1 files changed, 12 insertions, 17 deletions

diff --git a/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java b/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java
index eca0c8058a1..43d0e08886d 100644
--- a/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java
+++ b/container-search/src/main/java/com/yahoo/search/dispatch/Dispatcher.java
@@ -60,20 +60,19 @@ public class Dispatcher extends AbstractComponent {
     private final DispatchConfig dispatchConfig;
     private final RpcConnectionPool rpcResourcePool;
     private final SearchCluster searchCluster;
+    private final ClusterMonitor<Node> clusterMonitor;
     private volatile VolatileItems volatileItems;
 
     private static class VolatileItems {
 
         final LoadBalancer loadBalancer;
         final InvokerFactory invokerFactory;
-        final ClusterMonitor<Node> clusterMonitor;
         final AtomicInteger inflight = new AtomicInteger(1); // Initial reference.
         Runnable cleanup = () -> { };
 
-        VolatileItems(LoadBalancer loadBalancer, InvokerFactory invokerFactory, ClusterMonitor<Node> clusterMonitor) {
+        VolatileItems(LoadBalancer loadBalancer, InvokerFactory invokerFactory) {
             this.loadBalancer = loadBalancer;
             this.invokerFactory = invokerFactory;
-            this.clusterMonitor = clusterMonitor;
         }
 
         private void countDown() {
@@ -128,7 +127,7 @@ public class Dispatcher extends AbstractComponent {
     Dispatcher(DispatchConfig dispatchConfig, RpcConnectionPool rpcConnectionPool,
                SearchCluster searchCluster, InvokerFactoryFactory invokerFactories) {
         this(dispatchConfig, rpcConnectionPool, searchCluster, new ClusterMonitor<>(searchCluster, false), invokerFactories);
-        this.volatileItems.clusterMonitor.start(); // Populate nodes to monitor before starting it.
+        this.clusterMonitor.start(); // Populate nodes to monitor before starting it.
     }
 
     Dispatcher(DispatchConfig dispatchConfig, RpcConnectionPool rpcConnectionPool,
@@ -137,7 +136,8 @@ public class Dispatcher extends AbstractComponent {
         this.rpcResourcePool = rpcConnectionPool;
         this.searchCluster = searchCluster;
         this.invokerFactories = invokerFactories;
-        this.volatileItems = update(clusterMonitor);
+        this.clusterMonitor = clusterMonitor;
+        this.volatileItems = update();
         searchCluster.addMonitoring(clusterMonitor);
     }
 
@@ -171,7 +171,7 @@ public class Dispatcher extends AbstractComponent {
      * 3. The load balancer is owned by the volatile snapshot, and is swapped atomically with it;
      *    it is used internally by the dispatcher to select search nodes for queries, and is discarded with its snapshot.
      * 4. The cluster monitor is a subordinate to the search cluster, and does whatever that tells it to, at any time;
-     *    it is technically owned by the volatile snapshot, but mostly to show it is swapped together with that.
+     *    it is technically owned by the dispatcher, but in updated by the search cluster, when that is updated.
      * 5. The search cluster is owned by the dispatcher, and is updated on node set changes;
      *    its responsibility is to keep track of the state of the backend, and to provide a view of it to the dispatcher,
      *    as well as keep the container vip status updated accordingly; it should therefore preserve as much as possible
@@ -192,21 +192,16 @@ public class Dispatcher extends AbstractComponent {
             };
 
             // Update the nodes the search cluster keeps track of, and what nodes are monitored.
-            ClusterMonitor<Node> newMonitor = searchCluster.updateNodes(toNodes(searchCluster.name(), nodesConfig), dispatchConfig.minActivedocsPercentage());
+            searchCluster.updateNodes(toNodes(searchCluster.name(), nodesConfig), clusterMonitor, dispatchConfig.minActivedocsPercentage());
 
             // Update the snapshot to use the new nodes set in the search cluster; the RPC pool is ready for this.
-            this.volatileItems = update(newMonitor);
-
-            // Wait for the old cluster monitor to die; it may be pinging nodes we want to shut down RPC connections to.
-            items.get().clusterMonitor.shutdown();
+            this.volatileItems = update();
         }   // Close the old snapshot, which may trigger the RPC cleanup now, or when the last invoker is closed, by a search thread.
     }
 
-    private VolatileItems update(ClusterMonitor<Node> clusterMonitor) {
-        var items = new VolatileItems(new LoadBalancer(searchCluster.groupList().groups(), toLoadBalancerPolicy(dispatchConfig.distributionPolicy())),
-                                      invokerFactories.create(rpcResourcePool, searchCluster.groupList(), dispatchConfig),
-                                      clusterMonitor);
-        return items;
+    private VolatileItems update() {
+        return new VolatileItems(new LoadBalancer(searchCluster.groupList().groups(), toLoadBalancerPolicy(dispatchConfig.distributionPolicy())),
+                                 invokerFactories.create(rpcResourcePool, searchCluster.groupList(), dispatchConfig));
     }
 
     private void initialWarmup(double warmupTime) {
@@ -255,7 +250,7 @@ public class Dispatcher extends AbstractComponent {
     @Override
     public void deconstruct() {
         // The clustermonitor must be shutdown first as it uses the invokerfactory through the searchCluster.
-        volatileItems.clusterMonitor.shutdown();
+        clusterMonitor.shutdown();
         if (rpcResourcePool != null) {
             rpcResourcePool.close();
         }