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

   1 /*
   2  * Copyright (c) 2015, 2017 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 com.google.common.base.Optional;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.util.concurrent.CheckedFuture;
  14 import com.google.common.util.concurrent.FutureCallback;
  15 import com.google.common.util.concurrent.Futures;
  16 import org.opendaylight.controller.md.sal.binding.api.DataBroker;
  17 import org.opendaylight.controller.md.sal.binding.api.ReadOnlyTransaction;
  18 import org.opendaylight.controller.md.sal.common.api.clustering.CandidateAlreadyRegisteredException;
  19 import org.opendaylight.controller.md.sal.common.api.clustering.Entity;
  20 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipCandidateRegistration;
  21 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipChange;
  22 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListener;
  23 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipListenerRegistration;
  24 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipService;
  25 import org.opendaylight.controller.md.sal.common.api.clustering.EntityOwnershipState;
  26 import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
  27 import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
  28 import org.opendaylight.ovsdb.hwvtepsouthbound.reconciliation.ReconciliationManager;
  29 import org.opendaylight.ovsdb.hwvtepsouthbound.reconciliation.ReconciliationTask;
  30 import org.opendaylight.ovsdb.hwvtepsouthbound.reconciliation.configuration.HwvtepReconciliationTask;
  31 import org.opendaylight.ovsdb.hwvtepsouthbound.reconciliation.connection.ConnectionReconciliationTask;
  32 import org.opendaylight.ovsdb.hwvtepsouthbound.transact.DependencyQueue;
  33 import org.opendaylight.ovsdb.hwvtepsouthbound.transactions.md.HwvtepGlobalRemoveCommand;
  34 import org.opendaylight.ovsdb.hwvtepsouthbound.transactions.md.TransactionInvoker;
  35 import org.opendaylight.ovsdb.lib.OvsdbClient;
  36 import org.opendaylight.ovsdb.lib.OvsdbConnectionListener;
  37 import org.opendaylight.ovsdb.lib.impl.OvsdbConnectionService;
  38 import org.opendaylight.ovsdb.lib.operations.Operation;
  39 import org.opendaylight.ovsdb.lib.operations.OperationResult;
  40 import org.opendaylight.ovsdb.lib.operations.Select;
  41 import org.opendaylight.ovsdb.lib.schema.DatabaseSchema;
  42 import org.opendaylight.ovsdb.lib.schema.GenericTableSchema;
  43 import org.opendaylight.ovsdb.lib.schema.typed.TyperUtils;
  44 import org.opendaylight.ovsdb.schema.hardwarevtep.Global;
  45 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.HwvtepGlobalAugmentation;
  46 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.HwvtepPhysicalSwitchAttributes;
  47 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.PhysicalSwitchAugmentation;
  48 import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.ovsdb.hwvtep.rev150901.hwvtep.global.attributes.ConnectionInfo;
  49 import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Node;
  50 import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
  51 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  52 import org.slf4j.Logger;
  53 import org.slf4j.LoggerFactory;
  54
  55 import javax.annotation.Nonnull;
  56 import javax.annotation.Nullable;
  57 import java.net.ConnectException;
  58 import java.net.InetAddress;
  59 import java.net.UnknownHostException;
  60 import java.util.ArrayList;
  61 import java.util.List;
  62 import java.util.Map;
  63 import java.util.concurrent.ConcurrentHashMap;
  64 import java.util.concurrent.ExecutionException;
  65 import java.util.concurrent.TimeUnit;
  66 import java.util.concurrent.TimeoutException;
  67
  68 import static org.opendaylight.ovsdb.lib.operations.Operations.op;
  69
  70 public class HwvtepConnectionManager implements OvsdbConnectionListener, AutoCloseable{
  71     private Map<ConnectionInfo, HwvtepConnectionInstance> clients = new ConcurrentHashMap<>();
  72     private static final Logger LOG = LoggerFactory.getLogger(HwvtepConnectionManager.class);
  73     private static final String ENTITY_TYPE = "hwvtep";
  74     private static final int DB_FETCH_TIMEOUT = 1000;
  75
  76     private DataBroker db;
  77     private TransactionInvoker txInvoker;
  78     private Map<ConnectionInfo,InstanceIdentifier<Node>> instanceIdentifiers = new ConcurrentHashMap<>();
  79     private Map<Entity, HwvtepConnectionInstance> entityConnectionMap = new ConcurrentHashMap<>();
  80     private EntityOwnershipService entityOwnershipService;
  81     private HwvtepDeviceEntityOwnershipListener hwvtepDeviceEntityOwnershipListener;
  82     private final ReconciliationManager reconciliationManager;
  83     private final Map<InstanceIdentifier<Node>, HwvtepConnectionInstance> nodeIidVsConnectionInstance =
  84             new ConcurrentHashMap<>();
  85
  86     public HwvtepConnectionManager(DataBroker db, TransactionInvoker txInvoker,
  87                     EntityOwnershipService entityOwnershipService) {
  88         this.db = db;
  89         this.txInvoker = txInvoker;
  90         this.entityOwnershipService = entityOwnershipService;
  91         this.hwvtepDeviceEntityOwnershipListener = new HwvtepDeviceEntityOwnershipListener(this,entityOwnershipService);
  92         this.reconciliationManager = new ReconciliationManager(db);
  93     }
  94
  95     @Override
  96     public void close() throws Exception {
  97         if (hwvtepDeviceEntityOwnershipListener != null) {
  98             hwvtepDeviceEntityOwnershipListener.close();
  99         }
 100
 101         for (HwvtepConnectionInstance client: clients.values()) {
 102             client.disconnect();
 103         }
 104         DependencyQueue.close();
 105     }
 106
 107     @Override
 108     public void connected(@Nonnull final OvsdbClient externalClient) {
 109         LOG.info("Library connected {} from {}:{} to {}:{}",
 110                 externalClient.getConnectionInfo().getType(),
 111                 externalClient.getConnectionInfo().getRemoteAddress(),
 112                 externalClient.getConnectionInfo().getRemotePort(),
 113                 externalClient.getConnectionInfo().getLocalAddress(),
 114                 externalClient.getConnectionInfo().getLocalPort());
 115         List<String> databases = new ArrayList<>();
 116         try {
 117             databases = externalClient.getDatabases().get(DB_FETCH_TIMEOUT, TimeUnit.MILLISECONDS);
 118             if(databases.contains(HwvtepSchemaConstants.HARDWARE_VTEP)) {
 119                 HwvtepConnectionInstance hwClient = connectedButCallBacksNotRegistered(externalClient);
 120                 registerEntityForOwnership(hwClient);
 121             }
 122         } catch (InterruptedException | ExecutionException | TimeoutException e) {
 123             LOG.warn("Unable to fetch Database list from device {}. Disconnecting from the device.",
 124                     externalClient.getConnectionInfo().getRemoteAddress(), e);
 125             externalClient.disconnect();
 126         }
 127     }
 128
 129     @Override
 130     public void disconnected(OvsdbClient client) {
 131         LOG.info("Library disconnected {} from {}:{} to {}:{}. Cleaning up the operational data store",
 132                 client.getConnectionInfo().getType(),
 133                 client.getConnectionInfo().getRemoteAddress(),
 134                 client.getConnectionInfo().getRemotePort(),
 135                 client.getConnectionInfo().getLocalAddress(),
 136                 client.getConnectionInfo().getLocalPort());
 137         ConnectionInfo key = HwvtepSouthboundMapper.createConnectionInfo(client);
 138         HwvtepConnectionInstance hwvtepConnectionInstance = getConnectionInstance(key);
 139         if (hwvtepConnectionInstance != null) {
 140             // Unregister Entity ownership as soon as possible ,so this instance should
 141             // not be used as a candidate in Entity election (given that this instance is
 142             // about to disconnect as well), if current owner get disconnected from
 143             // HWVTEP device.
 144             unregisterEntityForOwnership(hwvtepConnectionInstance);
 145
 146             //TODO: remove all the hwvtep nodes
 147             txInvoker.invoke(new HwvtepGlobalRemoveCommand(hwvtepConnectionInstance, null, null));
 148
 149             removeConnectionInstance(key);
 150
 151             //Controller initiated connection can be terminated from switch side.
 152             //So cleanup the instance identifier cache.
 153             removeInstanceIdentifier(key);
 154             removeConnectionInstance(hwvtepConnectionInstance.getInstanceIdentifier());
 155             retryConnection(hwvtepConnectionInstance.getInstanceIdentifier(),
 156                     hwvtepConnectionInstance.getHwvtepGlobalAugmentation(),
 157                     ConnectionReconciliationTriggers.ON_DISCONNECT);
 158         } else {
 159             LOG.warn("HWVTEP disconnected event did not find connection instance for {}", key);
 160         }
 161         LOG.trace("HwvtepConnectionManager exit disconnected client: {}", client);
 162     }
 163
 164     public OvsdbClient connect(InstanceIdentifier<Node> iid,
 165                                HwvtepGlobalAugmentation hwvtepGlobal) throws UnknownHostException, ConnectException {
 166         LOG.info("Connecting to {}", HwvtepSouthboundUtil.connectionInfoToString(hwvtepGlobal.getConnectionInfo()));
 167         InetAddress ip = HwvtepSouthboundMapper.createInetAddress(hwvtepGlobal.getConnectionInfo().getRemoteIp());
 168         OvsdbClient client = OvsdbConnectionService.getService()
 169                         .connect(ip, hwvtepGlobal.getConnectionInfo().getRemotePort().getValue());
 170         if(client != null) {
 171             putInstanceIdentifier(hwvtepGlobal.getConnectionInfo(), iid.firstIdentifierOf(Node.class));
 172             HwvtepConnectionInstance hwvtepConnectionInstance = connectedButCallBacksNotRegistered(client);
 173             hwvtepConnectionInstance.setHwvtepGlobalAugmentation(hwvtepGlobal);
 174             hwvtepConnectionInstance.setInstanceIdentifier(iid.firstIdentifierOf(Node.class));
 175
 176             // Register Cluster Ownership for ConnectionInfo
 177             registerEntityForOwnership(hwvtepConnectionInstance);
 178         } else {
 179             LOG.warn("Failed to connect to OVSDB node: {}", hwvtepGlobal.getConnectionInfo());
 180         }
 181         return client;
 182     }
 183     public void disconnect(HwvtepGlobalAugmentation ovsdbNode) throws UnknownHostException {
 184         LOG.info("Diconnecting from {}", HwvtepSouthboundUtil.connectionInfoToString(ovsdbNode.getConnectionInfo()));
 185         HwvtepConnectionInstance client = getConnectionInstance(ovsdbNode.getConnectionInfo());
 186         if (client != null) {
 187             client.disconnect();
 188             // Unregister Cluster Ownership for ConnectionInfo
 189             unregisterEntityForOwnership(client);
 190             removeInstanceIdentifier(ovsdbNode.getConnectionInfo());
 191         }
 192     }
 193
 194     public HwvtepConnectionInstance connectedButCallBacksNotRegistered(final OvsdbClient externalClient) {
 195         LOG.info("OVSDB Connection from {}:{}",externalClient.getConnectionInfo().getRemoteAddress(),
 196                 externalClient.getConnectionInfo().getRemotePort());
 197         ConnectionInfo key = HwvtepSouthboundMapper.createConnectionInfo(externalClient);
 198         HwvtepConnectionInstance hwvtepConnectionInstance = getConnectionInstance(key);
 199
 200         // Check if existing hwvtepConnectionInstance for the OvsdbClient present.
 201         // In such cases, we will see if the hwvtepConnectionInstance has same externalClient.
 202         if (hwvtepConnectionInstance != null) {
 203             if (hwvtepConnectionInstance.hasOvsdbClient(externalClient)) {
 204                 LOG.warn("HWVTEP Connection Instance {} already exists for client {}", key, externalClient);
 205                 return hwvtepConnectionInstance;
 206             }
 207             LOG.warn("HWVTEP Connection Instance {} being replaced with client {}", key, externalClient);
 208             hwvtepConnectionInstance.disconnect();
 209
 210             // Unregister Cluster Ownership for ConnectionInfo
 211             // Because the hwvtepConnectionInstance is about to be completely replaced!
 212             unregisterEntityForOwnership(hwvtepConnectionInstance);
 213
 214             removeConnectionInstance(key);
 215         }
 216
 217         hwvtepConnectionInstance = new HwvtepConnectionInstance(this, key, externalClient, getInstanceIdentifier(key),
 218                 txInvoker, db);
 219         hwvtepConnectionInstance.createTransactInvokers();
 220         return hwvtepConnectionInstance;
 221     }
 222
 223     private void putConnectionInstance(ConnectionInfo key,HwvtepConnectionInstance instance) {
 224         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 225         clients.put(connectionInfo, instance);
 226         LOG.info("Clients after put: {}", clients);
 227     }
 228
 229     public HwvtepConnectionInstance getConnectionInstance(final ConnectionInfo key) {
 230         if (key == null) {
 231             return null;
 232         }
 233         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 234         return clients.get(connectionInfo);
 235     }
 236
 237     public HwvtepConnectionInstance getConnectionInstanceFromNodeIid(final InstanceIdentifier<Node> nodeIid) {
 238         HwvtepConnectionInstance hwvtepConnectionInstance = nodeIidVsConnectionInstance.get(nodeIid);
 239         if (hwvtepConnectionInstance != null) {
 240             return hwvtepConnectionInstance;
 241         }
 242         InstanceIdentifier<Node> globalNodeIid = HwvtepSouthboundUtil.getGlobalNodeIid(nodeIid);
 243         if (globalNodeIid != null) {
 244             return nodeIidVsConnectionInstance.get(globalNodeIid);
 245         }
 246         return null;
 247     }
 248
 249     public HwvtepConnectionInstance getConnectionInstance(Node node) {
 250         Preconditions.checkNotNull(node);
 251         HwvtepGlobalAugmentation hwvtepGlobal = node.getAugmentation(HwvtepGlobalAugmentation.class);
 252         PhysicalSwitchAugmentation pSwitchNode = node.getAugmentation(PhysicalSwitchAugmentation.class);
 253         if (hwvtepGlobal != null) {
 254             if(hwvtepGlobal.getConnectionInfo() != null) {
 255                 return getConnectionInstance(hwvtepGlobal.getConnectionInfo());
 256             } else {
 257                 //TODO: Case of user configured connection for now
 258                 //TODO: We could get it from Managers also.
 259                 return null;
 260             }
 261         }
 262         else if(pSwitchNode != null){
 263             return getConnectionInstance(pSwitchNode);
 264         } else {
 265             LOG.warn("This is not a node that gives any hint how to find its OVSDB Manager: {}",node);
 266             return null;
 267         }
 268     }
 269
 270     public HwvtepConnectionInstance getConnectionInstance(HwvtepPhysicalSwitchAttributes pNode) {
 271         Optional<HwvtepGlobalAugmentation> optional = HwvtepSouthboundUtil.getManagingNode(db, pNode);
 272         if(optional.isPresent()) {
 273             return getConnectionInstance(optional.get().getConnectionInfo());
 274         } else {
 275             return null;
 276         }
 277     }
 278
 279     public void stopConfigurationReconciliation(final InstanceIdentifier<Node> nodeIid) {
 280         final ReconciliationTask task = new HwvtepReconciliationTask(
 281                 reconciliationManager, HwvtepConnectionManager.this, nodeIid, null, null, db);
 282
 283         reconciliationManager.dequeue(task);
 284     }
 285
 286     public void reconcileConfigurations(final HwvtepConnectionInstance client, Node psNode) {
 287         final InstanceIdentifier<Node> nodeIid = client.getInstanceIdentifier();
 288         final ReconciliationTask task = new HwvtepReconciliationTask(
 289                 reconciliationManager, HwvtepConnectionManager.this, nodeIid, psNode, client, db);
 290
 291         reconciliationManager.enqueue(task);
 292     }
 293
 294     private void removeConnectionInstance(ConnectionInfo key) {
 295         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 296         clients.remove(connectionInfo);
 297         LOG.info("Clients after remove: {}", clients);
 298     }
 299
 300     private void putInstanceIdentifier(ConnectionInfo key,InstanceIdentifier<Node> iid) {
 301         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 302         instanceIdentifiers.put(connectionInfo, iid);
 303     }
 304
 305     public InstanceIdentifier<Node> getInstanceIdentifier(ConnectionInfo key) {
 306         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 307         return instanceIdentifiers.get(connectionInfo);
 308     }
 309
 310     private void removeInstanceIdentifier(ConnectionInfo key) {
 311         ConnectionInfo connectionInfo = HwvtepSouthboundMapper.suppressLocalIpPort(key);
 312         instanceIdentifiers.remove(connectionInfo);
 313     }
 314
 315     public OvsdbClient getClient(ConnectionInfo connectionInfo) {
 316         return getConnectionInstance(connectionInfo).getOvsdbClient();
 317     }
 318
 319     private void registerEntityForOwnership(HwvtepConnectionInstance hwvtepConnectionInstance) {
 320
 321         Entity candidateEntity = getEntityFromConnectionInstance(hwvtepConnectionInstance);
 322         entityConnectionMap.put(candidateEntity, hwvtepConnectionInstance);
 323         hwvtepConnectionInstance.setConnectedEntity(candidateEntity);
 324
 325         try {
 326             EntityOwnershipCandidateRegistration registration =
 327                     entityOwnershipService.registerCandidate(candidateEntity);
 328             hwvtepConnectionInstance.setDeviceOwnershipCandidateRegistration(registration);
 329             LOG.info("HWVTEP entity {} is registered for ownership.", candidateEntity);
 330
 331             //If entity already has owner, it won't get notification from EntityOwnershipService
 332             //so cache the connection instances.
 333             Optional<EntityOwnershipState> ownershipStateOpt =
 334                     entityOwnershipService.getOwnershipState(candidateEntity);
 335             if (ownershipStateOpt.isPresent()) {
 336                 EntityOwnershipState ownershipState = ownershipStateOpt.get();
 337                 if (ownershipState.hasOwner() && !ownershipState.isOwner()) {
 338                     if (getConnectionInstance(hwvtepConnectionInstance.getMDConnectionInfo()) != null) {
 339                         LOG.info("OVSDB entity {} is already owned by other southbound plugin "
 340                                 + "instance, so *this* instance is NOT an OWNER of the device",
 341                                 hwvtepConnectionInstance.getConnectionInfo());
 342                         putConnectionInstance(hwvtepConnectionInstance.getMDConnectionInfo(),hwvtepConnectionInstance);
 343                     }
 344                 }
 345             }
 346         } catch (CandidateAlreadyRegisteredException e) {
 347             LOG.warn("OVSDB entity {} was already registered for ownership", candidateEntity, e);
 348         }
 349
 350     }
 351
 352     private Global getHwvtepGlobalTableEntry(HwvtepConnectionInstance connectionInstance) {
 353         DatabaseSchema dbSchema = null;
 354         Global globalRow = null;
 355
 356         try {
 357             dbSchema = connectionInstance.getSchema(HwvtepSchemaConstants.HARDWARE_VTEP).get();
 358         } catch (InterruptedException | ExecutionException e) {
 359             LOG.warn("Not able to fetch schema for database {} from device {}",
 360                     HwvtepSchemaConstants.HARDWARE_VTEP,connectionInstance.getConnectionInfo(),e);
 361         }
 362
 363         if (dbSchema != null) {
 364             GenericTableSchema hwvtepSchema = TyperUtils.getTableSchema(dbSchema, Global.class);
 365
 366             List<String> hwvtepTableColumn = new ArrayList<>();
 367             hwvtepTableColumn.addAll(hwvtepSchema.getColumns());
 368             Select<GenericTableSchema> selectOperation = op.select(hwvtepSchema);
 369             selectOperation.setColumns(hwvtepTableColumn);
 370
 371             ArrayList<Operation> operations = new ArrayList<>();
 372             operations.add(selectOperation);
 373             operations.add(op.comment("Fetching hardware_vtep table rows"));
 374
 375             try {
 376                 List<OperationResult> results = connectionInstance.transact(dbSchema, operations).get();
 377                 if (results != null ) {
 378                     OperationResult selectResult = results.get(0);
 379                     globalRow = TyperUtils.getTypedRowWrapper(
 380                             dbSchema,Global.class,selectResult.getRows().get(0));
 381                 }
 382             } catch (InterruptedException | ExecutionException e) {
 383                 LOG.warn("Not able to fetch hardware_vtep table row from device {}",
 384                         connectionInstance.getConnectionInfo(),e);
 385             }
 386         }
 387         LOG.trace("Fetched global {} from hardware_vtep schema",globalRow);
 388         return globalRow;
 389     }
 390
 391     private Entity getEntityFromConnectionInstance(@Nonnull HwvtepConnectionInstance hwvtepConnectionInstance) {
 392         InstanceIdentifier<Node> iid = hwvtepConnectionInstance.getInstanceIdentifier();
 393         if ( iid == null ) {
 394             //TODO: Is Global the right one?
 395             Global hwvtepGlobalRow = getHwvtepGlobalTableEntry(hwvtepConnectionInstance);
 396             iid = HwvtepSouthboundMapper.getInstanceIdentifier(hwvtepGlobalRow);
 397             /* Let's set the iid now */
 398             hwvtepConnectionInstance.setInstanceIdentifier(iid);
 399             LOG.info("InstanceIdentifier {} generated for device "
 400                     + "connection {}",iid, hwvtepConnectionInstance.getConnectionInfo());
 401
 402         }
 403         YangInstanceIdentifier entityId =
 404                 HwvtepSouthboundUtil.getInstanceIdentifierCodec().getYangInstanceIdentifier(iid);
 405         Entity deviceEntity = new Entity(ENTITY_TYPE, entityId);
 406         LOG.debug("Entity {} created for device connection {}",
 407                 deviceEntity, hwvtepConnectionInstance.getConnectionInfo());
 408         return deviceEntity;
 409     }
 410     private void unregisterEntityForOwnership(HwvtepConnectionInstance hwvtepConnectionInstance) {
 411         hwvtepConnectionInstance.closeDeviceOwnershipCandidateRegistration();
 412         entityConnectionMap.remove(hwvtepConnectionInstance.getConnectedEntity());
 413     }
 414
 415     public void reconcileConnection(InstanceIdentifier<Node> iid, HwvtepGlobalAugmentation hwvtepNode) {
 416         this.retryConnection(iid, hwvtepNode,
 417                 ConnectionReconciliationTriggers.ON_CONTROLLER_INITIATED_CONNECTION_FAILURE);
 418         }
 419
 420     public void stopConnectionReconciliationIfActive(InstanceIdentifier<?> iid, HwvtepGlobalAugmentation hwvtepNode) {
 421         final ReconciliationTask task = new ConnectionReconciliationTask(
 422                 reconciliationManager,
 423                 this,
 424                 iid,
 425                 hwvtepNode);
 426         reconciliationManager.dequeue(task);
 427     }
 428
 429     private void retryConnection(final InstanceIdentifier<Node> iid, final HwvtepGlobalAugmentation hwvtepNode,
 430                                  ConnectionReconciliationTriggers trigger) {
 431         final ReconciliationTask task = new ConnectionReconciliationTask(
 432                 reconciliationManager,
 433                 this,
 434                 iid,
 435                 hwvtepNode);
 436
 437         if(reconciliationManager.isEnqueued(task)){
 438             return;
 439         }
 440         switch(trigger){
 441             case ON_CONTROLLER_INITIATED_CONNECTION_FAILURE:
 442                 reconciliationManager.enqueueForRetry(task);
 443                 break;
 444             case ON_DISCONNECT:
 445             {
 446                 ReadOnlyTransaction tx = db.newReadOnlyTransaction();
 447                 CheckedFuture<Optional<Node>, ReadFailedException> readNodeFuture =
 448                         tx.read(LogicalDatastoreType.CONFIGURATION, iid);
 449
 450                 final HwvtepConnectionManager connectionManager = this;
 451                 Futures.addCallback(readNodeFuture, new FutureCallback<Optional<Node>>() {
 452                     @Override
 453                     public void onSuccess(@Nullable Optional<Node> node) {
 454                         if (node.isPresent()) {
 455                             LOG.info("Disconnected/Failed connection {} was controller initiated, attempting " +
 456                                     "reconnection", hwvtepNode.getConnectionInfo());
 457                             reconciliationManager.enqueue(task);
 458
 459                         } else {
 460                             LOG.debug("Connection {} was switch initiated, no reconciliation is required"
 461                                     , iid.firstKeyOf(Node.class).getNodeId());
 462                         }
 463                     }
 464
 465                     @Override
 466                     public void onFailure(Throwable t) {
 467                         LOG.warn("Read Config/DS for Node failed! {}", iid, t);
 468                     }
 469                 });
 470                 break;
 471             }
 472             default:
 473                 break;
 474         }
 475     }
 476
 477     public void handleOwnershipChanged(EntityOwnershipChange ownershipChange) {
 478         HwvtepConnectionInstance hwvtepConnectionInstance = getConnectionInstanceFromEntity(ownershipChange.getEntity());
 479         LOG.info("handleOwnershipChanged: {} event received for device {}",
 480                 ownershipChange, hwvtepConnectionInstance != null ? hwvtepConnectionInstance.getConnectionInfo()
 481                         : "THAT'S NOT REGISTERED BY THIS SOUTHBOUND PLUGIN INSTANCE");
 482
 483         if (hwvtepConnectionInstance == null) {
 484             if (ownershipChange.isOwner()) {
 485                 LOG.warn("handleOwnershipChanged: found no connection instance for {}", ownershipChange.getEntity());
 486             } else {
 487                 // EntityOwnershipService sends notification to all the nodes, irrespective of whether
 488                 // that instance registered for the device ownership or not. It is to make sure that
 489                 // If all the controller instance that was connected to the device are down, so the
 490                 // running instance can clear up the operational data store even though it was not
 491                 // connected to the device.
 492                 LOG.debug("handleOwnershipChanged: found no connection instance for {}", ownershipChange.getEntity());
 493             }
 494
 495             // If entity has no owner, clean up the operational data store (it's possible because owner controller
 496             // might went down abruptly and didn't get a chance to clean up the operational data store.
 497             if (!ownershipChange.hasOwner()) {
 498                 LOG.debug("{} has no owner, cleaning up the operational data store", ownershipChange.getEntity());
 499                 // If first cleanEntityOperationalData() was called, this call will be no-op.
 500                 cleanEntityOperationalData(ownershipChange.getEntity());
 501             }
 502             return;
 503         }
 504         //Connection detail need to be cached, irrespective of ownership result.
 505         putConnectionInstance(hwvtepConnectionInstance.getMDConnectionInfo(), hwvtepConnectionInstance);
 506
 507         if (ownershipChange.isOwner() == hwvtepConnectionInstance.getHasDeviceOwnership()) {
 508             LOG.debug("handleOwnershipChanged: no change in ownership for {}. Ownership status is : {}",
 509                     hwvtepConnectionInstance.getConnectionInfo(), hwvtepConnectionInstance.getHasDeviceOwnership());
 510             return;
 511         }
 512
 513         hwvtepConnectionInstance.setHasDeviceOwnership(ownershipChange.isOwner());
 514         // You were not an owner, but now you are
 515         if (ownershipChange.isOwner()) {
 516             LOG.info("handleOwnershipChanged: *this* southbound plugin instance is owner of device {}",
 517                     hwvtepConnectionInstance.getConnectionInfo());
 518
 519             //*this* instance of southbound plugin is owner of the device,
 520             //so register for monitor callbacks
 521             hwvtepConnectionInstance.registerCallbacks();
 522
 523         } else {
 524             //You were owner of the device, but now you are not. With the current ownership
 525             //grant mechanism, this scenario should not occur. Because this scenario will occur
 526             //when this controller went down or switch flap the connection, but in both the case
 527             //it will go through the re-registration process. We need to implement this condition
 528             //when clustering service implement a ownership grant strategy which can revoke the
 529             //device ownership for load balancing the devices across the instances.
 530             //Once this condition occur, we should unregister the callback.
 531             LOG.error("handleOwnershipChanged: *this* southbound plugin instance is no longer the owner of device {}",
 532                     hwvtepConnectionInstance.getNodeId().getValue());
 533         }
 534     }
 535
 536     private void cleanEntityOperationalData(Entity entity) {
 537         @SuppressWarnings("unchecked") final InstanceIdentifier<Node> nodeIid =
 538                 (InstanceIdentifier<Node>) HwvtepSouthboundUtil
 539                         .getInstanceIdentifierCodec().bindingDeserializer(entity.getId());
 540         txInvoker.invoke(new HwvtepGlobalRemoveCommand(nodeIid));
 541     }
 542
 543     private HwvtepConnectionInstance getConnectionInstanceFromEntity(Entity entity) {
 544         return entityConnectionMap.get(entity);
 545     }
 546
 547     void putConnectionInstance(final InstanceIdentifier<Node> nodeIid,
 548                                final HwvtepConnectionInstance connectionInstance) {
 549         nodeIidVsConnectionInstance.put(nodeIid, connectionInstance);
 550     }
 551
 552     private void removeConnectionInstance(final InstanceIdentifier<Node> nodeIid) {
 553          if (nodeIid != null) {
 554              nodeIidVsConnectionInstance.remove(nodeIid);
 555          }
 556     }
 557
 558     private class HwvtepDeviceEntityOwnershipListener implements EntityOwnershipListener {
 559         private HwvtepConnectionManager hcm;
 560         private EntityOwnershipListenerRegistration listenerRegistration;
 561
 562         HwvtepDeviceEntityOwnershipListener(HwvtepConnectionManager hcm, EntityOwnershipService entityOwnershipService) {
 563             this.hcm = hcm;
 564             listenerRegistration = entityOwnershipService.registerListener(ENTITY_TYPE, this);
 565         }
 566         public void close() {
 567             listenerRegistration.close();
 568         }
 569         @Override
 570         public void ownershipChanged(EntityOwnershipChange ownershipChange) {
 571             hcm.handleOwnershipChanged(ownershipChange);
 572         }
 573     }
 574
 575     private enum ConnectionReconciliationTriggers {
 576         /*
 577         Reconciliation trigger for scenario where controller's attempt
 578         to connect to switch fails on config data store notification
 579         */
 580         ON_CONTROLLER_INITIATED_CONNECTION_FAILURE,
 581
 582         /*
 583         Reconciliation trigger for the scenario where controller
 584         initiated connection disconnects.
 585         */
 586         ON_DISCONNECT
 587     }
 588 }