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.util.Collections;
  14 import org.opendaylight.controller.cluster.PersistentDataProvider;
  15 import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
  16 import org.opendaylight.controller.cluster.raft.persisted.ApplyJournalEntries;
  17 import org.opendaylight.controller.cluster.raft.persisted.DeleteEntries;
  18 import org.opendaylight.controller.cluster.raft.persisted.EmptyState;
  19 import org.opendaylight.controller.cluster.raft.persisted.MigratedSerializable;
  20 import org.opendaylight.controller.cluster.raft.persisted.ServerConfigurationPayload;
  21 import org.opendaylight.controller.cluster.raft.persisted.Snapshot;
  22 import org.opendaylight.controller.cluster.raft.persisted.Snapshot.State;
  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(final Object message, final 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         Snapshot 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         log.debug("{}: Restore snapshot: {}", context.getId(), restoreFromSnapshot);
  95
  96         context.getSnapshotManager().apply(new ApplySnapshot(restoreFromSnapshot));
  97     }
  98
  99     private ReplicatedLog replicatedLog() {
 100         return context.getReplicatedLog();
 101     }
 102
 103     private void initRecoveryTimer() {
 104         if (recoveryTimer == null) {
 105             recoveryTimer = Stopwatch.createStarted();
 106         }
 107     }
 108
 109     private void onRecoveredSnapshot(final SnapshotOffer offer) {
 110         log.debug("{}: SnapshotOffer called.", context.getId());
 111
 112         initRecoveryTimer();
 113
 114         Snapshot snapshot = (Snapshot) offer.snapshot();
 115
 116         for (ReplicatedLogEntry entry: snapshot.getUnAppliedEntries()) {
 117             if (isMigratedPayload(entry)) {
 118                 hasMigratedDataRecovered = true;
 119             }
 120         }
 121
 122         if (!context.getPersistenceProvider().isRecoveryApplicable()) {
 123             // We may have just transitioned to disabled and have a snapshot containing state data and/or log
 124             // entries - we don't want to preserve these, only the server config and election term info.
 125
 126             snapshot = Snapshot.create(
 127                     EmptyState.INSTANCE, Collections.emptyList(), -1, -1, -1, -1,
 128                     snapshot.getElectionTerm(), snapshot.getElectionVotedFor(), snapshot.getServerConfiguration());
 129         }
 130
 131         // Create a replicated log with the snapshot information
 132         // The replicated log can be used later on to retrieve this snapshot
 133         // when we need to install it on a peer
 134
 135         context.setReplicatedLog(ReplicatedLogImpl.newInstance(snapshot, context));
 136         context.setLastApplied(snapshot.getLastAppliedIndex());
 137         context.setCommitIndex(snapshot.getLastAppliedIndex());
 138         context.getTermInformation().update(snapshot.getElectionTerm(), snapshot.getElectionVotedFor());
 139
 140         final Stopwatch timer = Stopwatch.createStarted();
 141
 142         // Apply the snapshot to the actors state
 143         final State snapshotState = snapshot.getState();
 144         if (snapshotState.needsMigration()) {
 145             hasMigratedDataRecovered = true;
 146         }
 147         if (!(snapshotState instanceof EmptyState)) {
 148             cohort.applyRecoverySnapshot(snapshotState);
 149         }
 150
 151         if (snapshot.getServerConfiguration() != null) {
 152             context.updatePeerIds(snapshot.getServerConfiguration());
 153         }
 154
 155         timer.stop();
 156         log.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size={}",
 157                 context.getId(), timer, replicatedLog().getSnapshotIndex(), replicatedLog().getSnapshotTerm(),
 158                 replicatedLog().size());
 159     }
 160
 161     private void onRecoveredJournalLogEntry(final ReplicatedLogEntry logEntry) {
 162         if (log.isDebugEnabled()) {
 163             log.debug("{}: Received ReplicatedLogEntry for recovery: index: {}, size: {}", context.getId(),
 164                     logEntry.getIndex(), logEntry.size());
 165         }
 166
 167         if (isServerConfigurationPayload(logEntry)) {
 168             context.updatePeerIds((ServerConfigurationPayload)logEntry.getData());
 169         }
 170
 171         if (isMigratedPayload(logEntry)) {
 172             hasMigratedDataRecovered = true;
 173         }
 174
 175         if (context.getPersistenceProvider().isRecoveryApplicable()) {
 176             replicatedLog().append(logEntry);
 177         } else if (!isPersistentPayload(logEntry)) {
 178             dataRecoveredWithPersistenceDisabled = true;
 179         }
 180     }
 181
 182     private void onRecoveredApplyLogEntries(final long toIndex) {
 183         if (!context.getPersistenceProvider().isRecoveryApplicable()) {
 184             dataRecoveredWithPersistenceDisabled = true;
 185             return;
 186         }
 187
 188         long lastUnappliedIndex = context.getLastApplied() + 1;
 189
 190         if (log.isDebugEnabled()) {
 191             // it can happen that lastUnappliedIndex > toIndex, if the AJE is in the persistent journal
 192             // but the entry itself has made it to that state and recovered via the snapshot
 193             log.debug("{}: Received apply journal entries for recovery, applying to state: {} to {}",
 194                     context.getId(), lastUnappliedIndex, toIndex);
 195         }
 196
 197         long lastApplied = lastUnappliedIndex - 1;
 198         for (long i = lastUnappliedIndex; i <= toIndex; i++) {
 199             ReplicatedLogEntry logEntry = replicatedLog().get(i);
 200             if (logEntry != null) {
 201                 lastApplied++;
 202                 batchRecoveredLogEntry(logEntry);
 203             } else {
 204                 // Shouldn't happen but cover it anyway.
 205                 log.error("{}: Log entry not found for index {}", context.getId(), i);
 206                 break;
 207             }
 208         }
 209
 210         context.setLastApplied(lastApplied);
 211         context.setCommitIndex(lastApplied);
 212     }
 213
 214     private void onDeleteEntries(final DeleteEntries deleteEntries) {
 215         if (context.getPersistenceProvider().isRecoveryApplicable()) {
 216             replicatedLog().removeFrom(deleteEntries.getFromIndex());
 217         } else {
 218             dataRecoveredWithPersistenceDisabled = true;
 219         }
 220     }
 221
 222     private void batchRecoveredLogEntry(final ReplicatedLogEntry logEntry) {
 223         initRecoveryTimer();
 224
 225         int batchSize = context.getConfigParams().getJournalRecoveryLogBatchSize();
 226         if (!isServerConfigurationPayload(logEntry)) {
 227             if (currentRecoveryBatchCount == 0) {
 228                 cohort.startLogRecoveryBatch(batchSize);
 229             }
 230
 231             cohort.appendRecoveredLogEntry(logEntry.getData());
 232
 233             if (++currentRecoveryBatchCount >= batchSize) {
 234                 endCurrentLogRecoveryBatch();
 235             }
 236         }
 237     }
 238
 239     private void endCurrentLogRecoveryBatch() {
 240         cohort.applyCurrentLogRecoveryBatch();
 241         currentRecoveryBatchCount = 0;
 242     }
 243
 244     private void onRecoveryCompletedMessage(final PersistentDataProvider persistentProvider) {
 245         if (currentRecoveryBatchCount > 0) {
 246             endCurrentLogRecoveryBatch();
 247         }
 248
 249         final String recoveryTime;
 250         if (recoveryTimer != null) {
 251             recoveryTime = " in " + recoveryTimer.stop();
 252             recoveryTimer = null;
 253         } else {
 254             recoveryTime = "";
 255         }
 256
 257         log.info("{}: Recovery completed {} - Switching actor to Follower - last log index = {}, last log term = {}, "
 258                 + "snapshot index = {}, snapshot term = {}, journal size = {}", context.getId(), recoveryTime,
 259                 replicatedLog().lastIndex(), replicatedLog().lastTerm(), 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(
 276                     EmptyState.INSTANCE, 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(final ReplicatedLogEntry repLogEntry) {
 294         return repLogEntry.getData() instanceof ServerConfigurationPayload;
 295     }
 296
 297     private static boolean isPersistentPayload(final ReplicatedLogEntry repLogEntry) {
 298         return repLogEntry.getData() instanceof PersistentPayload;
 299     }
 300
 301     private static boolean isMigratedPayload(final ReplicatedLogEntry repLogEntry) {
 302         return isMigratedSerializable(repLogEntry.getData());
 303     }
 304
 305     private static boolean isMigratedSerializable(final Object message) {
 306         return message instanceof MigratedSerializable && ((MigratedSerializable)message).isMigrated();
 307     }
 308 }