Remove followers as an explicit field

[controller.git] / opendaylight / md-sal / sal-akka-raft / src / main / java / org / opendaylight / controller / cluster / raft / behaviors / AbstractLeader.java

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractLeader.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractLeader.java
index 5606453e31be9a9303be5a28652c6e3b0b12caf9..4993d25f202ecee0be55f7ec17b26528924a2e67 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractLeader.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/behaviors/AbstractLeader.java
@@ -14,14 +14,17 @@ 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.collect.ImmutableMap;
+import com.google.common.collect.ImmutableMap.Builder;
 import com.google.protobuf.ByteString;
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
+import java.util.Map.Entry;
 import java.util.concurrent.TimeUnit;
 import org.opendaylight.controller.cluster.raft.ClientRequestTracker;
 import org.opendaylight.controller.cluster.raft.ClientRequestTrackerImpl;
@@ -76,10 +79,8 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
     // This would be passed as the hash code of the last chunk when sending the first chunk
     public static final int INITIAL_LAST_CHUNK_HASH_CODE = -1;
 
-    protected final Map<String, FollowerLogInformation> followerToLog = new HashMap<>();
-    protected final Map<String, FollowerToSnapshot> mapFollowerToSnapshot = new HashMap<>();
-
-    protected final Set<String> followers;
+    private final Map<String, FollowerLogInformation> followerToLog;
+    private final Map<String, FollowerToSnapshot> mapFollowerToSnapshot = new HashMap<>();
 
     private Cancellable heartbeatSchedule = null;
 
@@ -94,24 +95,22 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
     public AbstractLeader(RaftActorContext context) {
         super(context);
 
-        followers = context.getPeerAddresses().keySet();
-
-        for (String followerId : followers) {
+        final Builder<String, FollowerLogInformation> ftlBuilder = ImmutableMap.builder();
+        for (String followerId : context.getPeerAddresses().keySet()) {
             FollowerLogInformation followerLogInformation =
                 new FollowerLogInformationImpl(followerId,
                     context.getCommitIndex(), -1,
                     context.getConfigParams().getElectionTimeOutInterval());
 
-            followerToLog.put(followerId, followerLogInformation);
+            ftlBuilder.put(followerId, followerLogInformation);
         }
+        followerToLog = ftlBuilder.build();
 
         leaderId = context.getId();
 
-        if(LOG.isDebugEnabled()) {
-            LOG.debug("Election:Leader has following peers: {}", followers);
-        }
+        LOG.debug("Election:Leader has following peers: {}", getFollowerIds());
 
-        minReplicationCount = getMajorityVoteCount(followers.size());
+        minReplicationCount = getMajorityVoteCount(getFollowerIds().size());
 
         // the isolated Leader peer count will be 1 less than the majority vote count.
         // this is because the vote count has the self vote counted in it
@@ -130,6 +129,15 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
         scheduleHeartBeat(new FiniteDuration(0, TimeUnit.SECONDS));
     }
 
+    /**
+     * Return an immutable collection of follower identifiers.
+     *
+     * @return Collection of follower IDs
+     */
+    protected final Collection<String> getFollowerIds() {
+        return followerToLog.keySet();
+    }
+
     private Optional<ByteString> getSnapshot() {
         return snapshot;
     }
@@ -374,7 +382,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
                 logIndex)
         );
 
-        if (followers.size() == 0) {
+        if (followerToLog.isEmpty()) {
             context.setCommitIndex(logIndex);
             applyLogToStateMachine(logIndex);
         } else {
@@ -384,7 +392,8 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
 
     private void sendAppendEntries() {
         // Send an AppendEntries to all followers
-        for (String followerId : followers) {
+        for (Entry<String, FollowerLogInformation> e : followerToLog.entrySet()) {
+            final String followerId = e.getKey();
             ActorSelection followerActor = context.getPeerActorSelection(followerId);
 
             if (followerActor != null) {
@@ -471,23 +480,19 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
      *
      */
     private void installSnapshotIfNeeded() {
-        for (String followerId : followers) {
-            ActorSelection followerActor =
-                context.getPeerActorSelection(followerId);
+        for (Entry<String, FollowerLogInformation> e : followerToLog.entrySet()) {
+            final ActorSelection followerActor = context.getPeerActorSelection(e.getKey());
 
-            if(followerActor != null) {
-                FollowerLogInformation followerLogInformation =
-                    followerToLog.get(followerId);
-
-                long nextIndex = followerLogInformation.getNextIndex().get();
+            if (followerActor != null) {
+                long nextIndex = e.getValue().getNextIndex().get();
 
                 if (!context.getReplicatedLog().isPresent(nextIndex) &&
                     context.getReplicatedLog().isInSnapshot(nextIndex)) {
-                    LOG.info("{} follower needs a snapshot install", followerId);
+                    LOG.info("{} follower needs a snapshot install", e.getKey());
                     if (snapshot.isPresent()) {
                         // if a snapshot is present in the memory, most likely another install is in progress
                         // no need to capture snapshot
-                        sendSnapshotChunk(followerActor, followerId);
+                        sendSnapshotChunk(followerActor, e.getKey());
 
                     } else {
                         initiateCaptureSnapshot();
@@ -526,16 +531,15 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
 
 
     private void sendInstallSnapshot() {
-        for (String followerId : followers) {
-            ActorSelection followerActor = context.getPeerActorSelection(followerId);
+        for (Entry<String, FollowerLogInformation> e : followerToLog.entrySet()) {
+            ActorSelection followerActor = context.getPeerActorSelection(e.getKey());
 
-            if(followerActor != null) {
-                FollowerLogInformation followerLogInformation = followerToLog.get(followerId);
-                long nextIndex = followerLogInformation.getNextIndex().get();
+            if (followerActor != null) {
+                long nextIndex = e.getValue().getNextIndex().get();
 
                 if (!context.getReplicatedLog().isPresent(nextIndex) &&
                     context.getReplicatedLog().isInSnapshot(nextIndex)) {
-                    sendSnapshotChunk(followerActor, followerId);
+                    sendSnapshotChunk(followerActor, e.getKey());
                 }
             }
         }
@@ -586,7 +590,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
     }
 
     private void sendHeartBeat() {
-        if (followers.size() > 0) {
+        if (!followerToLog.isEmpty()) {
             sendAppendEntries();
         }
     }
@@ -598,7 +602,7 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
     }
 
     private void scheduleHeartBeat(FiniteDuration interval) {
-        if(followers.size() == 0){
+        if (followerToLog.isEmpty()) {
             // Optimization - do not bother scheduling a heartbeat as there are
             // no followers
             return;
@@ -773,7 +777,22 @@ public abstract class AbstractLeader extends AbstractRaftActorBehavior {
     }
 
     @VisibleForTesting
-    void markFollowerActive(String followerId) {
-        followerToLog.get(followerId).markFollowerActive();
+    public FollowerLogInformation getFollower(String followerId) {
+        return followerToLog.get(followerId);
+    }
+
+    @VisibleForTesting
+    protected void setFollowerSnapshot(String followerId, FollowerToSnapshot snapshot) {
+        mapFollowerToSnapshot.put(followerId, snapshot);
+    }
+
+    @VisibleForTesting
+    public int followerSnapshotSize() {
+        return mapFollowerToSnapshot.size();
+    }
+
+    @VisibleForTesting
+    public int followerLogSize() {
+        return followerToLog.size();
     }
 }