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             possiblyRestoreFromSnapshot();
  98         } else {
  99             boolean isServerConfigPayload = false;
 100             if(message instanceof ReplicatedLogEntry){
 101                 ReplicatedLogEntry repLogEntry = (ReplicatedLogEntry)message;
 102                 if(isServerConfigurationPayload(repLogEntry)){
 103                     isServerConfigPayload = true;
 104                     context.updatePeerIds((ServerConfigurationPayload)repLogEntry.getData());
 105                 }
 106             }
 107
 108             if(!isServerConfigPayload){
 109                 dataRecoveredWithPersistenceDisabled = true;
 110             }
 111         }
 112
 113         return recoveryComplete;
 114     }
 115
 116     private void possiblyRestoreFromSnapshot() {
 117         byte[] restoreFromSnapshot = cohort.getRestoreFromSnapshot();
 118         if(restoreFromSnapshot == null) {
 119             return;
 120         }
 121
 122         if(anyDataRecovered) {
 123             log.warn("{}: The provided restore snapshot was not applied because the persistence store is not empty",
 124                     context.getId());
 125             return;
 126         }
 127
 128         try(ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(restoreFromSnapshot))) {
 129             Snapshot snapshot = (Snapshot) ois.readObject();
 130
 131             log.debug("{}: Deserialized restore snapshot: {}", context.getId(), snapshot);
 132
 133             context.getSnapshotManager().apply(new ApplySnapshot(snapshot));
 134         } catch(Exception e) {
 135             log.error("{}: Error deserializing snapshot restore", context.getId(), e);
 136         }
 137     }
 138
 139     private ReplicatedLog replicatedLog() {
 140         return context.getReplicatedLog();
 141     }
 142
 143     private void initRecoveryTimer() {
 144         if(recoveryTimer == null) {
 145             recoveryTimer = Stopwatch.createStarted();
 146         }
 147     }
 148
 149     private void onRecoveredSnapshot(SnapshotOffer offer) {
 150         if(log.isDebugEnabled()) {
 151             log.debug("{}: SnapshotOffer called..", context.getId());
 152         }
 153
 154         initRecoveryTimer();
 155
 156         Snapshot snapshot = (Snapshot) offer.snapshot();
 157
 158         // Create a replicated log with the snapshot information
 159         // The replicated log can be used later on to retrieve this snapshot
 160         // when we need to install it on a peer
 161
 162         context.setReplicatedLog(ReplicatedLogImpl.newInstance(snapshot, context));
 163         context.setLastApplied(snapshot.getLastAppliedIndex());
 164         context.setCommitIndex(snapshot.getLastAppliedIndex());
 165         context.getTermInformation().update(snapshot.getElectionTerm(), snapshot.getElectionVotedFor());
 166
 167         Stopwatch timer = Stopwatch.createStarted();
 168
 169         // Apply the snapshot to the actors state
 170         cohort.applyRecoverySnapshot(snapshot.getState());
 171
 172         if (snapshot.getServerConfiguration() != null) {
 173             context.updatePeerIds(snapshot.getServerConfiguration());
 174         }
 175
 176         timer.stop();
 177         log.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size={}",
 178                 context.getId(), timer.toString(), replicatedLog().getSnapshotIndex(),
 179                 replicatedLog().getSnapshotTerm(), replicatedLog().size());
 180     }
 181
 182     private void onRecoveredJournalLogEntry(ReplicatedLogEntry logEntry) {
 183         if(log.isDebugEnabled()) {
 184             log.debug("{}: Received ReplicatedLogEntry for recovery: index: {}, size: {}", context.getId(),
 185                     logEntry.getIndex(), logEntry.size());
 186         }
 187
 188         if(isServerConfigurationPayload(logEntry)){
 189             context.updatePeerIds((ServerConfigurationPayload)logEntry.getData());
 190         }
 191         replicatedLog().append(logEntry);
 192     }
 193
 194     private void onRecoveredApplyLogEntries(long toIndex) {
 195         long lastUnappliedIndex = context.getLastApplied() + 1;
 196
 197         if(log.isDebugEnabled()) {
 198             // it can happen that lastUnappliedIndex > toIndex, if the AJE is in the persistent journal
 199             // but the entry itself has made it to that state and recovered via the snapshot
 200             log.debug("{}: Received apply journal entries for recovery, applying to state: {} to {}",
 201                     context.getId(), lastUnappliedIndex, toIndex);
 202         }
 203
 204         long lastApplied = lastUnappliedIndex - 1;
 205         for (long i = lastUnappliedIndex; i <= toIndex; i++) {
 206             ReplicatedLogEntry logEntry = replicatedLog().get(i);
 207             if(logEntry != null) {
 208                 lastApplied++;
 209                 batchRecoveredLogEntry(logEntry);
 210             } else {
 211                 // Shouldn't happen but cover it anyway.
 212                 log.error("{}: Log entry not found for index {}", context.getId(), i);
 213                 break;
 214             }
 215         }
 216
 217         context.setLastApplied(lastApplied);
 218         context.setCommitIndex(lastApplied);
 219     }
 220
 221     private void batchRecoveredLogEntry(ReplicatedLogEntry logEntry) {
 222         initRecoveryTimer();
 223
 224         int batchSize = context.getConfigParams().getJournalRecoveryLogBatchSize();
 225         if(!isServerConfigurationPayload(logEntry)){
 226             if(currentRecoveryBatchCount == 0) {
 227                 cohort.startLogRecoveryBatch(batchSize);
 228             }
 229
 230             cohort.appendRecoveredLogEntry(logEntry.getData());
 231
 232             if(++currentRecoveryBatchCount >= batchSize) {
 233                 endCurrentLogRecoveryBatch();
 234             }
 235         }
 236     }
 237
 238     private void endCurrentLogRecoveryBatch() {
 239         cohort.applyCurrentLogRecoveryBatch();
 240         currentRecoveryBatchCount = 0;
 241     }
 242
 243     private void onRecoveryCompletedMessage() {
 244         if(currentRecoveryBatchCount > 0) {
 245             endCurrentLogRecoveryBatch();
 246         }
 247
 248         String recoveryTime = "";
 249         if(recoveryTimer != null) {
 250             recoveryTimer.stop();
 251             recoveryTime = " in " + recoveryTimer.toString();
 252             recoveryTimer = null;
 253         }
 254
 255         log.info("Recovery completed" + recoveryTime + " - Switching actor to Follower - " +
 256                  "Persistence Id =  " + context.getId() +
 257                  " Last index in log = {}, snapshotIndex = {}, snapshotTerm = {}, " +
 258                  "journal-size = {}", replicatedLog().lastIndex(), replicatedLog().getSnapshotIndex(),
 259                  replicatedLog().getSnapshotTerm(), replicatedLog().size());
 260     }
 261
 262     private static boolean isServerConfigurationPayload(ReplicatedLogEntry repLogEntry){
 263         return (repLogEntry.getData() instanceof ServerConfigurationPayload);
 264     }
 265 }