opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/ProxyHistory.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 akka.actor.ActorRef;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.base.Verify;
  13 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  14 import java.util.Collection;
  15 import java.util.Iterator;
  16 import java.util.LinkedHashMap;
  17 import java.util.Map;
  18 import java.util.Optional;
  19 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
  20 import java.util.concurrent.locks.Lock;
  21 import java.util.concurrent.locks.ReentrantLock;
  22 import java.util.function.BiConsumer;
  23 import java.util.function.Consumer;
  24 import javax.annotation.concurrent.GuardedBy;
  25 import org.opendaylight.controller.cluster.access.client.AbstractClientConnection;
  26 import org.opendaylight.controller.cluster.access.client.ClientActorContext;
  27 import org.opendaylight.controller.cluster.access.client.ConnectedClientConnection;
  28 import org.opendaylight.controller.cluster.access.client.ConnectionEntry;
  29 import org.opendaylight.controller.cluster.access.commands.CreateLocalHistoryRequest;
  30 import org.opendaylight.controller.cluster.access.commands.DestroyLocalHistoryRequest;
  31 import org.opendaylight.controller.cluster.access.commands.LocalHistoryRequest;
  32 import org.opendaylight.controller.cluster.access.commands.PurgeLocalHistoryRequest;
  33 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  34 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  35 import org.opendaylight.controller.cluster.access.concepts.Request;
  36 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  37 import org.opendaylight.controller.cluster.access.concepts.Response;
  38 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  39 import org.opendaylight.yangtools.concepts.Identifiable;
  40 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
  41 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
  42 import org.slf4j.Logger;
  43 import org.slf4j.LoggerFactory;
  44
  45 /**
  46  * Per-connection representation of a local history. This class handles state replication across a single connection.
  47  *
  48  * @author Robert Varga
  49  */
  50 abstract class ProxyHistory implements Identifiable<LocalHistoryIdentifier> {
  51     private abstract static class AbstractLocal extends ProxyHistory {
  52         private final DataTree dataTree;
  53
  54         AbstractLocal(final AbstractClientHistory parent, final AbstractClientConnection<ShardBackendInfo> connection,
  55             final LocalHistoryIdentifier identifier, final DataTree dataTree) {
  56             super(parent, connection, identifier);
  57             this.dataTree = Preconditions.checkNotNull(dataTree);
  58         }
  59
  60         final DataTreeSnapshot takeSnapshot() {
  61             return dataTree.takeSnapshot();
  62         }
  63     }
  64
  65     private abstract static class AbstractRemote extends ProxyHistory {
  66         AbstractRemote(final AbstractClientHistory parent, final AbstractClientConnection<ShardBackendInfo> connection,
  67             final LocalHistoryIdentifier identifier) {
  68             super(parent, connection, identifier);
  69         }
  70     }
  71
  72     private static final class Local extends AbstractLocal {
  73         private static final AtomicReferenceFieldUpdater<Local, LocalReadWriteProxyTransaction> LAST_SEALED_UPDATER =
  74                 AtomicReferenceFieldUpdater.newUpdater(Local.class, LocalReadWriteProxyTransaction.class, "lastSealed");
  75
  76         // Tracks the last open and last sealed transaction. We need to track both in case the user ends up aborting
  77         // the open one and attempts to create a new transaction again.
  78         private LocalReadWriteProxyTransaction lastOpen;
  79
  80         private volatile LocalReadWriteProxyTransaction lastSealed;
  81
  82         Local(final AbstractClientHistory parent, final AbstractClientConnection<ShardBackendInfo> connection,
  83             final LocalHistoryIdentifier identifier, final DataTree dataTree) {
  84             super(parent, connection, identifier, dataTree);
  85         }
  86
  87         @Override
  88         AbstractProxyTransaction doCreateTransactionProxy(final AbstractClientConnection<ShardBackendInfo> connection,
  89                 final TransactionIdentifier txId, final boolean snapshotOnly) {
  90             Preconditions.checkState(lastOpen == null, "Proxy %s has %s currently open", this, lastOpen);
  91
  92             // onTransactionCompleted() runs concurrently
  93             final LocalReadWriteProxyTransaction localSealed = lastSealed;
  94             final DataTreeSnapshot baseSnapshot;
  95             if (localSealed != null) {
  96                 baseSnapshot = localSealed.getSnapshot();
  97             } else {
  98                 baseSnapshot = takeSnapshot();
  99             }
 100
 101             if (snapshotOnly) {
 102                 return new LocalReadOnlyProxyTransaction(this, txId, baseSnapshot);
 103             }
 104
 105             lastOpen = new LocalReadWriteProxyTransaction(this, txId, baseSnapshot);
 106             LOG.debug("Proxy {} open transaction {}", this, lastOpen);
 107             return lastOpen;
 108         }
 109
 110         @Override
 111         ProxyHistory createSuccessor(final AbstractClientConnection<ShardBackendInfo> connection) {
 112             return createClient(parent(), connection, getIdentifier());
 113         }
 114
 115         @Override
 116         void onTransactionAborted(final AbstractProxyTransaction tx) {
 117             if (tx.equals(lastOpen)) {
 118                 lastOpen = null;
 119             }
 120         }
 121
 122         @Override
 123         void onTransactionCompleted(final AbstractProxyTransaction tx) {
 124             Verify.verify(tx instanceof LocalProxyTransaction);
 125             if (tx instanceof LocalReadWriteProxyTransaction) {
 126                 if (LAST_SEALED_UPDATER.compareAndSet(this, (LocalReadWriteProxyTransaction) tx, null)) {
 127                     LOG.debug("Completed last sealed transaction {}", tx);
 128                 }
 129             }
 130         }
 131
 132         @Override
 133         void onTransactionSealed(final AbstractProxyTransaction tx) {
 134             Preconditions.checkState(tx.equals(lastOpen));
 135             lastSealed = lastOpen;
 136             lastOpen = null;
 137         }
 138     }
 139
 140     private static final class LocalSingle extends AbstractLocal {
 141         LocalSingle(final AbstractClientHistory parent, final AbstractClientConnection<ShardBackendInfo> connection,
 142             final LocalHistoryIdentifier identifier, final DataTree dataTree) {
 143             super(parent, connection, identifier, dataTree);
 144         }
 145
 146         @Override
 147         AbstractProxyTransaction doCreateTransactionProxy(final AbstractClientConnection<ShardBackendInfo> connection,
 148                 final TransactionIdentifier txId, final boolean snapshotOnly) {
 149             final DataTreeSnapshot snapshot = takeSnapshot();
 150             return snapshotOnly ? new LocalReadOnlyProxyTransaction(this, txId, snapshot) :
 151                 new LocalReadWriteProxyTransaction(this, txId, snapshot);
 152         }
 153
 154         @Override
 155         ProxyHistory createSuccessor(final AbstractClientConnection<ShardBackendInfo> connection) {
 156             return createSingle(parent(), connection, getIdentifier());
 157         }
 158     }
 159
 160     private static final class Remote extends AbstractRemote {
 161         Remote(final AbstractClientHistory parent, final AbstractClientConnection<ShardBackendInfo> connection,
 162             final LocalHistoryIdentifier identifier) {
 163             super(parent, connection, identifier);
 164         }
 165
 166         @Override
 167         AbstractProxyTransaction doCreateTransactionProxy(final AbstractClientConnection<ShardBackendInfo> connection,
 168                 final TransactionIdentifier txId, final boolean snapshotOnly) {
 169             return new RemoteProxyTransaction(this, txId, snapshotOnly, true);
 170         }
 171
 172         @Override
 173         ProxyHistory createSuccessor(final AbstractClientConnection<ShardBackendInfo> connection) {
 174             return createClient(parent(), connection, getIdentifier());
 175         }
 176     }
 177
 178     private static final class RemoteSingle extends AbstractRemote {
 179         RemoteSingle(final AbstractClientHistory parent, final AbstractClientConnection<ShardBackendInfo> connection,
 180             final LocalHistoryIdentifier identifier) {
 181             super(parent, connection, identifier);
 182         }
 183
 184         @Override
 185         AbstractProxyTransaction doCreateTransactionProxy(final AbstractClientConnection<ShardBackendInfo> connection,
 186                 final TransactionIdentifier txId, final boolean snapshotOnly) {
 187             return new RemoteProxyTransaction(this, txId, snapshotOnly, false);
 188         }
 189
 190         @Override
 191         ProxyHistory createSuccessor(final AbstractClientConnection<ShardBackendInfo> connection) {
 192             return createSingle(parent(), connection, getIdentifier());
 193         }
 194     }
 195
 196     private static final class RequestReplayException extends RequestException {
 197         private static final long serialVersionUID = 1L;
 198
 199         RequestReplayException(final String format, final Object... args) {
 200             super(String.format(format, args));
 201         }
 202
 203         @Override
 204         public boolean isRetriable() {
 205             return false;
 206         }
 207     }
 208
 209     private final class ReconnectCohort extends ProxyReconnectCohort {
 210         @Override
 211         public LocalHistoryIdentifier getIdentifier() {
 212             return identifier;
 213         }
 214
 215         @GuardedBy("lock")
 216         @Override
 217         void replayRequests(final Collection<ConnectionEntry> previousEntries) {
 218             // First look for our Create message
 219             Iterator<ConnectionEntry> it = previousEntries.iterator();
 220             while (it.hasNext()) {
 221                 final ConnectionEntry e = it.next();
 222                 final Request<?, ?> req = e.getRequest();
 223                 if (identifier.equals(req.getTarget())) {
 224                     Verify.verify(req instanceof LocalHistoryRequest);
 225                     if (req instanceof CreateLocalHistoryRequest) {
 226                         successor.connection.enqueueRequest(req, e.getCallback(), e.getEnqueuedTicks());
 227                         it.remove();
 228                         break;
 229                     }
 230                 }
 231             }
 232
 233             for (AbstractProxyTransaction t : proxies.values()) {
 234                 LOG.debug("{} replaying messages to old proxy {} towards successor {}", identifier, t, successor);
 235                 t.replayMessages(successor, previousEntries);
 236             }
 237
 238             // Now look for any finalizing messages
 239             it = previousEntries.iterator();
 240             while (it.hasNext()) {
 241                 final ConnectionEntry e  = it.next();
 242                 final Request<?, ?> req = e.getRequest();
 243                 if (identifier.equals(req.getTarget())) {
 244                     Verify.verify(req instanceof LocalHistoryRequest);
 245                     if (req instanceof DestroyLocalHistoryRequest) {
 246                         successor.connection.enqueueRequest(req, e.getCallback(), e.getEnqueuedTicks());
 247                         it.remove();
 248                         break;
 249                     }
 250                 }
 251             }
 252         }
 253
 254         @GuardedBy("lock")
 255         @Override
 256         ProxyHistory finishReconnect() {
 257             final ProxyHistory ret = Verify.verifyNotNull(successor);
 258
 259             for (AbstractProxyTransaction t : proxies.values()) {
 260                 t.finishReconnect();
 261             }
 262
 263             LOG.debug("Finished reconnecting proxy history {}", this);
 264             lock.unlock();
 265             return ret;
 266         }
 267
 268         @Override
 269         void forwardRequest(final Request<?, ?> request, final Consumer<Response<?, ?>> callback,
 270                 final BiConsumer<Request<?, ?>, Consumer<Response<?, ?>>> forwardTo) throws RequestException {
 271             // FIXME: do not use sendRequest() once we have throttling in place, as we have already waited the
 272             //        period required to get into the queue.
 273             if (request instanceof TransactionRequest) {
 274                 forwardTransactionRequest((TransactionRequest<?>) request, callback);
 275             } else if (request instanceof LocalHistoryRequest) {
 276                 forwardTo.accept(request, callback);
 277             } else {
 278                 throw new IllegalArgumentException("Unhandled request " + request);
 279             }
 280         }
 281
 282         private void forwardTransactionRequest(final TransactionRequest<?> request,
 283                 final Consumer<Response<?, ?>> callback) throws RequestException {
 284
 285             final AbstractProxyTransaction proxy;
 286             lock.lock();
 287             try {
 288                 proxy = proxies.get(request.getTarget());
 289             } finally {
 290                 lock.unlock();
 291             }
 292             if (proxy == null) {
 293                 throw new RequestReplayException("Failed to find proxy for %s", request);
 294             }
 295
 296             proxy.forwardRequest(request, callback);
 297         }
 298     }
 299
 300     private static final Logger LOG = LoggerFactory.getLogger(ProxyHistory.class);
 301
 302     private final Lock lock = new ReentrantLock();
 303     private final LocalHistoryIdentifier identifier;
 304     private final AbstractClientConnection<ShardBackendInfo> connection;
 305     private final AbstractClientHistory parent;
 306
 307     @GuardedBy("lock")
 308     private final Map<TransactionIdentifier, AbstractProxyTransaction> proxies = new LinkedHashMap<>();
 309     @GuardedBy("lock")
 310     private ProxyHistory successor;
 311
 312     private ProxyHistory(final AbstractClientHistory parent,
 313             final AbstractClientConnection<ShardBackendInfo> connection, final LocalHistoryIdentifier identifier) {
 314         this.parent = Preconditions.checkNotNull(parent);
 315         this.connection = Preconditions.checkNotNull(connection);
 316         this.identifier = Preconditions.checkNotNull(identifier);
 317     }
 318
 319     static ProxyHistory createClient(final AbstractClientHistory parent,
 320             final AbstractClientConnection<ShardBackendInfo> connection, final LocalHistoryIdentifier identifier) {
 321         final Optional<DataTree> dataTree = connection.getBackendInfo().flatMap(ShardBackendInfo::getDataTree);
 322         return dataTree.isPresent() ? new Local(parent, connection, identifier, dataTree.get())
 323              : new Remote(parent, connection, identifier);
 324     }
 325
 326     static ProxyHistory createSingle(final AbstractClientHistory parent,
 327             final AbstractClientConnection<ShardBackendInfo> connection,
 328             final LocalHistoryIdentifier identifier) {
 329         final Optional<DataTree> dataTree = connection.getBackendInfo().flatMap(ShardBackendInfo::getDataTree);
 330         return dataTree.isPresent() ? new LocalSingle(parent, connection, identifier, dataTree.get())
 331              : new RemoteSingle(parent, connection, identifier);
 332     }
 333
 334     @Override
 335     public LocalHistoryIdentifier getIdentifier() {
 336         return identifier;
 337     }
 338
 339     final ClientActorContext context() {
 340         return connection.context();
 341     }
 342
 343     final long currentTime() {
 344         return connection.currentTime();
 345     }
 346
 347     final ActorRef localActor() {
 348         return connection.localActor();
 349     }
 350
 351     final AbstractClientHistory parent() {
 352         return parent;
 353     }
 354
 355     AbstractProxyTransaction createTransactionProxy(final TransactionIdentifier txId,
 356             final boolean snapshotOnly) {
 357         lock.lock();
 358         try {
 359             if (successor != null) {
 360                 return successor.createTransactionProxy(txId, snapshotOnly);
 361             }
 362
 363             final TransactionIdentifier proxyId = new TransactionIdentifier(identifier, txId.getTransactionId());
 364             final AbstractProxyTransaction ret = doCreateTransactionProxy(connection, proxyId, snapshotOnly);
 365             proxies.put(proxyId, ret);
 366             LOG.debug("Allocated proxy {} for transaction {}", proxyId, txId);
 367             return ret;
 368         } finally {
 369             lock.unlock();
 370         }
 371     }
 372
 373     final void abortTransaction(final AbstractProxyTransaction tx) {
 374         lock.lock();
 375         try {
 376             // Removal will be completed once purge completes
 377             LOG.debug("Proxy {} aborted transaction {}", this, tx);
 378             onTransactionAborted(tx);
 379         } finally {
 380             lock.unlock();
 381         }
 382     }
 383
 384     final void completeTransaction(final AbstractProxyTransaction tx) {
 385         lock.lock();
 386         try {
 387             proxies.remove(tx.getIdentifier());
 388             LOG.debug("Proxy {} completing transaction {}", this, tx);
 389             onTransactionCompleted(tx);
 390         } finally {
 391             lock.unlock();
 392         }
 393     }
 394
 395     final void close() {
 396         lock.lock();
 397         try {
 398             if (successor != null) {
 399                 successor.close();
 400                 return;
 401             }
 402
 403             LOG.debug("Proxy {} invoking destroy", this);
 404             connection.sendRequest(new DestroyLocalHistoryRequest(getIdentifier(), 1, localActor()),
 405                 this::onDestroyComplete);
 406         } finally {
 407             lock.unlock();
 408         }
 409     }
 410
 411     final void enqueueRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
 412             final long enqueuedTicks) {
 413         connection.enqueueRequest(request, callback, enqueuedTicks);
 414     }
 415
 416     final void sendRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
 417         connection.sendRequest(request, callback);
 418     }
 419
 420     @GuardedBy("lock")
 421     abstract AbstractProxyTransaction doCreateTransactionProxy(AbstractClientConnection<ShardBackendInfo> connection,
 422             TransactionIdentifier txId, boolean snapshotOnly);
 423
 424     abstract ProxyHistory createSuccessor(AbstractClientConnection<ShardBackendInfo> connection);
 425
 426     @SuppressFBWarnings(value = "UL_UNRELEASED_LOCK", justification = "Lock is released asynchronously via the cohort")
 427     ProxyReconnectCohort startReconnect(final ConnectedClientConnection<ShardBackendInfo> newConnection) {
 428         lock.lock();
 429         if (successor != null) {
 430             lock.unlock();
 431             throw new IllegalStateException("Proxy history " + this + " already has a successor");
 432         }
 433
 434         successor = createSuccessor(newConnection);
 435         LOG.debug("History {} instantiated successor {}", this, successor);
 436
 437         for (AbstractProxyTransaction t : proxies.values()) {
 438             t.startReconnect();
 439         }
 440
 441         return new ReconnectCohort();
 442     }
 443
 444     private void onDestroyComplete(final Response<?, ?> response) {
 445         LOG.debug("Proxy {} destroy completed with {}", this, response);
 446
 447         lock.lock();
 448         try {
 449             parent.onProxyDestroyed(this);
 450             connection.sendRequest(new PurgeLocalHistoryRequest(getIdentifier(), 2, localActor()),
 451                 this::onPurgeComplete);
 452         } finally {
 453             lock.unlock();
 454         }
 455     }
 456
 457     private void onPurgeComplete(final Response<?, ?> response) {
 458         LOG.debug("Proxy {} purge completed with {}", this, response);
 459     }
 460
 461     @GuardedBy("lock")
 462     void onTransactionAborted(final AbstractProxyTransaction tx) {
 463         // No-op for most implementations
 464     }
 465
 466     @GuardedBy("lock")
 467     void onTransactionCompleted(final AbstractProxyTransaction tx) {
 468         // No-op for most implementations
 469     }
 470
 471     void onTransactionSealed(final AbstractProxyTransaction tx) {
 472         // No-op on most implementations
 473     }
 474 }