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