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