Merge pull request #22181 from vespa-engine/hakonhall/remove-orphaned-wanted-states

Remove orphaned wanted state

38 files changed, 356 insertions, 254 deletions

diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterInfo.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterInfo.java
index c25dd5a5965..2cfaf64fe83 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterInfo.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterInfo.java
@@ -4,6 +4,7 @@ package com.yahoo.vespa.clustercontroller.core;
 import com.yahoo.vdslib.distribution.ConfiguredNode;
 import com.yahoo.vdslib.distribution.Distribution;
 import com.yahoo.vdslib.state.Node;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -40,11 +41,11 @@ public class ClusterInfo {
     /** Returns information about the given node id, or null if this node does not exist */
     public NodeInfo getNodeInfo(Node node) { return allNodeInfo.get(node); }
 
-    Collection<DistributorNodeInfo> getDistributorNodeInfo() { return Collections.unmodifiableCollection(distributorNodeInfo.values()); }
+    Collection<DistributorNodeInfo> getDistributorNodeInfos() { return Collections.unmodifiableCollection(distributorNodeInfo.values()); }
 
-    Collection<StorageNodeInfo> getStorageNodeInfo() { return Collections.unmodifiableCollection(storageNodeInfo.values()); }
+    Collection<StorageNodeInfo> getStorageNodeInfos() { return Collections.unmodifiableCollection(storageNodeInfo.values()); }
 
-    Collection<NodeInfo> getAllNodeInfo() { return Collections.unmodifiableCollection(allNodeInfo.values()); }
+    Collection<NodeInfo> getAllNodeInfos() { return Collections.unmodifiableCollection(allNodeInfo.values()); }
 
     /** Returns the configured nodes of this as a read-only map indexed on node index (distribution key) */
     Map<Integer, ConfiguredNode> getConfiguredNodes() { return Collections.unmodifiableMap(nodes); }
@@ -52,15 +53,23 @@ public class ClusterInfo {
     boolean hasConfiguredNode(int index) { return nodes.containsKey(index); }
 
     /** Sets the nodes which belongs to this cluster */
-    void setNodes(Collection<ConfiguredNode> newNodes, ContentCluster owner, Distribution distribution) {
+    void setNodes(Collection<ConfiguredNode> newNodes, ContentCluster owner,
+                  Distribution distribution, NodeListener nodeListener) {
         // Remove info for removed nodes
         Set<ConfiguredNode> newNodesSet = new HashSet<>(newNodes);
         for (ConfiguredNode existingNode : this.nodes.values()) {
             if ( ! newNodesSet.contains(existingNode)) {
-                Node existingStorageNode = storageNodeInfo.remove(existingNode.index()).getNode();
-                Node existingDistributorNode = distributorNodeInfo.remove(existingNode.index()).getNode();
-                allNodeInfo.remove(existingDistributorNode);
-                allNodeInfo.remove(existingStorageNode);
+                {
+                    Node existingStorageNode = storageNodeInfo.remove(existingNode.index()).getNode();
+                    allNodeInfo.remove(existingStorageNode);
+                    nodeListener.handleRemovedNode(existingStorageNode);
+                }
+
+                {
+                    Node existingDistributorNode = distributorNodeInfo.remove(existingNode.index()).getNode();
+                    allNodeInfo.remove(existingDistributorNode);
+                    nodeListener.handleRemovedNode(existingDistributorNode);
+                }
             }
         }
 
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGenerator.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGenerator.java
index f984c3cb3a2..75c6dbe6cec 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGenerator.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateGenerator.java
@@ -129,7 +129,7 @@ public class ClusterStateGenerator {
         final ClusterState workingState = ClusterState.emptyState();
         final Map<Node, NodeStateReason> nodeStateReasons = new HashMap<>();
 
-        for (final NodeInfo nodeInfo : cluster.getNodeInfo()) {
+        for (final NodeInfo nodeInfo : cluster.getNodeInfos()) {
             final NodeState nodeState = computeEffectiveNodeState(nodeInfo, params, nodeStateReasons);
             workingState.setNodeState(nodeInfo.getNode(), nodeState);
         }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentCluster.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentCluster.java
index fabc4999fe5..f2a4a9736c3 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentCluster.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentCluster.java
@@ -10,6 +10,7 @@ import com.yahoo.vdslib.state.Node;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
 import com.yahoo.vdslib.state.State;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import com.yahoo.vespa.clustercontroller.core.status.statuspage.HtmlTable;
 import com.yahoo.vespa.clustercontroller.core.status.statuspage.VdsClusterHtmlRenderer;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.requests.SetUnitStateRequest;
@@ -42,7 +43,7 @@ public class ContentCluster {
         if (configuredNodes == null) throw new IllegalArgumentException("Nodes must be set");
         this.clusterName = clusterName;
         this.distribution = distribution;
-        setNodes(configuredNodes);
+        setNodes(configuredNodes, new NodeListener() {});
     }
 
     // TODO move out, this doesn't belong in a domain model class
@@ -104,14 +105,14 @@ public class ContentCluster {
 
     public void setDistribution(Distribution distribution) {
         this.distribution = distribution;
-        for (NodeInfo info : clusterInfo.getAllNodeInfo()) {
+        for (NodeInfo info : clusterInfo.getAllNodeInfos()) {
             info.setGroup(distribution);
         }
     }
 
     /** Sets the configured nodes of this cluster */
-    public final void setNodes(Collection<ConfiguredNode> configuredNodes) {
-        clusterInfo.setNodes(configuredNodes, this, distribution);
+    public final void setNodes(Collection<ConfiguredNode> configuredNodes, NodeListener nodeListener) {
+        clusterInfo.setNodes(configuredNodes, this, distribution, nodeListener);
     }
 
     public void setStartTimestamp(Node n, long startTimestamp) {
@@ -128,7 +129,7 @@ public class ContentCluster {
     }
 
     public void clearStates() {
-        for (NodeInfo info : clusterInfo.getAllNodeInfo()) {
+        for (NodeInfo info : clusterInfo.getAllNodeInfos()) {
             info.setReportedState(null, 0);
         }
     }
@@ -145,8 +146,8 @@ public class ContentCluster {
         return clusterInfo.getConfiguredNodes();
     }
 
-    public Collection<NodeInfo> getNodeInfo() {
-        return Collections.unmodifiableCollection(clusterInfo.getAllNodeInfo());
+    public Collection<NodeInfo> getNodeInfos() {
+        return Collections.unmodifiableCollection(clusterInfo.getAllNodeInfos());
     }
 
     public ClusterInfo clusterInfo() { return clusterInfo; }
@@ -158,7 +159,7 @@ public class ContentCluster {
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append("ContentCluster(").append(clusterName).append(") {");
-        for (NodeInfo node : clusterInfo.getAllNodeInfo()) {
+        for (NodeInfo node : clusterInfo.getAllNodeInfos()) {
             sb.append("\n  ").append(node);
         }
         sb.append("\n}");
@@ -197,14 +198,14 @@ public class ContentCluster {
         switch (state) {
             case MAINTENANCE:  // Orchestrator's ALLOWED_TO_BE_DOWN
             case DOWN:  // Orchestrator's PERMANENTLY_DOWN
-                return clusterInfo.getStorageNodeInfo().stream()
-                        .filter(storageNodeInfo -> {
+                return clusterInfo.getStorageNodeInfos().stream()
+                                  .filter(storageNodeInfo -> {
                             NodeState userWantedState = storageNodeInfo.getUserWantedState();
                             return userWantedState.getState() == state &&
                                     Objects.equals(userWantedState.getDescription(), ORCHESTRATOR_RESERVED_DESCRIPTION);
                         })
-                        .map(NodeInfo::getNodeIndex)
-                        .collect(Collectors.toList());
+                                  .map(NodeInfo::getNodeIndex)
+                                  .collect(Collectors.toList());
             default:
                 // Note: There is no trace left if the Orchestrator set the state to UP, so that's handled
                 // like any other state:
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java
index 3137dfff606..7f385c6077c 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java
@@ -12,8 +12,8 @@ import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.database.DatabaseHandler;
 import com.yahoo.vespa.clustercontroller.core.database.ZooKeeperDatabaseFactory;
 import com.yahoo.vespa.clustercontroller.core.hostinfo.HostInfo;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import com.yahoo.vespa.clustercontroller.core.listeners.SystemStateListener;
 import com.yahoo.vespa.clustercontroller.core.rpc.RPCCommunicator;
 import com.yahoo.vespa.clustercontroller.core.rpc.RpcServer;
@@ -47,7 +47,7 @@ import java.util.logging.Logger;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAddedOrRemovedListener, SystemStateListener,
+public class FleetController implements NodeListener, SlobrokListener, SystemStateListener,
                                         Runnable, RemoteClusterControllerTaskScheduler {
 
     private static final Logger logger = Logger.getLogger(FleetController.class.getName());
@@ -332,6 +332,13 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
     }
 
     @Override
+    public void handleRemovedNode(Node node) {
+        verifyInControllerThread();
+        // Prune orphaned wanted states
+        wantedStateChanged = true;
+    }
+
+    @Override
     public void handleUpdatedHostInfo(NodeInfo nodeInfo, HostInfo newHostInfo) {
         verifyInControllerThread();
         triggerBundleRecomputationIfResourceExhaustionStateChanged(nodeInfo, newHostInfo);
@@ -380,7 +387,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         ClusterState baselineState = stateBundle.getBaselineClusterState();
         newStates.add(stateBundle);
         metricUpdater.updateClusterStateMetrics(cluster, baselineState,
-                ResourceUsageStats.calculateFrom(cluster.getNodeInfo(), options.clusterFeedBlockLimit, stateBundle.getFeedBlock()));
+                ResourceUsageStats.calculateFrom(cluster.getNodeInfos(), options.clusterFeedBlockLimit, stateBundle.getFeedBlock()));
         lastMetricUpdateCycleCount = cycleCount;
         systemStateBroadcaster.handleNewClusterStates(stateBundle);
         // Iff master, always store new version in ZooKeeper _before_ publishing to any
@@ -399,7 +406,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
             ClusterStateBundle stateBundle = stateVersionTracker.getVersionedClusterStateBundle();
             ClusterState baselineState = stateBundle.getBaselineClusterState();
             metricUpdater.updateClusterStateMetrics(cluster, baselineState,
-                    ResourceUsageStats.calculateFrom(cluster.getNodeInfo(), options.clusterFeedBlockLimit, stateBundle.getFeedBlock()));
+                    ResourceUsageStats.calculateFrom(cluster.getNodeInfos(), options.clusterFeedBlockLimit, stateBundle.getFeedBlock()));
             lastMetricUpdateCycleCount = cycleCount;
             return true;
         } else {
@@ -511,7 +518,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         eventLog.setMaxSize(options.eventLogMaxSize, options.eventNodeLogMaxSize);
         cluster.setPollingFrequency(options.statePollingFrequency);
         cluster.setDistribution(options.storageDistribution);
-        cluster.setNodes(options.nodes);
+        cluster.setNodes(options.nodes, databaseContext.getNodeStateUpdateListener());
         database.setZooKeeperAddress(options.zooKeeperServerAddress, databaseContext);
         database.setZooKeeperSessionTimeout(options.zooKeeperSessionTimeout, databaseContext);
         stateGatherer.setMaxSlobrokDisconnectGracePeriod(options.maxSlobrokDisconnectGracePeriod);
@@ -790,8 +797,8 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
             @Override public boolean inMasterMoratorium() { return inMasterMoratorium; }
         };
 
-        context.nodeStateOrHostInfoChangeHandler = this;
-        context.nodeAddedOrRemovedListener = this;
+        context.nodeListener = this;
+        context.slobrokListener = this;
         return context;
     }
 
@@ -806,10 +813,10 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         if (bundle == null) {
             return List.of();
         }
-        return cluster.getNodeInfo().stream().
-                filter(n -> effectiveActivatedStateVersion(n, bundle) < version).
-                map(NodeInfo::getNode).
-                collect(Collectors.toList());
+        return cluster.getNodeInfos().stream().
+                      filter(n -> effectiveActivatedStateVersion(n, bundle) < version).
+                      map(NodeInfo::getNode).
+                      collect(Collectors.toList());
     }
 
     private static <E> String stringifyListWithLimits(List<E> list, int limit) {
@@ -939,7 +946,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
                     .stateDeriver(createBucketSpaceStateDeriver())
                     .deferredActivation(options.enableTwoPhaseClusterStateActivation)
                     .feedBlock(createResourceExhaustionCalculator()
-                            .inferContentClusterFeedBlockOrNull(cluster.getNodeInfo()))
+                            .inferContentClusterFeedBlockOrNull(cluster.getNodeInfos()))
                     .deriveAndBuild();
             stateVersionTracker.updateLatestCandidateStateBundle(candidateBundle);
             invokeCandidateStateListeners(candidateBundle);
@@ -1095,7 +1102,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
                 didWork = true;
             }
             if (wantedStateChanged) {
-                database.saveWantedStates(databaseContext);
+                didWork |= database.saveWantedStates(databaseContext);
                 wantedStateChanged = false;
             }
         } else {
@@ -1150,9 +1157,9 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         @Override
         public FleetController getFleetController() { return FleetController.this; }
         @Override
-        public NodeAddedOrRemovedListener getNodeAddedOrRemovedListener() { return FleetController.this; }
+        public SlobrokListener getNodeAddedOrRemovedListener() { return FleetController.this; }
         @Override
-        public NodeStateOrHostInfoChangeHandler getNodeStateUpdateListener() { return FleetController.this; }
+        public NodeListener getNodeStateUpdateListener() { return FleetController.this; }
     };
 
     public void waitForCompleteCycle(long timeoutMS) {
@@ -1183,7 +1190,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         synchronized (monitor) {
             while (true) {
                 int ackedNodes = 0;
-                for (NodeInfo node : cluster.getNodeInfo()) {
+                for (NodeInfo node : cluster.getNodeInfos()) {
                     if (node.getClusterStateVersionBundleAcknowledged() >= version) {
                         ++ackedNodes;
                     }
@@ -1206,7 +1213,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         synchronized (monitor) {
             while (true) {
                 int distCount = 0, storCount = 0;
-                for (NodeInfo info : cluster.getNodeInfo()) {
+                for (NodeInfo info : cluster.getNodeInfos()) {
                     if (!info.isRpcAddressOutdated()) {
                         if (info.isDistributor()) ++distCount;
                         else ++storCount;
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeLookup.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeLookup.java
index cdf8b24e72d..882ae8894fa 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeLookup.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeLookup.java
@@ -1,7 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.core;
 
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
 
 /**
  * Interface for a node lookup service, such as slobrok, config, or tier controller.
@@ -10,7 +10,7 @@ public interface NodeLookup {
 
     void shutdown();
 
-    boolean updateCluster(ContentCluster cluster, NodeAddedOrRemovedListener listener);
+    boolean updateCluster(ContentCluster cluster, SlobrokListener listener);
 
     /**
      * Returns whether the lookup instance has been able to bootstrap itself with information about nodes.
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateChangeChecker.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateChangeChecker.java
index eb0368749f0..3ed03e94fda 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateChangeChecker.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateChangeChecker.java
@@ -359,7 +359,7 @@ public class NodeStateChangeChecker {
         // This method verifies both storage nodes and distributors are up (or retired).
         // The complicated part is making a summary error message.
 
-        for (NodeInfo storageNodeInfo : clusterInfo.getStorageNodeInfo()) {
+        for (NodeInfo storageNodeInfo : clusterInfo.getStorageNodeInfos()) {
             State wantedState = storageNodeInfo.getUserWantedState().getState();
             if (wantedState != State.UP && wantedState != State.RETIRED) {
                 return Result.createDisallowed("Another storage node wants state " +
@@ -373,7 +373,7 @@ public class NodeStateChangeChecker {
             }
         }
 
-        for (NodeInfo distributorNodeInfo : clusterInfo.getDistributorNodeInfo()) {
+        for (NodeInfo distributorNodeInfo : clusterInfo.getDistributorNodeInfos()) {
             State wantedState = distributorNodeInfo.getUserWantedState().getState();
             if (wantedState != State.UP && wantedState != State.RETIRED) {
                 return Result.createDisallowed("Another distributor wants state " + wantedState.toString().toUpperCase() +
@@ -418,10 +418,10 @@ public class NodeStateChangeChecker {
      * @param clusterStateVersion the cluster state we expect distributors to have
      */
     private Result checkDistributors(Node node, int clusterStateVersion) {
-        if (clusterInfo.getDistributorNodeInfo().isEmpty()) {
+        if (clusterInfo.getDistributorNodeInfos().isEmpty()) {
             return Result.createDisallowed("Not aware of any distributors, probably not safe to upgrade?");
         }
-        for (DistributorNodeInfo distributorNodeInfo : clusterInfo.getDistributorNodeInfo()) {
+        for (DistributorNodeInfo distributorNodeInfo : clusterInfo.getDistributorNodeInfos()) {
             Integer distributorClusterStateVersion = distributorNodeInfo.getHostInfo().getClusterStateVersionOrNull();
             if (distributorClusterStateVersion == null) {
                 return Result.createDisallowed("Distributor node " + distributorNodeInfo.getNodeIndex()
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateGatherer.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateGatherer.java
index e3fe371c05e..69e97de84f9 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateGatherer.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/NodeStateGatherer.java
@@ -7,7 +7,7 @@ import java.util.logging.Level;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.hostinfo.HostInfo;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 
 import java.util.LinkedList;
 import java.util.List;
@@ -54,10 +54,10 @@ public class NodeStateGatherer {
      * Sends state requests to nodes that does not have one pending and is due
      * for another attempt.
      */
-    public boolean sendMessages(ContentCluster cluster, Communicator communicator, NodeStateOrHostInfoChangeHandler listener) {
+    public boolean sendMessages(ContentCluster cluster, Communicator communicator, NodeListener listener) {
         boolean sentAnyMessages = false;
         long currentTime = timer.getCurrentTimeInMillis();
-        for (NodeInfo info : cluster.getNodeInfo()) {
+        for (NodeInfo info : cluster.getNodeInfos()) {
             Long requestTime = info.getLatestNodeStateRequestTime();
 
             if (requestTime != null && (currentTime - requestTime < nodeStateRequestTimeoutMS)) continue; // pending request
@@ -93,7 +93,7 @@ public class NodeStateGatherer {
     }
 
     /** Reads replies to get node state requests and create events. */
-    public boolean processResponses(NodeStateOrHostInfoChangeHandler listener) {
+    public boolean processResponses(NodeListener listener) {
         boolean processedAnyResponses = false;
         long currentTime = timer.getCurrentTimeInMillis();
         synchronized(monitor) {
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/RemoteClusterControllerTask.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/RemoteClusterControllerTask.java
index 949ad6f56a2..3c2143818e3 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/RemoteClusterControllerTask.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/RemoteClusterControllerTask.java
@@ -2,8 +2,8 @@
 package com.yahoo.vespa.clustercontroller.core;
 
 import com.yahoo.vdslib.state.ClusterState;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 
 import java.time.Instant;
 import java.util.Optional;
@@ -15,8 +15,8 @@ public abstract class RemoteClusterControllerTask {
         public ClusterState currentConsolidatedState;
         public ClusterStateBundle publishedClusterStateBundle;
         public MasterInterface masterInfo;
-        public NodeStateOrHostInfoChangeHandler nodeStateOrHostInfoChangeHandler;
-        public NodeAddedOrRemovedListener nodeAddedOrRemovedListener;
+        public NodeListener nodeListener;
+        public SlobrokListener slobrokListener;
     }
 
     private final Object monitor = new Object();
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java
index 46fafddfade..4c832592422 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandler.java
@@ -8,7 +8,7 @@ import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.database.DatabaseHandler;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 
 import java.util.Map;
 import java.util.Set;
@@ -113,7 +113,7 @@ public class StateChangeHandler {
     public void handleNewReportedNodeState(final ClusterState currentClusterState,
                                            final NodeInfo node,
                                            final NodeState reportedState,
-                                           final NodeStateOrHostInfoChangeHandler nodeListener)
+                                           final NodeListener nodeListener)
     {
         final NodeState currentState = currentClusterState.getNodeState(node.getNode());
         final Level level = (currentState.equals(reportedState) && node.getVersion() == 0) ? Level.FINEST : Level.FINE;
@@ -164,7 +164,7 @@ public class StateChangeHandler {
 
     public void handleMissingNode(final ClusterState currentClusterState,
                                   final NodeInfo node,
-                                  final NodeStateOrHostInfoChangeHandler nodeListener) {
+                                  final NodeListener nodeListener) {
         final long timeNow = timer.getCurrentTimeInMillis();
 
         if (node.getLatestNodeStateRequestTime() != null) {
@@ -241,12 +241,12 @@ public class StateChangeHandler {
     //  `--> this will require adding more event edges and premature crash handling to it. Which is fine.
     public boolean watchTimers(final ContentCluster cluster,
                                final ClusterState currentClusterState,
-                               final NodeStateOrHostInfoChangeHandler nodeListener)
+                               final NodeListener nodeListener)
     {
         boolean triggeredAnyTimers = false;
         final long currentTime = timer.getCurrentTimeInMillis();
 
-        for(NodeInfo node : cluster.getNodeInfo()) {
+        for(NodeInfo node : cluster.getNodeInfos()) {
             triggeredAnyTimers |= handleTimeDependentOpsForNode(currentClusterState, nodeListener, currentTime, node);
         }
 
@@ -257,7 +257,7 @@ public class StateChangeHandler {
     }
 
     private boolean handleTimeDependentOpsForNode(final ClusterState currentClusterState,
-                                                  final NodeStateOrHostInfoChangeHandler nodeListener,
+                                                  final NodeListener nodeListener,
                                                   final long currentTime,
                                                   final NodeInfo node)
     {
@@ -334,7 +334,7 @@ public class StateChangeHandler {
     }
 
     private boolean reportDownIfOutdatedSlobrokNode(ClusterState currentClusterState,
-                                                    NodeStateOrHostInfoChangeHandler nodeListener,
+                                                    NodeListener nodeListener,
                                                     long currentTime,
                                                     NodeInfo node,
                                                     NodeState lastReportedState)
@@ -379,7 +379,7 @@ public class StateChangeHandler {
     private void updateNodeInfoFromReportedState(final NodeInfo node,
                                                  final NodeState currentState,
                                                  final NodeState reportedState,
-                                                 final NodeStateOrHostInfoChangeHandler nodeListener) {
+                                                 final NodeListener nodeListener) {
         final long timeNow = timer.getCurrentTimeInMillis();
         log.log(Level.FINE, () -> String.format("Finding new cluster state entry for %s switching state %s", node, currentState.getTextualDifference(reportedState)));
 
@@ -400,7 +400,7 @@ public class StateChangeHandler {
     private void markNodeUnstableIfDownEdgeDuringInit(final NodeInfo node,
                                                       final NodeState currentState,
                                                       final NodeState reportedState,
-                                                      final NodeStateOrHostInfoChangeHandler nodeListener,
+                                                      final NodeListener nodeListener,
                                                       final long timeNow) {
         if (currentState.getState().equals(State.INITIALIZING)
                 && reportedState.getState().oneOf("ds")
@@ -419,7 +419,7 @@ public class StateChangeHandler {
     private boolean handleImplicitCrashEdgeFromReverseInitProgress(final NodeInfo node,
                                                                    final NodeState currentState,
                                                                    final NodeState reportedState,
-                                                                   final NodeStateOrHostInfoChangeHandler nodeListener,
+                                                                   final NodeListener nodeListener,
                                                                    final long timeNow) {
         if (currentState.getState().equals(State.INITIALIZING) &&
             (reportedState.getState().equals(State.INITIALIZING) && reportedState.getInitProgress() < currentState.getInitProgress()))
@@ -438,7 +438,7 @@ public class StateChangeHandler {
     }
 
     private boolean handleReportedNodeCrashEdge(NodeInfo node, NodeState currentState,
-                                                NodeState reportedState, NodeStateOrHostInfoChangeHandler nodeListener,
+                                                NodeState reportedState, NodeListener nodeListener,
                                                 long timeNow) {
         if (nodeUpToDownEdge(node, currentState, reportedState)) {
             node.setTransitionTime(timeNow);
@@ -467,7 +467,7 @@ public class StateChangeHandler {
             && (node.getWantedState().getState().equals(State.RETIRED) || !reportedState.getState().equals(State.INITIALIZING));
     }
 
-    private boolean handlePrematureCrash(NodeInfo node, NodeStateOrHostInfoChangeHandler changeListener) {
+    private boolean handlePrematureCrash(NodeInfo node, NodeListener changeListener) {
         node.setPrematureCrashCount(node.getPrematureCrashCount() + 1);
         if (disableUnstableNodes && node.getPrematureCrashCount() > maxPrematureCrashes) {
             NodeState wantedState = new NodeState(node.getNode().getType(), State.DOWN)
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java
index d061f7edbea..2359e4d8389 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcaster.java
@@ -188,18 +188,18 @@ public class SystemStateBroadcaster {
     }
 
     private List<NodeInfo> resolveStateVersionSendSet(DatabaseHandler.DatabaseContext dbContext) {
-        return dbContext.getCluster().getNodeInfo().stream()
-                .filter(this::nodeNeedsClusterStateBundle)
-                .filter(node -> !newestStateBundleAlreadySentToNode(node))
-                .collect(Collectors.toList());
+        return dbContext.getCluster().getNodeInfos().stream()
+                        .filter(this::nodeNeedsClusterStateBundle)
+                        .filter(node -> !newestStateBundleAlreadySentToNode(node))
+                        .collect(Collectors.toList());
     }
 
     // Precondition: no nodes in the cluster need to receive the current cluster state version bundle
     private List<NodeInfo> resolveStateActivationSendSet(DatabaseHandler.DatabaseContext dbContext) {
-        return dbContext.getCluster().getNodeInfo().stream()
-                .filter(this::nodeNeedsClusterStateActivation)
-                .filter(node -> !newestStateActivationAlreadySentToNode(node))
-                .collect(Collectors.toList());
+        return dbContext.getCluster().getNodeInfos().stream()
+                        .filter(this::nodeNeedsClusterStateActivation)
+                        .filter(node -> !newestStateActivationAlreadySentToNode(node))
+                        .collect(Collectors.toList());
     }
 
     private boolean newestStateBundleAlreadySentToNode(NodeInfo node) {
@@ -222,9 +222,9 @@ public class SystemStateBroadcaster {
             return; // Nothing to do for the current state
         }
         final int currentStateVersion = clusterStateBundle.getVersion();
-        boolean anyDistributorsNeedStateBundle = dbContext.getCluster().getNodeInfo().stream()
-                .filter(NodeInfo::isDistributor)
-                .anyMatch(this::nodeNeedsClusterStateBundle);
+        boolean anyDistributorsNeedStateBundle = dbContext.getCluster().getNodeInfos().stream()
+                                                          .filter(NodeInfo::isDistributor)
+                                                          .anyMatch(this::nodeNeedsClusterStateBundle);
 
         if (!anyDistributorsNeedStateBundle && (currentStateVersion > lastStateVersionBundleAcked)) {
             markCurrentClusterStateBundleAsReceivedByAllDistributors();
@@ -243,9 +243,9 @@ public class SystemStateBroadcaster {
             return;
         }
 
-        boolean anyDistributorsNeedActivation = dbContext.getCluster().getNodeInfo().stream()
-                .filter(NodeInfo::isDistributor)
-                .anyMatch(this::nodeNeedsClusterStateActivation);
+        boolean anyDistributorsNeedActivation = dbContext.getCluster().getNodeInfos().stream()
+                                                         .filter(NodeInfo::isDistributor)
+                                                         .anyMatch(this::nodeNeedsClusterStateActivation);
 
         if (!anyDistributorsNeedActivation && (currentStateVersion > lastClusterStateVersionConverged)) {
             markCurrentClusterStateAsConverged(database, dbContext, fleetController);
@@ -352,7 +352,7 @@ public class SystemStateBroadcaster {
 
     private static ClusterState buildModifiedClusterState(ClusterState sourceState, DatabaseHandler.DatabaseContext dbContext) {
         ClusterState newState = sourceState.clone();
-        for (NodeInfo n : dbContext.getCluster().getNodeInfo()) {
+        for (NodeInfo n : dbContext.getCluster().getNodeInfos()) {
             NodeState ns = newState.getNodeState(n.getNode());
             if (!n.isDistributor() && ns.getStartTimestamp() == 0) {
                 ns.setStartTimestamp(n.getStartTimestamp());
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseFactory.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseFactory.java
index 45a416fade4..31f6bbfe932 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseFactory.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseFactory.java
@@ -1,8 +1,6 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.core.database;
 
-import com.yahoo.vespa.clustercontroller.core.ContentCluster;
-
 /**
  * Database factory to enable test mocking of DB features. In practice, this
  * will always be {@link ZooKeeperDatabase} due to rather heavy ZK feature
@@ -11,14 +9,10 @@ import com.yahoo.vespa.clustercontroller.core.ContentCluster;
 public interface DatabaseFactory {
 
     class Params {
-        ContentCluster cluster;
-        int nodeIndex;
         String dbAddress;
         int dbSessionTimeout;
         Database.DatabaseListener listener;
 
-        Params cluster(ContentCluster c) { this.cluster = c; return this; }
-        Params nodeIndex(int i) { this.nodeIndex = i; return this; }
         Params databaseAddress(String address) { this.dbAddress = address; return this; }
         Params databaseSessionTimeout(int timeout) { this.dbSessionTimeout = timeout; return this; }
         Params databaseListener(Database.DatabaseListener listener) { this.listener = listener; return this; }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java
index 0c6c773a9bc..01b8ed48c80 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/DatabaseHandler.java
@@ -10,8 +10,8 @@ import com.yahoo.vespa.clustercontroller.core.FleetControllerContext;
 import com.yahoo.vespa.clustercontroller.core.FleetController;
 import com.yahoo.vespa.clustercontroller.core.NodeInfo;
 import com.yahoo.vespa.clustercontroller.core.Timer;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import org.apache.zookeeper.KeeperException;
 
 import java.io.PrintWriter;
@@ -32,8 +32,8 @@ public class DatabaseHandler {
     public interface DatabaseContext {
         ContentCluster getCluster();
         FleetController getFleetController();
-        NodeAddedOrRemovedListener getNodeAddedOrRemovedListener();
-        NodeStateOrHostInfoChangeHandler getNodeStateUpdateListener();
+        SlobrokListener getNodeAddedOrRemovedListener();
+        NodeListener getNodeStateUpdateListener();
     }
 
     private static class Data {
@@ -191,9 +191,8 @@ public class DatabaseHandler {
                 // being called, but after receiving a database loss event.
                 clearSessionMetaData(false);
                 fleetControllerContext.log(logger, Level.INFO, "Setting up new ZooKeeper session at " + zooKeeperAddress);
-                DatabaseFactory.Params params = new DatabaseFactory.Params()
-                        .cluster(cluster)
-                        .nodeIndex(fleetControllerContext.id().index())
+                DatabaseFactory.Params params = new DatabaseFactory
+                        .Params()
                         .databaseAddress(zooKeeperAddress)
                         .databaseSessionTimeout(zooKeeperSessionTimeout)
                         .databaseListener(dbListener);
@@ -426,10 +425,10 @@ public class DatabaseHandler {
         }
     }
 
-    public void saveWantedStates(DatabaseContext databaseContext) {
+    public boolean saveWantedStates(DatabaseContext databaseContext) {
         fleetControllerContext.log(logger, Level.FINE, () -> "Checking whether wanted states have changed compared to zookeeper version.");
         Map<Node, NodeState> wantedStates = new TreeMap<>();
-        for (NodeInfo info : databaseContext.getCluster().getNodeInfo()) {
+        for (NodeInfo info : databaseContext.getCluster().getNodeInfos()) {
             if (!info.getUserWantedState().equals(new NodeState(info.getNode().getType(), State.UP))) {
                 wantedStates.put(info.getNode(), info.getUserWantedState());
             }
@@ -444,6 +443,9 @@ public class DatabaseHandler {
             fleetControllerContext.log(logger, Level.FINE, () -> "Scheduling new wanted states to be stored into zookeeper.");
             pendingStore.wantedStates = wantedStates;
             doNextZooKeeperTask(databaseContext);
+            return true;
+        } else {
+            return false;
         }
     }
 
@@ -466,7 +468,11 @@ public class DatabaseHandler {
         boolean altered = false;
         for (Node node : wantedStates.keySet()) {
             NodeInfo nodeInfo = databaseContext.getCluster().getNodeInfo(node);
-            if (nodeInfo == null) continue; // ignore wanted state of nodes which doesn't exist
+            if (nodeInfo == null) {
+                databaseContext.getNodeStateUpdateListener().handleRemovedNode(node);
+                altered = true;
+                continue;
+            }
             NodeState wantedState = wantedStates.get(node);
             if ( ! nodeInfo.getUserWantedState().equals(wantedState)) {
                 nodeInfo.setWantedState(wantedState);
@@ -477,7 +483,7 @@ public class DatabaseHandler {
         }
 
         // Remove wanted state from any node having a wanted state set that is no longer valid
-        for (NodeInfo info : databaseContext.getCluster().getNodeInfo()) {
+        for (NodeInfo info : databaseContext.getCluster().getNodeInfos()) {
             NodeState wantedState = wantedStates.get(info.getNode());
             if (wantedState == null && !info.getUserWantedState().equals(new NodeState(info.getNode().getType(), State.UP))) {
                 info.setWantedState(null);
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/MasterDataGatherer.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/MasterDataGatherer.java
index 907f2e0c5e9..0c32d8ef6c2 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/MasterDataGatherer.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/MasterDataGatherer.java
@@ -24,7 +24,7 @@ public class MasterDataGatherer {
         return Integer.parseInt(nodeName.substring(lastSlash + 1));
     }
 
-    private final String zooKeeperRoot; // The root path in zookeeper, typically /vespa/fleetcontroller/<clustername>/
+    private final ZooKeeperPaths paths;
     private Map<Integer, Integer> masterData = new TreeMap<>(); // The master state last reported to the fleetcontroller
     private final Map<Integer, Integer> nextMasterData = new TreeMap<>(); // Temporary master state while gathering new info from zookeeper
     private final AsyncCallback.ChildrenCallback childListener = new DirCallback(); // Dir change listener
@@ -46,7 +46,7 @@ public class MasterDataGatherer {
             switch (watchedEvent.getType()) {
                 case NodeChildrenChanged: // Fleetcontrollers have either connected or disconnected to ZooKeeper
                     log.log(Level.INFO, "Fleetcontroller " + nodeIndex + ": A change occurred in the list of registered fleetcontrollers. Requesting new information");
-                    session.getChildren(zooKeeperRoot + "indexes", this, childListener, null);
+                    session.getChildren(paths.indexesRoot(), this, childListener, null);
                     break;
                 case NodeDataChanged: // A fleetcontroller has changed what node it is voting for
                     log.log(Level.INFO, "Fleetcontroller " + nodeIndex + ": Altered data in node " + watchedEvent.getPath() + ". Requesting new vote");
@@ -54,7 +54,7 @@ public class MasterDataGatherer {
                     synchronized (nextMasterData) {
                         nextMasterData.put(index, null);
                     }
-                    session.getData(zooKeeperRoot + "indexes/" + index, this, nodeListener, null);
+                    session.getData(paths.indexOf(index), this, nodeListener, null);
                     break;
                 case NodeCreated: // How can this happen? Can one leave watches on non-existing nodes?
                     log.log(Level.WARNING, "Fleetcontroller " + nodeIndex + ": Got unexpected ZooKeeper event NodeCreated");
@@ -85,8 +85,8 @@ public class MasterDataGatherer {
                     int index = Integer.parseInt(node);
                     nextMasterData.put(index, null);
                     log.log(Level.FINE, () -> "Fleetcontroller " + nodeIndex + ": Attempting to fetch data in node '"
-                            + zooKeeperRoot + index + "' to see vote");
-                    session.getData(zooKeeperRoot + "indexes/" + index, changeWatcher, nodeListener, null);
+                                              + paths.indexOf(index) + "' to see vote");
+                    session.getData(paths.indexOf(index), changeWatcher, nodeListener, null);
                     // Invocation of cycleCompleted() for fully accumulated election state will happen
                     // as soon as all getData calls have been processed.
                 }
@@ -146,8 +146,8 @@ public class MasterDataGatherer {
     }
 
     /** Constructor setting up the various needed members, and initializing the first data fetch to start things up */
-    public MasterDataGatherer(ZooKeeper session, String zooKeeperRoot, Database.DatabaseListener listener, int nodeIndex) {
-        this.zooKeeperRoot = zooKeeperRoot;
+    public MasterDataGatherer(ZooKeeper session, ZooKeeperPaths paths, Database.DatabaseListener listener, int nodeIndex) {
+        this.paths = paths;
         this.session = session;
         this.listener = listener;
         this.nodeIndex = nodeIndex;
@@ -161,7 +161,7 @@ public class MasterDataGatherer {
         synchronized (nextMasterData) {
             masterData = new TreeMap<>();
             nextMasterData.clear();
-            session.getChildren(zooKeeperRoot + "indexes", changeWatcher, childListener, null);
+            session.getChildren(paths.indexesRoot(), changeWatcher, childListener, null);
         }
     }
 
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabase.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabase.java
index 72c81489351..ea745a56066 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabase.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabase.java
@@ -6,7 +6,6 @@ import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.AnnotatedClusterState;
 import com.yahoo.vespa.clustercontroller.core.ClusterStateBundle;
-import com.yahoo.vespa.clustercontroller.core.ContentCluster;
 import com.yahoo.vespa.clustercontroller.core.FleetControllerContext;
 import com.yahoo.vespa.clustercontroller.core.rpc.EnvelopedClusterStateBundleCodec;
 import com.yahoo.vespa.clustercontroller.core.rpc.SlimeClusterStateBundleCodec;
@@ -38,13 +37,12 @@ public class ZooKeeperDatabase extends Database {
     private static final Charset utf8 = StandardCharsets.UTF_8;
     private static final List<ACL> acl = ZooDefs.Ids.OPEN_ACL_UNSAFE;
 
-    private final String zooKeeperRoot;
+    private final ZooKeeperPaths paths;
     private final Database.DatabaseListener listener;
     private final ZooKeeperWatcher watcher = new ZooKeeperWatcher();
     private final ZooKeeper session;
     private boolean sessionOpen = true;
     private final FleetControllerContext context;
-    private final int nodeIndex;
     private final MasterDataGatherer masterDataGatherer;
     // Expected ZK znode versions. Note: these are _not_ -1 as that would match anything.
     // We expect the caller to invoke the load methods prior to calling any store methods.
@@ -102,31 +100,30 @@ public class ZooKeeperDatabase extends Database {
         }
     }
 
-    public ZooKeeperDatabase(FleetControllerContext context, ContentCluster cluster, int nodeIndex, String address, int timeout, DatabaseListener zksl) throws IOException, KeeperException, InterruptedException {
+    public ZooKeeperDatabase(FleetControllerContext context, String address, int timeout, DatabaseListener zksl) throws IOException, KeeperException, InterruptedException {
         this.context = context;
-        this.nodeIndex = nodeIndex;
-        zooKeeperRoot = "/vespa/fleetcontroller/" + cluster.getName() + "/";
+        this.paths = new ZooKeeperPaths(context.id());
         session = new ZooKeeper(address, timeout, watcher, new ZkClientConfigBuilder().toConfig());
         boolean completedOk = false;
         try{
             this.listener = zksl;
             setupRoot();
             context.log(log, Level.FINEST, "Asking for initial data on master election");
-            masterDataGatherer = new MasterDataGatherer(session, zooKeeperRoot, listener, nodeIndex);
+            masterDataGatherer = new MasterDataGatherer(session, paths, listener, context.id().index());
             completedOk = true;
         } finally {
             if (!completedOk) session.close();
         }
     }
 
-    private void createNode(String prefix, String nodename, byte[] value) throws KeeperException, InterruptedException {
+    private void createNode(String path, byte[] value) throws KeeperException, InterruptedException {
         try{
-            if (session.exists(prefix + nodename, false) != null) {
-                context.log(log, Level.FINE, () -> "Zookeeper node '" + prefix + nodename + "' already exists. Not creating it");
+            if (session.exists(path, false) != null) {
+                context.log(log, Level.FINE, () -> "Zookeeper node '" + path + "' already exists. Not creating it");
                 return;
             }
-            session.create(prefix + nodename, value, acl, CreateMode.PERSISTENT);
-            context.log(log, Level.FINE, () -> "Created zookeeper node '" + prefix + nodename + "'");
+            session.create(path, value, acl, CreateMode.PERSISTENT);
+            context.log(log, Level.FINE, () -> "Created zookeeper node '" + path + "'");
         } catch (KeeperException.NodeExistsException e) {
             context.log(log, Level.FINE, "Node to create existed, but this is normal as other nodes " +
                                          "may create them at the same time.");
@@ -134,21 +131,21 @@ public class ZooKeeperDatabase extends Database {
     }
 
     private void setupRoot() throws KeeperException, InterruptedException {
-        String[] pathElements = zooKeeperRoot.substring(1).split("/");
+        String[] pathElements = paths.root().substring(1).split("/");
         String path = "";
         for (String elem : pathElements) {
             path += "/" + elem;
-            createNode("", path, new byte[0]);
+            createNode(path, new byte[0]);
         }
-        createNode(zooKeeperRoot, "indexes", new byte[0]);
-        createNode(zooKeeperRoot, "wantedstates", new byte[0]);
-        createNode(zooKeeperRoot, "starttimestamps", new byte[0]);
-        createNode(zooKeeperRoot, "latestversion", Integer.valueOf(0).toString().getBytes(utf8));
-        createNode(zooKeeperRoot, "published_state_bundle", new byte[0]); // TODO dedupe string constants
-        byte[] val = String.valueOf(nodeIndex).getBytes(utf8);
-        deleteNodeIfExists(getMyIndexPath());
+        createNode(paths.indexesRoot(), new byte[0]);
+        createNode(paths.wantedStates(), new byte[0]);
+        createNode(paths.startTimestamps(), new byte[0]);
+        createNode(paths.latestVersion(), Integer.valueOf(0).toString().getBytes(utf8));
+        createNode(paths.publishedStateBundle(), new byte[0]);
+        byte[] val = String.valueOf(context.id().index()).getBytes(utf8);
+        deleteNodeIfExists(paths.indexOfMe());
         context.log(log, Level.INFO, "Creating ephemeral master vote node with vote to self.");
-        session.create(getMyIndexPath(), val, acl, CreateMode.EPHEMERAL);
+        session.create(paths.indexOfMe(), val, acl, CreateMode.EPHEMERAL);
     }
 
     private void deleteNodeIfExists(String path) throws KeeperException, InterruptedException {
@@ -158,10 +155,6 @@ public class ZooKeeperDatabase extends Database {
         }
     }
 
-    private String getMyIndexPath() {
-        return zooKeeperRoot + "indexes/" + nodeIndex;
-    }
-
     /**
      * If this is called, we assume we're in shutdown situation, or we are doing it because we need a new session.
      * Thus we only need to free up resources, no need to notify anyone.
@@ -192,8 +185,8 @@ public class ZooKeeperDatabase extends Database {
     public boolean storeMasterVote(int wantedMasterIndex) {
         byte[] val = String.valueOf(wantedMasterIndex).getBytes(utf8);
         try{
-            session.setData(getMyIndexPath(), val, -1);
-            context.log(log, Level.INFO, "Stored new vote in ephemeral node. " + nodeIndex + " -> " + wantedMasterIndex);
+            session.setData(paths.indexOfMe(), val, -1);
+            context.log(log, Level.INFO, "Stored new vote in ephemeral node. " + context.id().index() + " -> " + wantedMasterIndex);
             return true;
         } catch (InterruptedException e) {
             throw new RuntimeException(e);
@@ -206,7 +199,7 @@ public class ZooKeeperDatabase extends Database {
         byte[] data = Integer.toString(version).getBytes(utf8);
         try{
             context.log(log, Level.INFO, "Storing new cluster state version in ZooKeeper: " + version);
-            var stat = session.setData(zooKeeperRoot + "latestversion", data, lastKnownStateVersionZNodeVersion);
+            var stat = session.setData(paths.latestVersion(), data, lastKnownStateVersionZNodeVersion);
             lastKnownStateVersionZNodeVersion = stat.getVersion();
             return true;
         } catch (InterruptedException e) {
@@ -222,17 +215,17 @@ public class ZooKeeperDatabase extends Database {
 
     public Integer retrieveLatestSystemStateVersion() {
         Stat stat = new Stat();
-        context.log(log, Level.FINE, "Fetching latest cluster state at '%slatestversion'", zooKeeperRoot);
+        context.log(log, Level.FINE, "Fetching latest cluster state at '%s'", paths.latestVersion());
         final byte[] data;
         try {
-            data = session.getData(zooKeeperRoot + "latestversion", false, stat);
+            data = session.getData(paths.latestVersion(), false, stat);
         } catch (KeeperException.NoNodeException e) {
             // Initial condition: No latest version has ever been written (or ZK state completely wiped!)
             lastKnownStateVersionZNodeVersion = 0;
             maybeLogExceptionWarning(e, "No latest system state found");
             return null;
         } catch (InterruptedException | KeeperException e) {
-            throw new RuntimeException("Failed to get " + zooKeeperRoot + "latestversion", e);
+            throw new RuntimeException("Failed to get " + paths.latestVersion(), e);
         }
 
         lastKnownStateVersionZNodeVersion = stat.getVersion();
@@ -257,8 +250,8 @@ public class ZooKeeperDatabase extends Database {
         }
         byte[] val = sb.toString().getBytes(utf8);
         try{
-            context.log(log, Level.FINE, () -> "Storing wanted states at '" + zooKeeperRoot + "wantedstates'");
-            session.setData(zooKeeperRoot + "wantedstates", val, -1);
+            context.log(log, Level.FINE, () -> "Storing wanted states at '" + paths.wantedStates() + "'");
+            session.setData(paths.wantedStates(), val, -1);
             return true;
         } catch (InterruptedException e) {
             throw new RuntimeException(e);
@@ -270,9 +263,9 @@ public class ZooKeeperDatabase extends Database {
 
     public Map<Node, NodeState> retrieveWantedStates() {
         try{
-            context.log(log, Level.FINE, () -> "Fetching wanted states at '" + zooKeeperRoot + "wantedstates'");
+            context.log(log, Level.FINE, () -> "Fetching wanted states at '" + paths.wantedStates() + "'");
             Stat stat = new Stat();
-            byte[] data = session.getData(zooKeeperRoot + "wantedstates", false, stat);
+            byte[] data = session.getData(paths.wantedStates(), false, stat);
             Map<Node, NodeState> wanted = new TreeMap<>();
             if (data != null && data.length > 0) {
                 StringTokenizer st = new StringTokenizer(new String(data, utf8), "\n", false);
@@ -308,8 +301,8 @@ public class ZooKeeperDatabase extends Database {
         }
         byte val[] = sb.toString().getBytes(utf8);
         try{
-            context.log(log, Level.FINE, () -> "Storing start timestamps at '" + zooKeeperRoot + "starttimestamps");
-            session.setData(zooKeeperRoot + "starttimestamps", val, -1);
+            context.log(log, Level.FINE, () -> "Storing start timestamps at '" + paths.startTimestamps() + "'");
+            session.setData(paths.startTimestamps(), val, -1);
             return true;
         } catch (InterruptedException e) {
             throw new RuntimeException(e);
@@ -322,9 +315,9 @@ public class ZooKeeperDatabase extends Database {
     @Override
     public Map<Node, Long> retrieveStartTimestamps() {
         try{
-            context.log(log, Level.FINE, () -> "Fetching start timestamps at '" + zooKeeperRoot + "starttimestamps'");
+            context.log(log, Level.FINE, () -> "Fetching start timestamps at '" + paths.startTimestamps() + "'");
             Stat stat = new Stat();
-            byte[] data = session.getData(zooKeeperRoot + "starttimestamps", false, stat);
+            byte[] data = session.getData(paths.startTimestamps(), false, stat);
             Map<Node, Long> wanted = new TreeMap<Node, Long>();
             if (data != null && data.length > 0) {
                 StringTokenizer st = new StringTokenizer(new String(data, utf8), "\n", false);
@@ -357,10 +350,9 @@ public class ZooKeeperDatabase extends Database {
         try{
             context.log(log,
                         Level.FINE,
-                        () -> String.format("Storing published state bundle %s at " +
-                                            "'%spublished_state_bundle' with expected znode version %d",
-                                            stateBundle, zooKeeperRoot, lastKnownStateBundleZNodeVersion));
-            var stat = session.setData(zooKeeperRoot + "published_state_bundle", encodedBundle, lastKnownStateBundleZNodeVersion);
+                        () -> String.format("Storing published state bundle %s at '%s' with expected znode version %d",
+                                            stateBundle, paths.publishedStateBundle(), lastKnownStateBundleZNodeVersion));
+            var stat = session.setData(paths.publishedStateBundle(), encodedBundle, lastKnownStateBundleZNodeVersion);
             lastKnownStateBundleZNodeVersion = stat.getVersion();
         } catch (InterruptedException e) {
             throw new RuntimeException(e);
@@ -378,7 +370,7 @@ public class ZooKeeperDatabase extends Database {
     public ClusterStateBundle retrieveLastPublishedStateBundle() {
         Stat stat = new Stat();
         try {
-            byte[] data = session.getData(zooKeeperRoot + "published_state_bundle", false, stat);
+            byte[] data = session.getData(paths.publishedStateBundle(), false, stat);
             lastKnownStateBundleZNodeVersion = stat.getVersion();
             if (data != null && data.length != 0) {
                 EnvelopedClusterStateBundleCodec envelopedBundleCodec = new SlimeClusterStateBundleCodec();
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabaseFactory.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabaseFactory.java
index 71f39135609..3263c06a95c 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabaseFactory.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperDatabaseFactory.java
@@ -13,8 +13,7 @@ public class ZooKeeperDatabaseFactory implements DatabaseFactory {
 
     @Override
     public Database create(Params params) throws Exception {
-        return new ZooKeeperDatabase(context, params.cluster, params.nodeIndex, params.dbAddress,
-                                     params.dbSessionTimeout, params.listener);
+        return new ZooKeeperDatabase(context, params.dbAddress, params.dbSessionTimeout, params.listener);
     }
 
 }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperPaths.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperPaths.java
new file mode 100644
index 00000000000..06a9b240175
--- /dev/null
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/database/ZooKeeperPaths.java
@@ -0,0 +1,26 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core.database;
+
+import com.yahoo.vespa.clustercontroller.core.FleetControllerId;
+
+/**
+ * @author hakonhall
+ */
+public class ZooKeeperPaths {
+    private final String root;
+    private final int myIndex;
+
+    public ZooKeeperPaths(FleetControllerId id) {
+        this.root = "/vespa/fleetcontroller/" + id.clusterName();
+        this.myIndex = id.index();
+    }
+
+    public String root() { return root; }
+    public String indexesRoot() { return root + "/indexes"; }
+    public String indexOf(int index) { return indexesRoot() + "/" + index; }
+    public String indexOfMe() { return indexOf(myIndex); }
+    public String wantedStates() { return root + "/wantedstates"; }
+    public String publishedStateBundle() { return root + "/published_state_bundle"; }
+    public String latestVersion() { return root + "/latestversion"; }
+    public String startTimestamps() { return root + "/starttimestamps"; }
+}
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeListener.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeListener.java
new file mode 100644
index 00000000000..351b68b3b57
--- /dev/null
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeListener.java
@@ -0,0 +1,25 @@
+// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.vespa.clustercontroller.core.listeners;
+
+import com.yahoo.vdslib.state.Node;
+import com.yahoo.vdslib.state.NodeState;
+import com.yahoo.vespa.clustercontroller.core.NodeInfo;
+import com.yahoo.vespa.clustercontroller.core.hostinfo.HostInfo;
+
+/**
+ * Implemented by classes wanting events when there are node changes.
+ */
+public interface NodeListener {
+
+    default void handleNewNodeState(NodeInfo currentInfo, NodeState newState) {}
+    default void handleNewWantedNodeState(NodeInfo node, NodeState newState) {}
+
+    /** Invoked after NodeInfo has been removed from the content cluster. */
+    default void handleRemovedNode(Node node) {}
+
+    /**
+     * For every getnodestate RPC call, handleUpdatedHostInfo() will be called with the host info JSON string.
+     */
+    default void handleUpdatedHostInfo(NodeInfo node, HostInfo newHostInfo) {}
+
+}
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeStateOrHostInfoChangeHandler.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeStateOrHostInfoChangeHandler.java
deleted file mode 100644
index b76b46b216b..00000000000
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeStateOrHostInfoChangeHandler.java
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.clustercontroller.core.listeners;
-
-import com.yahoo.vdslib.state.NodeState;
-import com.yahoo.vespa.clustercontroller.core.NodeInfo;
-import com.yahoo.vespa.clustercontroller.core.hostinfo.HostInfo;
-
-/**
- * Implemented by classes wanting events when node states changes.
- */
-public interface NodeStateOrHostInfoChangeHandler {
-
-    void handleNewNodeState(NodeInfo currentInfo, NodeState newState);
-    void handleNewWantedNodeState(NodeInfo node, NodeState newState);
-
-    /**
-     * For every getnodestate RPC call, handleUpdatedHostInfo() will be called with the host info JSON string.
-     */
-    void handleUpdatedHostInfo(NodeInfo node, HostInfo newHostInfo);
-
-}
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeAddedOrRemovedListener.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/SlobrokListener.java
index d811708c999..5a397cc4935 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/NodeAddedOrRemovedListener.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/listeners/SlobrokListener.java
@@ -4,9 +4,9 @@ package com.yahoo.vespa.clustercontroller.core.listeners;
 import com.yahoo.vespa.clustercontroller.core.NodeInfo;
 
 /**
- * Listeners for new nodes detected.
+ * Implemented by classes that wants to be notified of Slobrok events.
  */
-public interface NodeAddedOrRemovedListener {
+public interface SlobrokListener {
     void handleNewNode(NodeInfo node);
     void handleMissingNode(NodeInfo node);
     void handleNewRpcAddress(NodeInfo node);
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequest.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequest.java
index 431c207af5c..ddbda2bf776 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequest.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequest.java
@@ -11,7 +11,7 @@ import com.yahoo.vespa.clustercontroller.core.ContentCluster;
 import com.yahoo.vespa.clustercontroller.core.NodeInfo;
 import com.yahoo.vespa.clustercontroller.core.NodeStateChangeChecker;
 import com.yahoo.vespa.clustercontroller.core.RemoteClusterControllerTask;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import com.yahoo.vespa.clustercontroller.core.restapiv2.Id;
 import com.yahoo.vespa.clustercontroller.core.restapiv2.MissingIdException;
 import com.yahoo.vespa.clustercontroller.core.restapiv2.Request;
@@ -62,7 +62,7 @@ public class SetNodeStateRequest extends Request<SetResponse> {
                 condition,
                 newStates,
                 id.getNode(),
-                context.nodeStateOrHostInfoChangeHandler,
+                context.nodeListener,
                 context.currentConsolidatedState,
                 context.masterInfo.inMasterMoratorium(),
                 probe);
@@ -112,7 +112,7 @@ public class SetNodeStateRequest extends Request<SetResponse> {
             SetUnitStateRequest.Condition condition,
             Map<String, UnitState> newStates,
             Node node,
-            NodeStateOrHostInfoChangeHandler stateListener,
+            NodeListener stateListener,
             ClusterState currentClusterState,
             boolean inMasterMoratorium,
             boolean probe) throws StateRestApiException {
@@ -159,7 +159,7 @@ public class SetNodeStateRequest extends Request<SetResponse> {
             SetUnitStateRequest.Condition condition,
             NodeInfo nodeInfo,
             ContentCluster cluster,
-            NodeStateOrHostInfoChangeHandler stateListener,
+            NodeListener stateListener,
             boolean probe) {
         if (result.settingWantedStateIsAllowed()) {
             setNewWantedState(nodeInfo, newWantedState, stateListener, probe);
@@ -186,7 +186,7 @@ public class SetNodeStateRequest extends Request<SetResponse> {
     private static void setDistributorWantedState(ContentCluster cluster,
                                                   int index,
                                                   NodeState newStorageWantedState,
-                                                  NodeStateOrHostInfoChangeHandler stateListener,
+                                                  NodeListener stateListener,
                                                   boolean probe) {
         Node distributorNode = new Node(NodeType.DISTRIBUTOR, index);
         NodeInfo nodeInfo = cluster.getNodeInfo(distributorNode);
@@ -224,7 +224,7 @@ public class SetNodeStateRequest extends Request<SetResponse> {
 
     private static void setNewWantedState(NodeInfo nodeInfo,
                                           NodeState newWantedState,
-                                          NodeStateOrHostInfoChangeHandler stateListener,
+                                          NodeListener stateListener,
                                           boolean probe) {
         if (probe) return;
         nodeInfo.setWantedState(newWantedState);
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStatesForClusterRequest.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStatesForClusterRequest.java
index 55ac75957bc..1cc8f2860c6 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStatesForClusterRequest.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStatesForClusterRequest.java
@@ -70,7 +70,7 @@ public class SetNodeStatesForClusterRequest extends Request<SetResponse> {
                     condition,
                     newStates,
                     node,
-                    context.nodeStateOrHostInfoChangeHandler,
+                    context.nodeListener,
                     context.currentConsolidatedState,
                     context.masterInfo.inMasterMoratorium(),
                     probe);
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/WantedStateSetter.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/WantedStateSetter.java
index 8095d37d641..51b2f1cfe4f 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/WantedStateSetter.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/WantedStateSetter.java
@@ -4,7 +4,7 @@ package com.yahoo.vespa.clustercontroller.core.restapiv2.requests;
 import com.yahoo.vdslib.state.ClusterState;
 import com.yahoo.vdslib.state.Node;
 import com.yahoo.vespa.clustercontroller.core.ContentCluster;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.StateRestApiException;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.requests.SetUnitStateRequest;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.response.SetResponse;
@@ -21,7 +21,7 @@ public interface WantedStateSetter {
                     SetUnitStateRequest.Condition condition,
                     Map<String, UnitState> newStates,
                     Node node,
-                    NodeStateOrHostInfoChangeHandler stateListener,
+                    NodeListener stateListener,
                     ClusterState currentClusterState,
                     boolean inMasterMoratorium,
                     boolean probe) throws StateRestApiException;
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RpcServer.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RpcServer.java
index 65c8a9df28e..6e416ce4906 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RpcServer.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/RpcServer.java
@@ -27,8 +27,8 @@ import com.yahoo.vespa.clustercontroller.core.ContentCluster;
 import com.yahoo.vespa.clustercontroller.core.MasterElectionHandler;
 import com.yahoo.vespa.clustercontroller.core.NodeInfo;
 import com.yahoo.vespa.clustercontroller.core.Timer;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 
 import java.io.PrintWriter;
 import java.io.StringWriter;
@@ -186,8 +186,8 @@ public class RpcServer {
     }
 
     public boolean handleRpcRequests(ContentCluster cluster, ClusterState systemState,
-                                     NodeStateOrHostInfoChangeHandler changeListener,
-                                     NodeAddedOrRemovedListener addedListener)
+                                     NodeListener changeListener,
+                                     SlobrokListener addedListener)
     {
         boolean handledAnyRequests = false;
         if (!isConnected()) {
@@ -234,7 +234,7 @@ public class RpcServer {
                     log.log(Level.FINE, "Resolving RPC getNodeList request");
                     List<String> slobrok = new ArrayList<String>();
                     List<String> rpc = new ArrayList<String>();
-                    for(NodeInfo node : cluster.getNodeInfo()) {
+                    for(NodeInfo node : cluster.getNodeInfos()) {
                         String s1 = node.getSlobrokAddress();
                         String s2 = node.getRpcAddress();
                         assert(s1 != null);
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/SlobrokClient.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/SlobrokClient.java
index 7487f9546b7..c88bf71af09 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/SlobrokClient.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/rpc/SlobrokClient.java
@@ -13,7 +13,7 @@ import com.yahoo.vespa.clustercontroller.core.FleetControllerContext;
 import com.yahoo.vespa.clustercontroller.core.NodeInfo;
 import com.yahoo.vespa.clustercontroller.core.NodeLookup;
 import com.yahoo.vespa.clustercontroller.core.Timer;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
 
 import java.util.Iterator;
 import java.util.LinkedList;
@@ -78,7 +78,7 @@ public class SlobrokClient implements NodeLookup {
     }
 
     @Override
-    public boolean updateCluster(ContentCluster cluster, NodeAddedOrRemovedListener listener) {
+    public boolean updateCluster(ContentCluster cluster, SlobrokListener listener) {
         if (mirror == null) return false;
         int mirrorVersion = mirror.updates();
         if (freshMirror) {
@@ -149,7 +149,7 @@ public class SlobrokClient implements NodeLookup {
             }
         }
         cluster.setSlobrokGenerationCount(mirrorVersion);
-        for (NodeInfo nodeInfo : cluster.getNodeInfo()) {
+        for (NodeInfo nodeInfo : cluster.getNodeInfos()) {
             if (slobrokNodes.containsKey(nodeInfo.getNode()) && nodeInfo.isRpcAddressOutdated()) {
                 context.log(log,
                             Level.WARNING,
@@ -174,7 +174,7 @@ public class SlobrokClient implements NodeLookup {
             List<SlobrokData> alteredRpcAddress,
             List<NodeInfo> returningRpcAddressNodeInfos)
     {
-        Iterator<NodeInfo> oldIt = oldCluster.getNodeInfo().iterator();
+        Iterator<NodeInfo> oldIt = oldCluster.getNodeInfos().iterator();
         Iterator<SlobrokData> newIt = slobrokNodes.values().iterator();
         NodeInfo oldNext = null;
         SlobrokData newNext = null;
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFixture.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFixture.java
index 4ce32484098..f8d41405e85 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFixture.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterFixture.java
@@ -8,7 +8,7 @@ import com.yahoo.vdslib.state.Node;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
 import com.yahoo.vdslib.state.State;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 
 import java.util.Collection;
 import java.util.HashSet;
@@ -57,7 +57,7 @@ public class ClusterFixture {
     private void doReportNodeState(final Node node, final NodeState nodeState) {
         final ClusterState stateBefore = rawGeneratedClusterState();
 
-        NodeStateOrHostInfoChangeHandler handler = mock(NodeStateOrHostInfoChangeHandler.class);
+        NodeListener handler = mock(NodeListener.class);
         NodeInfo nodeInfo = cluster.getNodeInfo(node);
 
         nodeStateChangeHandler.handleNewReportedNodeState(stateBefore, nodeInfo, nodeState, handler);
@@ -142,7 +142,7 @@ public class ClusterFixture {
     }
 
     public ClusterFixture assignDummyRpcAddresses() {
-        cluster.getNodeInfo().forEach(ni -> {
+        cluster.getNodeInfos().forEach(ni -> {
             ni.setRpcAddress(String.format("tcp/%s.%d.local:0",
                     ni.isStorage() ? "storage" : "distributor",
                     ni.getNodeIndex()));
@@ -169,7 +169,7 @@ public class ClusterFixture {
         Set<ConfiguredNode> configuredNodes = new HashSet<>(cluster.getConfiguredNodes().values());
         configuredNodes.remove(new ConfiguredNode(nodeIndex, false));
         configuredNodes.add(new ConfiguredNode(nodeIndex, true));
-        cluster.setNodes(configuredNodes);
+        cluster.setNodes(configuredNodes, new NodeListener() {});
         return this;
     }
 
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java
index a621b0f565a..1f7b9293960 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DatabaseHandlerTest.java
@@ -1,23 +1,42 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.core;
 
+import com.yahoo.vdslib.state.Node;
+import com.yahoo.vdslib.state.NodeState;
+import com.yahoo.vdslib.state.NodeType;
+import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.database.Database;
 import com.yahoo.vespa.clustercontroller.core.database.DatabaseFactory;
 import com.yahoo.vespa.clustercontroller.core.database.DatabaseHandler;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
+import org.junit.After;
+import org.junit.Before;
 import org.junit.Test;
+import org.mockito.ArgumentCaptor;
+import org.mockito.Captor;
+import org.mockito.MockitoAnnotations;
+
+import java.util.Map;
+import java.util.TreeMap;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 public class DatabaseHandlerTest {
 
+    private AutoCloseable openMock = null;
+
+    @Captor
+    ArgumentCaptor<TreeMap<Node, NodeState>> wantedStatesArgument;
+
     static class Fixture {
         final ClusterFixture clusterFixture = ClusterFixture.forFlatCluster(10);
         final FleetController mockController = mock(FleetController.class);
@@ -52,12 +71,12 @@ public class DatabaseHandlerTest {
                 }
 
                 @Override
-                public NodeAddedOrRemovedListener getNodeAddedOrRemovedListener() {
+                public SlobrokListener getNodeAddedOrRemovedListener() {
                     return null;
                 }
 
                 @Override
-                public NodeStateOrHostInfoChangeHandler getNodeStateUpdateListener() {
+                public NodeListener getNodeStateUpdateListener() {
                     return null;
                 }
             };
@@ -70,6 +89,16 @@ public class DatabaseHandlerTest {
         }
     }
 
+    @Before
+    public void setUp() {
+        openMock = MockitoAnnotations.openMocks(this);
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        openMock.close();
+    }
+
     @Test
     public void can_store_latest_cluster_state_bundle() throws Exception {
         Fixture f = new Fixture();
@@ -104,4 +133,29 @@ public class DatabaseHandlerTest {
         assertEquals(ClusterStateBundle.empty(), retrievedBundle);
     }
 
+    @Test
+    public void save_wanted_state_of_configured_nodes() throws Exception {
+        var fixture = new Fixture();
+        DatabaseHandler handler = fixture.createHandler();
+        DatabaseHandler.DatabaseContext databaseContext = fixture.createMockContext();
+
+        // The test fixture contains 10 nodes with indices 1-10.  A wanted state for
+        // an existing node (5) should be preserved.  Note that it is not possible to set a
+        // wanted state outside the existing nodes.
+        Node storageNode5 = Node.ofStorage(5);
+        NodeState maintenance = new NodeState(NodeType.STORAGE, State.MAINTENANCE);
+        databaseContext.getCluster().getNodeInfo(storageNode5).setWantedState(maintenance);
+        var expectedWantedStates = new TreeMap<>(Map.of(storageNode5, maintenance));
+
+        // Ensure database is connected to ZooKeeper
+        assertTrue(handler.doNextZooKeeperTask(databaseContext));
+
+        // Verify ZooKeeperDatabase::storeWantedStates is invoked once
+        verify(fixture.mockDatabase, times(0)).storeWantedStates(any());
+        assertTrue(handler.saveWantedStates(databaseContext));
+        verify(fixture.mockDatabase, times(1)).storeWantedStates(wantedStatesArgument.capture());
+
+        // Verify ZooKeeperDatabase::storeWantedStates only saves states for existing nodes
+        assertEquals(expectedWantedStates, wantedStatesArgument.getValue());
+    }
 }
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DummyCommunicator.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DummyCommunicator.java
index 3c232a7c52b..3127201a342 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DummyCommunicator.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/DummyCommunicator.java
@@ -6,7 +6,7 @@ import com.yahoo.vdslib.state.ClusterState;
 import com.yahoo.vdslib.state.Node;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.State;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -133,14 +133,14 @@ public class DummyCommunicator implements Communicator, NodeLookup {
     }
 
     @Override
-    public boolean updateCluster(ContentCluster cluster, NodeAddedOrRemovedListener listener) {
+    public boolean updateCluster(ContentCluster cluster, SlobrokListener listener) {
         if (newNodes != null) {
             List<Node> tmp = newNodes;
 
             for (Node node : tmp)
                 cluster.clusterInfo().setRpcAddress(node, "foo");
 
-            for (NodeInfo info : cluster.getNodeInfo()) {
+            for (NodeInfo info : cluster.getNodeInfos()) {
                 if (!tmp.contains(info.getNode())) {
                     info.markRpcAddressOutdated(timer);
                     listener.handleMissingNode(info);
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
index 254f863e9ea..1d4b2a73560 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/GroupAutoTakedownTest.java
@@ -7,20 +7,19 @@ import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.database.DatabaseHandler;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
-
-import static com.yahoo.vespa.clustercontroller.core.matchers.EventForNode.eventForNode;
-import static com.yahoo.vespa.clustercontroller.core.matchers.NodeEventWithDescription.nodeEventWithDescription;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import org.junit.Test;
 
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
+import static com.yahoo.vespa.clustercontroller.core.matchers.EventForNode.eventForNode;
+import static com.yahoo.vespa.clustercontroller.core.matchers.NodeEventWithDescription.nodeEventWithDescription;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.AllOf.allOf;
 import static org.hamcrest.core.IsCollectionContaining.hasItem;
 import static org.junit.Assert.assertEquals;
-import static org.hamcrest.MatcherAssert.assertThat;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -179,7 +178,7 @@ public class GroupAutoTakedownTest {
 
         // However, once grace period expires the group should be taken down.
         fixture.timer.advanceTime(1001);
-        NodeStateOrHostInfoChangeHandler changeListener = mock(NodeStateOrHostInfoChangeHandler.class);
+        NodeListener changeListener = mock(NodeListener.class);
         fixture.nodeStateChangeHandler.watchTimers(
                 fixture.cluster, fixture.annotatedGeneratedClusterState().getClusterState(), changeListener);
 
@@ -253,7 +252,7 @@ public class GroupAutoTakedownTest {
         nodes.add(new ConfiguredNode(5, true));
         // TODO this should ideally also set the retired flag in the distribution
         // config, but only the ConfiguredNodes are actually looked at currently.
-        fixture.cluster.setNodes(nodes);
+        fixture.cluster.setNodes(nodes, new NodeListener() {});
 
         assertEquals("distributor:6 storage:6 .4.s:d .5.s:r",
                 stateAfterStorageTransition(fixture, 5, State.UP));
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceExhaustionCalculatorTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceExhaustionCalculatorTest.java
index 7e02f63d56e..e136ddfa72d 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceExhaustionCalculatorTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceExhaustionCalculatorTest.java
@@ -23,7 +23,7 @@ public class ResourceExhaustionCalculatorTest {
         var calc = new ResourceExhaustionCalculator(true, mapOf(usage("disk", 0.5), usage("memory", 0.8)));
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.49), usage("memory", 0.79)),
                                                  forNode(2, usage("disk", 0.4), usage("memory", 0.6)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNull(feedBlock);
     }
 
@@ -32,7 +32,7 @@ public class ResourceExhaustionCalculatorTest {
         var calc = new ResourceExhaustionCalculator(true, mapOf(usage("disk", 0.5), usage("memory", 0.8)));
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.51), usage("memory", 0.79)),
                                                  forNode(2, usage("disk", 0.4), usage("memory", 0.6)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNotNull(feedBlock);
         assertTrue(feedBlock.blockFeedInCluster());
         assertEquals("disk on node 1 [storage.1.local] (0.510 > 0.500)", feedBlock.getDescription());
@@ -43,7 +43,7 @@ public class ResourceExhaustionCalculatorTest {
         var calc = new ResourceExhaustionCalculator(true, mapOf(usage("disk", 0.5), usage("memory", 0.8)));
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", "a-fancy-disk", 0.51), usage("memory", 0.79)),
                                                  forNode(2, usage("disk", 0.4), usage("memory", 0.6)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNotNull(feedBlock);
         assertTrue(feedBlock.blockFeedInCluster());
         assertEquals("disk:a-fancy-disk on node 1 [storage.1.local] (0.510 > 0.500)", feedBlock.getDescription());
@@ -56,7 +56,7 @@ public class ResourceExhaustionCalculatorTest {
                                                  forNode(2, usage("disk", 0.4), usage("memory", 0.85)));
         cf.cluster().getNodeInfo(storageNode(1)).setRpcAddress(null);
         cf.cluster().getNodeInfo(storageNode(2)).setRpcAddress("max mekker");
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNotNull(feedBlock);
         assertTrue(feedBlock.blockFeedInCluster());
         assertEquals("disk on node 1 [unknown hostname] (0.510 > 0.500), " +
@@ -68,7 +68,7 @@ public class ResourceExhaustionCalculatorTest {
         var calc = new ResourceExhaustionCalculator(true, mapOf(usage("disk", 0.4), usage("memory", 0.8)));
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.51), usage("memory", 0.85)),
                                                  forNode(2, usage("disk", 0.45), usage("memory", 0.6)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNotNull(feedBlock);
         assertTrue(feedBlock.blockFeedInCluster());
         assertEquals("disk on node 1 [storage.1.local] (0.510 > 0.400), " +
@@ -83,7 +83,7 @@ public class ResourceExhaustionCalculatorTest {
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.51), usage("memory", 0.85)),
                                                  forNode(2, usage("disk", 0.45), usage("memory", 0.6)),
                                                  forNode(3, usage("disk", 0.6), usage("memory", 0.9)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNotNull(feedBlock);
         assertTrue(feedBlock.blockFeedInCluster());
         assertEquals("disk on node 1 [storage.1.local] (0.510 > 0.400), " +
@@ -97,7 +97,7 @@ public class ResourceExhaustionCalculatorTest {
         var calc = new ResourceExhaustionCalculator(false, mapOf(usage("disk", 0.5), usage("memory", 0.8)));
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.51), usage("memory", 0.79)),
                                                  forNode(2, usage("disk", 0.4), usage("memory", 0.6)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNull(feedBlock);
     }
 
@@ -109,7 +109,7 @@ public class ResourceExhaustionCalculatorTest {
         // Node 2 is at 0.49 but was not previously blocked and should not be blocked now either.
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.3), usage("memory", 0.49)),
                                                  forNode(2, usage("disk", 0.3), usage("memory", 0.49)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNotNull(feedBlock);
         // TODO should we not change the limits themselves? Explicit mention of hysteresis state?
         assertEquals("memory on node 1 [storage.1.local] (0.490 > 0.400)",
@@ -124,7 +124,7 @@ public class ResourceExhaustionCalculatorTest {
         // Node 2 is at 0.49 but was not previously blocked and should not be blocked now either.
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.3), usage("memory", 0.48)),
                                                  forNode(2, usage("disk", 0.3), usage("memory", 0.49)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNotNull(feedBlock);
         assertEquals("memory on node 1 [storage.1.local] (0.480 > 0.400)",
                 feedBlock.getDescription());
@@ -138,7 +138,7 @@ public class ResourceExhaustionCalculatorTest {
         // Node 2 is at 0.49 but was not previously blocked and should not be blocked now either.
         var cf = createFixtureWithReportedUsages(forNode(1, usage("disk", 0.3), usage("memory", 0.39)),
                                                  forNode(2, usage("disk", 0.3), usage("memory", 0.49)));
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNull(feedBlock);
     }
 
@@ -149,7 +149,7 @@ public class ResourceExhaustionCalculatorTest {
                                                  forNode(2, usage("disk", 0.6), usage("memory", 0.6)));
         cf.reportStorageNodeState(1, State.DOWN);
         cf.reportStorageNodeState(2, State.DOWN);
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNull(feedBlock);
     }
 
@@ -160,7 +160,7 @@ public class ResourceExhaustionCalculatorTest {
                                                  forNode(2, usage("disk", 0.6), usage("memory", 0.6)));
         cf.proposeStorageNodeWantedState(1, State.DOWN);
         cf.proposeStorageNodeWantedState(2, State.MAINTENANCE);
-        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfo());
+        var feedBlock = calc.inferContentClusterFeedBlockOrNull(cf.cluster().getNodeInfos());
         assertNull(feedBlock);
     }
 
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceUsageStatsTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceUsageStatsTest.java
index 3a5f9954a20..2eeaf7658ff 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceUsageStatsTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ResourceUsageStatsTest.java
@@ -66,7 +66,7 @@ public class ResourceUsageStatsTest {
     }
 
     private static Collection<NodeInfo> createNodeInfo(FeedBlockUtil.NodeAndUsages... nodeAndUsages) {
-        return createFixtureWithReportedUsages(nodeAndUsages).cluster().getNodeInfo();
+        return createFixtureWithReportedUsages(nodeAndUsages).cluster().getNodeInfos();
     }
 
     private static Map<String, Double> createFeedBlockLimits(double diskLimit, double memoryLimit) {
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SlobrokTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SlobrokTest.java
index 5395048cad9..47ba7e1cb77 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SlobrokTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SlobrokTest.java
@@ -99,7 +99,7 @@ public class SlobrokTest extends FleetControllerTest {
     private boolean clusterAvailable() {
         boolean ok = true;
         ContentCluster cluster = fleetController.getCluster();
-        for (NodeInfo info : cluster.getNodeInfo()) {
+        for (NodeInfo info : cluster.getNodeInfos()) {
             if (info.getConnectionAttemptCount() > 0) ok = false;
             if (info.getLatestNodeStateRequestTime() == null) ok = false;
         }
@@ -107,7 +107,7 @@ public class SlobrokTest extends FleetControllerTest {
     }
     private void assertClusterAvailable() {
         ContentCluster cluster = fleetController.getCluster();
-        for (NodeInfo info : cluster.getNodeInfo()) {
+        for (NodeInfo info : cluster.getNodeInfos()) {
             assertEquals("Node " + info + " connection attempts.", 0, info.getConnectionAttemptCount());
             assertTrue("Node " + info + " has no last request time.", info.getLatestNodeStateRequestTime() != 0);
         }
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandlerTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandlerTest.java
index 95c097c5920..699a35a190c 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandlerTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeHandlerTest.java
@@ -9,7 +9,7 @@ import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.hostinfo.HostInfo;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import com.yahoo.vespa.clustercontroller.core.mocks.TestEventLog;
 import com.yahoo.vespa.clustercontroller.core.testutils.LogFormatter;
 import org.junit.Before;
@@ -34,7 +34,7 @@ public class StateChangeHandlerTest {
         int maxPrematureCrashes = 3;
     }
 
-    private static class TestNodeStateOrHostInfoChangeHandler implements NodeStateOrHostInfoChangeHandler {
+    private static class TestNodeListener implements NodeListener {
 
         LinkedList<String> events = new LinkedList<>();
 
@@ -49,6 +49,11 @@ public class StateChangeHandlerTest {
         }
 
         @Override
+        public void handleRemovedNode(Node node) {
+            events.add("removed: " + node);
+        }
+
+        @Override
         public void handleUpdatedHostInfo(NodeInfo node, HostInfo newHostInfo) {
             events.add(node + " - " + newHostInfo);
         }
@@ -68,7 +73,7 @@ public class StateChangeHandlerTest {
     private Config config;
     private ContentCluster cluster;
     private StateChangeHandler nodeStateChangeHandler;
-    private TestNodeStateOrHostInfoChangeHandler nodeStateUpdateListener;
+    private TestNodeListener nodeStateUpdateListener;
     private final ClusterStateGenerator.Params params = new ClusterStateGenerator.Params();
 
     @Before
@@ -88,7 +93,7 @@ public class StateChangeHandlerTest {
                 .maxPrematureCrashes(config.maxPrematureCrashes)
                 .transitionTimes(5000)
                 .cluster(cluster);
-        nodeStateUpdateListener = new TestNodeStateOrHostInfoChangeHandler();
+        nodeStateUpdateListener = new TestNodeListener();
     }
 
     private ClusterState currentClusterState() {
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java
index a5bb65e11d0..5a33414c955 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateChangeTest.java
@@ -1294,7 +1294,7 @@ public class StateChangeTest extends FleetControllerTest {
             NodeState newNodeState = new NodeState(NodeType.STORAGE, State.MAINTENANCE);
             NodeInfo nodeInfo = ctx.cluster.getNodeInfo(new Node(NodeType.STORAGE, 0));
             nodeInfo.setWantedState(newNodeState);
-            ctx.nodeStateOrHostInfoChangeHandler.handleNewWantedNodeState(nodeInfo, newNodeState);
+            ctx.nodeListener.handleNewWantedNodeState(nodeInfo, newNodeState);
             invoked = true;
         }
     }
@@ -1312,7 +1312,7 @@ public class StateChangeTest extends FleetControllerTest {
             NodeState newNodeState = new NodeState(NodeType.STORAGE, State.DOWN);
             NodeInfo nodeInfo = ctx.cluster.getNodeInfo(new Node(NodeType.STORAGE, 0));
             nodeInfo.setWantedState(newNodeState);
-            ctx.nodeStateOrHostInfoChangeHandler.handleNewWantedNodeState(nodeInfo, newNodeState);
+            ctx.nodeListener.handleNewWantedNodeState(nodeInfo, newNodeState);
             invoked = true;
         }
     }
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java
index 45593375c0b..1832f1132ac 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/SystemStateBroadcasterTest.java
@@ -6,8 +6,8 @@ import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vdslib.state.NodeType;
 import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.database.DatabaseHandler;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
 
@@ -69,12 +69,12 @@ public class SystemStateBroadcasterTest {
             }
 
             @Override
-            public NodeAddedOrRemovedListener getNodeAddedOrRemovedListener() {
+            public SlobrokListener getNodeAddedOrRemovedListener() {
                 return null;
             }
 
             @Override
-            public NodeStateOrHostInfoChangeHandler getNodeStateUpdateListener() {
+            public NodeListener getNodeStateUpdateListener() {
                 return null;
             }
         };
@@ -91,7 +91,7 @@ public class SystemStateBroadcasterTest {
         ClusterFixture cf = ClusterFixture.forFlatCluster(2).bringEntireClusterUp().assignDummyRpcAddresses();
         f.broadcaster.handleNewClusterStates(stateBundle);
         f.broadcaster.broadcastNewStateBundleIfRequired(dbContextFrom(cf.cluster()), f.mockCommunicator, 3);
-        cf.cluster().getNodeInfo().forEach(nodeInfo -> verify(f.mockCommunicator).setSystemState(eq(stateBundle), eq(nodeInfo), any()));
+        cf.cluster().getNodeInfos().forEach(nodeInfo -> verify(f.mockCommunicator).setSystemState(eq(stateBundle), eq(nodeInfo), any()));
     }
 
     @Test
@@ -121,7 +121,7 @@ public class SystemStateBroadcasterTest {
         f.broadcaster.handleNewClusterStates(stateBundle);
         f.broadcaster.broadcastNewStateBundleIfRequired(dbContextFrom(cf.cluster()), f.mockCommunicator, 3);
 
-        cf.cluster().getNodeInfo().forEach(nodeInfo -> verify(f.mockCommunicator).setSystemState(eq(stateBundle), eq(nodeInfo), any()));
+        cf.cluster().getNodeInfos().forEach(nodeInfo -> verify(f.mockCommunicator).setSystemState(eq(stateBundle), eq(nodeInfo), any()));
     }
 
     @Test
@@ -153,7 +153,7 @@ public class SystemStateBroadcasterTest {
         f.broadcaster.handleNewClusterStates(stateBundle);
         f.broadcaster.broadcastNewStateBundleIfRequired(dbContextFrom(cf.cluster()), f.mockCommunicator, 99);
 
-        cf.cluster().getNodeInfo().forEach(nodeInfo -> {
+        cf.cluster().getNodeInfos().forEach(nodeInfo -> {
             verify(f.mockCommunicator, times(0)).setSystemState(any(), eq(nodeInfo), any());
         });
     }
@@ -166,7 +166,7 @@ public class SystemStateBroadcasterTest {
         f.broadcaster.handleNewClusterStates(stateBundle);
         f.broadcaster.broadcastNewStateBundleIfRequired(dbContextFrom(cf.cluster()), f.mockCommunicator, 100);
 
-        cf.cluster().getNodeInfo().forEach(nodeInfo -> {
+        cf.cluster().getNodeInfos().forEach(nodeInfo -> {
             verify(f.mockCommunicator, times(1)).setSystemState(any(), eq(nodeInfo), any());
         });
     }
@@ -276,7 +276,7 @@ public class SystemStateBroadcasterTest {
         f.simulateBroadcastTick(cf, 123);
 
         // No activations should be sent yet
-        cf.cluster().getNodeInfo().forEach(nodeInfo -> {
+        cf.cluster().getNodeInfos().forEach(nodeInfo -> {
             verify(f.mockCommunicator, times(0)).activateClusterStateVersion(eq(123), eq(nodeInfo), any());
         });
         assertNull(f.broadcaster.getLastClusterStateBundleConverged());
@@ -285,7 +285,7 @@ public class SystemStateBroadcasterTest {
         f.simulateBroadcastTick(cf, 123);
 
         // Activation should now be sent to _all_ nodes (distributor and storage)
-        cf.cluster().getNodeInfo().forEach(nodeInfo -> {
+        cf.cluster().getNodeInfos().forEach(nodeInfo -> {
             verify(f.mockCommunicator).activateClusterStateVersion(eq(123), eq(nodeInfo), any());
         });
         // But not converged yet, as activations have not been ACKed
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ZooKeeperDatabaseTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ZooKeeperDatabaseTest.java
index 7d64a8f8878..1ce7586adea 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ZooKeeperDatabaseTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ZooKeeperDatabaseTest.java
@@ -37,7 +37,7 @@ public class ZooKeeperDatabaseTest {
             closeDatabaseIfOpen();
             var id = new FleetControllerId(clusterFixture.cluster.getName(), nodeIndex);
             var context = new TestFleetControllerContext(id);
-            zkDatabase = new ZooKeeperDatabase(context, clusterFixture.cluster(), nodeIndex, zkServer.getAddress(),
+            zkDatabase = new ZooKeeperDatabase(context, zkServer.getAddress(),
                                                (int)sessionTimeout.toMillis(), mockListener);
         }
 
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerMock.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerMock.java
index 95071931a75..f53b2898145 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerMock.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/ClusterControllerMock.java
@@ -2,11 +2,12 @@
 package com.yahoo.vespa.clustercontroller.core.restapiv2;
 
 import com.yahoo.vdslib.state.ClusterState;
+import com.yahoo.vdslib.state.Node;
 import com.yahoo.vdslib.state.NodeState;
 import com.yahoo.vespa.clustercontroller.core.*;
 import com.yahoo.vespa.clustercontroller.core.hostinfo.HostInfo;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeAddedOrRemovedListener;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.SlobrokListener;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 
 public class ClusterControllerMock implements RemoteClusterControllerTaskScheduler {
     public RemoteClusterControllerTask.Context context = new RemoteClusterControllerTask.Context();
@@ -40,16 +41,21 @@ public class ClusterControllerMock implements RemoteClusterControllerTaskSchedul
                 return fleetControllerMaster;
             }
         };
-        context.nodeStateOrHostInfoChangeHandler = new NodeStateOrHostInfoChangeHandler() {
+        context.nodeListener = new NodeListener() {
 
             @Override
             public void handleNewNodeState(NodeInfo currentInfo, NodeState newState) {
-                events.append("newNodeState(").append(currentInfo.getNode()).append(": ").append(newState).append("\n");
+                events.append("newNodeState(").append(currentInfo.getNode()).append(": ").append(newState).append('\n');
             }
 
             @Override
             public void handleNewWantedNodeState(NodeInfo node, NodeState newState) {
-                events.append("newWantedNodeState(").append(node.getNode()).append(": ").append(newState).append("\n");
+                events.append("newWantedNodeState(").append(node.getNode()).append(": ").append(newState).append('\n');
+            }
+
+            @Override
+            public void handleRemovedNode(Node node) {
+                events.append("handleRemovedNode(").append(node).append(")\n");
             }
 
             @Override
@@ -59,7 +65,7 @@ public class ClusterControllerMock implements RemoteClusterControllerTaskSchedul
             }
 
         };
-        context.nodeAddedOrRemovedListener = new NodeAddedOrRemovedListener() {
+        context.slobrokListener = new SlobrokListener() {
 
             @Override
             public void handleNewNode(NodeInfo node) {
@@ -68,12 +74,12 @@ public class ClusterControllerMock implements RemoteClusterControllerTaskSchedul
 
             @Override
             public void handleMissingNode(NodeInfo node) {
-                events.append("newMissingNode(").append(node.getNode()).append("\n");
+                events.append("newMissingNode(").append(node.getNode()).append('\n');
             }
 
             @Override
             public void handleNewRpcAddress(NodeInfo node) {
-                events.append("newRpcAddress(").append(node.getNode()).append("\n");
+                events.append("newRpcAddress(").append(node.getNode()).append('\n');
             }
 
             @Override
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequestTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequestTest.java
index 090e80361e5..9f14b2e71d2 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequestTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/restapiv2/requests/SetNodeStateRequestTest.java
@@ -10,7 +10,7 @@ import com.yahoo.vdslib.state.State;
 import com.yahoo.vespa.clustercontroller.core.ContentCluster;
 import com.yahoo.vespa.clustercontroller.core.NodeInfo;
 import com.yahoo.vespa.clustercontroller.core.NodeStateChangeChecker;
-import com.yahoo.vespa.clustercontroller.core.listeners.NodeStateOrHostInfoChangeHandler;
+import com.yahoo.vespa.clustercontroller.core.listeners.NodeListener;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.errors.StateRestApiException;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.requests.SetUnitStateRequest;
 import com.yahoo.vespa.clustercontroller.utils.staterestapi.response.SetResponse;
@@ -38,7 +38,7 @@ public class SetNodeStateRequestTest {
     private final UnitState unitState = mock(UnitState.class);
     private final int NODE_INDEX = 2;
     private final Node storageNode = new Node(NodeType.STORAGE, NODE_INDEX);
-    private final NodeStateOrHostInfoChangeHandler stateListener = mock(NodeStateOrHostInfoChangeHandler.class);
+    private final NodeListener stateListener = mock(NodeListener.class);
     private final ClusterState currentClusterState = mock(ClusterState.class);
     private boolean inMasterMoratorium = false;
     private boolean probe = false;
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/testutils/WaitTask.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/testutils/WaitTask.java
index 6362d6fe9a7..d9967381e75 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/testutils/WaitTask.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/testutils/WaitTask.java
@@ -25,7 +25,7 @@ public abstract class WaitTask {
         public boolean performWaitTask() {
             boolean didWork = false;
             synchronized (fleetController.getMonitor()) {
-                for (NodeInfo info : fleetController.getCluster().getNodeInfo()) {
+                for (NodeInfo info : fleetController.getCluster().getNodeInfos()) {
                     if (info.getTimeForNextStateRequestAttempt() != 0) didWork = true;
                     info.setNextGetStateAttemptTime(0);
                 }