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.ApplyLogEntries;
  20 import org.opendaylight.controller.cluster.raft.base.messages.ApplySnapshot;
  21 import org.opendaylight.controller.cluster.raft.base.messages.DeleteEntries;
  22 import org.opendaylight.controller.cluster.raft.base.messages.UpdateElectionTerm;
  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 ApplyLogEntries) {
  68                 // Handle this message for backwards compatibility with pre-Lithium versions.
  69                 onRecoveredApplyLogEntries(((ApplyLogEntries) message).getToIndex());
  70             } else if (message instanceof ApplyJournalEntries) {
  71                 onRecoveredApplyLogEntries(((ApplyJournalEntries) message).getToIndex());
  72             } else if (message instanceof DeleteEntries) {
  73                 replicatedLog().removeFrom(((DeleteEntries) message).getFromIndex());
  74             } else if (message instanceof org.opendaylight.controller.cluster.raft.RaftActor.DeleteEntries) {
  75                 // Handle this message for backwards compatibility with pre-Lithium versions.
  76                 replicatedLog().removeFrom(((org.opendaylight.controller.cluster.raft.RaftActor.DeleteEntries) message).getFromIndex());
  77             } else if (message instanceof RecoveryCompleted) {
  78                 onRecoveryCompletedMessage();
  79                 possiblyRestoreFromSnapshot();
  80                 recoveryComplete = true;
  81             }
  82         } else if (message instanceof RecoveryCompleted) {
  83             recoveryComplete = true;
  84
  85             if(dataRecoveredWithPersistenceDisabled) {
  86                 // Data persistence is disabled but we recovered some data entries so we must have just
  87                 // transitioned to disabled or a persistence backup was restored. Either way, delete all the
  88                 // messages from the akka journal for efficiency and so that we do not end up with consistency
  89                 // issues in case persistence is -re-enabled.
  90                 persistentProvider.deleteMessages(persistentProvider.getLastSequenceNumber());
  91
  92                 // Delete all the akka snapshots as they will not be needed
  93                 persistentProvider.deleteSnapshots(new SnapshotSelectionCriteria(scala.Long.MaxValue(),
  94                         scala.Long.MaxValue(), 0L, 0L));
  95
  96                 // Since we cleaned out the journal, we need to re-write the current election info.
  97                 context.getTermInformation().updateAndPersist(context.getTermInformation().getCurrentTerm(),
  98                         context.getTermInformation().getVotedFor());
  99             }
 100
 101             possiblyRestoreFromSnapshot();
 102         } else {
 103             boolean isServerConfigPayload = false;
 104             if(message instanceof ReplicatedLogEntry){
 105                 ReplicatedLogEntry repLogEntry = (ReplicatedLogEntry)message;
 106                 if(isServerConfigurationPayload(repLogEntry)){
 107                     isServerConfigPayload = true;
 108                     context.updatePeerIds((ServerConfigurationPayload)repLogEntry.getData());
 109                 }
 110             }
 111
 112             if(!isServerConfigPayload){
 113                 dataRecoveredWithPersistenceDisabled = true;
 114             }
 115         }
 116
 117         return recoveryComplete;
 118     }
 119
 120     private void possiblyRestoreFromSnapshot() {
 121         byte[] restoreFromSnapshot = cohort.getRestoreFromSnapshot();
 122         if(restoreFromSnapshot == null) {
 123             return;
 124         }
 125
 126         if(anyDataRecovered) {
 127             log.warn("{}: The provided restore snapshot was not applied because the persistence store is not empty",
 128                     context.getId());
 129             return;
 130         }
 131
 132         try(ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(restoreFromSnapshot))) {
 133             Snapshot snapshot = (Snapshot) ois.readObject();
 134
 135             log.debug("{}: Deserialized restore snapshot: {}", context.getId(), snapshot);
 136
 137             context.getSnapshotManager().apply(new ApplySnapshot(snapshot));
 138         } catch(Exception e) {
 139             log.error("{}: Error deserializing snapshot restore", context.getId(), e);
 140         }
 141     }
 142
 143     private ReplicatedLog replicatedLog() {
 144         return context.getReplicatedLog();
 145     }
 146
 147     private void initRecoveryTimer() {
 148         if(recoveryTimer == null) {
 149             recoveryTimer = Stopwatch.createStarted();
 150         }
 151     }
 152
 153     private void onRecoveredSnapshot(SnapshotOffer offer) {
 154         if(log.isDebugEnabled()) {
 155             log.debug("{}: SnapshotOffer called..", context.getId());
 156         }
 157
 158         initRecoveryTimer();
 159
 160         Snapshot snapshot = (Snapshot) offer.snapshot();
 161
 162         // Create a replicated log with the snapshot information
 163         // The replicated log can be used later on to retrieve this snapshot
 164         // when we need to install it on a peer
 165
 166         context.setReplicatedLog(ReplicatedLogImpl.newInstance(snapshot, context));
 167         context.setLastApplied(snapshot.getLastAppliedIndex());
 168         context.setCommitIndex(snapshot.getLastAppliedIndex());
 169         context.getTermInformation().update(snapshot.getElectionTerm(), snapshot.getElectionVotedFor());
 170
 171         Stopwatch timer = Stopwatch.createStarted();
 172
 173         // Apply the snapshot to the actors state
 174         cohort.applyRecoverySnapshot(snapshot.getState());
 175
 176         if (snapshot.getServerConfiguration() != null) {
 177             context.updatePeerIds(snapshot.getServerConfiguration());
 178         }
 179
 180         timer.stop();
 181         log.info("Recovery snapshot applied for {} in {}: snapshotIndex={}, snapshotTerm={}, journal-size={}",
 182                 context.getId(), timer.toString(), replicatedLog().getSnapshotIndex(),
 183                 replicatedLog().getSnapshotTerm(), replicatedLog().size());
 184     }
 185
 186     private void onRecoveredJournalLogEntry(ReplicatedLogEntry logEntry) {
 187         if(log.isDebugEnabled()) {
 188             log.debug("{}: Received ReplicatedLogEntry for recovery: index: {}, size: {}", context.getId(),
 189                     logEntry.getIndex(), logEntry.size());
 190         }
 191
 192         if(isServerConfigurationPayload(logEntry)){
 193             context.updatePeerIds((ServerConfigurationPayload)logEntry.getData());
 194         }
 195         replicatedLog().append(logEntry);
 196     }
 197
 198     private void onRecoveredApplyLogEntries(long toIndex) {
 199         long lastUnappliedIndex = context.getLastApplied() + 1;
 200
 201         if(log.isDebugEnabled()) {
 202             // it can happen that lastUnappliedIndex > toIndex, if the AJE is in the persistent journal
 203             // but the entry itself has made it to that state and recovered via the snapshot
 204             log.debug("{}: Received apply journal entries for recovery, applying to state: {} to {}",
 205                     context.getId(), lastUnappliedIndex, toIndex);
 206         }
 207
 208         long lastApplied = lastUnappliedIndex - 1;
 209         for (long i = lastUnappliedIndex; i <= toIndex; i++) {
 210             ReplicatedLogEntry logEntry = replicatedLog().get(i);
 211             if(logEntry != null) {
 212                 lastApplied++;
 213                 batchRecoveredLogEntry(logEntry);
 214             } else {
 215                 // Shouldn't happen but cover it anyway.
 216                 log.error("{}: Log entry not found for index {}", context.getId(), i);
 217                 break;
 218             }
 219         }
 220
 221         context.setLastApplied(lastApplied);
 222         context.setCommitIndex(lastApplied);
 223     }
 224
 225     private void batchRecoveredLogEntry(ReplicatedLogEntry logEntry) {
 226         initRecoveryTimer();
 227
 228         int batchSize = context.getConfigParams().getJournalRecoveryLogBatchSize();
 229         if(!isServerConfigurationPayload(logEntry)){
 230             if(currentRecoveryBatchCount == 0) {
 231                 cohort.startLogRecoveryBatch(batchSize);
 232             }
 233
 234             cohort.appendRecoveredLogEntry(logEntry.getData());
 235
 236             if(++currentRecoveryBatchCount >= batchSize) {
 237                 endCurrentLogRecoveryBatch();
 238             }
 239         }
 240     }
 241
 242     private void endCurrentLogRecoveryBatch() {
 243         cohort.applyCurrentLogRecoveryBatch();
 244         currentRecoveryBatchCount = 0;
 245     }
 246
 247     private void onRecoveryCompletedMessage() {
 248         if(currentRecoveryBatchCount > 0) {
 249             endCurrentLogRecoveryBatch();
 250         }
 251
 252         String recoveryTime = "";
 253         if(recoveryTimer != null) {
 254             recoveryTimer.stop();
 255             recoveryTime = " in " + recoveryTimer.toString();
 256             recoveryTimer = null;
 257         }
 258
 259         log.info("Recovery completed" + recoveryTime + " - Switching actor to Follower - " +
 260                  "Persistence Id =  " + context.getId() +
 261                  " Last index in log = {}, snapshotIndex = {}, snapshotTerm = {}, " +
 262                  "journal-size = {}", replicatedLog().lastIndex(), replicatedLog().getSnapshotIndex(),
 263                  replicatedLog().getSnapshotTerm(), replicatedLog().size());
 264     }
 265
 266     private static boolean isServerConfigurationPayload(ReplicatedLogEntry repLogEntry){
 267         return (repLogEntry.getData() instanceof ServerConfigurationPayload);
 268     }
 269 }