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 appendAndPersist(final ReplicatedLogEntry replicatedLogEntry,
  66             final Procedure<ReplicatedLogEntry> callback)  {
  67
  68         if(context.getLogger().isDebugEnabled()) {
  69             context.getLogger().debug("{}: Append log entry and persist {} ", context.getId(), replicatedLogEntry);
  70         }
  71
  72         // FIXME : By adding the replicated log entry to the in-memory journal we are not truly ensuring durability of the logs
  73         append(replicatedLogEntry);
  74
  75         // When persisting events with persist it is guaranteed that the
  76         // persistent actor will not receive further commands between the
  77         // persist call and the execution(s) of the associated event
  78         // handler. This also holds for multiple persist calls in context
  79         // of a single command.
  80         context.getPersistenceProvider().persist(replicatedLogEntry,
  81             new Procedure<ReplicatedLogEntry>() {
  82                 @Override
  83                 public void apply(ReplicatedLogEntry evt) throws Exception {
  84                     int logEntrySize = replicatedLogEntry.size();
  85
  86                     long dataSizeForCheck = dataSize();
  87
  88                     dataSizeSinceLastSnapshot += logEntrySize;
  89
  90                     if (!context.hasFollowers()) {
  91                         // When we do not have followers we do not maintain an in-memory log
  92                         // due to this the journalSize will never become anything close to the
  93                         // snapshot batch count. In fact will mostly be 1.
  94                         // Similarly since the journal's dataSize depends on the entries in the
  95                         // journal the journal's dataSize will never reach a value close to the
  96                         // memory threshold.
  97                         // By maintaining the dataSize outside the journal we are tracking essentially
  98                         // what we have written to the disk however since we no longer are in
  99                         // need of doing a snapshot just for the sake of freeing up memory we adjust
 100                         // the real size of data by the DATA_SIZE_DIVIDER so that we do not snapshot as often
 101                         // as if we were maintaining a real snapshot
 102                         dataSizeForCheck = dataSizeSinceLastSnapshot / DATA_SIZE_DIVIDER;
 103                     }
 104                     long journalSize = replicatedLogEntry.getIndex() + 1;
 105                     long dataThreshold = context.getTotalMemory() *
 106                             context.getConfigParams().getSnapshotDataThresholdPercentage() / 100;
 107
 108                     if ((journalSize % context.getConfigParams().getSnapshotBatchCount() == 0
 109                             || dataSizeForCheck > dataThreshold)) {
 110
 111                         boolean started = context.getSnapshotManager().capture(replicatedLogEntry,
 112                                 currentBehavior.getReplicatedToAllIndex());
 113
 114                         if(started){
 115                             dataSizeSinceLastSnapshot = 0;
 116                         }
 117                     }
 118
 119                     if (callback != null){
 120                         callback.apply(replicatedLogEntry);
 121                     }
 122                 }
 123             }
 124         );
 125     }
 126 }