opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/sharding/DistributedShardChangePublisher.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. 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.controller.cluster.sharding;
   9
  10 import static com.google.common.base.Preconditions.checkState;
  11 import static java.util.Objects.requireNonNull;
  12
  13 import java.util.ArrayList;
  14 import java.util.Collection;
  15 import java.util.Collections;
  16 import java.util.Iterator;
  17 import java.util.LinkedList;
  18 import java.util.List;
  19 import java.util.Map;
  20 import java.util.Optional;
  21 import java.util.concurrent.ConcurrentHashMap;
  22 import java.util.stream.Collectors;
  23 import javax.annotation.concurrent.GuardedBy;
  24 import org.opendaylight.controller.cluster.databroker.actors.dds.DataStoreClient;
  25 import org.opendaylight.controller.cluster.datastore.AbstractDataStore;
  26 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  27 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  28 import org.opendaylight.mdsal.dom.spi.AbstractDOMDataTreeChangeListenerRegistration;
  29 import org.opendaylight.mdsal.dom.spi.AbstractRegistrationTree;
  30 import org.opendaylight.mdsal.dom.spi.RegistrationTreeNode;
  31 import org.opendaylight.mdsal.dom.spi.shard.ChildShardContext;
  32 import org.opendaylight.mdsal.dom.spi.store.DOMStoreTreeChangePublisher;
  33 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  34 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  35 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  36 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  37 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  38 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  39 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  40 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidates;
  41 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeConfiguration;
  42 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  43 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataValidationFailedException;
  44 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  45 import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory;
  46 import org.opendaylight.yangtools.yang.data.impl.schema.tree.SchemaValidationFailedException;
  47 import org.slf4j.Logger;
  48 import org.slf4j.LoggerFactory;
  49
  50 public class DistributedShardChangePublisher
  51         extends AbstractRegistrationTree<AbstractDOMDataTreeChangeListenerRegistration<?>>
  52         implements DOMStoreTreeChangePublisher {
  53
  54     private static final Logger LOG = LoggerFactory.getLogger(DistributedShardChangePublisher.class);
  55
  56     private final AbstractDataStore distributedDataStore;
  57     private final YangInstanceIdentifier shardPath;
  58
  59     private final Map<DOMDataTreeIdentifier, ChildShardContext> childShards;
  60
  61     @GuardedBy("this")
  62     private final DataTree dataTree;
  63
  64     public DistributedShardChangePublisher(final DataStoreClient client,
  65                                            final AbstractDataStore distributedDataStore,
  66                                            final DOMDataTreeIdentifier prefix,
  67                                            final Map<DOMDataTreeIdentifier, ChildShardContext> childShards) {
  68         this.distributedDataStore = distributedDataStore;
  69         // TODO keeping the whole dataTree thats contained in subshards doesn't seem like a good idea
  70         // maybe the whole listener logic would be better in the backend shards where we have direct access to the
  71         // dataTree and wont have to cache it redundantly.
  72
  73         final DataTreeConfiguration baseConfig;
  74         switch (prefix.getDatastoreType()) {
  75             case CONFIGURATION:
  76                 baseConfig = DataTreeConfiguration.DEFAULT_CONFIGURATION;
  77                 break;
  78             case OPERATIONAL:
  79                 baseConfig = DataTreeConfiguration.DEFAULT_OPERATIONAL;
  80                 break;
  81             default:
  82                 throw new UnsupportedOperationException("Unknown prefix type " + prefix.getDatastoreType());
  83         }
  84
  85         this.dataTree = new InMemoryDataTreeFactory().create(new DataTreeConfiguration.Builder(baseConfig.getTreeType())
  86                 .setMandatoryNodesValidation(baseConfig.isMandatoryNodesValidationEnabled())
  87                 .setUniqueIndexes(baseConfig.isUniqueIndexEnabled())
  88                 .setRootPath(prefix.getRootIdentifier())
  89                 .build());
  90
  91         // XXX: can we guarantee that the root is present in the schemacontext?
  92         this.dataTree.setSchemaContext(distributedDataStore.getActorUtils().getSchemaContext());
  93         this.shardPath = prefix.getRootIdentifier();
  94         this.childShards = childShards;
  95     }
  96
  97     protected void registrationRemoved(final AbstractDOMDataTreeChangeListenerRegistration<?> registration) {
  98         LOG.debug("Closing registration {}", registration);
  99     }
 100
 101     @Override
 102     public <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L>
 103             registerTreeChangeListener(final YangInstanceIdentifier path, final L listener) {
 104         takeLock();
 105         try {
 106             return setupListenerContext(path, listener);
 107         } finally {
 108             releaseLock();
 109         }
 110     }
 111
 112     private <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L>
 113             setupListenerContext(final YangInstanceIdentifier listenerPath, final L listener) {
 114         // we need to register the listener registration path based on the shards root
 115         // we have to strip the shard path from the listener path and then register
 116         YangInstanceIdentifier strippedIdentifier = listenerPath;
 117         if (!shardPath.isEmpty()) {
 118             strippedIdentifier = YangInstanceIdentifier.create(stripShardPath(shardPath, listenerPath));
 119         }
 120
 121         final DOMDataTreeListenerWithSubshards subshardListener =
 122                 new DOMDataTreeListenerWithSubshards(strippedIdentifier, listener);
 123         final AbstractDOMDataTreeChangeListenerRegistration<L> reg =
 124                 setupContextWithoutSubshards(listenerPath, strippedIdentifier, subshardListener);
 125
 126         for (final ChildShardContext maybeAffected : childShards.values()) {
 127             if (listenerPath.contains(maybeAffected.getPrefix().getRootIdentifier())) {
 128                 // consumer has initialDataChangeEvent subshard somewhere on lower level
 129                 // register to the notification manager with snapshot and forward child notifications to parent
 130                 LOG.debug("Adding new subshard{{}} to listener at {}", maybeAffected.getPrefix(), listenerPath);
 131                 subshardListener.addSubshard(maybeAffected);
 132             } else if (maybeAffected.getPrefix().getRootIdentifier().contains(listenerPath)) {
 133                 // bind path is inside subshard
 134                 // TODO can this happen? seems like in ShardedDOMDataTree we are
 135                 // already registering to the lowest shard possible
 136                 throw new UnsupportedOperationException("Listener should be registered directly "
 137                         + "into initialDataChangeEvent subshard");
 138             }
 139         }
 140
 141         return reg;
 142     }
 143
 144     private <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L>
 145             setupContextWithoutSubshards(final YangInstanceIdentifier shardLookup,
 146                                          final YangInstanceIdentifier listenerPath,
 147                                          final DOMDataTreeListenerWithSubshards listener) {
 148
 149         LOG.debug("Registering root listener full path: {}, path inside shard: {}", shardLookup, listenerPath);
 150
 151         // register in the shard tree
 152         final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node =
 153                 findNodeFor(listenerPath.getPathArguments());
 154
 155         // register listener in CDS
 156         ListenerRegistration<DOMDataTreeChangeListener> listenerReg = distributedDataStore
 157                 .registerProxyListener(shardLookup, listenerPath, listener);
 158
 159         @SuppressWarnings("unchecked")
 160         final AbstractDOMDataTreeChangeListenerRegistration<L> registration =
 161             new AbstractDOMDataTreeChangeListenerRegistration<L>((L) listener) {
 162                 @Override
 163                 protected void removeRegistration() {
 164                     listener.close();
 165                     DistributedShardChangePublisher.this.removeRegistration(node, this);
 166                     registrationRemoved(this);
 167                     listenerReg.close();
 168                 }
 169             };
 170         addRegistration(node, registration);
 171
 172         return registration;
 173     }
 174
 175     private static Iterable<PathArgument> stripShardPath(final YangInstanceIdentifier shardPath,
 176                                                          final YangInstanceIdentifier listenerPath) {
 177         if (shardPath.isEmpty()) {
 178             return listenerPath.getPathArguments();
 179         }
 180
 181         final List<PathArgument> listenerPathArgs = new ArrayList<>(listenerPath.getPathArguments());
 182         final Iterator<PathArgument> shardIter = shardPath.getPathArguments().iterator();
 183         final Iterator<PathArgument> listenerIter = listenerPathArgs.iterator();
 184
 185         while (shardIter.hasNext()) {
 186             if (shardIter.next().equals(listenerIter.next())) {
 187                 listenerIter.remove();
 188             } else {
 189                 break;
 190             }
 191         }
 192
 193         return listenerPathArgs;
 194     }
 195
 196     synchronized DataTreeCandidate applyChanges(final YangInstanceIdentifier listenerPath,
 197             final Collection<DataTreeCandidate> changes) throws DataValidationFailedException {
 198         final DataTreeModification modification = dataTree.takeSnapshot().newModification();
 199         for (final DataTreeCandidate change : changes) {
 200             try {
 201                 DataTreeCandidates.applyToModification(modification, change);
 202             } catch (SchemaValidationFailedException e) {
 203                 LOG.error("Validation failed", e);
 204             }
 205         }
 206
 207         modification.ready();
 208
 209         final DataTreeCandidate candidate;
 210
 211         dataTree.validate(modification);
 212
 213         // strip nodes we dont need since this listener doesn't have to be registered at the root of the DataTree
 214         candidate = dataTree.prepare(modification);
 215         dataTree.commit(candidate);
 216
 217
 218         DataTreeCandidateNode modifiedChild = candidate.getRootNode();
 219
 220         for (final PathArgument pathArgument : listenerPath.getPathArguments()) {
 221             modifiedChild = modifiedChild.getModifiedChild(pathArgument);
 222         }
 223
 224         if (modifiedChild == null) {
 225             modifiedChild = new EmptyDataTreeCandidateNode(dataTree.getRootPath().getLastPathArgument());
 226         }
 227
 228         return DataTreeCandidates.newDataTreeCandidate(dataTree.getRootPath(), modifiedChild);
 229     }
 230
 231
 232     private final class DOMDataTreeListenerWithSubshards implements DOMDataTreeChangeListener {
 233
 234         private final YangInstanceIdentifier listenerPath;
 235         private final DOMDataTreeChangeListener delegate;
 236         private final Map<YangInstanceIdentifier, ListenerRegistration<DOMDataTreeChangeListener>> registrations =
 237                 new ConcurrentHashMap<>();
 238
 239         @GuardedBy("this")
 240         private final Collection<DataTreeCandidate> stashedDataTreeCandidates = new LinkedList<>();
 241
 242         DOMDataTreeListenerWithSubshards(final YangInstanceIdentifier listenerPath,
 243                                          final DOMDataTreeChangeListener delegate) {
 244             this.listenerPath = requireNonNull(listenerPath);
 245             this.delegate = requireNonNull(delegate);
 246         }
 247
 248         @Override
 249         public synchronized void onDataTreeChanged(final Collection<DataTreeCandidate> changes) {
 250             LOG.debug("Received data changed {}", changes);
 251
 252             if (!stashedDataTreeCandidates.isEmpty()) {
 253                 LOG.debug("Adding stashed subshards' changes {}", stashedDataTreeCandidates);
 254                 changes.addAll(stashedDataTreeCandidates);
 255                 stashedDataTreeCandidates.clear();
 256             }
 257
 258             try {
 259                 applyChanges(listenerPath, changes);
 260             } catch (final DataValidationFailedException e) {
 261                 // TODO should we fail here? What if stashed changes
 262                 // (changes from subshards) got ahead more than one generation
 263                 // from current shard. Than we can fail to apply this changes
 264                 // upon current data tree, but once we get respective changes
 265                 // from current shard, we can apply also changes from
 266                 // subshards.
 267                 //
 268                 // However, we can loose ability to notice and report some
 269                 // errors then. For example, we cannot detect potential lost
 270                 // changes from current shard.
 271                 LOG.error("Validation failed for modification built from changes {}, current data tree: {}",
 272                         changes, dataTree, e);
 273                 throw new RuntimeException("Notification validation failed", e);
 274             }
 275
 276             delegate.onDataTreeChanged(changes);
 277         }
 278
 279         synchronized void onDataTreeChanged(final YangInstanceIdentifier pathFromRoot,
 280                                             final Collection<DataTreeCandidate> changes) {
 281             final YangInstanceIdentifier changeId =
 282                     YangInstanceIdentifier.create(stripShardPath(dataTree.getRootPath(), pathFromRoot));
 283
 284             final List<DataTreeCandidate> newCandidates = changes.stream()
 285                     .map(candidate -> DataTreeCandidates.newDataTreeCandidate(changeId, candidate.getRootNode()))
 286                     .collect(Collectors.toList());
 287
 288             try {
 289                 delegate.onDataTreeChanged(Collections.singleton(applyChanges(listenerPath, newCandidates)));
 290             } catch (final DataValidationFailedException e) {
 291                 // We cannot apply changes from subshard to current data tree.
 292                 // Maybe changes from current shard haven't been applied to
 293                 // data tree yet. Postpone processing of these changes till we
 294                 // receive changes from current shard.
 295                 LOG.debug("Validation for modification built from subshard {} changes {} failed, current data tree {}.",
 296                         pathFromRoot, changes, dataTree, e);
 297                 stashedDataTreeCandidates.addAll(newCandidates);
 298             }
 299         }
 300
 301         void addSubshard(final ChildShardContext context) {
 302             checkState(context.getShard() instanceof DOMStoreTreeChangePublisher,
 303                     "All subshards that are initialDataChangeEvent part of ListenerContext need to be listenable");
 304
 305             final DOMStoreTreeChangePublisher listenableShard = (DOMStoreTreeChangePublisher) context.getShard();
 306             // since this is going into subshard we want to listen for ALL changes in the subshard
 307             registrations.put(context.getPrefix().getRootIdentifier(),
 308                     listenableShard.registerTreeChangeListener(
 309                             context.getPrefix().getRootIdentifier(), changes -> onDataTreeChanged(
 310                                     context.getPrefix().getRootIdentifier(), changes)));
 311         }
 312
 313         void close() {
 314             for (final ListenerRegistration<DOMDataTreeChangeListener> registration : registrations.values()) {
 315                 registration.close();
 316             }
 317             registrations.clear();
 318         }
 319     }
 320
 321     private static final class EmptyDataTreeCandidateNode implements DataTreeCandidateNode {
 322
 323         private final PathArgument identifier;
 324
 325         EmptyDataTreeCandidateNode(final PathArgument identifier) {
 326             this.identifier = requireNonNull(identifier, "Identifier should not be null");
 327         }
 328
 329         @Override
 330         public PathArgument getIdentifier() {
 331             return identifier;
 332         }
 333
 334         @Override
 335         public Collection<DataTreeCandidateNode> getChildNodes() {
 336             return Collections.emptySet();
 337         }
 338
 339         @Override
 340         @SuppressWarnings("checkstyle:hiddenField")
 341         public DataTreeCandidateNode getModifiedChild(final PathArgument identifier) {
 342             return null;
 343         }
 344
 345         @Override
 346         public ModificationType getModificationType() {
 347             return ModificationType.UNMODIFIED;
 348         }
 349
 350         @Override
 351         public Optional<NormalizedNode<?, ?>> getDataAfter() {
 352             return Optional.empty();
 353         }
 354
 355         @Override
 356         public Optional<NormalizedNode<?, ?>> getDataBefore() {
 357             return Optional.empty();
 358         }
 359     }
 360 }