Send commitIndex updates to followers as soon as possible
[controller.git] / opendaylight / md-sal / sal-akka-raft / src / main / java / org / opendaylight / controller / cluster / raft / behaviors / AbstractLeader.java
index fbdfd49a3ff48c9c8eaee2012fbc2c7ff0460286..4ce84bd11f8ed8edccc4d8699a5202850dbef5be 100644 (file)
@@ -5,16 +5,17 @@
  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
  * and is available at http://www.eclipse.org/legal/epl-v10.html
  */
-
 package org.opendaylight.controller.cluster.raft.behaviors;
 
+import static java.util.Objects.requireNonNull;
+
 import akka.actor.ActorRef;
 import akka.actor.ActorSelection;
 import akka.actor.Cancellable;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Optional;
-import com.google.common.base.Preconditions;
 import com.google.common.io.ByteSource;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.io.IOException;
 import java.io.ObjectOutputStream;
 import java.util.Collection;
@@ -27,7 +28,7 @@ import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Queue;
 import java.util.concurrent.TimeUnit;
-import javax.annotation.Nullable;
+import org.eclipse.jdt.annotation.Nullable;
 import org.opendaylight.controller.cluster.io.SharedFileBackedOutputStream;
 import org.opendaylight.controller.cluster.messaging.MessageSlicer;
 import org.opendaylight.controller.cluster.messaging.SliceOptions;
@@ -101,7 +102,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
     private int minReplicationCount;
 
     protected AbstractLeader(final RaftActorContext context, final RaftState state,
-            @Nullable final AbstractLeader initializeFromLeader) {
+            final @Nullable AbstractLeader initializeFromLeader) {
         super(context, state);
 
         appendEntriesMessageSlicer = MessageSlicer.builder().logContext(logName())
@@ -184,7 +185,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
     }
 
     @VisibleForTesting
-    void setSnapshotHolder(@Nullable final SnapshotHolder snapshotHolder) {
+    void setSnapshotHolder(final @Nullable SnapshotHolder snapshotHolder) {
         this.snapshotHolder = Optional.fromNullable(snapshotHolder);
     }
 
@@ -455,7 +456,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
 
     @Override
     public RaftActorBehavior handleMessage(final ActorRef sender, final Object message) {
-        Preconditions.checkNotNull(sender, "sender should not be null");
+        requireNonNull(sender, "sender should not be null");
 
         if (appendEntriesMessageSlicer.handleMessage(message)) {
             return this;
@@ -511,6 +512,8 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
         return this;
     }
 
+    @SuppressFBWarnings(value = "NP_NULL_PARAM_DEREF_ALL_TARGETS_DANGEROUS",
+            justification = "JDT nullness with SpotBugs at setSnapshotHolder(null)")
     private void handleInstallSnapshotReply(final InstallSnapshotReply reply) {
         log.debug("{}: handleInstallSnapshotReply: {}", logName(), reply);
 
@@ -530,6 +533,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
             return;
         }
 
+        installSnapshotState.resetChunkTimer();
         followerLogInformation.markFollowerActive();
 
         if (installSnapshotState.getChunkIndex() == reply.getChunkIndex()) {
@@ -661,10 +665,19 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
 
             LeaderInstallSnapshotState installSnapshotState = followerLogInformation.getInstallSnapshotState();
             if (installSnapshotState != null) {
+
                 // if install snapshot is in process , then sent next chunk if possible
-                if (isFollowerActive && installSnapshotState.canSendNextChunk()) {
-                    sendSnapshotChunk(followerActor, followerLogInformation);
-                } else if (sendHeartbeat) {
+                if (isFollowerActive) {
+                    // 30 seconds with default settings, can be modified via heartbeat or election timeout factor
+                    FiniteDuration snapshotReplyTimeout = context.getConfigParams().getHeartBeatInterval()
+                            .$times(context.getConfigParams().getElectionTimeoutFactor() * 3);
+
+                    if (installSnapshotState.isChunkTimedOut(snapshotReplyTimeout)) {
+                        sendAppendEntries = !resendSnapshotChunk(followerActor, followerLogInformation);
+                    } else if (installSnapshotState.canSendNextChunk()) {
+                        sendSnapshotChunk(followerActor, followerLogInformation);
+                    }
+                } else if (sendHeartbeat || followerLogInformation.hasStaleCommitIndex(context.getCommitIndex())) {
                     // we send a heartbeat even if we have not received a reply for the last chunk
                     sendAppendEntries = true;
                 }
@@ -685,7 +698,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
                     log.debug("{}: sendAppendEntries: {} is present for follower {}", logName(),
                             followerNextIndex, followerId);
 
-                    if (followerLogInformation.okToReplicate()) {
+                    if (followerLogInformation.okToReplicate(context.getCommitIndex())) {
                         entries = getEntriesToSend(followerLogInformation, followerActor);
                         sendAppendEntries = true;
                     }
@@ -713,7 +726,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
                                 context.getReplicatedLog().size());
                     }
 
-                } else if (sendHeartbeat) {
+                } else if (sendHeartbeat || followerLogInformation.hasStaleCommitIndex(context.getCommitIndex())) {
                     // we send an AppendEntries, even if the follower is inactive
                     // in-order to update the followers timestamp, in case it becomes active again
                     sendAppendEntries = true;
@@ -824,6 +837,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
                     appendEntries);
         }
 
+        followerLogInformation.setSentCommitIndex(leaderCommitIndex);
         followerActor.tell(appendEntries, actor());
     }
 
@@ -928,18 +942,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
                     serverConfig = Optional.fromNullable(context.getPeerServerInfo(true));
                 }
 
-                followerActor.tell(
-                    new InstallSnapshot(currentTerm(), context.getId(),
-                        snapshotHolder.get().getLastIncludedIndex(),
-                        snapshotHolder.get().getLastIncludedTerm(),
-                        nextSnapshotChunk,
-                        nextChunkIndex,
-                        installSnapshotState.getTotalChunks(),
-                        Optional.of(installSnapshotState.getLastChunkHashCode()),
-                        serverConfig
-                    ).toSerializable(followerLogInfo.getRaftVersion()),
-                    actor()
-                );
+                sendSnapshotChunk(followerActor, followerLogInfo, nextSnapshotChunk, nextChunkIndex, serverConfig);
 
             } catch (IOException e) {
                 throw new RuntimeException(e);
@@ -950,6 +953,46 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
         }
     }
 
+    private void sendSnapshotChunk(final ActorSelection followerActor, final FollowerLogInformation followerLogInfo,
+                                   final byte[] snapshotChunk, final int chunkIndex,
+                                   final Optional<ServerConfigurationPayload> serverConfig) {
+        LeaderInstallSnapshotState installSnapshotState = followerLogInfo.getInstallSnapshotState();
+
+        installSnapshotState.startChunkTimer();
+        followerActor.tell(
+                new InstallSnapshot(currentTerm(), context.getId(),
+                        snapshotHolder.get().getLastIncludedIndex(),
+                        snapshotHolder.get().getLastIncludedTerm(),
+                        snapshotChunk,
+                        chunkIndex,
+                        installSnapshotState.getTotalChunks(),
+                        Optional.of(installSnapshotState.getLastChunkHashCode()),
+                        serverConfig
+                ).toSerializable(followerLogInfo.getRaftVersion()),
+                actor()
+        );
+    }
+
+    private boolean resendSnapshotChunk(final ActorSelection followerActor,
+                                        final FollowerLogInformation followerLogInfo) {
+        if (!snapshotHolder.isPresent()) {
+            // Seems like we should never hit this case, but just in case we do, reset the snapshot progress so that it
+            // can restart from the next AppendEntries.
+            log.warn("{}: Attempting to resend snapshot with no snapshot holder present.", logName());
+            followerLogInfo.clearLeaderInstallSnapshotState();
+            return false;
+        }
+
+        LeaderInstallSnapshotState installSnapshotState = followerLogInfo.getInstallSnapshotState();
+        // we are resending, timer needs to be reset
+        installSnapshotState.resetChunkTimer();
+        installSnapshotState.markSendStatus(false);
+
+        sendSnapshotChunk(followerActor, followerLogInfo);
+
+        return true;
+    }
+
     private void sendHeartBeat() {
         if (!followerToLog.isEmpty()) {
             log.trace("{}: Sending heartbeat", logName());