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