl<Type> extends ManagerBase implements
         List<String> serviceStates = new ArrayList<String>();
         List<LoadBalancerVMMapVO> vmLoadBalancerMappings = null;
         vmLoadBalancerMappings = _lb2VmMapDao.listByLoadBalancerId(loadBalancerId);
+        if(vmLoadBalancerMappings == null) {
+            String msg = "no VM Loadbalancer Mapping found";
+            s_logger.error(msg);
+            throw new CloudRuntimeException(msg);
+        }
         Map<Long, String> vmServiceState = new HashMap<Long, String>(vmLoadBalancerMappings.size());
         List<Long> appliedInstanceIdList = new ArrayList<Long>();