openflowplugin-impl/src/main/java/org/opendaylight/openflowplugin/impl/lifecycle/ContextChainHolderImpl.java

   1 /*
   2  * Copyright (c) 2016 Pantheon Technologies s.r.o. and others. All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.openflowplugin.impl.lifecycle;
   9
  10 import com.google.common.annotations.VisibleForTesting;
  11 import com.google.common.util.concurrent.FutureCallback;
  12 import com.google.common.util.concurrent.Futures;
  13 import com.google.common.util.concurrent.ListenableFuture;
  14 import com.google.common.util.concurrent.MoreExecutors;
  15 import com.google.common.util.concurrent.ThreadFactoryBuilder;
  16 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  17 import java.util.HashMap;
  18 import java.util.List;
  19 import java.util.Map;
  20 import java.util.Objects;
  21 import java.util.Optional;
  22 import java.util.concurrent.ConcurrentHashMap;
  23 import java.util.concurrent.ExecutionException;
  24 import java.util.concurrent.ExecutorService;
  25 import java.util.concurrent.Executors;
  26 import java.util.concurrent.ScheduledExecutorService;
  27 import java.util.concurrent.ThreadFactory;
  28 import java.util.concurrent.TimeUnit;
  29 import java.util.concurrent.TimeoutException;
  30 import java.util.stream.Collectors;
  31 import org.eclipse.jdt.annotation.NonNull;
  32 import org.opendaylight.mdsal.eos.binding.api.EntityOwnershipChange;
  33 import org.opendaylight.mdsal.eos.binding.api.EntityOwnershipListenerRegistration;
  34 import org.opendaylight.mdsal.eos.binding.api.EntityOwnershipService;
  35 import org.opendaylight.mdsal.eos.common.api.EntityOwnershipState;
  36 import org.opendaylight.mdsal.singleton.common.api.ClusterSingletonServiceProvider;
  37 import org.opendaylight.openflowplugin.api.openflow.OFPManager;
  38 import org.opendaylight.openflowplugin.api.openflow.connection.ConnectionContext;
  39 import org.opendaylight.openflowplugin.api.openflow.connection.ConnectionStatus;
  40 import org.opendaylight.openflowplugin.api.openflow.device.DeviceContext;
  41 import org.opendaylight.openflowplugin.api.openflow.device.DeviceInfo;
  42 import org.opendaylight.openflowplugin.api.openflow.device.DeviceManager;
  43 import org.opendaylight.openflowplugin.api.openflow.lifecycle.ContextChain;
  44 import org.opendaylight.openflowplugin.api.openflow.lifecycle.ContextChainHolder;
  45 import org.opendaylight.openflowplugin.api.openflow.lifecycle.ContextChainMastershipState;
  46 import org.opendaylight.openflowplugin.api.openflow.lifecycle.MasterChecker;
  47 import org.opendaylight.openflowplugin.api.openflow.lifecycle.OwnershipChangeListener;
  48 import org.opendaylight.openflowplugin.api.openflow.role.RoleContext;
  49 import org.opendaylight.openflowplugin.api.openflow.role.RoleManager;
  50 import org.opendaylight.openflowplugin.api.openflow.rpc.RpcContext;
  51 import org.opendaylight.openflowplugin.api.openflow.rpc.RpcManager;
  52 import org.opendaylight.openflowplugin.api.openflow.statistics.StatisticsContext;
  53 import org.opendaylight.openflowplugin.api.openflow.statistics.StatisticsManager;
  54 import org.opendaylight.openflowplugin.impl.util.DeviceStateUtil;
  55 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId;
  56 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
  57 import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeKey;
  58 import org.opendaylight.yang.gen.v1.urn.opendaylight.openflow.protocol.rev130731.FeaturesReply;
  59 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.mdsal.core.general.entity.rev150930.Entity;
  60 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.openflow.provider.config.rev160510.OpenflowProviderConfig;
  61 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.openflowplugin.rf.state.rev170713.ResultState;
  62 import org.opendaylight.yangtools.yang.binding.KeyedInstanceIdentifier;
  63 import org.opendaylight.yangtools.yang.common.Uint8;
  64 import org.slf4j.Logger;
  65 import org.slf4j.LoggerFactory;
  66
  67 public class ContextChainHolderImpl implements ContextChainHolder, MasterChecker {
  68     private static final Logger LOG = LoggerFactory.getLogger(ContextChainHolderImpl.class);
  69     private static final Logger OF_EVENT_LOG = LoggerFactory.getLogger("OfEventLog");
  70
  71     private static final String CONTEXT_CREATED_FOR_CONNECTION = " context created for connection: {}";
  72     private static final long REMOVE_DEVICE_FROM_DS_TIMEOUT = 5000L;
  73     private static final String ASYNC_SERVICE_ENTITY_TYPE = "org.opendaylight.mdsal.AsyncServiceCloseEntityType";
  74     private static final String SERVICE_ENTITY_TYPE = "org.opendaylight.mdsal.ServiceEntityType";
  75     private static final String SEPARATOR = ":";
  76     private final Map<DeviceInfo, ContextChain> contextChainMap = new ConcurrentHashMap<>();
  77     private final Map<DeviceInfo, ? super ConnectionContext> connectingDevices = new ConcurrentHashMap<>();
  78     private final EntityOwnershipListenerRegistration eosListenerRegistration;
  79     private final ClusterSingletonServiceProvider singletonServiceProvider;
  80     private final ExecutorService executorService;
  81     private final OwnershipChangeListener ownershipChangeListener;
  82     private final ThreadFactory threadFactory = new ThreadFactoryBuilder().setDaemon(true)
  83             .setNameFormat("node-cleaner-%d").setUncaughtExceptionHandler((thread, throwable) -> {
  84                 LOG.warn("Uncaught exception while removing node data from operational datastore.", throwable);
  85             }).build();
  86     private final ScheduledExecutorService nodeCleanerExecutor = Executors.newScheduledThreadPool(
  87             Runtime.getRuntime().availableProcessors() , threadFactory);
  88     private final EntityOwnershipService entityOwnershipService;
  89     private final OpenflowProviderConfig config;
  90     private DeviceManager deviceManager;
  91     private RpcManager rpcManager;
  92     private StatisticsManager statisticsManager;
  93     private RoleManager roleManager;
  94
  95     public ContextChainHolderImpl(final ExecutorService executorService,
  96                                   final ClusterSingletonServiceProvider singletonServiceProvider,
  97                                   final EntityOwnershipService entityOwnershipService,
  98                                   final OwnershipChangeListener ownershipChangeListener,
  99                                   final OpenflowProviderConfig config) {
 100         this.singletonServiceProvider = singletonServiceProvider;
 101         this.executorService = executorService;
 102         this.ownershipChangeListener = ownershipChangeListener;
 103         this.ownershipChangeListener.setMasterChecker(this);
 104         this.entityOwnershipService = entityOwnershipService;
 105         this.config = config;
 106         this.eosListenerRegistration = Objects
 107                 .requireNonNull(entityOwnershipService.registerListener(ASYNC_SERVICE_ENTITY_TYPE, this));
 108     }
 109
 110     @Override
 111     public <T extends OFPManager> void addManager(final T manager) {
 112         if (deviceManager == null && manager instanceof DeviceManager) {
 113             LOG.trace("Context chain holder: Device manager OK.");
 114             deviceManager = (DeviceManager) manager;
 115         } else if (rpcManager == null && manager instanceof RpcManager) {
 116             LOG.trace("Context chain holder: RPC manager OK.");
 117             rpcManager = (RpcManager) manager;
 118         } else if (statisticsManager == null && manager instanceof StatisticsManager) {
 119             LOG.trace("Context chain holder: Statistics manager OK.");
 120             statisticsManager = (StatisticsManager) manager;
 121         } else if (roleManager == null && manager instanceof RoleManager) {
 122             LOG.trace("Context chain holder: Role manager OK.");
 123             roleManager = (RoleManager) manager;
 124         }
 125     }
 126
 127     @VisibleForTesting
 128     void createContextChain(final ConnectionContext connectionContext) {
 129         final DeviceInfo deviceInfo = connectionContext.getDeviceInfo();
 130
 131         final DeviceContext deviceContext = deviceManager.createContext(connectionContext);
 132         deviceContext.registerMastershipWatcher(this);
 133         LOG.debug("Device" + CONTEXT_CREATED_FOR_CONNECTION, deviceInfo);
 134
 135         final RpcContext rpcContext = rpcManager.createContext(deviceContext);
 136         rpcContext.registerMastershipWatcher(this);
 137         LOG.debug("RPC" + CONTEXT_CREATED_FOR_CONNECTION, deviceInfo);
 138
 139         final StatisticsContext statisticsContext = statisticsManager
 140                 .createContext(deviceContext, ownershipChangeListener.isReconciliationFrameworkRegistered());
 141         statisticsContext.registerMastershipWatcher(this);
 142         LOG.debug("Statistics" + CONTEXT_CREATED_FOR_CONNECTION, deviceInfo);
 143
 144         final RoleContext roleContext = roleManager.createContext(deviceContext);
 145         roleContext.registerMastershipWatcher(this);
 146         LOG.debug("Role" + CONTEXT_CREATED_FOR_CONNECTION, deviceInfo);
 147
 148         final ContextChain contextChain = new ContextChainImpl(this, connectionContext, executorService);
 149         contextChain.registerDeviceRemovedHandler(deviceManager);
 150         contextChain.registerDeviceRemovedHandler(rpcManager);
 151         contextChain.registerDeviceRemovedHandler(statisticsManager);
 152         contextChain.registerDeviceRemovedHandler(roleManager);
 153         contextChain.registerDeviceRemovedHandler(this);
 154         contextChain.addContext(deviceContext);
 155         contextChain.addContext(rpcContext);
 156         contextChain.addContext(statisticsContext);
 157         contextChain.addContext(roleContext);
 158         contextChainMap.put(deviceInfo, contextChain);
 159         connectingDevices.remove(deviceInfo);
 160         LOG.debug("Context chain" + CONTEXT_CREATED_FOR_CONNECTION, deviceInfo);
 161
 162         deviceContext.onPublished();
 163         contextChain.registerServices(singletonServiceProvider);
 164     }
 165
 166     @Override
 167     public ConnectionStatus deviceConnected(final ConnectionContext connectionContext) {
 168         final DeviceInfo deviceInfo = connectionContext.getDeviceInfo();
 169         final ContextChain contextChain = contextChainMap.get(deviceInfo);
 170         final FeaturesReply featuresReply = connectionContext.getFeatures();
 171         final Uint8 auxiliaryId = featuresReply != null ? featuresReply.getAuxiliaryId() : null;
 172
 173         if (auxiliaryId != null && auxiliaryId.toJava() != 0) {
 174             if (contextChain == null) {
 175                 LOG.warn("An auxiliary connection for device {}, but no primary connection. Refusing connection.",
 176                          deviceInfo);
 177                 return ConnectionStatus.REFUSING_AUXILIARY_CONNECTION;
 178             } else {
 179                 if (contextChain.addAuxiliaryConnection(connectionContext)) {
 180                     LOG.info("An auxiliary connection was added to device: {}", deviceInfo);
 181                     return ConnectionStatus.MAY_CONTINUE;
 182                 } else {
 183                     LOG.warn("Not able to add auxiliary connection to the device {}", deviceInfo);
 184                     return ConnectionStatus.REFUSING_AUXILIARY_CONNECTION;
 185                 }
 186             }
 187         } else {
 188             LOG.info("Device {} connected.", deviceInfo);
 189             final boolean contextExists = contextChain != null;
 190             final boolean isClosing = contextExists && contextChain.isClosing();
 191
 192             if (!isClosing && connectingDevices.putIfAbsent(deviceInfo, connectionContext) != null) {
 193                 LOG.warn("Device {} is already trying to connect, wait until succeeded or disconnected.", deviceInfo);
 194                 return ConnectionStatus.ALREADY_CONNECTED;
 195             }
 196
 197             if (contextExists) {
 198                 if (isClosing) {
 199                     LOG.warn("Device {} is already in termination state, closing all incoming connections.",
 200                              deviceInfo);
 201                     return ConnectionStatus.CLOSING;
 202                 }
 203
 204                 LOG.warn("Device {} already connected. Closing previous connection", deviceInfo);
 205                 destroyContextChain(deviceInfo);
 206                 LOG.info("Old connection dropped, creating new context chain for device {}", deviceInfo);
 207                 createContextChain(connectionContext);
 208             } else {
 209                 LOG.info("No context chain found for device: {}, creating new.", deviceInfo);
 210                 createContextChain(connectionContext);
 211             }
 212
 213             return ConnectionStatus.MAY_CONTINUE;
 214         }
 215
 216     }
 217
 218     @Override
 219     public void onNotAbleToStartMastership(@NonNull final DeviceInfo deviceInfo, @NonNull final String reason,
 220                                            final boolean mandatory) {
 221         LOG.warn("Not able to set MASTER role on device {}, reason: {}", deviceInfo, reason);
 222
 223         if (!mandatory) {
 224             return;
 225         }
 226
 227         Optional.ofNullable(contextChainMap.get(deviceInfo)).ifPresent(contextChain -> {
 228             LOG.warn("This mastering is mandatory, destroying context chain and closing connection for device {}.",
 229                      deviceInfo);
 230             destroyContextChain(deviceInfo);
 231         });
 232     }
 233
 234     @Override
 235     public void onMasterRoleAcquired(@NonNull final DeviceInfo deviceInfo,
 236                                      @NonNull final ContextChainMastershipState mastershipState) {
 237         Optional.ofNullable(contextChainMap.get(deviceInfo)).ifPresent(contextChain -> {
 238             if (!ContextChainMastershipState.INITIAL_SUBMIT.equals(mastershipState)) {
 239                 if (contextChain.isMastered(mastershipState, true)) {
 240                     Futures.addCallback(ownershipChangeListener.becomeMasterBeforeSubmittedDS(deviceInfo),
 241                                         reconciliationFrameworkCallback(deviceInfo, contextChain, mastershipState),
 242                                         MoreExecutors.directExecutor());
 243                 }
 244             } else if (contextChain.isMastered(mastershipState, false)) {
 245                 LOG.info("Role MASTER was granted to device {}", deviceInfo);
 246                 deviceManager.sendNodeAddedNotification(deviceInfo.getNodeInstanceIdentifier());
 247             }
 248         });
 249     }
 250
 251     @Override
 252     public void onSlaveRoleAcquired(final DeviceInfo deviceInfo) {
 253         ownershipChangeListener.becomeSlaveOrDisconnect(deviceInfo);
 254         LOG.info("Role SLAVE was granted to device {}", deviceInfo);
 255         Optional.ofNullable(contextChainMap.get(deviceInfo)).ifPresent(ContextChain::makeContextChainStateSlave);
 256     }
 257
 258     @Override
 259     public void onSlaveRoleNotAcquired(final DeviceInfo deviceInfo, final String reason) {
 260         LOG.warn("Not able to set SLAVE role on device {}, reason: {}", deviceInfo, reason);
 261         Optional.ofNullable(contextChainMap.get(deviceInfo)).ifPresent(contextChain -> destroyContextChain(deviceInfo));
 262     }
 263
 264     @Override
 265     public void onDeviceDisconnected(final ConnectionContext connectionContext) {
 266         final DeviceInfo deviceInfo = connectionContext.getDeviceInfo();
 267
 268         Optional.ofNullable(connectionContext.getDeviceInfo()).map(contextChainMap::get).ifPresent(contextChain -> {
 269             if (contextChain.auxiliaryConnectionDropped(connectionContext)) {
 270                 LOG.info("Auxiliary connection from device {} disconnected.", deviceInfo);
 271             } else {
 272                 LOG.info("Device {} disconnected.", deviceInfo);
 273                 destroyContextChain(deviceInfo);
 274             }
 275         });
 276     }
 277
 278     @VisibleForTesting
 279     boolean checkAllManagers() {
 280         return deviceManager != null && rpcManager != null && statisticsManager != null && roleManager != null;
 281     }
 282
 283     @Override
 284     public ContextChain getContextChain(final DeviceInfo deviceInfo) {
 285         return contextChainMap.get(deviceInfo);
 286     }
 287
 288     @Override
 289     public void close() {
 290         Map<DeviceInfo, ContextChain> copyOfChains = new HashMap<>(contextChainMap);
 291         copyOfChains.keySet().forEach(this::destroyContextChain);
 292         copyOfChains.clear();
 293         contextChainMap.clear();
 294         eosListenerRegistration.close();
 295         OF_EVENT_LOG.debug("EOS registration closed for all devices");
 296         nodeCleanerExecutor.shutdownNow();
 297     }
 298
 299     @Override
 300     @SuppressFBWarnings("BC_UNCONFIRMED_CAST_OF_RETURN_VALUE")
 301     public void ownershipChanged(final EntityOwnershipChange entityOwnershipChange) {
 302         LOG.info("Entity ownership change received for node : {}", entityOwnershipChange);
 303         if (entityOwnershipChange.inJeopardy()) {
 304             LOG.warn("Controller is in Jeopardy, ignore ownership change notification. {}", entityOwnershipChange);
 305             return;
 306         }
 307         if (entityOwnershipChange.getState().hasOwner()) {
 308             return;
 309         }
 310
 311         // Findbugs flags a false violation for "Unchecked/unconfirmed cast" from GenericEntity to Entity hence the
 312         // suppression above. The suppression is temporary until EntityOwnershipChange is modified to eliminate the
 313         // violation.
 314         final String entityName = entityOwnershipChange
 315                 .getEntity()
 316                 .getIdentifier()
 317                 .firstKeyOf(Entity.class)
 318                 .getName();
 319
 320         if (entityName != null && entityName.startsWith("openflow:")) {
 321             if (nodeCleanerExecutor.isShutdown()) {
 322                 LOG.warn("Node cleaner executor thread-pool is down.");
 323                 return;
 324             }
 325             LOG.debug("Device {} will be removed from datastore in {} msec, if it's not transient notification.",
 326                     entityName, config.getDeviceDatastoreRemovalDelay().getValue());
 327             final String dpnId = getDpnIdFromNodeName(entityName);
 328             nodeCleanerExecutor.schedule(() -> {
 329                 try {
 330                     Optional<EntityOwnershipState> ownershipState = getCurrentOwnershipStatus(entityName);
 331                     if (!ownershipState.isPresent()
 332                             || Objects.equals(ownershipState.get(), EntityOwnershipState.NO_OWNER)) {
 333                         LOG.debug("Entity {} has no owner", entityName);
 334                         final KeyedInstanceIdentifier<Node, NodeKey> nodeInstanceIdentifier =
 335                                 DeviceStateUtil.createNodeInstanceIdentifier(new NodeId(entityName));
 336                         deviceManager.sendNodeRemovedNotification(nodeInstanceIdentifier);
 337                         LOG.info("Try to remove device {} from operational DS", entityName);
 338                         ListenableFuture<?> future =
 339                                 deviceManager.removeDeviceFromOperationalDS(nodeInstanceIdentifier);
 340                         Futures.addCallback(future, new FutureCallback<Object>() {
 341                             @Override
 342                             public void onSuccess(final Object result) {
 343                                 LOG.debug("Node removed from Oper DS, Node: {}", dpnId);
 344                                 OF_EVENT_LOG.debug("Node removed from Oper DS, Node: {}", dpnId);
 345                             }
 346
 347                             @Override
 348                             public void onFailure(final Throwable throwable) {
 349                                 LOG.error("Could not remove device {} from operational DS", dpnId, throwable);
 350                             }
 351                         }, MoreExecutors.directExecutor());
 352                         future.get(REMOVE_DEVICE_FROM_DS_TIMEOUT, TimeUnit.MILLISECONDS);
 353                     } else {
 354                         LOG.warn("Seems like device is still owned by other controller instance. Skip deleting {} "
 355                                 + "node from operational datastore.", entityName);
 356                     }
 357                 } catch (TimeoutException | ExecutionException | NullPointerException | InterruptedException e) {
 358                     LOG.warn("Not able to remove device {} from operational DS. ", entityName, e);
 359                 }
 360             }, config.getDeviceDatastoreRemovalDelay().getValue().toJava(), TimeUnit.MILLISECONDS);
 361         }
 362     }
 363
 364     private void destroyContextChain(final DeviceInfo deviceInfo) {
 365         OF_EVENT_LOG.debug("Destroying context chain for device {}", deviceInfo.getDatapathId());
 366         ownershipChangeListener.becomeSlaveOrDisconnect(deviceInfo);
 367         Optional.ofNullable(contextChainMap.get(deviceInfo)).ifPresent(contextChain -> {
 368             deviceManager.sendNodeRemovedNotification(deviceInfo.getNodeInstanceIdentifier());
 369             contextChain.close();
 370             connectingDevices.remove(deviceInfo);
 371         });
 372     }
 373
 374     @Override
 375     public List<DeviceInfo> listOfMasteredDevices() {
 376         return contextChainMap.entrySet().stream()
 377                 .filter(deviceInfoContextChainEntry -> deviceInfoContextChainEntry.getValue()
 378                         .isMastered(ContextChainMastershipState.CHECK, false)).map(Map.Entry::getKey)
 379                 .collect(Collectors.toList());
 380     }
 381
 382     @Override
 383     public boolean isAnyDeviceMastered() {
 384         return contextChainMap.entrySet().stream().findAny()
 385                 .filter(deviceInfoContextChainEntry -> deviceInfoContextChainEntry.getValue()
 386                         .isMastered(ContextChainMastershipState.CHECK, false)).isPresent();
 387     }
 388
 389     @Override
 390     public void onDeviceRemoved(final DeviceInfo deviceInfo) {
 391         contextChainMap.remove(deviceInfo);
 392         LOG.debug("Context chain removed for node {}", deviceInfo);
 393     }
 394
 395     private FutureCallback<ResultState> reconciliationFrameworkCallback(@NonNull final DeviceInfo deviceInfo,
 396             final ContextChain contextChain, final ContextChainMastershipState mastershipState) {
 397         return new FutureCallback<>() {
 398             @Override
 399             public void onSuccess(final ResultState result) {
 400                 if (ResultState.DONOTHING == result) {
 401                     OF_EVENT_LOG.debug("Device {} connection is enabled by reconciliation framework", deviceInfo);
 402                     LOG.info("Device {} connection is enabled by reconciliation framework.", deviceInfo);
 403                     if (mastershipState == ContextChainMastershipState.MASTER_ON_DEVICE) {
 404                         ownershipChangeListener.becomeMaster(deviceInfo);
 405                         contextChain.initializeDevice();
 406                     }
 407                     contextChain.continueInitializationAfterReconciliation();
 408                 } else {
 409                     OF_EVENT_LOG.debug("Reconciliation framework failure for device {}", deviceInfo);
 410                     LOG.warn("Reconciliation framework failure for device {} with result {}", deviceInfo, result);
 411                     destroyContextChain(deviceInfo);
 412                 }
 413             }
 414
 415             @Override
 416             public void onFailure(final Throwable throwable) {
 417                 OF_EVENT_LOG.debug("Reconciliation framework failure for device {} with error {}", deviceInfo,
 418                         throwable.getMessage());
 419                 LOG.warn("Reconciliation framework failure.", throwable);
 420                 destroyContextChain(deviceInfo);
 421             }
 422         };
 423     }
 424
 425     private String getDpnIdFromNodeName(final String nodeName) {
 426         return nodeName.substring(nodeName.lastIndexOf(SEPARATOR) + 1);
 427     }
 428
 429     private Optional<EntityOwnershipState> getCurrentOwnershipStatus(final String nodeId) {
 430         org.opendaylight.mdsal.eos.binding.api.Entity entity = createNodeEntity(nodeId);
 431         Optional<EntityOwnershipState> ownershipStatus
 432                 = entityOwnershipService.getOwnershipState(entity);
 433
 434         if (ownershipStatus.isPresent()) {
 435             LOG.debug("Current ownership status for node {} is {}", nodeId, ownershipStatus.get());
 436             return Optional.of(ownershipStatus.get());
 437         } else {
 438             LOG.trace("Ownership status is not available for node {}", nodeId);
 439         }
 440         return Optional.empty();
 441     }
 442
 443     private org.opendaylight.mdsal.eos.binding.api.Entity createNodeEntity(final String nodeId) {
 444         return new org.opendaylight.mdsal.eos.binding.api.Entity(ASYNC_SERVICE_ENTITY_TYPE, nodeId);
 445     }
 446 }