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