hwvtepsouthbound/hwvtepsouthbound-impl/src/main/java/org/opendaylight/ovsdb/hwvtepsouthbound/HwvtepConnectionManager.java

   1 /*
   2  * Copyright (c) 2015 Ericsson India Global Services Pvt Ltd. 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
   9 package org.opendaylight.ovsdb.hwvtepsouthbound;
  10
  11 import static org.opendaylight.ovsdb.lib.operations.Operations.op;
  12
  13 import java.net.InetAddress;
  14 import java.net.UnknownHostException;
  15 import java.util.ArrayList;
  16 import java.util.List;
  17 import java.util.Map;
  18 import java.util.concurrent.ConcurrentHashMap;
  19 import java.util.concurrent.ExecutionException;
  20
  21 import javax.annotation.Nonnull;
  22
  23 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  24 import org.opendaylight.controller.md.sal.binding.api.ReadWriteTransaction;
  25 import org.opendaylight.controller.md.sal.common.api.clustering.CandidateAlreadyRegisteredException;
  26 import org.opendaylight.controller.md.sal.common.api.clustering.Entity;
  27 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipCandidateRegistration;
  28 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipChange;
  29 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListener;
  30 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListenerRegistration;
  31 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipService;
  32 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipState;
  33 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  34 import org.opendaylight.ovsdb.hwvtepsouthbound.transactions.md.HwvtepGlobalRemoveCommand;
  35 import org.opendaylight.ovsdb.hwvtepsouthbound.transactions.md.TransactionCommand;
  36 import org.opendaylight.ovsdb.hwvtepsouthbound.transactions.md.TransactionInvoker;
  37 import org.opendaylight.ovsdb.lib.OvsdbClient;
  38 import org.opendaylight.ovsdb.lib.OvsdbConnectionListener;
  39 import org.opendaylight.ovsdb.lib.impl.OvsdbConnectionService;
  40 import org.opendaylight.ovsdb.lib.operations.Operation;
  41 import org.opendaylight.ovsdb.lib.operations.OperationResult;
  42 import org.opendaylight.ovsdb.lib.operations.Select;
  43 import org.opendaylight.ovsdb.lib.schema.DatabaseSchema;
  44 import org.opendaylight.ovsdb.lib.schema.GenericTableSchema;
  45 import org.opendaylight.ovsdb.lib.schema.typed.TyperUtils;
  46 import org.opendaylight.ovsdb.schema.hardwarevtep.Global;
  47 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.HwvtepGlobalAugmentation;
  48 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.HwvtepPhysicalSwitchAttributes;
  49 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.PhysicalSwitchAugmentation;
  50 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.hwvtep.global.attributes.ConnectionInfo;
  51 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Node;
  52 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  53 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  54 import org.slf4j.Logger;
  55 import org.slf4j.LoggerFactory;
  56
  57 import com.google.common.base.Optional;
  58 import com.google.common.base.Preconditions;
  59
  60 public class HwvtepConnectionManager implements OvsdbConnectionListener, AutoCloseable{
  61     private Map<ConnectionInfo, HwvtepConnectionInstance> clients = new ConcurrentHashMap<>();
  62     private static final Logger LOG = LoggerFactory.getLogger(HwvtepConnectionManager.class);
  63     private static final String ENTITY_TYPE = "hwvtep";
  64
  65     private DataBroker db;
  66     private TransactionInvoker txInvoker;
  67     private Map<ConnectionInfo,InstanceIdentifier<Node>> instanceIdentifiers = new ConcurrentHashMap<>();
  68     private Map<Entity, HwvtepConnectionInstance> entityConnectionMap = new ConcurrentHashMap<>();
  69     private EntityOwnershipService entityOwnershipService;
  70     private HwvtepDeviceEntityOwnershipListener hwvtepDeviceEntityOwnershipListener;
  71
  72     public HwvtepConnectionManager(DataBroker db, TransactionInvoker txInvoker,
  73                     EntityOwnershipService entityOwnershipService) {
  74         this.db = db;
  75         this.txInvoker = txInvoker;
  76         this.entityOwnershipService = entityOwnershipService;
  77         this.hwvtepDeviceEntityOwnershipListener = new HwvtepDeviceEntityOwnershipListener(this,entityOwnershipService);
  78     }
  79
  80     @Override
  81     public void close() throws Exception {
  82         if (hwvtepDeviceEntityOwnershipListener != null) {
  83             hwvtepDeviceEntityOwnershipListener.close();
  84         }
  85
  86         for (OvsdbClient client: clients.values()) {
  87             client.disconnect();
  88         }
  89     }
  90
  91     @Override
  92     public void connected(@Nonnull final OvsdbClient client) {
  93         LOG.info("Library connected {} from {}:{} to {}:{}",
  94                 client.getConnectionInfo().getType(),
  95                 client.getConnectionInfo().getRemoteAddress(),
  96                 client.getConnectionInfo().getRemotePort(),
  97                 client.getConnectionInfo().getLocalAddress(),
  98                 client.getConnectionInfo().getLocalPort());
  99         HwvtepConnectionInstance hwClient = connectedButCallBacksNotRegistered(client);
 100         registerEntityForOwnership(hwClient);
 101     }
 102
 103     @Override
 104     public void disconnected(OvsdbClient client) {
 105         LOG.info("Library disconnected {} from {}:{} to {}:{}. Cleaning up the operational data store",
 106                 client.getConnectionInfo().getType(),
 107                 client.getConnectionInfo().getRemoteAddress(),
 108                 client.getConnectionInfo().getRemotePort(),
 109                 client.getConnectionInfo().getLocalAddress(),
 110                 client.getConnectionInfo().getLocalPort());
 111         ConnectionInfo key = HwvtepSouthboundMapper.createConnectionInfo(client);
 112         HwvtepConnectionInstance hwvtepConnectionInstance = getConnectionInstance(key);
 113         if (hwvtepConnectionInstance != null) {
 114             //TODO: remove all the hwvtep nodes
 115             txInvoker.invoke(new HwvtepGlobalRemoveCommand(hwvtepConnectionInstance, null, null));
 116             removeConnectionInstance(key);
 117
 118             // Unregister Cluster Ownership for ConnectionInfo
 119             unregisterEntityForOwnership(hwvtepConnectionInstance);
 120         } else {
 121             LOG.warn("HWVTEP disconnected event did not find connection instance for {}", key);
 122         }
 123         LOG.trace("HwvtepConnectionManager exit disconnected client: {}", client);
 124     }
 125
 126     public OvsdbClient connect(InstanceIdentifier<Node> iid, HwvtepGlobalAugmentation hwvtepGlobal) throws UnknownHostException {
 127         LOG.info("Connecting to {}", HwvtepSouthboundUtil.connectionInfoToString(hwvtepGlobal.getConnectionInfo()));
 128         InetAddress ip = HwvtepSouthboundMapper.createInetAddress(hwvtepGlobal.getConnectionInfo().getRemoteIp());
 129         OvsdbClient client = OvsdbConnectionService.getService()
 130                         .connect(ip, hwvtepGlobal.getConnectionInfo().getRemotePort().getValue());
 131         if(client != null) {
 132             putInstanceIdentifier(hwvtepGlobal.getConnectionInfo(), iid.firstIdentifierOf(Node.class));
 133             HwvtepConnectionInstance hwvtepConnectionInstance = connectedButCallBacksNotRegistered(client);
 134             hwvtepConnectionInstance.setHwvtepGlobalAugmentation(hwvtepGlobal);
 135             hwvtepConnectionInstance.setInstanceIdentifier(iid.firstIdentifierOf(Node.class));
 136
 137             // Register Cluster Ownership for ConnectionInfo
 138             registerEntityForOwnership(hwvtepConnectionInstance);
 139         } else {
 140             LOG.warn("Failed to connect to OVSDB node: {}", hwvtepGlobal.getConnectionInfo());
 141         }
 142         return client;
 143     }
 144     public void disconnect(HwvtepGlobalAugmentation ovsdbNode) throws UnknownHostException {
 145         LOG.info("Diconnecting from {}", HwvtepSouthboundUtil.connectionInfoToString(ovsdbNode.getConnectionInfo()));
 146         HwvtepConnectionInstance client = getConnectionInstance(ovsdbNode.getConnectionInfo());
 147         if (client != null) {
 148             client.disconnect();
 149             // Unregister Cluster Ownership for ConnectionInfo
 150             unregisterEntityForOwnership(client);
 151             removeInstanceIdentifier(ovsdbNode.getConnectionInfo());
 152         }
 153     }
 154
 155     public HwvtepConnectionInstance connectedButCallBacksNotRegistered(final OvsdbClient externalClient) {
 156         LOG.info("OVSDB Connection from {}:{}",externalClient.getConnectionInfo().getRemoteAddress(),
 157                 externalClient.getConnectionInfo().getRemotePort());
 158         ConnectionInfo key = HwvtepSouthboundMapper.createConnectionInfo(externalClient);
 159         HwvtepConnectionInstance hwvtepConnectionInstance = getConnectionInstance(key);
 160
 161         // Check if existing hwvtepConnectionInstance for the OvsdbClient present.
 162         // In such cases, we will see if the hwvtepConnectionInstance has same externalClient.
 163         if (hwvtepConnectionInstance != null) {
 164             if (hwvtepConnectionInstance.hasOvsdbClient(externalClient)) {
 165                 LOG.warn("HWVTEP Connection Instance {} already exists for client {}", key, externalClient);
 166                 return hwvtepConnectionInstance;
 167             }
 168             LOG.warn("HWVTEP Connection Instance {} being replaced with client {}", key, externalClient);
 169             hwvtepConnectionInstance.disconnect();
 170
 171             // Unregister Cluster Ownership for ConnectionInfo
 172             // Because the hwvtepConnectionInstance is about to be completely replaced!
 173             unregisterEntityForOwnership(hwvtepConnectionInstance);
 174
 175             removeConnectionInstance(key);
 176         }
 177
 178         hwvtepConnectionInstance = new HwvtepConnectionInstance(key, externalClient, getInstanceIdentifier(key),
 179                 txInvoker);
 180         hwvtepConnectionInstance.createTransactInvokers();
 181         return hwvtepConnectionInstance;
 182     }
 183
 184     private void putConnectionInstance(ConnectionInfo key,HwvtepConnectionInstance instance) {
 185         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 186         clients.put(connectionInfo, instance);
 187         LOG.info("Clients after put: {}", clients);
 188     }
 189
 190     public HwvtepConnectionInstance getConnectionInstance(ConnectionInfo key) {
 191         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 192         return clients.get(connectionInfo);
 193     }
 194
 195     public HwvtepConnectionInstance getConnectionInstance(Node node) {
 196         Preconditions.checkNotNull(node);
 197         HwvtepGlobalAugmentation hwvtepGlobal = node.getAugmentation(HwvtepGlobalAugmentation.class);
 198         PhysicalSwitchAugmentation pSwitchNode = node.getAugmentation(PhysicalSwitchAugmentation.class);
 199         if (hwvtepGlobal != null) {
 200             if(hwvtepGlobal.getConnectionInfo() != null) {
 201                 return getConnectionInstance(hwvtepGlobal.getConnectionInfo());
 202             } else {
 203                 // TODO: Case of user configured connection
 204                 return null; //for now
 205             }
 206         } //TODO: We could get it from Managers also.
 207         else if(pSwitchNode != null){
 208             return getConnectionInstance(pSwitchNode);
 209         } else {
 210             LOG.warn("This is not a node that gives any hint how to find its OVSDB Manager: {}",node);
 211             return null;
 212         }
 213     }
 214
 215     private HwvtepConnectionInstance getConnectionInstance(HwvtepPhysicalSwitchAttributes pNode) {
 216         Optional<HwvtepGlobalAugmentation> optional = HwvtepSouthboundUtil.getManagingNode(db, pNode);
 217         if(optional.isPresent()) {
 218             return getConnectionInstance(optional.get().getConnectionInfo());
 219         } else {
 220             return null;
 221         }
 222     }
 223
 224     private void removeConnectionInstance(ConnectionInfo key) {
 225         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 226         clients.remove(connectionInfo);
 227         LOG.info("Clients after remove: {}", clients);
 228     }
 229
 230     private void putInstanceIdentifier(ConnectionInfo key,InstanceIdentifier<Node> iid) {
 231         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 232         instanceIdentifiers.put(connectionInfo, iid);
 233     }
 234
 235     public InstanceIdentifier<Node> getInstanceIdentifier(ConnectionInfo key) {
 236         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 237         return instanceIdentifiers.get(connectionInfo);
 238     }
 239
 240     private void removeInstanceIdentifier(ConnectionInfo key) {
 241         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 242         instanceIdentifiers.remove(connectionInfo);
 243     }
 244
 245     public OvsdbClient getClient(ConnectionInfo connectionInfo) {
 246         return getConnectionInstance(connectionInfo);
 247     }
 248
 249     private void registerEntityForOwnership(HwvtepConnectionInstance hwvtepConnectionInstance) {
 250
 251         Entity candidateEntity = getEntityFromConnectionInstance(hwvtepConnectionInstance);
 252         entityConnectionMap.put(candidateEntity, hwvtepConnectionInstance);
 253         hwvtepConnectionInstance.setConnectedEntity(candidateEntity);
 254
 255         try {
 256             EntityOwnershipCandidateRegistration registration =
 257                     entityOwnershipService.registerCandidate(candidateEntity);
 258             hwvtepConnectionInstance.setDeviceOwnershipCandidateRegistration(registration);
 259             LOG.info("HWVTEP entity {} is registered for ownership.", candidateEntity);
 260
 261             //If entity already has owner, it won't get notification from EntityOwnershipService
 262             //so cache the connection instances.
 263             Optional<EntityOwnershipState> ownershipStateOpt =
 264                     entityOwnershipService.getOwnershipState(candidateEntity);
 265             if (ownershipStateOpt.isPresent()) {
 266                 EntityOwnershipState ownershipState = ownershipStateOpt.get();
 267                 if (ownershipState.hasOwner() && !ownershipState.isOwner()) {
 268                     if (getConnectionInstance(hwvtepConnectionInstance.getMDConnectionInfo()) != null) {
 269                         LOG.info("OVSDB entity {} is already owned by other southbound plugin "
 270                                 + "instance, so *this* instance is NOT an OWNER of the device",
 271                                 hwvtepConnectionInstance.getConnectionInfo());
 272                         putConnectionInstance(hwvtepConnectionInstance.getMDConnectionInfo(),hwvtepConnectionInstance);
 273                     }
 274                 }
 275             }
 276         } catch (CandidateAlreadyRegisteredException e) {
 277             LOG.warn("OVSDB entity {} was already registered for {} ownership", candidateEntity, e);
 278         }
 279
 280     }
 281
 282     private Global getHwvtepGlobalTableEntry(HwvtepConnectionInstance connectionInstance) {
 283         DatabaseSchema dbSchema = null;
 284         Global globalRow = null;
 285
 286         try {
 287             dbSchema = connectionInstance.getSchema(HwvtepSchemaConstants.HARDWARE_VTEP).get();
 288         } catch (InterruptedException | ExecutionException e) {
 289             LOG.warn("Not able to fetch schema for database {} from device {}",
 290                     HwvtepSchemaConstants.HARDWARE_VTEP,connectionInstance.getConnectionInfo(),e);
 291         }
 292
 293         if (dbSchema != null) {
 294             GenericTableSchema hwvtepSchema = TyperUtils.getTableSchema(dbSchema, Global.class);
 295
 296             List<String> hwvtepTableColumn = new ArrayList<>();
 297             hwvtepTableColumn.addAll(hwvtepSchema.getColumns());
 298             Select<GenericTableSchema> selectOperation = op.select(hwvtepSchema);
 299             selectOperation.setColumns(hwvtepTableColumn);
 300
 301             ArrayList<Operation> operations = new ArrayList<>();
 302             operations.add(selectOperation);
 303             operations.add(op.comment("Fetching hardware_vtep table rows"));
 304
 305             try {
 306                 List<OperationResult> results = connectionInstance.transact(dbSchema, operations).get();
 307                 if (results != null ) {
 308                     OperationResult selectResult = results.get(0);
 309                     globalRow = TyperUtils.getTypedRowWrapper(
 310                             dbSchema,Global.class,selectResult.getRows().get(0));
 311                 }
 312             } catch (InterruptedException | ExecutionException e) {
 313                 LOG.warn("Not able to fetch hardware_vtep table row from device {}",
 314                         connectionInstance.getConnectionInfo(),e);
 315             }
 316         }
 317         LOG.trace("Fetched global {} from hardware_vtep schema",globalRow);
 318         return globalRow;
 319     }
 320
 321     private Entity getEntityFromConnectionInstance(@Nonnull HwvtepConnectionInstance hwvtepConnectionInstance) {
 322         InstanceIdentifier<Node> iid = hwvtepConnectionInstance.getInstanceIdentifier();
 323         if ( iid == null ) {
 324             //TODO: Is Global the right one?
 325             Global hwvtepGlobalRow = getHwvtepGlobalTableEntry(hwvtepConnectionInstance);
 326             iid = HwvtepSouthboundMapper.getInstanceIdentifier(hwvtepGlobalRow);
 327             /* Let's set the iid now */
 328             hwvtepConnectionInstance.setInstanceIdentifier(iid);
 329             LOG.info("InstanceIdentifier {} generated for device "
 330                     + "connection {}",iid, hwvtepConnectionInstance.getConnectionInfo());
 331
 332         }
 333         YangInstanceIdentifier entityId =
 334                 HwvtepSouthboundUtil.getInstanceIdentifierCodec().getYangInstanceIdentifier(iid);
 335         Entity deviceEntity = new Entity(ENTITY_TYPE, entityId);
 336         LOG.debug("Entity {} created for device connection {}",
 337                 deviceEntity, hwvtepConnectionInstance.getConnectionInfo());
 338         return deviceEntity;
 339     }
 340     private void unregisterEntityForOwnership(HwvtepConnectionInstance hwvtepConnectionInstance) {
 341         hwvtepConnectionInstance.closeDeviceOwnershipCandidateRegistration();
 342         entityConnectionMap.remove(hwvtepConnectionInstance.getConnectedEntity());
 343     }
 344
 345     public void handleOwnershipChanged(EntityOwnershipChange ownershipChange) {
 346         HwvtepConnectionInstance hwvtepConnectionInstance = getConnectionInstanceFromEntity(ownershipChange.getEntity());
 347         LOG.info("handleOwnershipChanged: {} event received for device {}",
 348                 ownershipChange, hwvtepConnectionInstance != null ? hwvtepConnectionInstance.getConnectionInfo()
 349                         : "THAT'S NOT REGISTERED BY THIS SOUTHBOUND PLUGIN INSTANCE");
 350
 351         if (hwvtepConnectionInstance == null) {
 352             if (ownershipChange.isOwner()) {
 353                 LOG.warn("handleOwnershipChanged: found no connection instance for {}", ownershipChange.getEntity());
 354             } else {
 355                 // EntityOwnershipService sends notification to all the nodes, irrespective of whether
 356                 // that instance registered for the device ownership or not. It is to make sure that
 357                 // If all the controller instance that was connected to the device are down, so the
 358                 // running instance can clear up the operational data store even though it was not
 359                 // connected to the device.
 360                 LOG.debug("handleOwnershipChanged: found no connection instance for {}", ownershipChange.getEntity());
 361             }
 362
 363             // If entity has no owner, clean up the operational data store (it's possible because owner controller
 364             // might went down abruptly and didn't get a chance to clean up the operational data store.
 365             if (!ownershipChange.hasOwner()) {
 366                 LOG.debug("{} has no owner, cleaning up the operational data store", ownershipChange.getEntity());
 367                 // Below code might look weird but it's required. We want to give first opportunity to the
 368                 // previous owner of the device to clean up the operational data store if there is no owner now.
 369                 // That way we will avoid lot of nasty md-sal exceptions because of concurrent delete.
 370                 if (ownershipChange.wasOwner()) {
 371                     cleanEntityOperationalData(ownershipChange.getEntity());
 372                 }
 373                 // If first cleanEntityOperationalData() was called, this call will be no-op.
 374                 cleanEntityOperationalData(ownershipChange.getEntity());
 375             }
 376             return;
 377         }
 378         //Connection detail need to be cached, irrespective of ownership result.
 379         putConnectionInstance(hwvtepConnectionInstance.getMDConnectionInfo(),hwvtepConnectionInstance);
 380
 381         if (ownershipChange.isOwner() == hwvtepConnectionInstance.getHasDeviceOwnership()) {
 382             LOG.debug("handleOwnershipChanged: no change in ownership for {}. Ownership status is : {}",
 383                     hwvtepConnectionInstance.getConnectionInfo(), hwvtepConnectionInstance.getHasDeviceOwnership());
 384             return;
 385         }
 386
 387         hwvtepConnectionInstance.setHasDeviceOwnership(ownershipChange.isOwner());
 388         // You were not an owner, but now you are
 389         if (ownershipChange.isOwner()) {
 390             LOG.info("handleOwnershipChanged: *this* southbound plugin instance is owner of device {}",
 391                     hwvtepConnectionInstance.getConnectionInfo());
 392
 393             //*this* instance of southbound plugin is owner of the device,
 394             //so register for monitor callbacks
 395             hwvtepConnectionInstance.registerCallbacks();
 396
 397         } else {
 398             //You were owner of the device, but now you are not. With the current ownership
 399             //grant mechanism, this scenario should not occur. Because this scenario will occur
 400             //when this controller went down or switch flap the connection, but in both the case
 401             //it will go through the re-registration process. We need to implement this condition
 402             //when clustering service implement a ownership grant strategy which can revoke the
 403             //device ownership for load balancing the devices across the instances.
 404             //Once this condition occur, we should unregister the callback.
 405             LOG.error("handleOwnershipChanged: *this* southbound plugin instance is no longer the owner of device {}",
 406                     hwvtepConnectionInstance.getNodeId().getValue());
 407         }
 408     }
 409
 410     private void cleanEntityOperationalData(Entity entity) {
 411         @SuppressWarnings("unchecked") final InstanceIdentifier<Node> nodeIid =
 412                 (InstanceIdentifier<Node>) HwvtepSouthboundUtil
 413                         .getInstanceIdentifierCodec().bindingDeserializer(entity.getId());
 414
 415         txInvoker.invoke(new TransactionCommand() {
 416             @Override
 417             public void execute(ReadWriteTransaction transaction) {
 418                 transaction.delete(LogicalDatastoreType.OPERATIONAL, nodeIid);
 419             }
 420         });
 421     }
 422
 423     private HwvtepConnectionInstance getConnectionInstanceFromEntity(Entity entity) {
 424         return entityConnectionMap.get(entity);
 425     }
 426
 427     private class HwvtepDeviceEntityOwnershipListener implements EntityOwnershipListener {
 428         private HwvtepConnectionManager hcm;
 429         private EntityOwnershipListenerRegistration listenerRegistration;
 430
 431         HwvtepDeviceEntityOwnershipListener(HwvtepConnectionManager hcm, EntityOwnershipService entityOwnershipService) {
 432             this.hcm = hcm;
 433             listenerRegistration = entityOwnershipService.registerListener(ENTITY_TYPE, this);
 434         }
 435         public void close() {
 436             listenerRegistration.close();
 437         }
 438         @Override
 439         public void ownershipChanged(EntityOwnershipChange ownershipChange) {
 440             hcm.handleOwnershipChanged(ownershipChange);
 441         }
 442     }
 443 }