opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/RemoteProxyTransaction.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.databroker.actors.dds;
   9
  10 import com.google.common.base.Optional;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.util.concurrent.CheckedFuture;
  13 import com.google.common.util.concurrent.Futures;
  14 import com.google.common.util.concurrent.ListenableFuture;
  15 import com.google.common.util.concurrent.SettableFuture;
  16 import java.util.function.Consumer;
  17 import javax.annotation.Nullable;
  18 import org.opendaylight.controller.cluster.access.commands.AbstractReadTransactionRequest;
  19 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionRequest;
  20 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionSuccess;
  21 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  22 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequestBuilder;
  23 import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
  24 import org.opendaylight.controller.cluster.access.commands.ReadTransactionRequest;
  25 import org.opendaylight.controller.cluster.access.commands.ReadTransactionSuccess;
  26 import org.opendaylight.controller.cluster.access.commands.TransactionAbortRequest;
  27 import org.opendaylight.controller.cluster.access.commands.TransactionDelete;
  28 import org.opendaylight.controller.cluster.access.commands.TransactionDoCommitRequest;
  29 import org.opendaylight.controller.cluster.access.commands.TransactionMerge;
  30 import org.opendaylight.controller.cluster.access.commands.TransactionModification;
  31 import org.opendaylight.controller.cluster.access.commands.TransactionPreCommitRequest;
  32 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  33 import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
  34 import org.opendaylight.controller.cluster.access.commands.TransactionWrite;
  35 import org.opendaylight.controller.cluster.access.concepts.RequestFailure;
  36 import org.opendaylight.controller.cluster.access.concepts.Response;
  37 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  38 import org.opendaylight.mdsal.common.api.ReadFailedException;
  39 import org.opendaylight.yangtools.util.concurrent.MappingCheckedFuture;
  40 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  41 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  42 import org.slf4j.Logger;
  43 import org.slf4j.LoggerFactory;
  44
  45 /**
  46  * An {@link AbstractProxyTransaction} for dispatching a transaction towards a shard leader whose location is currently
  47  * not known or is known to be not co-located with the client.
  48  *
  49  * <p>
  50  * It packages operations and sends them via the client actor queue to the shard leader. That queue is responsible for
  51  * maintaining any submitted operations until the leader is discovered.
  52  *
  53  * <p>
  54  * This class is not safe to access from multiple application threads, as is usual for transactions. Its internal state
  55  * transitions based on backend responses are thread-safe.
  56  *
  57  * @author Robert Varga
  58  */
  59 final class RemoteProxyTransaction extends AbstractProxyTransaction {
  60     private static final Logger LOG = LoggerFactory.getLogger(RemoteProxyTransaction.class);
  61
  62     // FIXME: make this tuneable
  63     private static final int REQUEST_MAX_MODIFICATIONS = 1000;
  64
  65     private final ModifyTransactionRequestBuilder builder;
  66     private final boolean snapshotOnly;
  67
  68     private boolean builderBusy;
  69
  70     private volatile Exception operationFailure;
  71
  72     RemoteProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier,
  73             final boolean snapshotOnly) {
  74         super(parent);
  75         this.snapshotOnly = snapshotOnly;
  76         builder = new ModifyTransactionRequestBuilder(identifier, localActor());
  77     }
  78
  79     @Override
  80     boolean isSnapshotOnly() {
  81         return snapshotOnly;
  82     }
  83
  84     @Override
  85     public TransactionIdentifier getIdentifier() {
  86         return builder.getIdentifier();
  87     }
  88
  89     @Override
  90     void doDelete(final YangInstanceIdentifier path) {
  91         appendModification(new TransactionDelete(path));
  92     }
  93
  94     @Override
  95     void doMerge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  96         appendModification(new TransactionMerge(path, data));
  97     }
  98
  99     @Override
 100     void doWrite(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
 101         appendModification(new TransactionWrite(path, data));
 102     }
 103
 104     private <T> CheckedFuture<T, ReadFailedException> sendReadRequest(final AbstractReadTransactionRequest<?> request,
 105             final Consumer<Response<?, ?>> completer, final ListenableFuture<T> future) {
 106         // Check if a previous operation failed. If it has, do not bother sending anything and report a failure
 107         final Exception local = operationFailure;
 108         if (local != null) {
 109             return Futures.immediateFailedCheckedFuture(new ReadFailedException("Previous operation failed", local));
 110         }
 111
 112         // Make sure we send any modifications before issuing a read
 113         ensureFlushedBuider();
 114         sendRequest(request, completer);
 115         return MappingCheckedFuture.create(future, ReadFailedException.MAPPER);
 116     }
 117
 118     @Override
 119     CheckedFuture<Boolean, ReadFailedException> doExists(final YangInstanceIdentifier path) {
 120         final SettableFuture<Boolean> future = SettableFuture.create();
 121         return sendReadRequest(new ExistsTransactionRequest(getIdentifier(), nextSequence(), localActor(), path,
 122             isSnapshotOnly()), t -> completeExists(future, t), future);
 123     }
 124
 125     @Override
 126     CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> doRead(final YangInstanceIdentifier path) {
 127         final SettableFuture<Optional<NormalizedNode<?, ?>>> future = SettableFuture.create();
 128         return sendReadRequest(new ReadTransactionRequest(getIdentifier(), nextSequence(), localActor(), path,
 129             isSnapshotOnly()), t -> completeRead(future, t), future);
 130     }
 131
 132     @Override
 133     void doAbort() {
 134         ensureInitializedBuider();
 135         builder.setAbort();
 136         flushBuilder();
 137     }
 138
 139     private void ensureInitializedBuider() {
 140         if (!builderBusy) {
 141             builder.setSequence(nextSequence());
 142             builderBusy = true;
 143         }
 144     }
 145
 146     private void ensureFlushedBuider() {
 147         if (builderBusy) {
 148             flushBuilder();
 149         }
 150     }
 151
 152     private void flushBuilder() {
 153         final ModifyTransactionRequest request = builder.build();
 154         builderBusy = false;
 155
 156         sendModification(request);
 157     }
 158
 159     private void sendModification(final TransactionRequest<?> request) {
 160         sendRequest(request, response -> completeModify(request, response));
 161     }
 162
 163     @Override
 164     void handleForwardedRemoteRequest(final TransactionRequest<?> request,
 165             final @Nullable Consumer<Response<?, ?>> callback) {
 166         nextSequence();
 167
 168         if (callback == null) {
 169             sendModification(request);
 170             return;
 171         }
 172
 173         /*
 174          * FindBugs is utterly stupid, as it does not recognize the fact that we have checked for null
 175          * and reports NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE in the lambda below.
 176          */
 177         final Consumer<Response<?, ?>> findBugsIsStupid = callback;
 178
 179         // FIXME: do not use sendRequest() once we have throttling in place, as we have already waited the
 180         //        period required to get into the queue.
 181         sendRequest(request, response -> {
 182             findBugsIsStupid.accept(Preconditions.checkNotNull(response));
 183             completeModify(request, response);
 184         });
 185     }
 186
 187     private void appendModification(final TransactionModification modification) {
 188         if (operationFailure == null) {
 189             ensureInitializedBuider();
 190
 191             builder.addModification(modification);
 192             if (builder.size() >= REQUEST_MAX_MODIFICATIONS) {
 193                 flushBuilder();
 194             }
 195         } else {
 196             LOG.debug("Transaction {} failed, not attempting further transactions", getIdentifier());
 197         }
 198     }
 199
 200     private void completeModify(final TransactionRequest<?> request, final Response<?, ?> response) {
 201         LOG.debug("Modification request {} completed with {}", request, response);
 202
 203         if (response instanceof TransactionSuccess) {
 204             // Happy path
 205             recordSuccessfulRequest(request);
 206         } else {
 207             recordFailedResponse(response);
 208         }
 209     }
 210
 211     private Exception recordFailedResponse(final Response<?, ?> response) {
 212         final Exception failure;
 213         if (response instanceof RequestFailure) {
 214             failure = ((RequestFailure<?, ?>) response).getCause();
 215         } else {
 216             LOG.warn("Unhandled response {}", response);
 217             failure = new IllegalArgumentException("Unhandled response " + response.getClass());
 218         }
 219
 220         if (operationFailure == null) {
 221             LOG.debug("Transaction {} failed", getIdentifier(), failure);
 222             operationFailure = failure;
 223         }
 224         return failure;
 225     }
 226
 227     private void failFuture(final SettableFuture<?> future, final Response<?, ?> response) {
 228         future.setException(recordFailedResponse(response));
 229     }
 230
 231     private void completeExists(final SettableFuture<Boolean> future, final Response<?, ?> response) {
 232         LOG.debug("Exists request completed with {}", response);
 233
 234         if (response instanceof ExistsTransactionSuccess) {
 235             future.set(((ExistsTransactionSuccess) response).getExists());
 236         } else {
 237             failFuture(future, response);
 238         }
 239
 240         recordFinishedRequest();
 241     }
 242
 243     private void completeRead(final SettableFuture<Optional<NormalizedNode<?, ?>>> future,
 244             final Response<?, ?> response) {
 245         LOG.debug("Read request completed with {}", response);
 246
 247         if (response instanceof ReadTransactionSuccess) {
 248             future.set(((ReadTransactionSuccess) response).getData());
 249         } else {
 250             failFuture(future, response);
 251         }
 252
 253         recordFinishedRequest();
 254     }
 255
 256     @Override
 257     ModifyTransactionRequest commitRequest(final boolean coordinated) {
 258         ensureInitializedBuider();
 259         builder.setCommit(coordinated);
 260
 261         final ModifyTransactionRequest ret = builder.build();
 262         builderBusy = false;
 263         return ret;
 264     }
 265
 266     @Override
 267     void doSeal() {
 268         // No-op
 269     }
 270
 271     @Override
 272     void flushState(final AbstractProxyTransaction successor) {
 273         if (builderBusy) {
 274             final ModifyTransactionRequest request = builder.build();
 275             builderBusy = false;
 276             successor.handleForwardedRemoteRequest(request, null);
 277         }
 278     }
 279
 280     @Override
 281     void forwardToRemote(final RemoteProxyTransaction successor, final TransactionRequest<?> request,
 282             final Consumer<Response<?, ?>> callback) {
 283         successor.handleForwardedRequest(request, callback);
 284     }
 285
 286     private void handleForwardedRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 287         if (request instanceof ModifyTransactionRequest) {
 288             final ModifyTransactionRequest req = (ModifyTransactionRequest) request;
 289
 290             req.getModifications().forEach(this::appendModification);
 291
 292             final java.util.Optional<PersistenceProtocol> maybeProto = req.getPersistenceProtocol();
 293             if (maybeProto.isPresent()) {
 294                 seal();
 295
 296                 switch (maybeProto.get()) {
 297                     case ABORT:
 298                         sendAbort(callback);
 299                         break;
 300                     case SIMPLE:
 301                         sendRequest(commitRequest(false), callback);
 302                         break;
 303                     case THREE_PHASE:
 304                         sendRequest(commitRequest(true), callback);
 305                         break;
 306                     default:
 307                         throw new IllegalArgumentException("Unhandled protocol " + maybeProto.get());
 308                 }
 309             }
 310         } else if (request instanceof ReadTransactionRequest) {
 311             ensureFlushedBuider();
 312             sendRequest(new ReadTransactionRequest(getIdentifier(), nextSequence(), localActor(),
 313                 ((ReadTransactionRequest) request).getPath(), isSnapshotOnly()), callback);
 314         } else if (request instanceof ExistsTransactionRequest) {
 315             ensureFlushedBuider();
 316             sendRequest(new ExistsTransactionRequest(getIdentifier(), nextSequence(), localActor(),
 317                 ((ExistsTransactionRequest) request).getPath(), isSnapshotOnly()), callback);
 318         } else if (request instanceof TransactionPreCommitRequest) {
 319             ensureFlushedBuider();
 320             sendRequest(new TransactionPreCommitRequest(getIdentifier(), nextSequence(), localActor()), callback);
 321         } else if (request instanceof TransactionDoCommitRequest) {
 322             ensureFlushedBuider();
 323             sendRequest(new TransactionDoCommitRequest(getIdentifier(), nextSequence(), localActor()), callback);
 324         } else if (request instanceof TransactionAbortRequest) {
 325             ensureFlushedBuider();
 326             sendAbort(callback);
 327         } else {
 328             throw new IllegalArgumentException("Unhandled request {}" + request);
 329         }
 330     }
 331
 332     @Override
 333     void forwardToLocal(final LocalProxyTransaction successor, final TransactionRequest<?> request,
 334             final Consumer<Response<?, ?>> callback) {
 335         successor.handleForwardedRemoteRequest(request, callback);
 336     }
 337 }