opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/ReplicatedLogImpl.java

   1 /*
   2  * Copyright (c) 2015 Cisco 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.japi.Procedure;
  11 import java.util.Collections;
  12 import java.util.List;
  13 import org.opendaylight.controller.cluster.DataPersistenceProvider;
  14 import org.opendaylight.controller.cluster.raft.RaftActor.DeleteEntries;
  15 import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
  16
  17 /**
  18  * Implementation of ReplicatedLog used by the RaftActor.
  19  */
  20 class ReplicatedLogImpl extends AbstractReplicatedLogImpl {
  21     private static final int DATA_SIZE_DIVIDER = 5;
  22
  23     private long dataSizeSinceLastSnapshot = 0L;
  24     private final RaftActorContext context;
  25     private final DataPersistenceProvider persistence;
  26     private final RaftActorBehavior currentBehavior;
  27
  28     private final Procedure<DeleteEntries> deleteProcedure = new Procedure<DeleteEntries>() {
  29         @Override
  30         public void apply(DeleteEntries param) {
  31             dataSize = 0;
  32             for (ReplicatedLogEntry entry : journal) {
  33                 dataSize += entry.size();
  34             }
  35         }
  36     };
  37
  38     static ReplicatedLog newInstance(Snapshot snapshot, RaftActorContext context,
  39             DataPersistenceProvider persistence, RaftActorBehavior currentBehavior) {
  40         return new ReplicatedLogImpl(snapshot.getLastAppliedIndex(), snapshot.getLastAppliedTerm(),
  41                 snapshot.getUnAppliedEntries(), context, persistence, currentBehavior);
  42     }
  43
  44     static ReplicatedLog newInstance(RaftActorContext context,
  45             DataPersistenceProvider persistence, RaftActorBehavior currentBehavior) {
  46         return new ReplicatedLogImpl(-1L, -1L, Collections.<ReplicatedLogEntry>emptyList(), context,
  47                 persistence, currentBehavior);
  48     }
  49
  50     private ReplicatedLogImpl(long snapshotIndex, long snapshotTerm, List<ReplicatedLogEntry> unAppliedEntries,
  51             RaftActorContext context, DataPersistenceProvider persistence, RaftActorBehavior currentBehavior) {
  52         super(snapshotIndex, snapshotTerm, unAppliedEntries);
  53         this.context = context;
  54         this.persistence = persistence;
  55         this.currentBehavior = currentBehavior;
  56     }
  57
  58     @Override
  59     public void removeFromAndPersist(long logEntryIndex) {
  60         int adjustedIndex = adjustedIndex(logEntryIndex);
  61
  62         if (adjustedIndex < 0) {
  63             return;
  64         }
  65
  66         // FIXME: Maybe this should be done after the command is saved
  67         journal.subList(adjustedIndex , journal.size()).clear();
  68
  69         persistence.persist(new DeleteEntries(adjustedIndex), deleteProcedure);
  70     }
  71
  72     @Override
  73     public void appendAndPersist(final ReplicatedLogEntry replicatedLogEntry) {
  74         appendAndPersist(replicatedLogEntry, null);
  75     }
  76
  77     @Override
  78     public void appendAndPersist(final ReplicatedLogEntry replicatedLogEntry,
  79             final Procedure<ReplicatedLogEntry> callback)  {
  80
  81         if(context.getLogger().isDebugEnabled()) {
  82             context.getLogger().debug("{}: Append log entry and persist {} ", context.getId(), replicatedLogEntry);
  83         }
  84
  85         // FIXME : By adding the replicated log entry to the in-memory journal we are not truly ensuring durability of the logs
  86         journal.add(replicatedLogEntry);
  87
  88         // When persisting events with persist it is guaranteed that the
  89         // persistent actor will not receive further commands between the
  90         // persist call and the execution(s) of the associated event
  91         // handler. This also holds for multiple persist calls in context
  92         // of a single command.
  93         persistence.persist(replicatedLogEntry,
  94             new Procedure<ReplicatedLogEntry>() {
  95                 @Override
  96                 public void apply(ReplicatedLogEntry evt) throws Exception {
  97                     int logEntrySize = replicatedLogEntry.size();
  98
  99                     dataSize += logEntrySize;
 100                     long dataSizeForCheck = dataSize;
 101
 102                     dataSizeSinceLastSnapshot += logEntrySize;
 103
 104                     if (!context.hasFollowers()) {
 105                         // When we do not have followers we do not maintain an in-memory log
 106                         // due to this the journalSize will never become anything close to the
 107                         // snapshot batch count. In fact will mostly be 1.
 108                         // Similarly since the journal's dataSize depends on the entries in the
 109                         // journal the journal's dataSize will never reach a value close to the
 110                         // memory threshold.
 111                         // By maintaining the dataSize outside the journal we are tracking essentially
 112                         // what we have written to the disk however since we no longer are in
 113                         // need of doing a snapshot just for the sake of freeing up memory we adjust
 114                         // the real size of data by the DATA_SIZE_DIVIDER so that we do not snapshot as often
 115                         // as if we were maintaining a real snapshot
 116                         dataSizeForCheck = dataSizeSinceLastSnapshot / DATA_SIZE_DIVIDER;
 117                     }
 118                     long journalSize = replicatedLogEntry.getIndex() + 1;
 119                     long dataThreshold = context.getTotalMemory() *
 120                             context.getConfigParams().getSnapshotDataThresholdPercentage() / 100;
 121
 122                     if ((journalSize % context.getConfigParams().getSnapshotBatchCount() == 0
 123                             || dataSizeForCheck > dataThreshold)) {
 124
 125                         boolean started = context.getSnapshotManager().capture(replicatedLogEntry,
 126                                 currentBehavior.getReplicatedToAllIndex());
 127
 128                         if(started){
 129                             dataSizeSinceLastSnapshot = 0;
 130                         }
 131                     }
 132
 133                     if (callback != null){
 134                         callback.apply(replicatedLogEntry);
 135                     }
 136                 }
 137             }
 138         );
 139     }
 140 }