Add handling of bucket spaces stats to HostInfo and ClusterStatsAggregator.

Handling of outstanding merge ops has been removed as this information has never been provided by the distributors.

13 files changed, 300 insertions, 445 deletions

diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateView.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateView.java
index a0e93c2a9ad..ea638010ab7 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateView.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStateView.java
@@ -29,31 +29,25 @@ public class ClusterStateView {
     private static Logger log = Logger.getLogger(ClusterStateView.class.getName());
     private final ClusterState clusterState;
     private final ClusterStatsAggregator statsAggregator;
-    private final MetricUpdater metricUpdater;
 
-    /**
-     * @param metricUpdater may be null, in which case no stats will be reported.
-     */
-    public static ClusterStateView create(String serializedClusterState, MetricUpdater metricUpdater)
-            throws ParseException {
+    public static ClusterStateView create(String serializedClusterState) throws ParseException {
         ClusterState clusterState = new ClusterState(serializedClusterState);
-        return new ClusterStateView(clusterState, createNewAggregator(clusterState, metricUpdater), metricUpdater);
+        return new ClusterStateView(clusterState, createNewAggregator(clusterState));
     }
 
-    public static ClusterStateView create(final ClusterState clusterState, final MetricUpdater metricUpdater) {
-        return new ClusterStateView(clusterState, createNewAggregator(clusterState, metricUpdater), metricUpdater);
+    public static ClusterStateView create(final ClusterState clusterState) {
+        return new ClusterStateView(clusterState, createNewAggregator(clusterState));
     }
 
-    private static ClusterStatsAggregator createNewAggregator(ClusterState clusterState, MetricUpdater metricUpdater) {
+    private static ClusterStatsAggregator createNewAggregator(ClusterState clusterState) {
         Set<Integer> upDistributors = getIndicesOfUpNodes(clusterState, NodeType.DISTRIBUTOR);
         Set<Integer> upStorageNodes = getIndicesOfUpNodes(clusterState, NodeType.STORAGE);
-        return new ClusterStatsAggregator(upDistributors, upStorageNodes, metricUpdater);
+        return new ClusterStatsAggregator(upDistributors, upStorageNodes);
     }
 
-    ClusterStateView(ClusterState clusterState, ClusterStatsAggregator statsAggregator, MetricUpdater metricUpdater) {
+    ClusterStateView(ClusterState clusterState, ClusterStatsAggregator statsAggregator) {
         this.clusterState = clusterState;
         this.statsAggregator = statsAggregator;
-        this.metricUpdater = metricUpdater;
     }
 
     /**
@@ -85,8 +79,7 @@ public class ClusterStateView {
         ClusterState clonedClusterState = clusterState.clone();
         return new ClusterStateView(
                 clonedClusterState,
-                createNewAggregator(clonedClusterState, metricUpdater),
-                metricUpdater);
+                createNewAggregator(clonedClusterState));
     }
 
     public ClusterState getClusterState() { return clusterState; }
@@ -115,8 +108,8 @@ public class ClusterStateView {
             return;
         }
 
-        statsAggregator.updateForDistributor(
-                hostnames, node.getNodeIndex(), StorageNodeStatsBridge.generate(hostInfo.getDistributor()));
+        statsAggregator.updateForDistributor(node.getNodeIndex(),
+                StorageNodeStatsBridge.generate(hostInfo.getDistributor()));
     }
 
     public String toString() {
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregator.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregator.java
index e1e626a7a71..3f7cd129fc1 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregator.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregator.java
@@ -4,16 +4,13 @@ package com.yahoo.vespa.clustercontroller.core;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
-import java.util.logging.Logger;
-
-import com.yahoo.log.LogLevel;
 
 /**
- * A class that stores stats about outstanding merge operations for
- * the current cluster state version, and exports metrics about these.
+ * Class that stores content cluster stats (with bucket space stats per node) for
+ * the current cluster state version.
  *
- * Each distributor reports outstanding merge operations for the different
- * storage nodes. These reports arrive with getnodestate RPC calls,
+ * Each distributor reports bucket space stats for the different content nodes.
+ * These reports arrive with getnodestate RPC calls,
  * and eventually ends up as calls to updateForDistributor().
  * No assumptions are made on the sequence of getnodestate calls.
  * For instance, it's perfectly fine for the calls to arrive in the
@@ -25,95 +22,53 @@ import com.yahoo.log.LogLevel;
  *   distributor 2
  *   ... etc
  *
- * Whereas the metrics we want, is how many merge operations are outstanding
- * for a given storage nodes. So we need to keep track of the latest info
- * from each distributor.
- *
  * @author hakonhall
  */
 public class ClusterStatsAggregator {
 
-    private static Logger log = Logger.getLogger(ClusterStatsAggregator.class.getName());
-
     private final Set<Integer> distributors;
-    private final MetricUpdater updater;
 
-    // Maps the distributor node index to a map of storage node index to the
-    // storage node's merge stats.
+    // Maps the distributor node index to a map of content node index to the
+    // content node's stats.
     private final Map<Integer, ContentClusterStats> distributorToStats = new HashMap<>();
 
-    // This is only needed as an optimization. should just be the sum of distributorToStats' ContentClusterStats.
-    // Maps the storage node index to the aggregate merge stats for that storage node.
+    // This is only needed as an optimization. Is just the sum of distributorToStats' ContentClusterStats.
+    // Maps the content node index to the content node stats for that node.
     // This MUST be kept up-to-date with distributorToStats;
     private final ContentClusterStats aggregatedStats;
 
-    private int hostToStatsMapHashCode = 0;
-
-    ClusterStatsAggregator(Set<Integer> distributors, Set<Integer> storageNodes, MetricUpdater updater) {
+    ClusterStatsAggregator(Set<Integer> distributors, Set<Integer> storageNodes) {
         this.distributors = distributors;
         aggregatedStats = new ContentClusterStats(storageNodes);
-        this.updater = updater;
+    }
+
+    ContentClusterStats getAggregatedStats() {
+        return aggregatedStats;
     }
 
     /**
      * Update the aggregator with the newest available stats from a distributor.
-     * Will update metrics if necessary.
      */
-    void updateForDistributor(Map<Integer, String> hostnames, int distributorIndex, ContentClusterStats clusterStats) {
+    void updateForDistributor(int distributorIndex, ContentClusterStats clusterStats) {
         if (!distributors.contains(distributorIndex)) {
             return;
         }
-
         addStatsFromDistributor(distributorIndex, clusterStats);
-
-        if (distributorToStats.size() < distributors.size()) {
-            // Not all distributors have reported their merge stats through getnodestate yet.
-            return;
-        }
-
-        Map<String, ContentNodeStats> hostToStatsMap = getHostToStatsMap(hostnames);
-        if (hostToStatsMap == null) {
-            return;
-        }
-
-        if (hostToStatsMapHashCode == 0 || hostToStatsMapHashCode != hostToStatsMap.hashCode()) {
-            updater.updateMergeOpMetrics(hostToStatsMap);
-            hostToStatsMapHashCode = hostToStatsMap.hashCode();
-        }
-    }
-
-    private Map<String, ContentNodeStats> getHostToStatsMap(Map<Integer, String> hostnames) {
-        Map<String, ContentNodeStats> hostToStatsMap = new HashMap<>(aggregatedStats.size());
-        for (ContentNodeStats nodeStats : aggregatedStats) {
-            // The hosts names are kept up-to-date from Slobrok, and MAY therefore be arbitrarily
-            // different from the node set used by aggregatedStats (and typically tied to a cluster state).
-            // If so, we will not pretend the returned map is complete, and will return null.
-            String host = hostnames.get(nodeStats.getNodeIndex());
-            if (host == null) {
-                log.log(LogLevel.DEBUG, "Failed to find the host name of storage node " + nodeStats.getNodeIndex() +
-                        ". Skipping the report from " + ClusterStatsAggregator.class.getName());
-                return null;
-            }
-
-            hostToStatsMap.put(host, nodeStats);
-        }
-
-        return hostToStatsMap;
     }
 
     private void addStatsFromDistributor(int distributorIndex, ContentClusterStats clusterStats) {
-        ContentClusterStats previousStorageStats = distributorToStats.put(distributorIndex, clusterStats);
+        ContentClusterStats prevClusterStats = distributorToStats.put(distributorIndex, clusterStats);
 
         for (ContentNodeStats contentNode : aggregatedStats) {
             Integer nodeIndex = contentNode.getNodeIndex();
 
-            ContentNodeStats statsToAdd = clusterStats.getStorageNode(nodeIndex);
+            ContentNodeStats statsToAdd = clusterStats.getContentNode(nodeIndex);
             if (statsToAdd != null) {
                 contentNode.add(statsToAdd);
             }
 
-            if (previousStorageStats != null) {
-                ContentNodeStats statsToSubtract = clusterStats.getStorageNode(nodeIndex);
+            if (prevClusterStats != null) {
+                ContentNodeStats statsToSubtract = prevClusterStats.getContentNode(nodeIndex);
                 if (statsToSubtract != null) {
                     contentNode.subtract(statsToSubtract);
                 }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentClusterStats.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentClusterStats.java
index 154113b95c0..ec64b2e8147 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentClusterStats.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentClusterStats.java
@@ -1,19 +1,16 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.core;
 
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.Map;
-import java.util.Set;
+import java.util.*;
 
 /**
- * Class for storing the pending merge operation stats for all the content nodes.
+ * Class for storing pending content node stats for all content nodes in the cluster.
  *
  * @author hakonhall
  */
 public class ContentClusterStats implements Iterable<ContentNodeStats> {
 
-    // Maps a storage node index to the storage node's pending merges stats.
+    // Maps a content node index to the content node's stats.
     private final Map<Integer, ContentNodeStats> mapToNodeStats;
 
     public ContentClusterStats(Set<Integer> storageNodes) {
@@ -32,7 +29,7 @@ public class ContentClusterStats implements Iterable<ContentNodeStats> {
         return mapToNodeStats.values().iterator();
     }
 
-    ContentNodeStats getStorageNode(Integer index) {
+    ContentNodeStats getContentNode(Integer index) {
         return mapToNodeStats.get(index);
     }
 
@@ -43,21 +40,19 @@ public class ContentClusterStats implements Iterable<ContentNodeStats> {
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;
-        if (!(o instanceof ContentClusterStats)) {
-            return false;
-        }
-
+        if (o == null || getClass() != o.getClass()) return false;
         ContentClusterStats that = (ContentClusterStats) o;
-
-        if (mapToNodeStats != null ? !mapToNodeStats.equals(that.mapToNodeStats) : that.mapToNodeStats != null) {
-            return false;
-        }
-        return true;
+        return Objects.equals(mapToNodeStats, that.mapToNodeStats);
     }
 
     @Override
     public int hashCode() {
-        return mapToNodeStats != null ? mapToNodeStats.hashCode() : 0;
+        return Objects.hash(mapToNodeStats);
     }
 
+    @Override
+    public String toString() {
+        return String.format("{mapToNodeStats=[%s]}",
+                Arrays.toString(mapToNodeStats.entrySet().toArray()));
+    }
 }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentNodeStats.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentNodeStats.java
index 11e05a74cf7..f589468ccdf 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentNodeStats.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/ContentNodeStats.java
@@ -3,149 +3,130 @@ package com.yahoo.vespa.clustercontroller.core;
 
 import com.yahoo.vespa.clustercontroller.core.hostinfo.StorageNode;
 
+import java.util.*;
+
 /**
  * @author hakonhall
  */
 public class ContentNodeStats {
 
-    /**
-     * Constructor that sets values to zero if not present.
-     */
-    public ContentNodeStats(StorageNode storageNodePojo) {
-        this.nodeIndex = storageNodePojo.getIndex();
+    private int nodeIndex;
+    private Map<String, BucketSpaceStats> bucketSpaces = new HashMap<>();
 
-        StorageNode.OutstandingMergeOps mergeOps = storageNodePojo.getOutstandingMergeOpsOrNull();
-        if (mergeOps == null) {
-            mergeOps = new StorageNode.OutstandingMergeOps();
-        }
-        syncing = createAmount(mergeOps.getSyncingOrNull());
-        copyingIn = createAmount(mergeOps.getCopyingInOrNull());
-        movingOut = createAmount(mergeOps.getMovingOutOrNull());
-        copyingOut = createAmount(mergeOps.getCopyingOutOrNull());
-    }
+    public static class BucketSpaceStats {
+        private long bucketsTotal;
+        private long bucketsPending;
 
-    private static Amount createAmount(StorageNode.Buckets bucketOrNull) {
-        if (bucketOrNull == null) {
-            return new Amount();
+        public BucketSpaceStats() {
+            this.bucketsTotal = 0;
+            this.bucketsPending = 0;
         }
-        return new Amount(bucketOrNull.getBuckets());
-    }
-
-    static public class Amount {
-        private long buckets;
 
-        Amount() { this(0); }
-        Amount(long buckets) { this.buckets = buckets; }
+        public BucketSpaceStats(long bucketsTotal, long bucketsPending) {
+            this.bucketsTotal = bucketsTotal;
+            this.bucketsPending = bucketsPending;
+        }
 
-        public void set(Amount other) {
-            buckets = other.buckets;
+        public long getBucketsTotal() {
+            return bucketsTotal;
         }
 
-        public long getBuckets() {
-            return buckets;
+        public long getBucketsPending() {
+            return bucketsPending;
         }
 
-        /**
-         * Logically, add (factor * amount) to this object.
-         */
-        void scaledAdd(int factor, Amount amount) {
-            buckets += factor * amount.buckets;
+        public void merge(BucketSpaceStats rhs, int factor) {
+            this.bucketsTotal += (factor * rhs.bucketsTotal);
+            this.bucketsPending += (factor * rhs.bucketsPending);
         }
 
-        public boolean equals(Object other) {
-            if (!(other instanceof Amount)) {
-                return false;
-            }
-            Amount otherAmount = (Amount) other;
-            return buckets == otherAmount.buckets;
+        @Override
+        public boolean equals(Object o) {
+            if (this == o) return true;
+            if (o == null || getClass() != o.getClass()) return false;
+            BucketSpaceStats that = (BucketSpaceStats) o;
+            return bucketsTotal == that.bucketsTotal &&
+                    bucketsPending == that.bucketsPending;
         }
 
+        @Override
         public int hashCode() {
-                return (int)buckets;
+            return Objects.hash(bucketsTotal, bucketsPending);
         }
 
+        @Override
         public String toString() {
-            return String.format("{buckets = %d}", buckets);
+            return "{bucketsTotal=" + bucketsTotal + ", bucketsPending=" + bucketsPending + "}";
         }
     }
 
-    private final Amount syncing;
-    private final Amount copyingIn;
-    private final Amount movingOut;
-    private final Amount copyingOut;
-    private int nodeIndex;
+    public ContentNodeStats(StorageNode storageNode) {
+        this.nodeIndex = storageNode.getIndex();
+        for (StorageNode.BucketSpaceStats stats : storageNode.getBucketSpacesStats()) {
+            if (stats.valid()) {
+                this.bucketSpaces.put(stats.getName(),
+                        new BucketSpaceStats(stats.getBucketStats().getTotal(),
+                                stats.getBucketStats().getPending()));
+            } else {
+                // TODO: better handling of invalid bucket space stats
+                this.bucketSpaces.put(stats.getName(), new BucketSpaceStats());
+            }
+        }
+    }
 
-    /**
-     * An instance with all 0 amounts.
-     */
     public ContentNodeStats(int index) {
-        this(index, new Amount(), new Amount(), new Amount(), new Amount());
+        this(index, new HashMap<>());
     }
 
-    ContentNodeStats(int index, Amount syncing, Amount copyingIn, Amount movingOut, Amount copyingOut) {
+    public ContentNodeStats(int index, Map<String, BucketSpaceStats> bucketSpaces) {
         this.nodeIndex = index;
-        this.syncing = syncing;
-        this.copyingIn = copyingIn;
-        this.movingOut = movingOut;
-        this.copyingOut = copyingOut;
+        this.bucketSpaces = bucketSpaces;
     }
 
-    public void set(ContentNodeStats stats) {
-        nodeIndex = stats.nodeIndex;
-        syncing.set(stats.syncing);
-        copyingIn.set(stats.copyingIn);
-        movingOut.set(stats.movingOut);
-        copyingOut.set(stats.copyingOut);
-    }
+    public int getNodeIndex() { return nodeIndex; }
 
-    int getNodeIndex() { return nodeIndex; }
-    public Amount getSyncing() { return syncing; }
-    public Amount getCopyingIn() { return copyingIn; }
-    public Amount getMovingOut() { return movingOut; }
-    public Amount getCopyingOut() { return copyingOut; }
+    public void add(ContentNodeStats stats) {
+        merge(stats, 1);
+    }
 
-    void add(ContentNodeStats stats) {
-        scaledAdd(1, stats);
+    public void subtract(ContentNodeStats stats) {
+        merge(stats, -1);
     }
 
-    void subtract(ContentNodeStats stats) {
-        scaledAdd(-1, stats);
+    private void merge(ContentNodeStats stats, int factor) {
+        for (Map.Entry<String, BucketSpaceStats> entry : stats.bucketSpaces.entrySet()) {
+            BucketSpaceStats statsToUpdate = bucketSpaces.get(entry.getKey());
+            if (statsToUpdate == null && factor == 1) {
+                statsToUpdate = new BucketSpaceStats();
+                bucketSpaces.put(entry.getKey(), statsToUpdate);
+            }
+            if (statsToUpdate != null) {
+                statsToUpdate.merge(entry.getValue(), factor);
+            }
+        }
     }
 
-    /**
-     * Logically, adds (factor * stats) to this object. factor of 1 is normal add, -1 is subtraction.
-     */
-    private void scaledAdd(int factor, ContentNodeStats stats) {
-        syncing.scaledAdd(factor, stats.syncing);
-        copyingIn.scaledAdd(factor, stats.copyingIn);
-        movingOut.scaledAdd(factor, stats.movingOut);
-        copyingOut.scaledAdd(factor, stats.copyingOut);
+    public Map<String, BucketSpaceStats> getBucketSpaces() {
+        return bucketSpaces;
     }
 
     @Override
-    public int hashCode() {
-        return (int) (syncing.buckets +
-                copyingIn.buckets * 31 +
-                movingOut.buckets * 17 +
-                copyingOut.buckets * 7);
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        ContentNodeStats that = (ContentNodeStats) o;
+        return nodeIndex == that.nodeIndex &&
+                Objects.equals(bucketSpaces, that.bucketSpaces);
     }
 
     @Override
-    public boolean equals(Object other) {
-        if (!(other instanceof ContentNodeStats)) {
-            return false;
-        }
-
-        ContentNodeStats otherStats = (ContentNodeStats) other;
-        return nodeIndex == otherStats.nodeIndex &&
-                syncing.equals(otherStats.syncing) &&
-                copyingIn.equals(otherStats.copyingIn) &&
-                movingOut.equals(otherStats.movingOut) &&
-                copyingOut.equals(otherStats.copyingOut);
+    public int hashCode() {
+        return Objects.hash(nodeIndex, bucketSpaces);
     }
 
+    @Override
     public String toString() {
-        return String.format("{index = %d, syncing = %s, copyingIn = %s, movingOut = %s, copyingOut = %s}",
-                nodeIndex, syncing, copyingIn, movingOut, copyingOut);
+        return String.format("{index=%d, bucketSpaces=[%s]}",
+                nodeIndex, Arrays.toString(bucketSpaces.entrySet().toArray()));
     }
 }
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 a5419c64818..ba56d75ab4c 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
@@ -122,7 +122,7 @@ public class FleetController implements NodeStateOrHostInfoChangeHandler, NodeAd
         this.stateGatherer = nodeStateGatherer;
         this.stateChangeHandler = stateChangeHandler;
         this.systemStateBroadcaster = systemStateBroadcaster;
-        this.stateVersionTracker = new StateVersionTracker(metricUpdater);
+        this.stateVersionTracker = new StateVersionTracker();
         this.metricUpdater = metricUpdater;
 
         this.statusPageServer = statusPage;
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MetricUpdater.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MetricUpdater.java
index 7c921be958b..199e9a3169b 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MetricUpdater.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/MetricUpdater.java
@@ -85,7 +85,4 @@ public class MetricUpdater {
         metricReporter.add("node-event", 1);
     }
 
-    public void updateMergeOpMetrics(Map<String, ContentNodeStats> contentNodeStats) {
-        // TODO(hakonhall): Remove this method once we figure out how to propagate metrics to state HTTP API.
-    }
 }
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateVersionTracker.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateVersionTracker.java
index 518361f18fc..902189fca8b 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateVersionTracker.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/StateVersionTracker.java
@@ -32,15 +32,13 @@ public class StateVersionTracker {
     private AnnotatedClusterState latestCandidateState = AnnotatedClusterState.emptyState();
     private AnnotatedClusterState currentClusterState = latestCandidateState;
 
-    private final MetricUpdater metricUpdater;
     private ClusterStateView clusterStateView;
 
     private final LinkedList<ClusterStateHistoryEntry> clusterStateHistory = new LinkedList<>();
     private int maxHistoryEntryCount = 50;
 
-    StateVersionTracker(final MetricUpdater metricUpdater) {
-        this.metricUpdater = metricUpdater;
-        clusterStateView = ClusterStateView.create(currentUnversionedState, metricUpdater);
+    StateVersionTracker() {
+        clusterStateView = ClusterStateView.create(currentUnversionedState);
     }
 
     void setVersionRetrievedFromZooKeeper(final int version) {
@@ -121,7 +119,7 @@ public class StateVersionTracker {
                 lowestObservedDistributionBits,
                 newState.getClusterState().getDistributionBitCount());
         // TODO should this take place in updateLatestCandidateState instead? I.e. does it require a consolidated state?
-        clusterStateView = ClusterStateView.create(currentClusterState.getClusterState(), metricUpdater);
+        clusterStateView = ClusterStateView.create(currentClusterState.getClusterState());
     }
 
     private void recordCurrentStateInHistoryAtTime(final long currentTimeMs) {
diff --git a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNode.java b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNode.java
index 9e951236c45..bf7c1fad6ca 100644
--- a/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNode.java
+++ b/clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNode.java
@@ -4,6 +4,9 @@ package com.yahoo.vespa.clustercontroller.core.hostinfo;
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * Keeping information about a storage node seen from the distributor.
  *
@@ -36,31 +39,43 @@ public class StorageNode {
         public Put getPut() { return put; }
     }
 
-    static public class Buckets {
-        private final long buckets;
+    static public class BucketStats {
+        private final long total;
+        private final long pending;
 
         @JsonCreator
-        public Buckets(@JsonProperty("buckets") Long buckets) {
-            this.buckets = buckets;
+        public BucketStats(@JsonProperty("total") Long total, @JsonProperty("pending") Long pending) {
+            this.total = total;
+            this.pending = pending;
         }
 
-        public long getBuckets() { return buckets; }
+        public long getTotal() {
+            return total;
+        }
+        public long getPending() {
+            return pending;
+        }
     }
 
-    static public class OutstandingMergeOps {
-        @JsonProperty("syncing")
-        private Buckets syncing;
-        @JsonProperty("copying-in")
-        private Buckets copyingIn;
-        @JsonProperty("moving-out")
-        private Buckets movingOut;
-        @JsonProperty("copying-out")
-        private Buckets copyingOut;
-
-        public Buckets getSyncingOrNull() { return syncing; }
-        public Buckets getCopyingInOrNull() { return copyingIn; }
-        public Buckets getMovingOutOrNull() { return movingOut; }
-        public Buckets getCopyingOutOrNull() { return copyingOut; }
+    static public class BucketSpaceStats {
+        private final String name;
+        @JsonProperty("buckets")
+        private BucketStats bucketStats = null;
+
+        @JsonCreator
+        public BucketSpaceStats(@JsonProperty("name") String name) {
+            this.name = name;
+        }
+
+        public String getName() {
+            return name;
+        }
+        public boolean valid() {
+            return bucketStats != null;
+        }
+        public BucketStats getBucketStats() {
+            return bucketStats;
+        }
     }
 
     private final Integer index;
@@ -74,8 +89,8 @@ public class StorageNode {
     @JsonProperty("min-current-replication-factor")
     private Integer minCurrentReplicationFactor;
 
-    @JsonProperty("outstanding-merge-ops")
-    private OutstandingMergeOps outstandingMergeOps;
+    @JsonProperty("bucket-spaces")
+    private List<BucketSpaceStats> bucketSpacesStats = new ArrayList<>();
 
     @JsonCreator
     public StorageNode(@JsonProperty("node-index") Integer index) {
@@ -95,8 +110,7 @@ public class StorageNode {
         return minCurrentReplicationFactor;
     }
 
-    public OutstandingMergeOps getOutstandingMergeOpsOrNull() {
-        return outstandingMergeOps;
+    public List<BucketSpaceStats> getBucketSpacesStats() {
+        return bucketSpacesStats;
     }
-
 }
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateViewTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateViewTest.java
index 6487a55b554..dc8a4a0d441 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateViewTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStateViewTest.java
@@ -23,8 +23,7 @@ public class ClusterStateViewTest {
     final Node node = mock(Node.class);
     final ClusterStatsAggregator statsAggregator = mock(ClusterStatsAggregator.class);
     final ClusterState clusterState = mock(ClusterState.class);
-    final MetricUpdater metricUpdater = mock(MetricUpdater.class);
-    final ClusterStateView clusterStateView = new ClusterStateView(clusterState, statsAggregator, metricUpdater);
+    final ClusterStateView clusterStateView = new ClusterStateView(clusterState, statsAggregator);
 
     HostInfo createHostInfo(String version) {
         return HostInfo.createHostInfo("{ \"cluster-state-version\": " + version + " }");
@@ -36,7 +35,7 @@ public class ClusterStateViewTest {
 
         clusterStateView.handleUpdatedHostInfo(hostnames, nodeInfo, createHostInfo("101"));
 
-        verify(statsAggregator, never()).updateForDistributor(any(), anyInt(), any());
+        verify(statsAggregator, never()).updateForDistributor(anyInt(), any());
     }
 
 
@@ -48,7 +47,7 @@ public class ClusterStateViewTest {
 
         clusterStateView.handleUpdatedHostInfo(hostnames, nodeInfo, createHostInfo("22"));
 
-        verify(statsAggregator, never()).updateForDistributor(any(), anyInt(), any());
+        verify(statsAggregator, never()).updateForDistributor(anyInt(), any());
     }
 
     @Test
@@ -58,7 +57,7 @@ public class ClusterStateViewTest {
 
         clusterStateView.handleUpdatedHostInfo(hostnames, nodeInfo, createHostInfo("22"));
 
-        verify(statsAggregator, never()).updateForDistributor(any(), anyInt(), any());
+        verify(statsAggregator, never()).updateForDistributor(anyInt(), any());
     }
 
     @Test
@@ -80,8 +79,7 @@ public class ClusterStateViewTest {
 
         clusterStateView.handleUpdatedHostInfo(hostnames, nodeInfo, hostInfo);
 
-        verify(statsAggregator).updateForDistributor(
-                hostnames, 3, StorageNodeStatsBridge.generate(hostInfo.getDistributor()));
+        verify(statsAggregator).updateForDistributor(3, StorageNodeStatsBridge.generate(hostInfo.getDistributor()));
     }
 
     @Test
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregatorTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregatorTest.java
index e5bda010faf..6035ae9d8ce 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregatorTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/ClusterStatsAggregatorTest.java
@@ -1,217 +1,142 @@
 // Copyright 2017 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.clustercontroller.core;
 
+import com.google.common.collect.Sets;
 import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.mockito.runners.MockitoJUnitRunner;
 
 import java.util.*;
 
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-import static org.mockito.Matchers.any;
-import static org.mockito.Mockito.*;
 
 /**
  * @author hakonhall
  * @since 5.34
  */
-@RunWith(MockitoJUnitRunner.class)
 public class ClusterStatsAggregatorTest {
 
-    final Set<Integer> distributors = new HashSet<>();
-    final Set<Integer> storageNodes = new HashSet<>();
-    final Map<Integer, String> hostnames = new HashMap<>();
-    final MetricUpdater updater = mock(MetricUpdater.class);
-    ContentClusterStats clusterStats;
+    private static class StatsBuilder {
+        private final Map<Integer, Map<String, ContentNodeStats.BucketSpaceStats> > stats = new HashMap<>();
 
-    private void addDistributors(Integer... indices) {
-        for (Integer i : indices) {
-            distributors.add(i);
+        public StatsBuilder add(int nodeIndex, String bucketSpace, long bucketsTotal, long bucketsPending) {
+            return add(nodeIndex, bucketSpace, new ContentNodeStats.BucketSpaceStats(bucketsTotal, bucketsPending));
         }
-    }
-
-    private static class StorageNodeSpec {
-        public StorageNodeSpec(Integer index, String hostname) {
-            this.index = index;
-            this.hostname = hostname;
+        public StatsBuilder add(int nodeIndex, String bucketSpace) {
+            return add(nodeIndex, bucketSpace, new ContentNodeStats.BucketSpaceStats());
+        }
+        public StatsBuilder add(int nodeIndex, String bucketSpace, ContentNodeStats.BucketSpaceStats bucketSpaceStats) {
+            Map<String, ContentNodeStats.BucketSpaceStats> contentNodeStats = stats.get(nodeIndex);
+            if (contentNodeStats == null) {
+                contentNodeStats = new HashMap<>();
+                stats.put(nodeIndex, contentNodeStats);
+            }
+            contentNodeStats.put(bucketSpace, bucketSpaceStats);
+            return this;
+        }
+        public StatsBuilder add(int nodeIndex) {
+            stats.put(nodeIndex, new HashMap<>());
+            return this;
+        }
+        public ContentClusterStats build() {
+            Map<Integer, ContentNodeStats> nodeToStatsMap = new HashMap<>();
+            stats.forEach((nodeIndex, bucketSpaces) ->
+                    nodeToStatsMap.put(nodeIndex, new ContentNodeStats(nodeIndex, bucketSpaces)));
+            return new ContentClusterStats(nodeToStatsMap);
         }
-        public Integer index;
-        public String hostname;
     }
 
-    private void addStorageNodes(StorageNodeSpec... specs) {
-        for (StorageNodeSpec spec : specs) {
-            storageNodes.add(spec.index);
-            hostnames.put(spec.index, spec.hostname);
+    private static class Fixture {
+        private ClusterStatsAggregator aggregator;
+        public Fixture(Set<Integer> distributorNodes,
+                Set<Integer> contentNodes) {
+            aggregator = new ClusterStatsAggregator(distributorNodes, contentNodes);
+        }
+        public void update(int distributorIndex, StatsBuilder clusterStats) {
+            aggregator.updateForDistributor(distributorIndex, clusterStats.build());
+        }
+        public void verify(StatsBuilder expectedStats) {
+            assertEquals(expectedStats.build(), aggregator.getAggregatedStats());
         }
-        clusterStats = new ContentClusterStats(storageNodes);
     }
 
-    private void putStorageStats(int index, int syncing, int copyingIn, int movingOut, int copyingOut) {
-        clusterStats.getStorageNode(index).set(createStats(index, syncing, copyingIn, movingOut, copyingOut));
+    private static Set<Integer> distributorNodes(Integer... indices) {
+        return Sets.newHashSet(indices);
     }
 
-    private static ContentNodeStats createStats(int index, int syncing, int copyingIn, int movingOut, int copyingOut) {
-        return new ContentNodeStats(
-                index,
-                new ContentNodeStats.Amount(syncing),
-                new ContentNodeStats.Amount(copyingIn),
-                new ContentNodeStats.Amount(movingOut),
-                new ContentNodeStats.Amount(copyingOut));
+    private static Set<Integer> contentNodes(Integer... indices) {
+        return Sets.newHashSet(indices);
     }
 
     @Test
-    public void testSimple() {
-        final int distributorIndex = 1;
-        addDistributors(distributorIndex);
-
-        final int storageNodeIndex = 11;
-        addStorageNodes(new StorageNodeSpec(storageNodeIndex, "storage-node"));
-
-        putStorageStats(storageNodeIndex, 5, 6, 7, 8);
-
-        ClusterStatsAggregator aggregator = new ClusterStatsAggregator(distributors, storageNodes, updater);
-        aggregator.updateForDistributor(hostnames, distributorIndex, clusterStats);
-
-        Map<String, ContentNodeStats> expectedContentNodeStats = new HashMap<>();
-        expectedContentNodeStats.put("storage-node", createStats(storageNodeIndex, 5, 6, 7, 8));
-
-        verify(updater).updateMergeOpMetrics(expectedContentNodeStats);
+    public void aggregator_handles_updates_to_single_distributor_and_content_node() {
+        Fixture f = new Fixture(distributorNodes(1), contentNodes(3));
+        StatsBuilder stats = new StatsBuilder()
+                .add(3, "default", 10, 1)
+                .add(3, "global", 11, 2);
+        f.update(1, stats);
+        f.verify(stats);
     }
 
     @Test
-    public void testComplex() {
-        final int distributor1 = 1;
-        final int distributor2 = 2;
-        addDistributors(distributor1, distributor2);
-
-        final int storageNode1 = 11;
-        final int storageNode2 = 12;
-        addStorageNodes(
-                new StorageNodeSpec(storageNode1, "storage-node-1"),
-                new StorageNodeSpec(storageNode2, "storage-node-2"));
-
-        ClusterStatsAggregator aggregator = new ClusterStatsAggregator(distributors, storageNodes, updater);
-
-        // Distributor 1.
-        putStorageStats(storageNode1, 0, 1, 2, 3);
-        putStorageStats(storageNode2, 20, 21, 22, 23);
-        aggregator.updateForDistributor(hostnames, distributor1, clusterStats);
-
-        // Distributor 2.
-        putStorageStats(storageNode1, 10, 11, 12, 13);
-        putStorageStats(storageNode2, 30, 31, 32, 33);
-        aggregator.updateForDistributor(hostnames, distributor2, clusterStats);
-
-        Map<String, ContentNodeStats> expectedContentNodeStats = new HashMap<>();
-        expectedContentNodeStats.put("storage-node-1", createStats(storageNode1, 0 + 10, 1 + 11, 2 + 12, 3 + 13));
-        expectedContentNodeStats.put("storage-node-2", createStats(storageNode2, 20 + 30, 21 + 31, 22 + 32, 23 + 33));
-
-        verify(updater, times(1)).updateMergeOpMetrics(expectedContentNodeStats);
+    public void aggregator_handles_updates_to_multiple_distributors_and_content_nodes() {
+        Fixture f = new Fixture(distributorNodes(1, 2), contentNodes(3, 4));
+
+        f.update(1, new StatsBuilder()
+                .add(3, "default", 10, 1)
+                .add(3, "global", 11, 2)
+                .add(4, "default", 12, 3)
+                .add(4, "global", 13, 4));
+        f.update(2, new StatsBuilder()
+                .add(3, "default", 14, 5)
+                .add(3, "global", 15, 6)
+                .add(4, "default", 16, 7)
+                .add(4, "global", 17, 8));
+        f.verify(new StatsBuilder()
+                .add(3, "default", 10 + 14, 1 + 5)
+                .add(3, "global", 11 + 15, 2 + 6)
+                .add(4, "default", 12 + 16, 3 + 7)
+                .add(4, "global", 13 + 17, 4 + 8));
     }
 
     @Test
-    public void testHashCodeCache() {
-        final int distributor1 = 1;
-        final int distributor2 = 2;
-        addDistributors(distributor1, distributor2);
+    public void aggregator_handles_multiple_updates_from_same_distributor() {
+        Fixture f = new Fixture(distributorNodes(1, 2), contentNodes(3));
 
-        final int storageNode1 = 11;
-        final int storageNode2 = 12;
-        addStorageNodes(
-                new StorageNodeSpec(storageNode1, "storage-node-1"),
-                new StorageNodeSpec(storageNode2, "storage-node-2"));
+        f.update(1, new StatsBuilder().add(3, "default"));
+        f.verify(new StatsBuilder().add(3, "default"));
 
-        ClusterStatsAggregator aggregator = new ClusterStatsAggregator(distributors, storageNodes, updater);
+        f.update(2, new StatsBuilder().add(3, "default", 10, 1));
+        f.verify(new StatsBuilder().add(3, "default", 10, 1));
 
-        // Distributor 1.
-        putStorageStats(storageNode1, 0, 1, 2, 3);
-        putStorageStats(storageNode2, 20, 21, 22, 23);
-        aggregator.updateForDistributor(hostnames, distributor1, clusterStats);
+        f.update(1, new StatsBuilder().add(3, "default", 11, 2));
+        f.verify(new StatsBuilder().add(3, "default", 10 + 11, 1 + 2));
 
-        // Distributor 2.
-        putStorageStats(storageNode1, 10, 11, 12, 13);
-        putStorageStats(storageNode2, 30, 31, 32, 33);
-        aggregator.updateForDistributor(hostnames, distributor2, clusterStats);
+        f.update(2, new StatsBuilder().add(3, "default", 15, 6));
+        f.verify(new StatsBuilder().add(3, "default", 11 + 15, 2 + 6));
 
-        // If we add call another updateForDistributor with the same arguments, updateMergeOpMetrics() should not be called.
-        // See times(1) below.
-        aggregator.updateForDistributor(hostnames, distributor2, clusterStats);
+        f.update(1, new StatsBuilder().add(3, "default", 16, 7));
+        f.verify(new StatsBuilder().add(3, "default", 15 + 16, 6 + 7));
 
-        Map<String, ContentNodeStats> expectedContentNodeStats = new HashMap<>();
-        expectedContentNodeStats.put("storage-node-1", createStats(storageNode1, 0 + 10, 1 + 11, 2 + 12, 3 + 13));
-        expectedContentNodeStats.put("storage-node-2", createStats(storageNode2, 20 + 30, 21 + 31, 22 + 32, 23 + 33));
-
-
-        verify(updater, times(1)).updateMergeOpMetrics(expectedContentNodeStats);
+        f.update(2, new StatsBuilder().add(3, "default", 12, 3));
+        f.verify(new StatsBuilder().add(3, "default", 16 + 12, 7 + 3));
     }
 
     @Test
-    public void testUnknownDistributor() {
-        final int upDistributor = 1;
-        final int DownDistributorIndex = 2;
-        addDistributors(upDistributor);
-
-        final int storageNodeIndex = 11;
-        addStorageNodes(new StorageNodeSpec(storageNodeIndex, "storage-node"));
-
-        putStorageStats(storageNodeIndex, 5, 6, 7, 8);
-
-        ClusterStatsAggregator aggregator = new ClusterStatsAggregator(distributors, storageNodes, updater);
-        aggregator.updateForDistributor(hostnames, DownDistributorIndex, clusterStats);
-
-        verify(updater, never()).updateMergeOpMetrics(any());
+    public void aggregator_handles_more_content_nodes_that_distributors() {
+        Fixture f = new Fixture(distributorNodes(1), contentNodes(3, 4));
+        StatsBuilder stats = new StatsBuilder()
+                .add(3, "default", 10, 1)
+                .add(4, "default", 11, 2);
+        f.update(1, stats);
+        f.verify(stats);
     }
 
     @Test
-    public void testMoreStorageNodesThanDistributors() {
-        final int distributor1 = 1;
-        addDistributors(distributor1);
-
-        final int storageNode1 = 11;
-        final int storageNode2 = 12;
-        addStorageNodes(
-                new StorageNodeSpec(storageNode1, "storage-node-1"),
-                new StorageNodeSpec(storageNode2, "storage-node-2"));
-
-        ClusterStatsAggregator aggregator = new ClusterStatsAggregator(distributors, storageNodes, updater);
-
-        // Distributor 1.
-        putStorageStats(storageNode1, 0, 1, 2, 3);
-        putStorageStats(storageNode2, 20, 21, 22, 23);
-        aggregator.updateForDistributor(hostnames, distributor1, clusterStats);
-
-        Map<String, ContentNodeStats> expectedContentNodeStats = new HashMap<>();
-        expectedContentNodeStats.put("storage-node-1", createStats(storageNode1, 0, 1, 2, 3));
-        expectedContentNodeStats.put("storage-node-2", createStats(storageNode2, 20, 21, 22, 23));
-
-        verify(updater, times(1)).updateMergeOpMetrics(expectedContentNodeStats);
+    public void aggregator_ignores_updates_to_unknown_distributor() {
+        Fixture f = new Fixture(distributorNodes(1), contentNodes(3));
+        final int downDistributorIndex = 2;
+        f.update(downDistributorIndex, new StatsBuilder()
+                .add(3, "default", 7, 3));
+        f.verify(new StatsBuilder().add(3));
     }
 
-    @Test
-    public void testMoreDistributorsThanStorageNodes() {
-        final int distributor1 = 1;
-        final int distributor2 = 2;
-        addDistributors(distributor1, distributor2);
-
-        final int storageNode1 = 11;
-        addStorageNodes(new StorageNodeSpec(storageNode1, "storage-node-1"));
-
-        ClusterStatsAggregator aggregator = new ClusterStatsAggregator(distributors, storageNodes, updater);
-
-        // Distributor 1.
-        putStorageStats(storageNode1, 0, 1, 2, 3);
-        aggregator.updateForDistributor(hostnames, distributor1, clusterStats);
-
-        // Distributor 2.
-        putStorageStats(storageNode1, 10, 11, 12, 13);
-        aggregator.updateForDistributor(hostnames, distributor2, clusterStats);
-
-        Map<String, ContentNodeStats> expectedContentNodeStats = new HashMap<>();
-        expectedContentNodeStats.put("storage-node-1", createStats(storageNode1, 0 + 10, 1 + 11, 2 + 12, 3 + 13));
-
-        verify(updater, times(1)).updateMergeOpMetrics(expectedContentNodeStats);
-    }
 }
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateVersionTrackerTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateVersionTrackerTest.java
index 0af7bcbfeaf..d27acf8bc17 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateVersionTrackerTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/StateVersionTrackerTest.java
@@ -11,14 +11,11 @@ import org.junit.Test;
 import java.util.Arrays;
 import java.util.Optional;
 
-import static org.hamcrest.CoreMatchers.hasItems;
 import static org.hamcrest.core.IsEqual.equalTo;
 import static org.hamcrest.core.Is.is;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-import static org.mockito.Mockito.mock;
 
 public class StateVersionTrackerTest {
 
@@ -28,7 +25,7 @@ public class StateVersionTrackerTest {
     }
 
     private static StateVersionTracker createWithMockedMetrics() {
-        return new StateVersionTracker(mock(MetricUpdater.class));
+        return new StateVersionTracker();
     }
 
     private static void updateAndPromote(final StateVersionTracker versionTracker,
diff --git a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNodeStatsBridgeTest.java b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNodeStatsBridgeTest.java
index c9ce54ae3be..5319d741503 100644
--- a/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNodeStatsBridgeTest.java
+++ b/clustercontroller-core/src/test/java/com/yahoo/vespa/clustercontroller/core/hostinfo/StorageNodeStatsBridgeTest.java
@@ -12,11 +12,11 @@ import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Iterator;
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.Is.is;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.*;
 
 /**
  * @author hakonhall
@@ -49,19 +49,30 @@ public class StorageNodeStatsBridgeTest {
     }
 
     @Test
-    public void testStorageMergeStats() throws IOException {
+    public void testContentNodeStats() throws IOException {
         String data = getJsonString();
         HostInfo hostInfo = HostInfo.createHostInfo(data);
 
         ContentClusterStats clusterStats = StorageNodeStatsBridge.generate(hostInfo.getDistributor());
-        int size = 0;
-        for (ContentNodeStats nodeStats : clusterStats) {
-            assertThat(nodeStats.getCopyingIn().getBuckets(), is(2L));
-            assertThat(nodeStats.getCopyingOut().getBuckets(), is(4L));
-            assertThat(nodeStats.getSyncing().getBuckets(), is(1L));
-            assertThat(nodeStats.getMovingOut().getBuckets(), is(3L));
-            size++;
+        Iterator<ContentNodeStats> itr = clusterStats.iterator();
+        { // content node 0
+            ContentNodeStats stats = itr.next();
+            assertThat(stats.getNodeIndex(), is(0));
+            assertThat(stats.getBucketSpaces().size(), is(2));
+            assertBucketSpaceStats(11, 3, stats.getBucketSpaces().get("default"));
+            assertBucketSpaceStats(13, 5, stats.getBucketSpaces().get("global"));
         }
-        assertThat(size, is(2));
+        { // content node 1
+            ContentNodeStats stats = itr.next();
+            assertThat(stats.getNodeIndex(), is(1));
+            assertThat(stats.getBucketSpaces().size(), is(1));
+            assertBucketSpaceStats(0, 0, stats.getBucketSpaces().get("default"));
+        }
+        assertFalse(itr.hasNext());
+    }
+
+    private static void assertBucketSpaceStats(long expBucketsTotal, long expBucketsPending, ContentNodeStats.BucketSpaceStats stats) {
+        assertThat(stats.getBucketsTotal(), is(expBucketsTotal));
+        assertThat(stats.getBucketsPending(), is(expBucketsPending));
     }
 }
diff --git a/protocols/getnodestate/host_info.json b/protocols/getnodestate/host_info.json
index 5ef62d1a84f..305f279c847 100644
--- a/protocols/getnodestate/host_info.json
+++ b/protocols/getnodestate/host_info.json
@@ -48,20 +48,22 @@
                         "count": 16
                     }
                 },
-                "outstanding-merge-ops": {
-                    "syncing": {
-                        "buckets": 1
+                "bucket-spaces": [
+                    {
+                        "name": "default",
+                        "buckets": {
+                            "total": 11,
+                            "pending": 3
+                        }
                     },
-                    "copying-in": {
-                        "buckets": 2
-                    },
-                    "moving-out": {
-                        "buckets": 3
-                    },
-                    "copying-out": {
-                        "buckets": 4
+                    {
+                        "name": "global",
+                        "buckets": {
+                            "total": 13,
+                            "pending": 5
+                        }
                     }
-                }
+                ]
             },
             {
                 "node-index": 1,
@@ -71,24 +73,13 @@
                         "latency-ms-sum": 17,
                         "count": 18
                     }
-                 },
-                 "outstanding-merge-ops": {
-                    "syncing": {
-                        "buckets": 1
-                    },
-                    "copying-in": {
-                        "buckets": 2
-                    },
-                    "moving-out": {
-                        "buckets": 3
-                    },
-                    "copying-out": {
-                        "buckets": 4
+                },
+                "bucket-spaces": [
+                    {
+                        "name": "default"
                     }
-                }
-
+                ]
             }
-
         ]
     }
 }