Implement ChangeServersVotingStatus message in RafActor

Added a new ChangeServersVotingStatus message to change servers to/from
voting members. The leader updates its local peer info and persists and
replicates a new ServerConfigurationPayload with the appropriate voting
states. If the leader changes to non-voting it steps down as leader by
initiating a leadership transfer.

Change-Id: If073e4665cb1a270aae6e3dce36a6b3e900d0282
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActor.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActor.java
index aea1e9fad427a114ec99cd884de7c3c8c80dd7e0..92b3ff80ace9c426dcccc4f388053f10015abb63 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActor.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActor.java
@@ -268,7 +268,7 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
         }
     }
 
-    private void initiateLeadershipTransfer(final RaftActorLeadershipTransferCohort.OnComplete onComplete) {
+    void initiateLeadershipTransfer(final RaftActorLeadershipTransferCohort.OnComplete onComplete) {
         LOG.debug("{}: Initiating leader transfer", persistenceId());
 
         if(leadershipTransferInProgress == null) {

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java
index 960ef15a6f7888792454699c987a93b023e37115..e78f39cdb1be0db11a39b1a91255effa5c3dc0aa 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupport.java
@@ -12,16 +12,23 @@ import akka.actor.ActorSelection;
 import akka.actor.Cancellable;
 import com.google.common.base.Preconditions;
 import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
 import java.util.Queue;
 import java.util.UUID;
 import javax.annotation.Nullable;
+import org.opendaylight.controller.cluster.raft.RaftActorLeadershipTransferCohort.OnComplete;
+import org.opendaylight.controller.cluster.raft.ServerConfigurationPayload.ServerInfo;
 import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
 import org.opendaylight.controller.cluster.raft.base.messages.SnapshotComplete;
 import org.opendaylight.controller.cluster.raft.behaviors.AbstractLeader;
 import org.opendaylight.controller.cluster.raft.messages.AddServer;
 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
+import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
+import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 import org.opendaylight.controller.cluster.raft.messages.UnInitializedFollowerSnapshotReply;
@@ -59,6 +66,9 @@ class RaftActorServerConfigurationSupport {
         } else if(message instanceof RemoveServer) {
             onRemoveServer((RemoveServer) message, sender);
             return true;
+        } else if(message instanceof ChangeServersVotingStatus) {
+            onChangeServersVotingStatus((ChangeServersVotingStatus) message, sender);
+            return true;
         } else if (message instanceof ServerOperationTimeout) {
             currentOperationState.onServerOperationTimeout((ServerOperationTimeout) message);
             return true;
@@ -75,6 +85,13 @@ class RaftActorServerConfigurationSupport {
         }
     }
 
+    private void onChangeServersVotingStatus(ChangeServersVotingStatus message, ActorRef sender) {
+        LOG.debug("{}: onChangeServersVotingStatus: {}, state: {}", raftContext.getId(), message,
+                currentOperationState);
+
+        onNewOperation(new ChangeServersVotingStatusContext(message, sender));
+    }
+
     private void onRemoveServer(RemoveServer removeServer, ActorRef sender) {
         LOG.debug("{}: onRemoveServer: {}, state: {}", raftContext.getId(), removeServer, currentOperationState);
         boolean isSelf = removeServer.getServerId().equals(raftActor.getId());
@@ -183,13 +200,14 @@ class RaftActorServerConfigurationSupport {
         protected void persistNewServerConfiguration(ServerOperationContext<?> operationContext){
             raftContext.setDynamicServerConfigurationInUse();
 
-            boolean includeSelf = !operationContext.getServerId().equals(raftActor.getId());
-            ServerConfigurationPayload payload = raftContext.getPeerServerInfo(includeSelf);
+            ServerConfigurationPayload payload = raftContext.getPeerServerInfo(
+                    operationContext.includeSelfInNewConfiguration(raftActor));
             LOG.debug("{}: New server configuration : {}", raftContext.getId(), payload.getServerConfig());
 
             raftActor.persistData(operationContext.getClientRequestor(), operationContext.getContextId(), payload);
 
-            currentOperationState = new Persisting(operationContext, newTimer(new ServerOperationTimeout(operationContext.getServerId())));
+            currentOperationState = new Persisting(operationContext, newTimer(new ServerOperationTimeout(
+                    operationContext.getLoggingContext())));
 
             sendReply(operationContext, ServerChangeStatus.OK);
         }
@@ -199,7 +217,7 @@ class RaftActorServerConfigurationSupport {
                 sendReply(operationContext, replyStatus);
             }
 
-            operationContext.operationComplete(raftActor, replyStatus);
+            operationContext.operationComplete(raftActor, replyStatus == null || replyStatus == ServerChangeStatus.OK);
 
             currentOperationState = IDLE;
 
@@ -272,7 +290,7 @@ class RaftActorServerConfigurationSupport {
         @Override
         public void onServerOperationTimeout(ServerOperationTimeout timeout) {
             LOG.warn("{}: Timeout occured while replicating the new server configuration for {}", raftContext.getId(),
-                    timeout.getServerId());
+                    timeout.getLoggingContext());
 
             timedOut = true;
 
@@ -313,7 +331,7 @@ class RaftActorServerConfigurationSupport {
         }
 
         void handleInstallSnapshotTimeout(ServerOperationTimeout timeout) {
-            String serverId = timeout.getServerId();
+            String serverId = timeout.getLoggingContext();
 
             LOG.debug("{}: handleInstallSnapshotTimeout for new server {}", raftContext.getId(), serverId);
 
@@ -398,7 +416,7 @@ class RaftActorServerConfigurationSupport {
             handleInstallSnapshotTimeout(timeout);
 
             LOG.warn("{}: Timeout occured for new server {} while installing snapshot", raftContext.getId(),
-                    timeout.getServerId());
+                    timeout.getLoggingContext());
         }
 
         @Override
@@ -463,7 +481,7 @@ class RaftActorServerConfigurationSupport {
             handleInstallSnapshotTimeout(timeout);
 
             LOG.warn("{}: Timeout occured for new server {} while waiting for prior snapshot to complete",
-                    raftContext.getId(), timeout.getServerId());
+                    raftContext.getId(), timeout.getLoggingContext());
         }
     }
 
@@ -495,13 +513,18 @@ class RaftActorServerConfigurationSupport {
             return clientRequestor;
         }
 
+        void operationComplete(RaftActor raftActor, boolean succeeded) {
+        }
+
+        boolean includeSelfInNewConfiguration(RaftActor raftActor) {
+            return true;
+        }
+
         abstract Object newReply(ServerChangeStatus status, String leaderId);
 
         abstract InitialOperationState newInitialOperationState(RaftActorServerConfigurationSupport support);
 
-        abstract void operationComplete(RaftActor raftActor, ServerChangeStatus serverChangeStatus);
-
-        abstract String getServerId();
+        abstract String getLoggingContext();
     }
 
     /**
@@ -523,12 +546,7 @@ class RaftActorServerConfigurationSupport {
         }
 
         @Override
-        void operationComplete(RaftActor raftActor, ServerChangeStatus serverChangeStatus) {
-
-        }
-
-        @Override
-        String getServerId() {
+        String getLoggingContext() {
             return getOperation().getNewServerId();
         }
     }
@@ -581,27 +599,113 @@ class RaftActorServerConfigurationSupport {
         }
 
         @Override
-        void operationComplete(RaftActor raftActor, ServerChangeStatus serverChangeStatus) {
+        void operationComplete(RaftActor raftActor, boolean succeeded) {
             if(peerAddress != null) {
                 raftActor.context().actorSelection(peerAddress).tell(new ServerRemoved(getOperation().getServerId()), raftActor.getSelf());
             }
         }
 
         @Override
-        String getServerId() {
+        boolean includeSelfInNewConfiguration(RaftActor raftActor) {
+            return !getOperation().getServerId().equals(raftActor.getId());
+        }
+
+        @Override
+        String getLoggingContext() {
             return getOperation().getServerId();
         }
     }
 
+    private static class ChangeServersVotingStatusContext extends ServerOperationContext<ChangeServersVotingStatus> {
+        ChangeServersVotingStatusContext(ChangeServersVotingStatus convertMessage, ActorRef clientRequestor) {
+            super(convertMessage, clientRequestor);
+        }
+
+        @Override
+        InitialOperationState newInitialOperationState(RaftActorServerConfigurationSupport support) {
+            return support.new ChangeServersVotingStatusState(this);
+        }
+
+        @Override
+        Object newReply(ServerChangeStatus status, String leaderId) {
+            return new ServerChangeReply(status, leaderId);
+        }
+
+        @Override
+        void operationComplete(final RaftActor raftActor, boolean succeeded) {
+            // If this leader changed to non-voting we need to step down as leader so we'll try to transfer
+            // leadership.
+            boolean localServerChangedToNonVoting = Boolean.FALSE.equals(getOperation().
+                    getServerVotingStatusMap().get(raftActor.getRaftActorContext().getId()));
+            if(succeeded && localServerChangedToNonVoting && raftActor.isLeader()) {
+                raftActor.initiateLeadershipTransfer(new OnComplete() {
+                    @Override
+                    public void onSuccess(ActorRef raftActorRef, ActorRef replyTo) {
+                        LOG.debug("{}: leader transfer succeeded after change to non-voting", raftActor.persistenceId());
+                        ensureFollowerState(raftActor);
+                    }
+
+                    @Override
+                    public void onFailure(ActorRef raftActorRef, ActorRef replyTo) {
+                        LOG.debug("{}: leader transfer failed after change to non-voting", raftActor.persistenceId());
+                        ensureFollowerState(raftActor);
+                    }
+
+                    private void ensureFollowerState(RaftActor raftActor) {
+                        // Whether or not leadership transfer succeeded, we have to step down as leader and
+                        // switch to Follower so ensure that.
+                        if(raftActor.getRaftState() != RaftState.Follower) {
+                            raftActor.initializeBehavior();
+                        }
+                    }
+                });
+            }
+        }
+
+        @Override
+        String getLoggingContext() {
+            return getOperation().getServerVotingStatusMap().toString();
+        }
+    }
+
+    private class ChangeServersVotingStatusState extends OperationState implements InitialOperationState {
+        private final ChangeServersVotingStatusContext changeVotingStatusContext;
+
+        ChangeServersVotingStatusState(ChangeServersVotingStatusContext changeVotingStatusContext) {
+            this.changeVotingStatusContext = changeVotingStatusContext;
+        }
+
+        @Override
+        public void initiate() {
+            LOG.debug("Initiating ChangeServersVotingStatusState");
+
+            Map<String, Boolean> serverVotingStatusMap = changeVotingStatusContext.getOperation().getServerVotingStatusMap();
+            List<ServerInfo> newServerInfoList = new ArrayList<>();
+            for(String peerId: raftContext.getPeerIds()) {
+                newServerInfoList.add(new ServerInfo(peerId, serverVotingStatusMap.containsKey(peerId) ?
+                        serverVotingStatusMap.get(peerId) : raftContext.getPeerInfo(peerId).isVoting()));
+            }
+
+            newServerInfoList.add(new ServerInfo(raftContext.getId(), serverVotingStatusMap.containsKey(
+                    raftContext.getId()) ? serverVotingStatusMap.get(raftContext.getId()) : raftContext.isVotingMember()));
+
+            raftContext.updatePeerIds(new ServerConfigurationPayload(newServerInfoList));
+            AbstractLeader leader = (AbstractLeader) raftActor.getCurrentBehavior();
+            leader.updateMinReplicaCount();
+
+            persistNewServerConfiguration(changeVotingStatusContext);
+        }
+    }
+
     static class ServerOperationTimeout {
-        private final String serverId;
+        private final String loggingContext;
 
-        ServerOperationTimeout(String serverId){
-           this.serverId = Preconditions.checkNotNull(serverId, "serverId should not be null");
+        ServerOperationTimeout(String loggingContext){
+           this.loggingContext = Preconditions.checkNotNull(loggingContext, "loggingContext should not be null");
         }
 
-        String getServerId() {
-            return serverId;
+        String getLoggingContext() {
+            return loggingContext;
         }
     }
 }

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/ChangeServersVotingStatus.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/ChangeServersVotingStatus.java
new file mode 100644 (file)
index 0000000..0f46012
--- /dev/null
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/ChangeServersVotingStatus.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2016 Brocade Communications Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * 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.messages;
+
+import com.google.common.base.Preconditions;
+import java.io.Serializable;
+import java.util.HashMap;
+import java.util.Map;
+import javax.annotation.Nonnull;
+
+/**
+ * Message sent to change the raft voting status for servers.
+ *
+ * @author Thomas Pantelis
+ */
+public class ChangeServersVotingStatus implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final Map<String, Boolean> serverVotingStatusMap;
+
+    public ChangeServersVotingStatus(@Nonnull Map<String, Boolean> serverVotingStatusMap) {
+        this.serverVotingStatusMap = new HashMap<>(Preconditions.checkNotNull(serverVotingStatusMap));
+    }
+
+    public Map<String, Boolean> getServerVotingStatusMap() {
+        return serverVotingStatusMap;
+    }
+
+    @Override
+    public String toString() {
+        return "ChangeServersVotingStatus [serverVotingStatusMap=" + serverVotingStatusMap + "]";
+    }
+}

diff --git a/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/ServerChangeReply.java b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/ServerChangeReply.java
new file mode 100644 (file)
index 0000000..4757b0b
--- /dev/null
+++ b/opendaylight/md-sal/sal-akka-raft/src/main/java/org/opendaylight/controller/cluster/raft/messages/ServerChangeReply.java
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2016 Brocade Communications Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * 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.messages;
+
+/**
+ * A general server change reply.
+ *
+ * @author Thomas Pantelis
+ */
+public class ServerChangeReply extends AbstractServerChangeReply {
+    private static final long serialVersionUID = 1L;
+
+    public ServerChangeReply(ServerChangeStatus status, String leaderHint) {
+        super(status, leaderHint);
+    }
+}

diff --git a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java
index 36f6fe7b1a4647d0db5e0b83482234be675321a0..3bf328bc167a001c64b33c3e905d1e5fe30f9697 100644 (file)
--- a/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java
+++ b/opendaylight/md-sal/sal-akka-raft/src/test/java/org/opendaylight/controller/cluster/raft/RaftActorServerConfigurationSupportTest.java
@@ -9,6 +9,7 @@ package org.opendaylight.controller.cluster.raft;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 import static org.opendaylight.controller.cluster.raft.utils.MessageCollectorActor.assertNoneMatching;
 import static org.opendaylight.controller.cluster.raft.utils.MessageCollectorActor.clearMessages;
 import static org.opendaylight.controller.cluster.raft.utils.MessageCollectorActor.expectFirstMatching;
@@ -20,6 +21,7 @@ import akka.dispatch.Dispatchers;
 import akka.testkit.JavaTestKit;
 import akka.testkit.TestActorRef;
 import com.google.common.base.Optional;
+import com.google.common.base.Stopwatch;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
@@ -44,9 +46,11 @@ import org.opendaylight.controller.cluster.raft.behaviors.RaftActorBehavior;
 import org.opendaylight.controller.cluster.raft.messages.AddServer;
 import org.opendaylight.controller.cluster.raft.messages.AddServerReply;
 import org.opendaylight.controller.cluster.raft.messages.AppendEntries;
+import org.opendaylight.controller.cluster.raft.messages.ChangeServersVotingStatus;
 import org.opendaylight.controller.cluster.raft.messages.InstallSnapshot;
 import org.opendaylight.controller.cluster.raft.messages.RemoveServer;
 import org.opendaylight.controller.cluster.raft.messages.RemoveServerReply;
+import org.opendaylight.controller.cluster.raft.messages.ServerChangeReply;
 import org.opendaylight.controller.cluster.raft.messages.ServerChangeStatus;
 import org.opendaylight.controller.cluster.raft.messages.ServerRemoved;
 import org.opendaylight.controller.cluster.raft.messages.UnInitializedFollowerSnapshotReply;
@@ -67,6 +71,7 @@ import scala.concurrent.duration.FiniteDuration;
 public class RaftActorServerConfigurationSupportTest extends AbstractActorTest {
     static final String LEADER_ID = "leader";
     static final String FOLLOWER_ID = "follower";
+    static final String FOLLOWER_ID2 = "follower2";
     static final String NEW_SERVER_ID = "new-server";
     static final String NEW_SERVER_ID2 = "new-server2";
     private static final Logger LOG = LoggerFactory.getLogger(RaftActorServerConfigurationSupportTest.class);
@@ -838,6 +843,155 @@ public class RaftActorServerConfigurationSupportTest extends AbstractActorTest {
         assertEquals("getStatus", ServerChangeStatus.NOT_SUPPORTED, removeServerReply.getStatus());
     }
 
+    @Test
+    public void testChangeServersVotingStatus() {
+        DefaultConfigParamsImpl configParams = new DefaultConfigParamsImpl();
+        configParams.setHeartBeatInterval(new FiniteDuration(1, TimeUnit.DAYS));
+        configParams.setCustomRaftPolicyImplementationClass(DisableElectionsRaftPolicy.class.getName());
+
+        final String follower1ActorId = actorFactory.generateActorId(FOLLOWER_ID);
+        final String follower1ActorPath = actorFactory.createTestActorPath(follower1ActorId);
+        final String follower2ActorId = actorFactory.generateActorId(FOLLOWER_ID2);
+        final String follower2ActorPath = actorFactory.createTestActorPath(follower2ActorId);
+
+        TestActorRef<MockLeaderRaftActor> leaderActor = actorFactory.createTestActor(
+                MockLeaderRaftActor.props(ImmutableMap.of(FOLLOWER_ID, follower1ActorPath,
+                        FOLLOWER_ID2, follower2ActorPath), new MockRaftActorContext()).
+                        withDispatcher(Dispatchers.DefaultDispatcherId()), actorFactory.generateActorId(LEADER_ID));
+        TestActorRef<MessageCollectorActor> leaderCollector = newLeaderCollectorActor(leaderActor.underlyingActor());
+
+        TestActorRef<CollectingMockRaftActor> follower1RaftActor = actorFactory.createTestActor(
+                CollectingMockRaftActor.props(FOLLOWER_ID, ImmutableMap.of(LEADER_ID, leaderActor.path().toString(),
+                        FOLLOWER_ID2, follower2ActorPath), configParams, NO_PERSISTENCE).
+                        withDispatcher(Dispatchers.DefaultDispatcherId()), follower1ActorId);
+        TestActorRef<MessageCollectorActor> follower1Collector = actorFactory.createTestActor(
+                MessageCollectorActor.props().withDispatcher(Dispatchers.DefaultDispatcherId()),
+                actorFactory.generateActorId("collector"));
+        follower1RaftActor.underlyingActor().setCollectorActor(follower1Collector);
+
+        TestActorRef<CollectingMockRaftActor> follower2RaftActor = actorFactory.createTestActor(
+                CollectingMockRaftActor.props(FOLLOWER_ID2, ImmutableMap.of(LEADER_ID, leaderActor.path().toString(),
+                        FOLLOWER_ID, follower1ActorPath), configParams, NO_PERSISTENCE).
+                        withDispatcher(Dispatchers.DefaultDispatcherId()), follower2ActorId);
+        TestActorRef<MessageCollectorActor> follower2Collector = actorFactory.createTestActor(
+                MessageCollectorActor.props().withDispatcher(Dispatchers.DefaultDispatcherId()),
+                actorFactory.generateActorId("collector"));
+        follower2RaftActor.underlyingActor().setCollectorActor(follower2Collector);
+
+        // Send first ChangeServersVotingStatus message
+
+        leaderActor.tell(new ChangeServersVotingStatus(ImmutableMap.of(FOLLOWER_ID, false, FOLLOWER_ID2, false)),
+                testKit.getRef());
+        ServerChangeReply reply = testKit.expectMsgClass(JavaTestKit.duration("5 seconds"), ServerChangeReply.class);
+        assertEquals("getStatus", ServerChangeStatus.OK, reply.getStatus());
+
+        final ApplyState applyState = MessageCollectorActor.expectFirstMatching(leaderCollector, ApplyState.class);
+        assertEquals(0L, applyState.getReplicatedLogEntry().getIndex());
+        verifyServerConfigurationPayloadEntry(leaderActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                votingServer(LEADER_ID), nonVotingServer(FOLLOWER_ID), nonVotingServer(FOLLOWER_ID2));
+
+        MessageCollectorActor.expectFirstMatching(follower1Collector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(follower1RaftActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                votingServer(LEADER_ID), nonVotingServer(FOLLOWER_ID), nonVotingServer(FOLLOWER_ID2));
+
+        MessageCollectorActor.expectFirstMatching(follower2Collector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(follower2RaftActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                votingServer(LEADER_ID), nonVotingServer(FOLLOWER_ID), nonVotingServer(FOLLOWER_ID2));
+
+        MessageCollectorActor.clearMessages(leaderCollector);
+        MessageCollectorActor.clearMessages(follower1Collector);
+        MessageCollectorActor.clearMessages(follower2Collector);
+
+        // Send second ChangeServersVotingStatus message
+
+        leaderActor.tell(new ChangeServersVotingStatus(ImmutableMap.of(FOLLOWER_ID, true)), testKit.getRef());
+        reply = testKit.expectMsgClass(JavaTestKit.duration("5 seconds"), ServerChangeReply.class);
+        assertEquals("getStatus", ServerChangeStatus.OK, reply.getStatus());
+
+        MessageCollectorActor.expectFirstMatching(leaderCollector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(leaderActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                votingServer(LEADER_ID), votingServer(FOLLOWER_ID), nonVotingServer(FOLLOWER_ID2));
+
+        MessageCollectorActor.expectFirstMatching(follower1Collector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(follower1RaftActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                votingServer(LEADER_ID), votingServer(FOLLOWER_ID), nonVotingServer(FOLLOWER_ID2));
+
+        MessageCollectorActor.expectFirstMatching(follower2Collector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(follower2RaftActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                votingServer(LEADER_ID), votingServer(FOLLOWER_ID), nonVotingServer(FOLLOWER_ID2));
+    }
+
+    @Test
+    public void testChangeLeaderToNonVoting() {
+        DefaultConfigParamsImpl configParams = new DefaultConfigParamsImpl();
+        configParams.setHeartBeatInterval(new FiniteDuration(500, TimeUnit.MILLISECONDS));
+
+        final String follower1ActorId = actorFactory.generateActorId(FOLLOWER_ID);
+        final String follower1ActorPath = actorFactory.createTestActorPath(follower1ActorId);
+        final String follower2ActorId = actorFactory.generateActorId(FOLLOWER_ID2);
+        final String follower2ActorPath = actorFactory.createTestActorPath(follower2ActorId);
+
+        TestActorRef<MockLeaderRaftActor> leaderActor = actorFactory.createTestActor(
+                MockLeaderRaftActor.props(ImmutableMap.of(FOLLOWER_ID, follower1ActorPath,
+                        FOLLOWER_ID2, follower2ActorPath), new MockRaftActorContext()).
+                        withDispatcher(Dispatchers.DefaultDispatcherId()), actorFactory.generateActorId(LEADER_ID));
+        TestActorRef<MessageCollectorActor> leaderCollector = newLeaderCollectorActor(leaderActor.underlyingActor());
+
+        TestActorRef<CollectingMockRaftActor> follower1RaftActor = actorFactory.createTestActor(
+                CollectingMockRaftActor.props(FOLLOWER_ID, ImmutableMap.of(LEADER_ID, leaderActor.path().toString(),
+                        FOLLOWER_ID2, follower2ActorPath), configParams, NO_PERSISTENCE).
+                        withDispatcher(Dispatchers.DefaultDispatcherId()), follower1ActorId);
+        TestActorRef<MessageCollectorActor> follower1Collector = actorFactory.createTestActor(
+                MessageCollectorActor.props().withDispatcher(Dispatchers.DefaultDispatcherId()),
+                actorFactory.generateActorId("collector"));
+        follower1RaftActor.underlyingActor().setCollectorActor(follower1Collector);
+
+        TestActorRef<CollectingMockRaftActor> follower2RaftActor = actorFactory.createTestActor(
+                CollectingMockRaftActor.props(FOLLOWER_ID2, ImmutableMap.of(LEADER_ID, leaderActor.path().toString(),
+                        FOLLOWER_ID, follower1ActorPath), configParams, NO_PERSISTENCE).
+                        withDispatcher(Dispatchers.DefaultDispatcherId()), follower2ActorId);
+        TestActorRef<MessageCollectorActor> follower2Collector = actorFactory.createTestActor(
+                MessageCollectorActor.props().withDispatcher(Dispatchers.DefaultDispatcherId()),
+                actorFactory.generateActorId("collector"));
+        follower2RaftActor.underlyingActor().setCollectorActor(follower2Collector);
+
+        // Send ChangeServersVotingStatus message
+
+        leaderActor.tell(new ChangeServersVotingStatus(ImmutableMap.of(LEADER_ID, false)), testKit.getRef());
+        ServerChangeReply reply = testKit.expectMsgClass(JavaTestKit.duration("5 seconds"), ServerChangeReply.class);
+        assertEquals("getStatus", ServerChangeStatus.OK, reply.getStatus());
+
+        MessageCollectorActor.expectFirstMatching(leaderCollector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(leaderActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                nonVotingServer(LEADER_ID), votingServer(FOLLOWER_ID), votingServer(FOLLOWER_ID2));
+
+        MessageCollectorActor.expectFirstMatching(follower1Collector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(follower1RaftActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                nonVotingServer(LEADER_ID), votingServer(FOLLOWER_ID), votingServer(FOLLOWER_ID2));
+
+        MessageCollectorActor.expectFirstMatching(follower2Collector, ApplyState.class);
+        verifyServerConfigurationPayloadEntry(follower2RaftActor.underlyingActor().getRaftActorContext().getReplicatedLog(),
+                nonVotingServer(LEADER_ID), votingServer(FOLLOWER_ID), votingServer(FOLLOWER_ID2));
+
+        verifyRaftState(RaftState.Leader, follower1RaftActor.underlyingActor(), follower2RaftActor.underlyingActor());
+        verifyRaftState(RaftState.Follower, leaderActor.underlyingActor());
+
+        MessageCollectorActor.expectMatching(leaderCollector, AppendEntries.class, 2);
+    }
+
+    private void verifyRaftState(RaftState expState, RaftActor... raftActors) {
+        Stopwatch sw = Stopwatch.createStarted();
+        while(sw.elapsed(TimeUnit.SECONDS) <= 5) {
+            for(RaftActor raftActor: raftActors) {
+                if(raftActor.getRaftState() == expState) {
+                    return;
+                }
+            }
+        }
+
+        fail("None of the RaftActors have state " + expState);
+    }
+
     private static ServerInfo votingServer(String id) {
         return new ServerInfo(id, true);
     }