Bug 4105: Change ownership on member down/up
[controller.git] / opendaylight / md-sal / sal-akka-raft / src / main / java / org / opendaylight / controller / cluster / raft / RaftActor.java
index 1738cc5fe001ab8b30cfd105f67dc4d9adcc8200..4e0f7702916796b83337ec5f359da4697907f385 100644 (file)
@@ -16,6 +16,7 @@ import akka.persistence.SnapshotSelectionCriteria;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Objects;
 import com.google.common.base.Optional;
+import com.google.common.base.Supplier;
 import com.google.common.collect.Lists;
 import java.io.Serializable;
 import java.util.Collection;
@@ -34,7 +35,9 @@ import org.opendaylight.controller.cluster.notifications.LeaderStateChanged;
 import org.opendaylight.controller.cluster.notifications.RoleChanged;
 import org.opendaylight.controller.cluster.raft.base.messages.ApplyJournalEntries;
 import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
+import org.opendaylight.controller.cluster.raft.base.messages.InitiateCaptureSnapshot;
 import org.opendaylight.controller.cluster.raft.base.messages.Replicate;
+import org.opendaylight.controller.cluster.raft.base.messages.SwitchBehavior;
 import org.opendaylight.controller.cluster.raft.behaviors.AbstractLeader;
 import org.opendaylight.controller.cluster.raft.behaviors.DelegatingRaftActorBehavior;
 import org.opendaylight.controller.cluster.raft.behaviors.Follower;
@@ -114,12 +117,10 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
 
     private final BehaviorStateHolder reusableBehaviorStateHolder = new BehaviorStateHolder();
 
-    public RaftActor(String id, Map<String, String> peerAddresses) {
-        this(id, peerAddresses, Optional.<ConfigParams>absent());
-    }
+    private final SwitchBehaviorSupplier reusableSwitchBehaviorSupplier = new SwitchBehaviorSupplier();
 
     public RaftActor(String id, Map<String, String> peerAddresses,
-         Optional<ConfigParams> configParams) {
+         Optional<ConfigParams> configParams, short payloadVersion) {
 
         context = new RaftActorContextImpl(this.getSelf(),
             this.getContext(), id, new ElectionTermImpl(delegatingPersistenceProvider, id, LOG),
@@ -127,6 +128,7 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
             (configParams.isPresent() ? configParams.get(): new DefaultConfigParamsImpl()),
             delegatingPersistenceProvider, LOG);
 
+        context.setPayloadVersion(payloadVersion);
         context.setReplicatedLog(ReplicatedLogImpl.newInstance(context, currentBehavior));
     }
 
@@ -193,7 +195,7 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
     }
 
     @Override
-    public void handleCommand(Object message) {
+    public void handleCommand(final Object message) {
         if (message instanceof ApplyState){
             ApplyState applyState = (ApplyState) message;
 
@@ -212,6 +214,16 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
             applyState(applyState.getClientActor(), applyState.getIdentifier(),
                 applyState.getReplicatedLogEntry().getData());
 
+            if (!hasFollowers()) {
+                // for single node, the capture should happen after the apply state
+                // as we delete messages from the persistent journal which have made it to the snapshot
+                // capturing the snapshot before applying makes the persistent journal and snapshot out of sync
+                // and recovery shows data missing
+                context.getReplicatedLog().captureSnapshotIfReady(applyState.getReplicatedLogEntry());
+
+                context.getSnapshotManager().trimLog(context.getLastApplied(), currentBehavior);
+            }
+
         } else if (message instanceof ApplyJournalEntries){
             ApplyJournalEntries applyEntries = (ApplyJournalEntries) message;
             if(LOG.isDebugEnabled()) {
@@ -227,15 +239,35 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
             );
         } else if(message instanceof GetOnDemandRaftState) {
             onGetOnDemandRaftStats();
+        } else if(message instanceof InitiateCaptureSnapshot) {
+            captureSnapshot();
+        } else if(message instanceof SwitchBehavior){
+            switchBehavior(((SwitchBehavior) message));
         } else if(!snapshotSupport.handleSnapshotMessage(message)) {
-            reusableBehaviorStateHolder.init(getCurrentBehavior());
-
-            setCurrentBehavior(currentBehavior.handleMessage(getSender(), message));
+            switchBehavior(reusableSwitchBehaviorSupplier.handleMessage(getSender(), message));
+        }
+    }
 
-            handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
+    private void switchBehavior(SwitchBehavior message) {
+        if(!getRaftActorContext().getRaftPolicy().automaticElectionsEnabled()) {
+            RaftState newState = message.getNewState();
+            if( newState == RaftState.Leader || newState == RaftState.Follower) {
+                switchBehavior(reusableSwitchBehaviorSupplier.handleMessage(getSender(), message));
+                getRaftActorContext().getTermInformation().updateAndPersist(message.getNewTerm(), "");
+            } else {
+                LOG.warn("Switching to behavior : {} - not supported", newState);
+            }
         }
     }
 
+    private void switchBehavior(Supplier<RaftActorBehavior> supplier){
+        reusableBehaviorStateHolder.init(getCurrentBehavior());
+
+        setCurrentBehavior(supplier.get());
+
+        handleBehaviorChange(reusableBehaviorStateHolder, getCurrentBehavior());
+    }
+
     protected RaftActorSnapshotMessageSupport newRaftActorSnapshotMessageSupport() {
         return new RaftActorSnapshotMessageSupport(context, currentBehavior,
                 getRaftActorSnapshotCohort());
@@ -291,17 +323,19 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
             onStateChanged();
         }
 
-        String oldBehaviorLeaderId = oldBehavior == null ? null : oldBehaviorState.getLeaderId();
+        String lastValidLeaderId = oldBehavior == null ? null : oldBehaviorState.getLastValidLeaderId();
         String oldBehaviorStateName = oldBehavior == null ? null : oldBehavior.state().name();
 
         // it can happen that the state has not changed but the leader has changed.
         Optional<ActorRef> roleChangeNotifier = getRoleChangeNotifier();
-        if(!Objects.equal(oldBehaviorLeaderId, currentBehavior.getLeaderId())) {
+        if(!Objects.equal(lastValidLeaderId, currentBehavior.getLeaderId()) ||
+           oldBehaviorState.getLeaderPayloadVersion() != currentBehavior.getLeaderPayloadVersion()) {
             if(roleChangeNotifier.isPresent()) {
-                roleChangeNotifier.get().tell(new LeaderStateChanged(getId(), currentBehavior.getLeaderId()), getSelf());
+                roleChangeNotifier.get().tell(newLeaderStateChanged(getId(), currentBehavior.getLeaderId(),
+                        currentBehavior.getLeaderPayloadVersion()), getSelf());
             }
 
-            onLeaderChanged(oldBehaviorLeaderId, currentBehavior.getLeaderId());
+            onLeaderChanged(lastValidLeaderId, currentBehavior.getLeaderId());
         }
 
         if (roleChangeNotifier.isPresent() &&
@@ -311,6 +345,20 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
         }
     }
 
+    protected LeaderStateChanged newLeaderStateChanged(String memberId, String leaderId, short leaderPayloadVersion) {
+        return new LeaderStateChanged(memberId, leaderId, leaderPayloadVersion);
+    }
+
+    @Override
+    public long snapshotSequenceNr() {
+        // When we do a snapshot capture, we also capture and save the sequence-number of the persistent journal,
+        // so that we can delete the persistent journal based on the saved sequence-number
+        // However , when akka replays the journal during recovery, it replays it from the sequence number when the snapshot
+        // was saved and not the number we saved.
+        // We would want to override it , by asking akka to use the last-sequence number known to us.
+        return context.getSnapshotManager().getLastSequenceNumber();
+    }
+
     /**
      * When a derived RaftActor needs to persist something it must call
      * persistData.
@@ -335,21 +383,21 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
         replicatedLog().appendAndPersist(replicatedLogEntry, new Procedure<ReplicatedLogEntry>() {
             @Override
             public void apply(ReplicatedLogEntry replicatedLogEntry) throws Exception {
-                if(!hasFollowers()){
+                if (!hasFollowers()){
                     // Increment the Commit Index and the Last Applied values
                     raftContext.setCommitIndex(replicatedLogEntry.getIndex());
                     raftContext.setLastApplied(replicatedLogEntry.getIndex());
 
-                    // Apply the state immediately
-                    applyState(clientActor, identifier, data);
+                    // Apply the state immediately.
+                    self().tell(new ApplyState(clientActor, identifier, replicatedLogEntry), self());
 
                     // Send a ApplyJournalEntries message so that we write the fact that we applied
                     // the state to durable storage
                     self().tell(new ApplyJournalEntries(replicatedLogEntry.getIndex()), self());
 
-                    context.getSnapshotManager().trimLog(context.getLastApplied(), currentBehavior);
-
                 } else if (clientActor != null) {
+                    context.getReplicatedLog().captureSnapshotIfReady(replicatedLogEntry);
+
                     // Send message for replication
                     currentBehavior.handleMessage(getSelf(),
                             new Replicate(clientActor, identifier, replicatedLogEntry));
@@ -564,14 +612,26 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
         return getRaftActorContext().hasFollowers();
     }
 
+    private void captureSnapshot() {
+        SnapshotManager snapshotManager = context.getSnapshotManager();
+
+        if(!snapshotManager.isCapturing()) {
+            LOG.debug("Take a snapshot of current state. lastReplicatedLog is {} and replicatedToAllIndex is {}",
+                replicatedLog().last(), currentBehavior.getReplicatedToAllIndex());
+
+            snapshotManager.capture(replicatedLog().last(), currentBehavior.getReplicatedToAllIndex());
+        }
+    }
+
     /**
-     * @deprecated Deprecated in favor of {@link org.opendaylight.controller.cluster.raft.base.messages.DeleteEntriesTest}
+     * @deprecated Deprecated in favor of {@link org.opendaylight.controller.cluster.raft.base.messages.DeleteEntries}
      *             whose type for fromIndex is long instead of int. This class was kept for backwards
      *             compatibility with Helium.
      */
+    // Suppressing this warning as we can't set serialVersionUID to maintain backwards compatibility.
+    @SuppressWarnings("serial")
     @Deprecated
     static class DeleteEntries implements Serializable {
-        private static final long serialVersionUID = 1L;
         private final int fromIndex;
 
         public DeleteEntries(int fromIndex) {
@@ -583,8 +643,14 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
         }
     }
 
+    /**
+     * @deprecated Deprecated in favor of non-inner class {@link org.opendaylight.controller.cluster.raft.base.messages.UpdateElectionTerm}
+     *             which has serialVersionUID set. This class was kept for backwards compatibility with Helium.
+     */
+    // Suppressing this warning as we can't set serialVersionUID to maintain backwards compatibility.
+    @SuppressWarnings("serial")
+    @Deprecated
     static class UpdateElectionTerm implements Serializable {
-        private static final long serialVersionUID = 1L;
         private final long currentTerm;
         private final String votedFor;
 
@@ -604,19 +670,48 @@ public abstract class RaftActor extends AbstractUntypedPersistentActor {
 
     private static class BehaviorStateHolder {
         private RaftActorBehavior behavior;
-        private String leaderId;
+        private String lastValidLeaderId;
+        private short leaderPayloadVersion;
 
         void init(RaftActorBehavior behavior) {
             this.behavior = behavior;
-            this.leaderId = behavior != null ? behavior.getLeaderId() : null;
+            this.leaderPayloadVersion = behavior != null ? behavior.getLeaderPayloadVersion() : -1;
+
+            String behaviorLeaderId = behavior != null ? behavior.getLeaderId() : null;
+            if(behaviorLeaderId != null) {
+                this.lastValidLeaderId = behaviorLeaderId;
+            }
         }
 
         RaftActorBehavior getBehavior() {
             return behavior;
         }
 
-        String getLeaderId() {
-            return leaderId;
+        String getLastValidLeaderId() {
+            return lastValidLeaderId;
+        }
+
+        short getLeaderPayloadVersion() {
+            return leaderPayloadVersion;
+        }
+    }
+
+    private class SwitchBehaviorSupplier implements Supplier<RaftActorBehavior> {
+        private Object message;
+        private ActorRef sender;
+
+        public SwitchBehaviorSupplier handleMessage(ActorRef sender, Object message){
+            this.sender = sender;
+            this.message = message;
+            return this;
+        }
+
+        @Override
+        public RaftActorBehavior get() {
+            if(this.message instanceof SwitchBehavior){
+                return ((SwitchBehavior) message).getNewState().createBehavior(getRaftActorContext());
+            }
+            return currentBehavior.handleMessage(sender, message);
         }
     }
 }