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