opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorRecoverySupport.java

   1 /*
   2  * Copyright (c) 2015 Brocade Communications 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.raft;
   9
  10 import akka.persistence.RecoveryCompleted;
  11 import akka.persistence.SnapshotOffer;
  12 import com.google.common.base.Stopwatch;
  13 import java.io.ByteArrayInputStream;
  14 import java.io.IOException;
  15 import java.io.ObjectInputStream;
  16 import java.util.Collections;
  17 import org.opendaylight.controller.cluster.PersistentDataProvider;
  18 import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
  19 import org.opendaylight.controller.cluster.raft.persisted.ApplyJournalEntries;
  20 import org.opendaylight.controller.cluster.raft.persisted.DeleteEntries;
  21 import org.opendaylight.controller.cluster.raft.persisted.EmptyState;
  22 import org.opendaylight.controller.cluster.raft.persisted.MigratedSerializable;
  23 import org.opendaylight.controller.cluster.raft.persisted.ServerConfigurationPayload;
  24 import org.opendaylight.controller.cluster.raft.persisted.Snapshot;
  25 import org.opendaylight.controller.cluster.raft.persisted.UpdateElectionTerm;
  26 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.PersistentPayload;
  27 import org.slf4j.Logger;
  28
  29 /**
  30  * Support class that handles persistence recovery for a RaftActor.
  31  *
  32  * @author Thomas Pantelis
  33  */
  34 class RaftActorRecoverySupport {
  35     private final RaftActorContext context;
  36     private final RaftActorRecoveryCohort cohort;
  37
  38     private int currentRecoveryBatchCount;
  39     private boolean dataRecoveredWithPersistenceDisabled;
  40     private boolean anyDataRecovered;
  41     private boolean hasMigratedDataRecovered;
  42
  43     private Stopwatch recoveryTimer;
  44     private final Logger log;
  45
  46     RaftActorRecoverySupport(final RaftActorContext context, final RaftActorRecoveryCohort cohort) {
  47         this.context = context;
  48         this.cohort = cohort;
  49         this.log = context.getLogger();
  50     }
  51
  52     boolean handleRecoveryMessage(Object message, PersistentDataProvider persistentProvider) {
  53         log.trace("{}: handleRecoveryMessage: {}", context.getId(), message);
  54
  55         anyDataRecovered = anyDataRecovered || !(message instanceof RecoveryCompleted);
  56
  57         if (isMigratedSerializable(message)) {
  58             hasMigratedDataRecovered = true;
  59         }
  60
  61         boolean recoveryComplete = false;
  62         if (message instanceof UpdateElectionTerm) {
  63             context.getTermInformation().update(((UpdateElectionTerm) message).getCurrentTerm(),
  64                     ((UpdateElectionTerm) message).getVotedFor());
  65         } else if (message instanceof SnapshotOffer) {
  66             onRecoveredSnapshot((SnapshotOffer) message);
  67         } else if (message instanceof ReplicatedLogEntry) {
  68             onRecoveredJournalLogEntry((ReplicatedLogEntry) message);
  69         } else if (message instanceof ApplyJournalEntries) {
  70             onRecoveredApplyLogEntries(((ApplyJournalEntries) message).getToIndex());
  71         } else if (message instanceof DeleteEntries) {
  72             onDeleteEntries((DeleteEntries) message);
  73         } else if (message instanceof ServerConfigurationPayload) {
  74             context.updatePeerIds((ServerConfigurationPayload)message);
  75         } else if (message instanceof RecoveryCompleted) {
  76             recoveryComplete = true;
  77             onRecoveryCompletedMessage(persistentProvider);
  78         }
  79
  80         return recoveryComplete;
  81     }
  82
  83     @SuppressWarnings("checkstyle:IllegalCatch")
  84     private void possiblyRestoreFromSnapshot() {
  85         byte[] restoreFromSnapshot = cohort.getRestoreFromSnapshot();
  86         if (restoreFromSnapshot == null) {
  87             return;
  88         }
  89
  90         if (anyDataRecovered) {
  91             log.warn("{}: The provided restore snapshot was not applied because the persistence store is not empty",
  92                     context.getId());
  93             return;
  94         }
  95
  96         try (ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(restoreFromSnapshot))) {
  97             Snapshot snapshot = (Snapshot) ois.readObject();
  98
  99             log.debug("{}: Deserialized restore snapshot: {}", context.getId(), snapshot);
 100
 101             context.getSnapshotManager().apply(new ApplySnapshot(snapshot));
 102         } catch (RuntimeException | ClassNotFoundException | IOException e) {
 103             log.error("{}: Error deserializing snapshot restore", context.getId(), e);
 104         }
 105     }
 106
 107     private ReplicatedLog replicatedLog() {
 108         return context.getReplicatedLog();
 109     }
 110
 111     private void initRecoveryTimer() {
 112         if (recoveryTimer == null) {
 113             recoveryTimer = Stopwatch.createStarted();
 114         }
 115     }
 116
 117     private void onRecoveredSnapshot(SnapshotOffer offer) {
 118         log.debug("{}: SnapshotOffer called.", context.getId());
 119
 120         initRecoveryTimer();
 121
 122         Object snapshotObj = offer.snapshot();
 123         Snapshot snapshot;
 124         if (snapshotObj instanceof org.opendaylight.controller.cluster.raft.Snapshot) {
 125             org.opendaylight.controller.cluster.raft.Snapshot legacy =
 126                     (org.opendaylight.controller.cluster.raft.Snapshot)snapshotObj;
 127             snapshot = Snapshot.create(cohort.deserializePreCarbonSnapshot(legacy.getState()),
 128                     legacy.getUnAppliedEntries(), legacy.getLastIndex(), legacy.getLastTerm(),
 129                     legacy.getLastAppliedIndex(), legacy.getLastAppliedTerm(),
 130                     legacy.getElectionTerm(), legacy.getElectionVotedFor(), legacy.getServerConfiguration());
 131             hasMigratedDataRecovered = true;
 132         } else {
 133             snapshot = (Snapshot) offer.snapshot();
 134         }
 135
 136         for (ReplicatedLogEntry entry: snapshot.getUnAppliedEntries()) {
 137             if (isMigratedPayload(entry)) {
 138                 hasMigratedDataRecovered = true;
 139             }
 140         }
 141
 142         if (!context.getPersistenceProvider().isRecoveryApplicable()) {
 143             // We may have just transitioned to disabled and have a snapshot containing state data and/or log
 144             // entries - we don't want to preserve these, only the server config and election term info.
 145
 146             snapshot = Snapshot.create(
 147                     EmptyState.INSTANCE, Collections.emptyList(), -1, -1, -1, -1,
 148                     snapshot.getElectionTerm(), snapshot.getElectionVotedFor(), snapshot.getServerConfiguration());
 149         }
 150
 151         // Create a replicated log with the snapshot information
 152         // The replicated log can be used later on to retrieve this snapshot
 153         // when we need to install it on a peer
 154
 155         context.setReplicatedLog(ReplicatedLogImpl.newInstance(snapshot, context));
 156         context.setLastApplied(snapshot.getLastAppliedIndex());
 157         context.setCommitIndex(snapshot.getLastAppliedIndex());
 158         context.getTermInformation().update(snapshot.getElectionTerm(), snapshot.getElectionVotedFor());
 159
 160         Stopwatch timer = Stopwatch.createStarted();
 161
 162         // Apply the snapshot to the actors state
 163         if (!(snapshot.getState() instanceof EmptyState)) {
 164             cohort.applyRecoverySnapshot(snapshot.getState());
 165         }
 166
 167         if (snapshot.getServerConfiguration() != null) {
 168             context.updatePeerIds(snapshot.getServerConfiguration());
 169
 170             if (isMigratedSerializable(snapshot.getServerConfiguration())) {
 171                 hasMigratedDataRecovered = true;
 172             }
 173         }
 174
 175         timer.stop();
 176         log.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size={}",
 177                 context.getId(), timer.toString(), replicatedLog().getSnapshotIndex(),
 178                 replicatedLog().getSnapshotTerm(), replicatedLog().size());
 179     }
 180
 181     private void onRecoveredJournalLogEntry(ReplicatedLogEntry logEntry) {
 182         if (log.isDebugEnabled()) {
 183             log.debug("{}: Received ReplicatedLogEntry for recovery: index: {}, size: {}", context.getId(),
 184                     logEntry.getIndex(), logEntry.size());
 185         }
 186
 187         if (isServerConfigurationPayload(logEntry)) {
 188             context.updatePeerIds((ServerConfigurationPayload)logEntry.getData());
 189         }
 190
 191         if (isMigratedPayload(logEntry)) {
 192             hasMigratedDataRecovered = true;
 193         }
 194
 195         if (context.getPersistenceProvider().isRecoveryApplicable()) {
 196             replicatedLog().append(logEntry);
 197         } else if (!isPersistentPayload(logEntry)) {
 198             dataRecoveredWithPersistenceDisabled = true;
 199         }
 200     }
 201
 202     private void onRecoveredApplyLogEntries(long toIndex) {
 203         if (!context.getPersistenceProvider().isRecoveryApplicable()) {
 204             dataRecoveredWithPersistenceDisabled = true;
 205             return;
 206         }
 207
 208         long lastUnappliedIndex = context.getLastApplied() + 1;
 209
 210         if (log.isDebugEnabled()) {
 211             // it can happen that lastUnappliedIndex > toIndex, if the AJE is in the persistent journal
 212             // but the entry itself has made it to that state and recovered via the snapshot
 213             log.debug("{}: Received apply journal entries for recovery, applying to state: {} to {}",
 214                     context.getId(), lastUnappliedIndex, toIndex);
 215         }
 216
 217         long lastApplied = lastUnappliedIndex - 1;
 218         for (long i = lastUnappliedIndex; i <= toIndex; i++) {
 219             ReplicatedLogEntry logEntry = replicatedLog().get(i);
 220             if (logEntry != null) {
 221                 lastApplied++;
 222                 batchRecoveredLogEntry(logEntry);
 223             } else {
 224                 // Shouldn't happen but cover it anyway.
 225                 log.error("{}: Log entry not found for index {}", context.getId(), i);
 226                 break;
 227             }
 228         }
 229
 230         context.setLastApplied(lastApplied);
 231         context.setCommitIndex(lastApplied);
 232     }
 233
 234     private void onDeleteEntries(DeleteEntries deleteEntries) {
 235         if (context.getPersistenceProvider().isRecoveryApplicable()) {
 236             replicatedLog().removeFrom(deleteEntries.getFromIndex());
 237         } else {
 238             dataRecoveredWithPersistenceDisabled = true;
 239         }
 240     }
 241
 242     private void batchRecoveredLogEntry(ReplicatedLogEntry logEntry) {
 243         initRecoveryTimer();
 244
 245         int batchSize = context.getConfigParams().getJournalRecoveryLogBatchSize();
 246         if (!isServerConfigurationPayload(logEntry)) {
 247             if (currentRecoveryBatchCount == 0) {
 248                 cohort.startLogRecoveryBatch(batchSize);
 249             }
 250
 251             cohort.appendRecoveredLogEntry(logEntry.getData());
 252
 253             if (++currentRecoveryBatchCount >= batchSize) {
 254                 endCurrentLogRecoveryBatch();
 255             }
 256         }
 257     }
 258
 259     private void endCurrentLogRecoveryBatch() {
 260         cohort.applyCurrentLogRecoveryBatch();
 261         currentRecoveryBatchCount = 0;
 262     }
 263
 264     private void onRecoveryCompletedMessage(PersistentDataProvider persistentProvider) {
 265         if (currentRecoveryBatchCount > 0) {
 266             endCurrentLogRecoveryBatch();
 267         }
 268
 269         String recoveryTime = "";
 270         if (recoveryTimer != null) {
 271             recoveryTimer.stop();
 272             recoveryTime = " in " + recoveryTimer.toString();
 273             recoveryTimer = null;
 274         }
 275
 276         log.info("Recovery completed" + recoveryTime + " - Switching actor to Follower - " + "Persistence Id =  "
 277                   + context.getId() + " Last index in log = {}, snapshotIndex = {}, snapshotTerm = {}, "
 278                   + "journal-size = {}", replicatedLog().lastIndex(), replicatedLog().getSnapshotIndex(),
 279                  replicatedLog().getSnapshotTerm(), replicatedLog().size());
 280
 281         if (dataRecoveredWithPersistenceDisabled
 282                 || hasMigratedDataRecovered && !context.getPersistenceProvider().isRecoveryApplicable()) {
 283             if (hasMigratedDataRecovered) {
 284                 log.info("{}: Saving snapshot after recovery due to migrated messages", context.getId());
 285             } else {
 286                 log.info("{}: Saving snapshot after recovery due to data persistence disabled", context.getId());
 287             }
 288
 289             // Either data persistence is disabled and we recovered some data entries (ie we must have just
 290             // transitioned to disabled or a persistence backup was restored) or we recovered migrated
 291             // messages. Either way, we persist a snapshot and delete all the messages from the akka journal
 292             // to clean out unwanted messages.
 293
 294             Snapshot snapshot = Snapshot.create(
 295                     EmptyState.INSTANCE, Collections.<ReplicatedLogEntry>emptyList(),
 296                     -1, -1, -1, -1,
 297                     context.getTermInformation().getCurrentTerm(), context.getTermInformation().getVotedFor(),
 298                     context.getPeerServerInfo(true));
 299
 300             persistentProvider.saveSnapshot(snapshot);
 301
 302             persistentProvider.deleteMessages(persistentProvider.getLastSequenceNumber());
 303         } else if (hasMigratedDataRecovered) {
 304             log.info("{}: Snapshot capture initiated after recovery due to migrated messages", context.getId());
 305
 306             context.getSnapshotManager().capture(replicatedLog().last(), -1);
 307         } else {
 308             possiblyRestoreFromSnapshot();
 309         }
 310     }
 311
 312     private static boolean isServerConfigurationPayload(ReplicatedLogEntry repLogEntry) {
 313         return repLogEntry.getData() instanceof ServerConfigurationPayload;
 314     }
 315
 316     private static boolean isPersistentPayload(ReplicatedLogEntry repLogEntry) {
 317         return repLogEntry.getData() instanceof PersistentPayload;
 318     }
 319
 320     private static boolean isMigratedPayload(ReplicatedLogEntry repLogEntry) {
 321         return isMigratedSerializable(repLogEntry.getData());
 322     }
 323
 324     private static boolean isMigratedSerializable(Object message) {
 325         return message instanceof MigratedSerializable && ((MigratedSerializable)message).isMigrated();
 326     }
 327 }