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.opendaylight.controller.cluster.raft.persisted.ServerConfigurationPayload;
  23 import org.slf4j.Logger;
  24
  25 /**
  26  * Support class that handles persistence recovery for a RaftActor.
  27  *
  28  * @author Thomas Pantelis
  29  */
  30 class RaftActorRecoverySupport {
  31     private final RaftActorContext context;
  32     private final RaftActorRecoveryCohort cohort;
  33
  34     private int currentRecoveryBatchCount;
  35     private boolean dataRecoveredWithPersistenceDisabled;
  36     private boolean anyDataRecovered;
  37
  38     private Stopwatch recoveryTimer;
  39     private final Logger log;
  40
  41     RaftActorRecoverySupport(final RaftActorContext context, final RaftActorRecoveryCohort cohort) {
  42         this.context = context;
  43         this.cohort = cohort;
  44         this.log = context.getLogger();
  45     }
  46
  47     boolean handleRecoveryMessage(Object message, PersistentDataProvider persistentProvider) {
  48         log.trace("{}: handleRecoveryMessage: {}", context.getId(), message);
  49
  50         anyDataRecovered = anyDataRecovered || !(message instanceof RecoveryCompleted);
  51
  52         boolean recoveryComplete = false;
  53         DataPersistenceProvider persistence = context.getPersistenceProvider();
  54         if (message instanceof org.opendaylight.controller.cluster.raft.RaftActor.UpdateElectionTerm) {
  55             // Handle this message for backwards compatibility with pre-Lithium versions.
  56             org.opendaylight.controller.cluster.raft.RaftActor.UpdateElectionTerm update =
  57                     (org.opendaylight.controller.cluster.raft.RaftActor.UpdateElectionTerm)message;
  58             context.getTermInformation().update(update.getCurrentTerm(), update.getVotedFor());
  59         } else if (message instanceof UpdateElectionTerm) {
  60             context.getTermInformation().update(((UpdateElectionTerm) message).getCurrentTerm(),
  61                     ((UpdateElectionTerm) message).getVotedFor());
  62         } else if(persistence.isRecoveryApplicable()) {
  63             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                 replicatedLog().removeFrom(((DeleteEntries) message).getFromIndex());
  71             } else if (message instanceof org.opendaylight.controller.cluster.raft.RaftActor.DeleteEntries) {
  72                 // Handle this message for backwards compatibility with pre-Lithium versions.
  73                 replicatedLog().removeFrom(((org.opendaylight.controller.cluster.raft.RaftActor.DeleteEntries) message).getFromIndex());
  74             } else if (message instanceof RecoveryCompleted) {
  75                 onRecoveryCompletedMessage();
  76                 possiblyRestoreFromSnapshot();
  77                 recoveryComplete = true;
  78             }
  79         } else if (message instanceof RecoveryCompleted) {
  80             recoveryComplete = true;
  81
  82             if(dataRecoveredWithPersistenceDisabled) {
  83                 // Data persistence is disabled but we recovered some data entries so we must have just
  84                 // transitioned to disabled or a persistence backup was restored. Either way, delete all the
  85                 // messages from the akka journal for efficiency and so that we do not end up with consistency
  86                 // issues in case persistence is -re-enabled.
  87                 persistentProvider.deleteMessages(persistentProvider.getLastSequenceNumber());
  88
  89                 // Delete all the akka snapshots as they will not be needed
  90                 persistentProvider.deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(),
  91                         scala.Long.MaxValue(), 0L, 0L));
  92
  93                 // Since we cleaned out the journal, we need to re-write the current election info.
  94                 context.getTermInformation().updateAndPersist(context.getTermInformation().getCurrentTerm(),
  95                         context.getTermInformation().getVotedFor());
  96             }
  97
  98             onRecoveryCompletedMessage();
  99             possiblyRestoreFromSnapshot();
 100         } else {
 101             boolean isServerConfigPayload = false;
 102             if(message instanceof ReplicatedLogEntry){
 103                 ReplicatedLogEntry repLogEntry = (ReplicatedLogEntry)message;
 104                 if(isServerConfigurationPayload(repLogEntry)){
 105                     isServerConfigPayload = true;
 106                     context.updatePeerIds((ServerConfigurationPayload)repLogEntry.getData());
 107                 }
 108             }
 109
 110             if(!isServerConfigPayload){
 111                 dataRecoveredWithPersistenceDisabled = true;
 112             }
 113         }
 114
 115         return recoveryComplete;
 116     }
 117
 118     private void possiblyRestoreFromSnapshot() {
 119         byte[] restoreFromSnapshot = cohort.getRestoreFromSnapshot();
 120         if(restoreFromSnapshot == null) {
 121             return;
 122         }
 123
 124         if(anyDataRecovered) {
 125             log.warn("{}: The provided restore snapshot was not applied because the persistence store is not empty",
 126                     context.getId());
 127             return;
 128         }
 129
 130         try(ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(restoreFromSnapshot))) {
 131             Snapshot snapshot = (Snapshot) ois.readObject();
 132
 133             log.debug("{}: Deserialized restore snapshot: {}", context.getId(), snapshot);
 134
 135             context.getSnapshotManager().apply(new ApplySnapshot(snapshot));
 136         } catch(Exception e) {
 137             log.error("{}: Error deserializing snapshot restore", context.getId(), e);
 138         }
 139     }
 140
 141     private ReplicatedLog replicatedLog() {
 142         return context.getReplicatedLog();
 143     }
 144
 145     private void initRecoveryTimer() {
 146         if(recoveryTimer == null) {
 147             recoveryTimer = Stopwatch.createStarted();
 148         }
 149     }
 150
 151     private void onRecoveredSnapshot(SnapshotOffer offer) {
 152         if(log.isDebugEnabled()) {
 153             log.debug("{}: SnapshotOffer called..", context.getId());
 154         }
 155
 156         initRecoveryTimer();
 157
 158         Snapshot snapshot = (Snapshot) offer.snapshot();
 159
 160         // Create a replicated log with the snapshot information
 161         // The replicated log can be used later on to retrieve this snapshot
 162         // when we need to install it on a peer
 163
 164         context.setReplicatedLog(ReplicatedLogImpl.newInstance(snapshot, context));
 165         context.setLastApplied(snapshot.getLastAppliedIndex());
 166         context.setCommitIndex(snapshot.getLastAppliedIndex());
 167         context.getTermInformation().update(snapshot.getElectionTerm(), snapshot.getElectionVotedFor());
 168
 169         Stopwatch timer = Stopwatch.createStarted();
 170
 171         // Apply the snapshot to the actors state
 172         cohort.applyRecoverySnapshot(snapshot.getState());
 173
 174         if (snapshot.getServerConfiguration() != null) {
 175             context.updatePeerIds(snapshot.getServerConfiguration());
 176         }
 177
 178         timer.stop();
 179         log.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size={}",
 180                 context.getId(), timer.toString(), replicatedLog().getSnapshotIndex(),
 181                 replicatedLog().getSnapshotTerm(), replicatedLog().size());
 182     }
 183
 184     private void onRecoveredJournalLogEntry(ReplicatedLogEntry logEntry) {
 185         if(log.isDebugEnabled()) {
 186             log.debug("{}: Received ReplicatedLogEntry for recovery: index: {}, size: {}", context.getId(),
 187                     logEntry.getIndex(), logEntry.size());
 188         }
 189
 190         if(isServerConfigurationPayload(logEntry)){
 191             context.updatePeerIds((ServerConfigurationPayload)logEntry.getData());
 192         }
 193         replicatedLog().append(logEntry);
 194     }
 195
 196     private void onRecoveredApplyLogEntries(long toIndex) {
 197         long lastUnappliedIndex = context.getLastApplied() + 1;
 198
 199         if(log.isDebugEnabled()) {
 200             // it can happen that lastUnappliedIndex > toIndex, if the AJE is in the persistent journal
 201             // but the entry itself has made it to that state and recovered via the snapshot
 202             log.debug("{}: Received apply journal entries for recovery, applying to state: {} to {}",
 203                     context.getId(), lastUnappliedIndex, toIndex);
 204         }
 205
 206         long lastApplied = lastUnappliedIndex - 1;
 207         for (long i = lastUnappliedIndex; i <= toIndex; i++) {
 208             ReplicatedLogEntry logEntry = replicatedLog().get(i);
 209             if(logEntry != null) {
 210                 lastApplied++;
 211                 batchRecoveredLogEntry(logEntry);
 212             } else {
 213                 // Shouldn't happen but cover it anyway.
 214                 log.error("{}: Log entry not found for index {}", context.getId(), i);
 215                 break;
 216             }
 217         }
 218
 219         context.setLastApplied(lastApplied);
 220         context.setCommitIndex(lastApplied);
 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() {
 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 - " +
 258                  "Persistence Id =  " + context.getId() +
 259                  " Last index in log = {}, snapshotIndex = {}, snapshotTerm = {}, " +
 260                  "journal-size = {}", replicatedLog().lastIndex(), replicatedLog().getSnapshotIndex(),
 261                  replicatedLog().getSnapshotTerm(), replicatedLog().size());
 262     }
 263
 264     private static boolean isServerConfigurationPayload(ReplicatedLogEntry repLogEntry){
 265         return (repLogEntry.getData() instanceof ServerConfigurationPayload);
 266     }
 267 }