diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/DistributedOpenstackNetworkStore.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/DistributedOpenstackNetworkStore.java
index 0cc63b9..63b4a49 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/DistributedOpenstackNetworkStore.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/DistributedOpenstackNetworkStore.java
@@ -29,7 +29,6 @@
 import org.onosproject.openstacknetworking.api.OpenstackNetworkEvent;
 import org.onosproject.openstacknetworking.api.OpenstackNetworkStore;
 import org.onosproject.openstacknetworking.api.OpenstackNetworkStoreDelegate;
-import org.onosproject.openstacknetworking.api.PreCommitPortService;
 import org.onosproject.store.AbstractStore;
 import org.onosproject.store.serializers.KryoNamespaces;
 import org.onosproject.store.service.ConsistentMap;
@@ -58,6 +57,7 @@
 
 import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.ExecutorService;
 
@@ -93,8 +93,6 @@
     private static final String ERR_NOT_FOUND = " does not exist";
     private static final String ERR_DUPLICATE = " already exists";
 
-    private static final long TIMEOUT_MS = 2000; // wait for 2s
-
     private static final KryoNamespace SERIALIZER_NEUTRON_L2 = KryoNamespace.newBuilder()
             .register(KryoNamespaces.API)
             .register(Network.class)
@@ -122,9 +120,6 @@
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected StorageService storageService;
 
-    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
-    protected PreCommitPortService preCommitPortService;
-
     private final ExecutorService eventExecutor = newSingleThreadExecutor(
             groupedThreads(this.getClass().getSimpleName(), "event-handler", log));
 
@@ -413,7 +408,7 @@
                     ImmutableList.of() : newPort.getSecurityGroups();
 
             oldSecurityGroups.stream()
-                    .filter(sgId -> !newPort.getSecurityGroups().contains(sgId))
+                    .filter(sgId -> !Objects.requireNonNull(newPort.getSecurityGroups()).contains(sgId))
                     .forEach(sgId -> notifyDelegate(new OpenstackNetworkEvent(
                             OPENSTACK_PORT_SECURITY_GROUP_REMOVED, newPort, sgId
                     )));
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenStackSwitchingDirectPortProvider.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenStackSwitchingDirectPortProvider.java
index 76c0197..14e6aa1 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenStackSwitchingDirectPortProvider.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenStackSwitchingDirectPortProvider.java
@@ -311,9 +311,6 @@
             ports.forEach(port -> {
                 addIntfToDevice(node, port);
             });
-
-
-
         }
 
         private void addIntfToDevice(OpenstackNode node, Port port) {
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java
index 92257fd..1db1da1 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackNetworkManager.java
@@ -339,7 +339,7 @@
                     osPort = osNetworkStore.ports()
                             .stream()
                             .filter(p -> p.getvNicType().equals(DIRECT) && p.getProfile().get(PCISLOT) != null)
-                            .filter(p -> getIntfNameFromPciAddress(p).equals(portName))
+                            .filter(p -> Objects.requireNonNull(getIntfNameFromPciAddress(p)).equals(portName))
                             .findFirst();
                     return osPort.orElse(null);
 
@@ -484,11 +484,11 @@
                 ByteBuffer.wrap(ethRequest.serialize())));
 
         externalPeerRouterMap.put(targetIp.toString(),
-                                    DefaultExternalPeerRouter.builder()
-                                                    .ipAddress(targetIp)
-                                                    .macAddress(MacAddress.NONE)
-                                                    .vlanId(vlanId)
-                                                    .build());
+                DefaultExternalPeerRouter.builder()
+                        .ipAddress(targetIp)
+                        .macAddress(MacAddress.NONE)
+                        .vlanId(vlanId)
+                        .build());
 
         log.info("Initializes external peer router map with peer router IP {}", targetIp.toString());
     }
@@ -641,7 +641,7 @@
 
         return subnets(network.getId()).stream()
                 .filter(s -> IpPrefix.valueOf(s.getCidr()).contains(ipAddress))
-                .map(s -> s.getGateway())
+                .map(Subnet::getGateway)
                 .findAny().orElse(null);
     }
 
@@ -704,4 +704,4 @@
 
         return externalSubnet.map(subnet -> IpAddress.valueOf(subnet.getGateway())).orElse(null);
     }
-}
+}
\ No newline at end of file
diff --git a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingIcmpHandler.java b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingIcmpHandler.java
index 764cefe..a7e008a 100644
--- a/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingIcmpHandler.java
+++ b/apps/openstacknetworking/app/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingIcmpHandler.java
@@ -221,7 +221,6 @@
                 });
             } catch (IllegalArgumentException e) {
                 log.warn("IllegalArgumentException occurred because of {}", e.toString());
-                return;
             }
         }
     }