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