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 akka.persistence.SnapshotSelectionCriteria;
  13 import com.google.common.base.Stopwatch;
  14 import java.io.ByteArrayInputStream;
  15 import java.io.ObjectInputStream;
  16 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  17 import org.opendaylight.controller.cluster.PersistentDataProvider;
  18 import org.opendaylight.controller.cluster.raft.base.messages.ApplyJournalEntries;
  19 import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
  20 import org.opendaylight.controller.cluster.raft.base.messages.DeleteEntries;
  21 import org.opendaylight.controller.cluster.raft.base.messages.UpdateElectionTerm;
  22 import org.slf4j.Logger;
  23
  24 /**
  25  * Support class that handles persistence recovery for a RaftActor.
  26  *
  27  * @author Thomas Pantelis
  28  */
  29 class RaftActorRecoverySupport {
  30     private final RaftActorContext context;
  31     private final RaftActorRecoveryCohort cohort;
  32
  33     private int currentRecoveryBatchCount;
  34     private boolean dataRecoveredWithPersistenceDisabled;
  35     private boolean anyDataRecovered;
  36
  37     private Stopwatch recoveryTimer;
  38     private final Logger log;
  39
  40     RaftActorRecoverySupport(final RaftActorContext context, final RaftActorRecoveryCohort cohort) {
  41         this.context = context;
  42         this.cohort = cohort;
  43         this.log = context.getLogger();
  44     }
  45
  46     boolean handleRecoveryMessage(Object message, PersistentDataProvider persistentProvider) {
  47         log.trace("{}: handleRecoveryMessage: {}", context.getId(), message);
  48
  49         anyDataRecovered = anyDataRecovered || !(message instanceof RecoveryCompleted);
  50
  51         boolean recoveryComplete = false;
  52         DataPersistenceProvider persistence = context.getPersistenceProvider();
  53         if (message instanceof org.opendaylight.controller.cluster.raft.RaftActor.UpdateElectionTerm) {
  54             // Handle this message for backwards compatibility with pre-Lithium versions.
  55             org.opendaylight.controller.cluster.raft.RaftActor.UpdateElectionTerm update =
  56                     (org.opendaylight.controller.cluster.raft.RaftActor.UpdateElectionTerm)message;
  57             context.getTermInformation().update(update.getCurrentTerm(), update.getVotedFor());
  58         } else if (message instanceof UpdateElectionTerm) {
  59             context.getTermInformation().update(((UpdateElectionTerm) message).getCurrentTerm(),
  60                     ((UpdateElectionTerm) message).getVotedFor());
  61         } else if(persistence.isRecoveryApplicable()) {
  62             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                 replicatedLog().removeFrom(((DeleteEntries) message).getFromIndex());
  70             } else if (message instanceof org.opendaylight.controller.cluster.raft.RaftActor.DeleteEntries) {
  71                 // Handle this message for backwards compatibility with pre-Lithium versions.
  72                 replicatedLog().removeFrom(((org.opendaylight.controller.cluster.raft.RaftActor.DeleteEntries) message).getFromIndex());
  73             } else if (message instanceof RecoveryCompleted) {
  74                 onRecoveryCompletedMessage();
  75                 possiblyRestoreFromSnapshot();
  76                 recoveryComplete = true;
  77             }
  78         } else if (message instanceof RecoveryCompleted) {
  79             recoveryComplete = true;
  80
  81             if(dataRecoveredWithPersistenceDisabled) {
  82                 // Data persistence is disabled but we recovered some data entries so we must have just
  83                 // transitioned to disabled or a persistence backup was restored. Either way, delete all the
  84                 // messages from the akka journal for efficiency and so that we do not end up with consistency
  85                 // issues in case persistence is -re-enabled.
  86                 persistentProvider.deleteMessages(persistentProvider.getLastSequenceNumber());
  87
  88                 // Delete all the akka snapshots as they will not be needed
  89                 persistentProvider.deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(),
  90                         scala.Long.MaxValue(), 0L, 0L));
  91
  92                 // Since we cleaned out the journal, we need to re-write the current election info.
  93                 context.getTermInformation().updateAndPersist(context.getTermInformation().getCurrentTerm(),
  94                         context.getTermInformation().getVotedFor());
  95             }
  96
  97             onRecoveryCompletedMessage();
  98             possiblyRestoreFromSnapshot();
  99         } else {
 100             boolean isServerConfigPayload = false;
 101             if(message instanceof ReplicatedLogEntry){
 102                 ReplicatedLogEntry repLogEntry = (ReplicatedLogEntry)message;
 103                 if(isServerConfigurationPayload(repLogEntry)){
 104                     isServerConfigPayload = true;
 105                     context.updatePeerIds((ServerConfigurationPayload)repLogEntry.getData());
 106                 }
 107             }
 108
 109             if(!isServerConfigPayload){
 110                 dataRecoveredWithPersistenceDisabled = true;
 111             }
 112         }
 113
 114         return recoveryComplete;
 115     }
 116
 117     private void possiblyRestoreFromSnapshot() {
 118         byte[] restoreFromSnapshot = cohort.getRestoreFromSnapshot();
 119         if(restoreFromSnapshot == null) {
 120             return;
 121         }
 122
 123         if(anyDataRecovered) {
 124             log.warn("{}: The provided restore snapshot was not applied because the persistence store is not empty",
 125                     context.getId());
 126             return;
 127         }
 128
 129         try(ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(restoreFromSnapshot))) {
 130             Snapshot snapshot = (Snapshot) ois.readObject();
 131
 132             log.debug("{}: Deserialized restore snapshot: {}", context.getId(), snapshot);
 133
 134             context.getSnapshotManager().apply(new ApplySnapshot(snapshot));
 135         } catch(Exception e) {
 136             log.error("{}: Error deserializing snapshot restore", context.getId(), e);
 137         }
 138     }
 139
 140     private ReplicatedLog replicatedLog() {
 141         return context.getReplicatedLog();
 142     }
 143
 144     private void initRecoveryTimer() {
 145         if(recoveryTimer == null) {
 146             recoveryTimer = Stopwatch.createStarted();
 147         }
 148     }
 149
 150     private void onRecoveredSnapshot(SnapshotOffer offer) {
 151         if(log.isDebugEnabled()) {
 152             log.debug("{}: SnapshotOffer called..", context.getId());
 153         }
 154
 155         initRecoveryTimer();
 156
 157         Snapshot snapshot = (Snapshot) offer.snapshot();
 158
 159         // Create a replicated log with the snapshot information
 160         // The replicated log can be used later on to retrieve this snapshot
 161         // when we need to install it on a peer
 162
 163         context.setReplicatedLog(ReplicatedLogImpl.newInstance(snapshot, context));
 164         context.setLastApplied(snapshot.getLastAppliedIndex());
 165         context.setCommitIndex(snapshot.getLastAppliedIndex());
 166         context.getTermInformation().update(snapshot.getElectionTerm(), snapshot.getElectionVotedFor());
 167
 168         Stopwatch timer = Stopwatch.createStarted();
 169
 170         // Apply the snapshot to the actors state
 171         cohort.applyRecoverySnapshot(snapshot.getState());
 172
 173         if (snapshot.getServerConfiguration() != null) {
 174             context.updatePeerIds(snapshot.getServerConfiguration());
 175         }
 176
 177         timer.stop();
 178         log.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size={}",
 179                 context.getId(), timer.toString(), replicatedLog().getSnapshotIndex(),
 180                 replicatedLog().getSnapshotTerm(), replicatedLog().size());
 181     }
 182
 183     private void onRecoveredJournalLogEntry(ReplicatedLogEntry logEntry) {
 184         if(log.isDebugEnabled()) {
 185             log.debug("{}: Received ReplicatedLogEntry for recovery: index: {}, size: {}", context.getId(),
 186                     logEntry.getIndex(), logEntry.size());
 187         }
 188
 189         if(isServerConfigurationPayload(logEntry)){
 190             context.updatePeerIds((ServerConfigurationPayload)logEntry.getData());
 191         }
 192         replicatedLog().append(logEntry);
 193     }
 194
 195     private void onRecoveredApplyLogEntries(long toIndex) {
 196         long lastUnappliedIndex = context.getLastApplied() + 1;
 197
 198         if(log.isDebugEnabled()) {
 199             // it can happen that lastUnappliedIndex > toIndex, if the AJE is in the persistent journal
 200             // but the entry itself has made it to that state and recovered via the snapshot
 201             log.debug("{}: Received apply journal entries for recovery, applying to state: {} to {}",
 202                     context.getId(), lastUnappliedIndex, toIndex);
 203         }
 204
 205         long lastApplied = lastUnappliedIndex - 1;
 206         for (long i = lastUnappliedIndex; i <= toIndex; i++) {
 207             ReplicatedLogEntry logEntry = replicatedLog().get(i);
 208             if(logEntry != null) {
 209                 lastApplied++;
 210                 batchRecoveredLogEntry(logEntry);
 211             } else {
 212                 // Shouldn't happen but cover it anyway.
 213                 log.error("{}: Log entry not found for index {}", context.getId(), i);
 214                 break;
 215             }
 216         }
 217
 218         context.setLastApplied(lastApplied);
 219         context.setCommitIndex(lastApplied);
 220     }
 221
 222     private void batchRecoveredLogEntry(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() {
 245         if(currentRecoveryBatchCount > 0) {
 246             endCurrentLogRecoveryBatch();
 247         }
 248
 249         String recoveryTime = "";
 250         if(recoveryTimer != null) {
 251             recoveryTimer.stop();
 252             recoveryTime = " in " + recoveryTimer.toString();
 253             recoveryTimer = null;
 254         }
 255
 256         log.info("Recovery completed" + recoveryTime + " - Switching actor to Follower - " +
 257                  "Persistence Id =  " + context.getId() +
 258                  " Last index in log = {}, snapshotIndex = {}, snapshotTerm = {}, " +
 259                  "journal-size = {}", replicatedLog().lastIndex(), replicatedLog().getSnapshotIndex(),
 260                  replicatedLog().getSnapshotTerm(), replicatedLog().size());
 261     }
 262
 263     private static boolean isServerConfigurationPayload(ReplicatedLogEntry repLogEntry){
 264         return (repLogEntry.getData() instanceof ServerConfigurationPayload);
 265     }
 266 }