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.ArrayList;
  17 import java.util.Collection;
  18 import java.util.function.Consumer;
  19 import javax.annotation.Nullable;
  20 import org.opendaylight.controller.cluster.access.commands.AbstractReadTransactionRequest;
  21 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionRequest;
  22 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionSuccess;
  23 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  24 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequestBuilder;
  25 import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
  26 import org.opendaylight.controller.cluster.access.commands.ReadTransactionRequest;
  27 import org.opendaylight.controller.cluster.access.commands.ReadTransactionSuccess;
  28 import org.opendaylight.controller.cluster.access.commands.TransactionDelete;
  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.TransactionRequest;
  32 import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
  33 import org.opendaylight.controller.cluster.access.commands.TransactionWrite;
  34 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  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 Collection<TransactionRequest<?>> successfulRequests = new ArrayList<>();
  66     private final ModifyTransactionRequestBuilder builder;
  67
  68     private boolean builderBusy;
  69
  70     private volatile Exception operationFailure;
  71
  72     RemoteProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier) {
  73         super(parent);
  74         builder = new ModifyTransactionRequestBuilder(identifier, localActor());
  75     }
  76
  77     @Override
  78     public TransactionIdentifier getIdentifier() {
  79         return builder.getIdentifier();
  80     }
  81
  82     @Override
  83     void doDelete(final YangInstanceIdentifier path) {
  84         appendModification(new TransactionDelete(path));
  85     }
  86
  87     @Override
  88     void doMerge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  89         appendModification(new TransactionMerge(path, data));
  90     }
  91
  92     @Override
  93     void doWrite(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  94         appendModification(new TransactionWrite(path, data));
  95     }
  96
  97     private <T> CheckedFuture<T, ReadFailedException> sendReadRequest(final AbstractReadTransactionRequest<?> request,
  98             final Consumer<Response<?, ?>> completer, final ListenableFuture<T> future) {
  99         // Check if a previous operation failed. If it has, do not bother sending anything and report a failure
 100         final Exception local = operationFailure;
 101         if (local != null) {
 102             return Futures.immediateFailedCheckedFuture(new ReadFailedException("Previous operation failed", local));
 103         }
 104
 105         // Make sure we send any modifications before issuing a read
 106         ensureFlushedBuider();
 107         sendRequest(request, completer);
 108         return MappingCheckedFuture.create(future, ReadFailedException.MAPPER);
 109     }
 110
 111     @Override
 112     CheckedFuture<Boolean, ReadFailedException> doExists(final YangInstanceIdentifier path) {
 113         final SettableFuture<Boolean> future = SettableFuture.create();
 114         return sendReadRequest(new ExistsTransactionRequest(getIdentifier(), nextSequence(), localActor(), path),
 115             t -> completeExists(future, t), future);
 116     }
 117
 118     @Override
 119     CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> doRead(final YangInstanceIdentifier path) {
 120         final SettableFuture<Optional<NormalizedNode<?, ?>>> future = SettableFuture.create();
 121         return sendReadRequest(new ReadTransactionRequest(getIdentifier(), nextSequence(), localActor(), path),
 122             t -> completeRead(future, t), future);
 123     }
 124
 125     @Override
 126     void doAbort() {
 127         ensureInitializedBuider();
 128         builder.setAbort();
 129         flushBuilder();
 130     }
 131
 132     private void ensureInitializedBuider() {
 133         if (!builderBusy) {
 134             builder.setSequence(nextSequence());
 135             builderBusy = true;
 136         }
 137     }
 138
 139     private void ensureFlushedBuider() {
 140         if (builderBusy) {
 141             flushBuilder();
 142         }
 143     }
 144
 145     private void flushBuilder() {
 146         final ModifyTransactionRequest request = builder.build();
 147         builderBusy = false;
 148
 149         sendModification(request);
 150     }
 151
 152     private void sendModification(final TransactionRequest<?> request) {
 153         sendRequest(request, response -> completeModify(request, response));
 154     }
 155
 156     @Override
 157     void handleForwardedRemoteRequest(final TransactionRequest<?> request,
 158             final @Nullable Consumer<Response<?, ?>> callback) {
 159         nextSequence();
 160
 161         if (callback == null) {
 162             sendModification(request);
 163             return;
 164         }
 165
 166         /*
 167          * FindBugs is utterly stupid, as it does not recognize the fact that we have checked for null
 168          * and reports NP_PARAMETER_MUST_BE_NONNULL_BUT_MARKED_AS_NULLABLE in the lambda below.
 169          */
 170         final Consumer<Response<?, ?>> findBugsIsStupid = callback;
 171
 172         // FIXME: do not use sendRequest() once we have throttling in place, as we have already waited the
 173         //        period required to get into the queue.
 174         sendRequest(request, response -> {
 175             findBugsIsStupid.accept(Preconditions.checkNotNull(response));
 176             completeModify(request, response);
 177         });
 178     }
 179
 180     private void appendModification(final TransactionModification modification) {
 181         if (operationFailure == null) {
 182             ensureInitializedBuider();
 183
 184             builder.addModification(modification);
 185             if (builder.size() >= REQUEST_MAX_MODIFICATIONS) {
 186                 flushBuilder();
 187             }
 188         } else {
 189             LOG.debug("Transaction {} failed, not attempting further transactions", getIdentifier());
 190         }
 191     }
 192
 193     private void completeModify(final TransactionRequest<?> request, final Response<?, ?> response) {
 194         LOG.debug("Modification request {} completed with {}", request, response);
 195
 196         if (response instanceof TransactionSuccess) {
 197             // Happy path
 198             successfulRequests.add(request);
 199         } else {
 200             recordFailedResponse(response);
 201         }
 202     }
 203
 204     private Exception recordFailedResponse(final Response<?, ?> response) {
 205         final Exception failure;
 206         if (response instanceof RequestFailure) {
 207             failure = ((RequestFailure<?, ?>) response).getCause();
 208         } else {
 209             LOG.warn("Unhandled response {}", response);
 210             failure = new IllegalArgumentException("Unhandled response " + response.getClass());
 211         }
 212
 213         if (operationFailure == null) {
 214             LOG.debug("Transaction {} failed", getIdentifier(), failure);
 215             operationFailure = failure;
 216         }
 217         return failure;
 218     }
 219
 220     private void failFuture(final SettableFuture<?> future, final Response<?, ?> response) {
 221         future.setException(recordFailedResponse(response));
 222     }
 223
 224     private void completeExists(final SettableFuture<Boolean> future, final Response<?, ?> response) {
 225         LOG.debug("Exists request completed with {}", response);
 226
 227         if (response instanceof ExistsTransactionSuccess) {
 228             future.set(((ExistsTransactionSuccess) response).getExists());
 229         } else {
 230             failFuture(future, response);
 231         }
 232     }
 233
 234     private void completeRead(final SettableFuture<Optional<NormalizedNode<?, ?>>> future,
 235             final Response<?, ?> response) {
 236         LOG.debug("Read request completed with {}", response);
 237
 238         if (response instanceof ReadTransactionSuccess) {
 239             future.set(((ReadTransactionSuccess) response).getData());
 240         } else {
 241             failFuture(future, response);
 242         }
 243     }
 244
 245     @Override
 246     ModifyTransactionRequest commitRequest(final boolean coordinated) {
 247         ensureInitializedBuider();
 248         builder.setCommit(coordinated);
 249
 250         final ModifyTransactionRequest ret = builder.build();
 251         builderBusy = false;
 252         return ret;
 253     }
 254
 255     @Override
 256     void doSeal() {
 257         // No-op
 258     }
 259
 260     @Override
 261     void replaySuccessfulRequests(final AbstractProxyTransaction successor) {
 262         super.replaySuccessfulRequests(successor);
 263
 264         for (TransactionRequest<?> req : successfulRequests) {
 265             LOG.debug("Forwarding request {} to successor {}", req, successor);
 266             successor.handleForwardedRemoteRequest(req, null);
 267         }
 268         successfulRequests.clear();
 269     }
 270
 271     @Override
 272     void forwardToRemote(final RemoteProxyTransaction successor, final TransactionRequest<?> request,
 273             final Consumer<Response<?, ?>> callback) throws RequestException {
 274         successor.handleForwardedRequest(request, callback);
 275     }
 276
 277     private void handleForwardedRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback)
 278             throws RequestException {
 279         if (request instanceof ModifyTransactionRequest) {
 280             final ModifyTransactionRequest req = (ModifyTransactionRequest) request;
 281
 282             req.getModifications().forEach(this::appendModification);
 283
 284             final java.util.Optional<PersistenceProtocol> maybeProto = req.getPersistenceProtocol();
 285             if (maybeProto.isPresent()) {
 286                 seal();
 287
 288                 switch (maybeProto.get()) {
 289                     case ABORT:
 290                         sendAbort(callback);
 291                         break;
 292                     case SIMPLE:
 293                         sendRequest(commitRequest(false), callback);
 294                         break;
 295                     case THREE_PHASE:
 296                         sendRequest(commitRequest(true), callback);
 297                         break;
 298                     default:
 299                         throw new IllegalArgumentException("Unhandled protocol " + maybeProto.get());
 300                 }
 301             }
 302         } else {
 303             throw new IllegalArgumentException("Unhandled request {}" + request);
 304         }
 305     }
 306
 307     @Override
 308     void forwardToLocal(final LocalProxyTransaction successor, final TransactionRequest<?> request,
 309             final Consumer<Response<?, ?>> callback) throws RequestException {
 310         successor.handleForwardedRemoteRequest(request, callback);
 311     }
 312 }