When no candidates are present for an entity do not return EntityOwnershipState
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / datastore / entityownership / EntityOwnershipShard.java
index 1f31d122cd271ac4824bb1d490c579233d1d51cd..89b7518a0326f5d1ae7044bf938e9ea7a5b20da1 100644 (file)
@@ -7,7 +7,6 @@
  */
 package org.opendaylight.controller.cluster.datastore.entityownership;
 
-import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.CANDIDATE_NAME_NODE_ID;
 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.CANDIDATE_NODE_ID;
 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_ID_NODE_ID;
 import static org.opendaylight.controller.cluster.datastore.entityownership.EntityOwnersModel.ENTITY_ID_QNAME;
@@ -140,6 +139,8 @@ class EntityOwnershipShard extends Shard {
     }
 
     private void onSelectOwner(SelectOwner selectOwner) {
+        LOG.debug("{}: onSelectOwner: {}", persistenceId(), selectOwner);
+
         String currentOwner = getCurrentOwner(selectOwner.getEntityPath());
         if(Strings.isNullOrEmpty(currentOwner)) {
             String entityType = EntityOwnersModel.entityTypeFromEntityPath(selectOwner.getEntityPath());
@@ -244,17 +245,23 @@ class EntityOwnershipShard extends Shard {
     protected void onStateChanged() {
         super.onStateChanged();
 
-        commitCoordinator.onStateChanged(this, isLeader());
+        boolean isLeader = isLeader();
+        if(LOG.isDebugEnabled()) {
+            LOG.debug("{}: onStateChanged: isLeader: {}, hasLeader: {}", persistenceId(), isLeader, hasLeader());
+        }
+
+        commitCoordinator.onStateChanged(this, isLeader);
     }
 
     @Override
     protected void onLeaderChanged(String oldLeader, String newLeader) {
         super.onLeaderChanged(oldLeader, newLeader);
 
+        boolean isLeader = isLeader();
         LOG.debug("{}: onLeaderChanged: oldLeader: {}, newLeader: {}, isLeader: {}", persistenceId(), oldLeader,
-                newLeader, isLeader());
+                newLeader, isLeader);
 
-        if(isLeader()) {
+        if(isLeader) {
             // We were just elected leader. If the old leader is down, select new owners for the entities
             // owned by the down leader.
 
@@ -263,8 +270,13 @@ class EntityOwnershipShard extends Shard {
             LOG.debug("{}: oldLeaderMemberName: {}", persistenceId(), oldLeaderMemberName);
 
             if(downPeerMemberNames.contains(oldLeaderMemberName)) {
-                selectNewOwnerForEntitiesOwnedBy(oldLeaderMemberName);
+                removeCandidateFromEntities(oldLeaderMemberName);
             }
+        } else {
+            // The leader changed - notify the coordinator to check if pending modifications need to be sent.
+            // While onStateChanged also does this, this method handles the case where the shard hears from a
+            // leader and stays in the follower state. In that case no behavior state change occurs.
+            commitCoordinator.onStateChanged(this, isLeader);
         }
     }
 
@@ -315,6 +327,8 @@ class EntityOwnershipShard extends Shard {
 
         String currentOwner = getCurrentOwner(message.getEntityPath());
         EntityOwnerSelectionStrategy strategy = getEntityOwnerElectionStrategy(message.getEntityPath());
+
+        LOG.debug("{}: Using strategy {} to select owner", persistenceId(), strategy);
         if(Strings.isNullOrEmpty(currentOwner)){
             if(strategy.getSelectionDelayInMillis() == 0L) {
                 String entityType = EntityOwnersModel.entityTypeFromEntityPath(message.getEntityPath());
@@ -341,32 +355,11 @@ class EntityOwnershipShard extends Shard {
 
         peerIdToMemberNames.put(peerUp.getPeerId(), peerUp.getMemberName());
         downPeerMemberNames.remove(peerUp.getMemberName());
-    }
-
-    private void selectNewOwnerForEntitiesOwnedBy(String owner) {
-        final BatchedModifications modifications = commitCoordinator.newBatchedModifications();
-        searchForEntitiesOwnedBy(owner, new EntityWalker() {
-            @Override
-            public void onEntity(MapEntryNode entityTypeNode, MapEntryNode entityNode) {
-
-                YangInstanceIdentifier entityPath = YangInstanceIdentifier.builder(ENTITY_TYPES_PATH).
-                        node(entityTypeNode.getIdentifier()).node(ENTITY_NODE_ID).node(entityNode.getIdentifier()).
-                        node(ENTITY_OWNER_NODE_ID).build();
-
-                String entityType = EntityOwnersModel.entityTypeFromEntityPath(entityPath);
 
-                Object newOwner = newOwner(getCandidateNames(entityNode),
-                        entityOwnershipStatistics.byEntityType(entityType),
-                        getEntityOwnerElectionStrategy(entityPath));
-
-                LOG.debug("{}: Found entity {}, writing new owner {}", persistenceId(), entityPath, newOwner);
-
-                modifications.addModification(new WriteModification(entityPath,
-                        ImmutableNodes.leafNode(ENTITY_OWNER_NODE_ID, newOwner)));
-            }
-        });
-
-        commitCoordinator.commitModifications(modifications, this);
+        // Notify the coordinator to check if pending modifications need to be sent. We do this here
+        // to handle the case where the leader's peer address isn't now yet when a prior state or
+        // leader change occurred.
+        commitCoordinator.onStateChanged(this, isLeader());
     }
 
     private void removeCandidateFromEntities(final String owner) {
@@ -435,16 +428,6 @@ class EntityOwnershipShard extends Shard {
         }
     }
 
-    private static Collection<String> getCandidateNames(MapEntryNode entity) {
-        Collection<MapEntryNode> candidates = ((MapNode) entity.getChild(CANDIDATE_NODE_ID).get()).getValue();
-        Collection<String> candidateNames = new ArrayList<>(candidates.size());
-        for(MapEntryNode candidate: candidates) {
-            candidateNames.add(candidate.getChild(CANDIDATE_NAME_NODE_ID).get().getValue().toString());
-        }
-
-        return candidateNames;
-    }
-
     private void writeNewOwner(YangInstanceIdentifier entityPath, String newOwner) {
         LOG.debug("{}: Writing new owner {} for entity {}", persistenceId(), newOwner, entityPath);
 
@@ -464,6 +447,9 @@ class EntityOwnershipShard extends Shard {
         if(lastScheduledTask != null && !lastScheduledTask.isCancelled()){
             lastScheduledTask.cancel();
         }
+
+        LOG.debug("{}: Scheduling owner selection after {} ms", persistenceId(), strategy.getSelectionDelayInMillis());
+
         lastScheduledTask = context().system().scheduler().scheduleOnce(
                 FiniteDuration.apply(strategy.getSelectionDelayInMillis(), TimeUnit.MILLISECONDS)
                 , self(), new SelectOwner(entityPath, allCandidates, strategy)