Revert "Preserve all node events"

24 files changed, 148 insertions, 198 deletions

diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java
index 853c67dc169..3db68a27234 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java
@@ -347,24 +347,19 @@ public final class Node implements Nodelike {
                         allocation, history, type, reports, Optional.empty(), reservedTo, exclusiveToApplicationId, exclusiveToClusterType, switchHostname, trustStoreItems);
     }
 
-    /** Returns a copy of this with a history record saying it was detected to be down at given instant */
+    /** Returns a copy of this with a history record saying it was detected to be down at this instant */
     public Node downAt(Instant instant, Agent agent) {
         return with(history.with(new History.Event(History.Event.Type.down, agent, instant)));
     }
 
-    /** Returns a copy of this with a history record saying it was detected to be up at given instant */
-    public Node upAt(Instant instant, Agent agent) {
-        return with(history.with(new History.Event(History.Event.Type.up, agent, instant)));
+    /** Returns a copy of this with any history record saying it has been detected down removed */
+    public Node up() {
+        return with(history.without(History.Event.Type.down));
     }
 
-    /** Returns whether this node is down, according to its recorded 'down' and 'up' events */
+    /** Returns whether this node has a record of being down */
     public boolean isDown() {
-        Optional<Instant> downAt = history().lastEvent(History.Event.Type.down).map(History.Event::at);
-        if (downAt.isEmpty()) return false;
-
-        Optional<Instant> upAt = history().lastEvent(History.Event.Type.up).map(History.Event::at);
-        if (upAt.isEmpty()) return true;
-        return !downAt.get().isBefore(upAt.get());
+        return history().event(History.Event.Type.down).isPresent();
     }
 
     /** Returns a copy of this with allocation set as specified. <code>node.state</code> is *not* changed. */
@@ -449,15 +444,12 @@ public final class Node implements Nodelike {
 
     /** Returns a copy of this node with the current OS version set to the given version at the given instant */
     public Node withCurrentOsVersion(Version version, Instant instant) {
-        Optional<Version> newVersion = Optional.of(version);
-        if (status.osVersion().current().equals(newVersion)) return this; // No change
-
-        History newHistory = history();
-        // Only update history if version was non-empty and changed to a different version
-        if (status.osVersion().current().isPresent() && !status.osVersion().current().equals(newVersion)) {
+        var newStatus = status.withOsVersion(status.osVersion().withCurrent(Optional.of(version)));
+        var newHistory = history();
+        // Only update history if version has changed
+        if (status.osVersion().current().isEmpty() || !status.osVersion().current().get().equals(version)) {
             newHistory = history.with(new History.Event(History.Event.Type.osUpgraded, Agent.system, instant));
         }
-        Status newStatus = status.withOsVersion(status.osVersion().withCurrent(newVersion));
         return this.with(newStatus).with(newHistory);
     }
 
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainer.java
index 45a90daac96..eab9f755db2 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainer.java
@@ -107,7 +107,7 @@ public class AutoscalingMaintainer extends NodeRepositoryMaintainer {
         // Scaling event is complete if:
         // - 1. no nodes which was retired by this are still present (which also implies data distribution is complete)
         if (clusterNodes.retired().stream()
-                        .anyMatch(node -> node.history().hasLastEventAt(event.at(), History.Event.Type.retired)))
+                        .anyMatch(node -> node.history().hasEventAt(History.Event.Type.retired, event.at())))
             return cluster;
         // - 2. all nodes have switched to the right config generation (currently only measured on containers)
         for (var nodeTimeseries : nodeRepository().metricsDb().getNodeTimeseries(Duration.between(event.at(), clock().instant()),
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainer.java
index 459ab6a3e1c..6eaee7b33de 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/DynamicProvisioningMaintainer.java
@@ -6,9 +6,9 @@ import com.yahoo.component.Vtag;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.ClusterMembership;
 import com.yahoo.config.provision.ClusterSpec;
-import com.yahoo.config.provision.NodeAllocationException;
 import com.yahoo.config.provision.NodeResources;
 import com.yahoo.config.provision.NodeType;
+import com.yahoo.config.provision.NodeAllocationException;
 import com.yahoo.jdisc.Metric;
 import com.yahoo.lang.MutableInteger;
 import com.yahoo.transaction.Mutex;
@@ -164,7 +164,8 @@ public class DynamicProvisioningMaintainer extends NodeRepositoryMaintainer {
         }
 
         return candidatesForRemoval(nodes).stream()
-                .sorted(Comparator.comparing(node -> node.history().asList().stream().findFirst().map(History.Event::at).orElse(Instant.MIN)))
+                .sorted(Comparator.comparing(node -> node.history().events().stream()
+                                                         .map(History.Event::at).min(Comparator.naturalOrder()).orElse(Instant.MIN)))
                 .filter(node -> {
                     if (!sharedHosts.containsKey(node.hostname()) || sharedHosts.size() > minCount) {
                         sharedHosts.remove(node.hostname());
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ExpeditedChangeApplicationMaintainer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ExpeditedChangeApplicationMaintainer.java
index ced0a161e59..fa6b201def4 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ExpeditedChangeApplicationMaintainer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ExpeditedChangeApplicationMaintainer.java
@@ -78,11 +78,11 @@ public class ExpeditedChangeApplicationMaintainer extends ApplicationMaintainer
 
         List<String> reasons = nodes.stream()
                                     .flatMap(node -> node.history()
-                                                         .asList()
-                                                         .stream()
-                                                         .filter(event -> expediteChangeBy(event.agent()))
-                                                         .filter(event -> lastDeployTime.get().isBefore(event.at()))
-                                                         .map(event -> event.type() + (event.agent() == Agent.system ? "" : " by " + event.agent())))
+                                                            .events()
+                                                            .stream()
+                                                            .filter(event -> expediteChangeBy(event.agent()))
+                                                            .filter(event -> lastDeployTime.get().isBefore(event.at()))
+                                                            .map(event -> event.type() + (event.agent() == Agent.system ? "" : " by " + event.agent())))
                                     .sorted()
                                     .distinct()
                                     .collect(Collectors.toList());
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/Expirer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/Expirer.java
index 51d73bd8a58..5a77fcca85c 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/Expirer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/Expirer.java
@@ -57,7 +57,7 @@ public abstract class Expirer extends NodeRepositoryMaintainer {
     }
 
     protected final boolean isExpired(Node node, Duration expiryTime) {
-        return node.history().hasLastEventBefore(clock().instant().minus(expiryTime), eventType);
+        return node.history().hasEventBefore(eventType, clock().instant().minus(expiryTime));
     }
 
     /** Implement this callback to take action to expire these nodes */
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/FailedExpirer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/FailedExpirer.java
index af17260ad84..3274f12dbc6 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/FailedExpirer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/FailedExpirer.java
@@ -73,10 +73,10 @@ public class FailedExpirer extends NodeRepositoryMaintainer {
         recycleIf(remainingNodes, node -> node.allocation().isEmpty());
         recycleIf(remainingNodes, node ->
                 !node.allocation().get().membership().cluster().isStateful() &&
-                node.history().hasLastEventBefore(clock().instant().minus(statelessExpiry), History.Event.Type.failed));
+                node.history().hasEventBefore(History.Event.Type.failed, clock().instant().minus(statelessExpiry)));
         recycleIf(remainingNodes, node ->
                 node.allocation().get().membership().cluster().isStateful() &&
-                node.history().hasLastEventBefore(clock().instant().minus(statefulExpiry), History.Event.Type.failed));
+                node.history().hasEventBefore(History.Event.Type.failed, clock().instant().minus(statefulExpiry)));
         return 1.0;
     }
 
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporter.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporter.java
index b117523dce0..1fe29c8b162 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporter.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/MetricsReporter.java
@@ -20,6 +20,7 @@ import com.yahoo.vespa.hosted.provision.NodeList;
 import com.yahoo.vespa.hosted.provision.NodeRepository;
 import com.yahoo.vespa.hosted.provision.node.Allocation;
 import com.yahoo.vespa.hosted.provision.node.ClusterId;
+import com.yahoo.vespa.hosted.provision.node.History;
 import com.yahoo.vespa.hosted.provision.persistence.CacheStats;
 import com.yahoo.vespa.service.monitor.ServiceModel;
 import com.yahoo.vespa.service.monitor.ServiceMonitor;
@@ -247,8 +248,8 @@ public class MetricsReporter extends NodeRepositoryMaintainer {
             boolean down = NodeHealthTracker.allDown(services);
             metric.set("nodeFailerBadNode", (down ? 1 : 0), context);
 
-            boolean recordedDown = node.isDown();
-            metric.set("downInNodeRepo", (recordedDown ? 1 : 0), context);
+            boolean nodeDownInNodeRepo = node.history().event(History.Event.Type.down).isPresent();
+            metric.set("downInNodeRepo", (nodeDownInNodeRepo ? 1 : 0), context);
         }
 
         metric.set("numberOfServices", numberOfServices, context);
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailer.java
index 661ba531de5..3900d10a53e 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeFailer.java
@@ -155,9 +155,9 @@ public class NodeFailer extends NodeRepositoryMaintainer {
 
         for (Node node : activeNodes) {
             Instant graceTimeStart = clock().instant().minus(nodeRepository().nodes().suspended(node) ? suspendedDownTimeLimit : downTimeLimit);
-            if (downBefore(graceTimeStart, node) && !applicationSuspended(node)) {
+            if (node.history().hasEventBefore(History.Event.Type.down, graceTimeStart) && !applicationSuspended(node)) {
                 // Allow a grace period after node re-activation
-                if (!node.history().hasLastEventAfter(graceTimeStart, History.Event.Type.activated))
+                if (!node.history().hasEventAfter(History.Event.Type.activated, graceTimeStart))
                     failingNodes.add(new FailingNode(node, "Node has been down longer than " + downTimeLimit));
             }
         }
@@ -278,11 +278,6 @@ public class NodeFailer extends NodeRepositoryMaintainer {
         }
     }
 
-    /** Returns whether node is down, and has been down since before given instant */
-    private static boolean downBefore(Instant instant, Node node) {
-        return node.isDown() && node.history().hasLastEventBefore(instant, History.Event.Type.down);
-    }
-
     private void wantToFail(Node node, boolean wantToFail, Mutex lock) {
         nodeRepository().nodes().write(node.withWantToFail(wantToFail, Agent.NodeFailer, clock().instant()), lock);
     }
@@ -293,8 +288,8 @@ public class NodeFailer extends NodeRepositoryMaintainer {
         Instant startOfThrottleWindow = clock().instant().minus(throttlePolicy.throttleWindow);
         NodeList allNodes = nodeRepository().nodes().list();
         NodeList recentlyFailedNodes = allNodes.state(Node.State.failed)
-                                               .matching(n -> n.history().hasLastEventAfter(startOfThrottleWindow, History.Event.Type.failed
-                                               ));
+                                               .matching(n -> n.history().hasEventAfter(History.Event.Type.failed,
+                                                                                        startOfThrottleWindow));
 
         // Allow failing any node within policy
         if (recentlyFailedNodes.size() < throttlePolicy.allowedToFailOf(allNodes.size())) return false;
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeHealthTracker.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeHealthTracker.java
index ab2cc2da257..874ff91d8a4 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeHealthTracker.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeHealthTracker.java
@@ -61,7 +61,7 @@ public class NodeHealthTracker extends NodeRepositoryMaintainer {
                 Optional<Instant> lastLocalRequest = hostLivenessTracker.lastRequestFrom(node.hostname());
                 if (lastLocalRequest.isEmpty()) continue;
 
-                if (!node.history().hasLastEventAfter(lastLocalRequest.get(), History.Event.Type.requested)) {
+                if (!node.history().hasEventAfter(History.Event.Type.requested, lastLocalRequest.get())) {
                     History updatedHistory = node.history()
                                                  .with(new History.Event(History.Event.Type.requested, Agent.NodeHealthTracker, lastLocalRequest.get()));
                     nodeRepository().nodes().write(node.with(updatedHistory), lock);
@@ -96,7 +96,7 @@ public class NodeHealthTracker extends NodeRepositoryMaintainer {
                 if (isDown) {
                     recordAsDown(node.get(), lock);
                 } else {
-                    recordAsUp(node.get(), lock);
+                    clearDownRecord(node.get(), lock);
                 }
             } catch (ApplicationLockException e) {
                 // Fine, carry on with other nodes. We'll try updating this one in the next run
@@ -129,14 +129,14 @@ public class NodeHealthTracker extends NodeRepositoryMaintainer {
 
     /** Record a node as down if not already recorded */
     private void recordAsDown(Node node, Mutex lock) {
-        if (node.isDown()) return; // already down: Don't change down timestamp
+        if (node.history().event(History.Event.Type.down).isPresent()) return; // already down: Don't change down timestamp
         nodeRepository().nodes().write(node.downAt(clock().instant(), Agent.NodeHealthTracker), lock);
     }
 
     /** Clear down record for node, if any */
-    private void recordAsUp(Node node, Mutex lock) {
-        if (!node.isDown()) return; // already up: Don't change up timestamp
-        nodeRepository().nodes().write(node.upAt(clock().instant(), Agent.NodeHealthTracker), lock);
+    private void clearDownRecord(Node node, Mutex lock) {
+        if (node.history().event(History.Event.Type.down).isEmpty()) return;
+        nodeRepository().nodes().write(node.up(), lock);
     }
 
 }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooter.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooter.java
index 6093977bc9d..3cd97c64e4d 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooter.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooter.java
@@ -55,11 +55,11 @@ public class NodeRebooter extends NodeRepositoryMaintainer {
         var rebootEvents = EnumSet.of(History.Event.Type.provisioned, History.Event.Type.rebooted, History.Event.Type.osUpgraded);
         var rebootInterval = Duration.ofDays(rebootIntervalInDays.value());
 
-        Optional<Duration> overdue = node.history().asList().stream()
-                                         .filter(event -> rebootEvents.contains(event.type()))
-                                         .map(History.Event::at)
-                                         .max(Comparator.naturalOrder())
-                                         .map(lastReboot -> Duration.between(lastReboot, clock().instant()).minus(rebootInterval));
+        Optional<Duration> overdue = node.history().events().stream()
+                .filter(event -> rebootEvents.contains(event.type()))
+                .map(History.Event::at)
+                .max(Comparator.naturalOrder())
+                .map(lastReboot -> Duration.between(lastReboot, clock().instant()).minus(rebootInterval));
 
         if (overdue.isEmpty()) // should never happen as all hosts should have provisioned timestamp
             return random.nextDouble() < interval().getSeconds() / (double) rebootInterval.getSeconds();
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ProvisionedExpirer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ProvisionedExpirer.java
index 39015306ae2..2db02992f40 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ProvisionedExpirer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/ProvisionedExpirer.java
@@ -54,7 +54,7 @@ public class ProvisionedExpirer extends Expirer {
     }
 
     private boolean parkedByProvisionedExpirer(Node node) {
-        return node.history().lastEvent(History.Event.Type.parked)
+        return node.history().event(History.Event.Type.parked)
                 .map(History.Event::agent)
                 .map(Agent.ProvisionedExpirer::equals)
                 .orElse(false);
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirer.java
index d4eb02b59b0..73c9a1ab55a 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/maintenance/RetiredExpirer.java
@@ -116,7 +116,7 @@ public class RetiredExpirer extends NodeRepositoryMaintainer {
                 // allowing the removal of any config server.
                 return false;
             }
-        } else if (node.history().hasLastEventBefore(clock().instant().minus(retiredExpiry), History.Event.Type.retired)) {
+        } else if (node.history().hasEventBefore(History.Event.Type.retired, clock().instant().minus(retiredExpiry))) {
             log.warning("Node " + node + " has been retired longer than " + retiredExpiry + ": Allowing removal. This may cause data loss");
             return true;
         }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/History.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/History.java
index 59e43fd9971..f1e62634235 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/History.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/History.java
@@ -1,19 +1,17 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.node;
 
+import com.google.common.collect.ImmutableMap;
 import com.yahoo.vespa.hosted.provision.Node;
 
 import java.time.Instant;
-import java.util.ArrayList;
-import java.util.Comparator;
-import java.util.List;
-import java.util.Objects;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.Optional;
 import java.util.stream.Collectors;
 
 /**
- * An immutable list of events happening to this node, in chronological order.
- *
+ * An immutable record of the last event of each type happening to this node.
  * Note that the history cannot be used to find the nodes current state - it will have a record of some
  * event happening in the past even if that event is later undone.
  *
@@ -21,60 +19,72 @@ import java.util.stream.Collectors;
  */
 public class History {
 
-    /** The maximum number of events to keep for a node */
-    private static final int MAX_SIZE = 15;
-
-    private final List<Event> events;
+    private final ImmutableMap<Event.Type, Event> events;
 
-    public History(List<Event> events) {
-        this(events, MAX_SIZE);
+    public History(Collection<Event> events) {
+        this(toImmutableMap(events));
     }
 
-    History(List<Event> events, int maxSize) {
-        this.events = Objects.requireNonNull(events, "events must be non-null")
-                             .stream()
-                             .sorted(Comparator.comparing(Event::at))
-                             .skip(Math.max(events.size() - maxSize, 0))
-                             .collect(Collectors.toUnmodifiableList());
+    private History(ImmutableMap<Event.Type, Event> events) {
+        this.events = events;
     }
 
-    /** Returns the last event of given type, if it is present in this history */
-    public Optional<Event> lastEvent(Event.Type type) {
-        return events.stream().filter(event -> event.type() == type).max(Comparator.comparing(Event::at));
+    private static ImmutableMap<Event.Type, Event> toImmutableMap(Collection<Event> events) {
+        ImmutableMap.Builder<Event.Type, Event> builder = new ImmutableMap.Builder<>();
+        for (Event event : events)
+            builder.put(event.type(), event);
+        return builder.build();
     }
 
-    /** Returns true if the last event of this type is registered in this history at the given time */
-    public boolean hasLastEventAt(Instant time, Event.Type type) {
-        return lastEvent(type).map(event -> event.at().equals(time))
-                              .orElse(false);
-    }
+    /** Returns this event if it is present in this history */
+    public Optional<Event> event(Event.Type type) { return Optional.ofNullable(events.get(type)); }
 
-    /** Returns true if the last event of this type is registered after the given time */
-    public boolean hasLastEventAfter(Instant time, Event.Type type) {
-        return lastEvent(type).map(event -> event.at().isAfter(time))
-                              .orElse(false);
+    /** Returns true if a given event is registered in this history at the given time */
+    public boolean hasEventAt(Event.Type type, Instant time) {
+        return event(type)
+                       .map(event -> event.at().equals(time))
+                       .orElse(false);
     }
 
-    /** Returns true if the last event of this type is registered before the given time */
-    public boolean hasLastEventBefore(Instant time, Event.Type type) {
-        return lastEvent(type).map(event -> event.at().isBefore(time))
-                              .orElse(false);
+    /** Returns true if a given event is registered in this history after the given time */
+    public boolean hasEventAfter(Event.Type type, Instant time) {
+        return event(type)
+                .map(event -> event.at().isAfter(time))
+                .orElse(false);
     }
 
-    public List<Event> asList() {
-        return events;
+    /** Returns true if a given event is registered in this history before the given time */
+    public boolean hasEventBefore(Event.Type type, Instant time) {
+        return event(type)
+                .map(event -> event.at().isBefore(time))
+                .orElse(false);
     }
 
+    public Collection<Event> events() { return events.values(); }
+
     /** Returns a copy of this history with the given event added */
     public History with(Event event) {
-        List<Event> copy = new ArrayList<>(events);
-        copy.add(event);
-        return new History(copy);
+        ImmutableMap.Builder<Event.Type, Event> builder = builderWithout(event.type());
+        builder.put(event.type(), event);
+        return new History(builder.build());
+    }
+
+    /** Returns a copy of this history with the given event type removed (or an identical history if it was not present) */
+    public History without(Event.Type type) {
+        return new History(builderWithout(type).build());
+    }
+
+    private ImmutableMap.Builder<Event.Type, Event> builderWithout(Event.Type type) {
+        ImmutableMap.Builder<Event.Type, Event> builder = new ImmutableMap.Builder<>();
+        for (Event event : events.values())
+            if (event.type() != type)
+                builder.put(event.type(), event);
+        return builder;
     }
 
     /** Returns a copy of this history with a record of this state transition added, if applicable */
     public History recordStateTransition(Node.State from, Node.State to, Agent agent, Instant at) {
-        // If the event is a re-reservation, allow the new event to overwrite the older one.
+        // If the event is a re-reservation, allow the new one to override the older one.
         if (from == to && from != Node.State.reserved) return this;
         switch (to) {
             case provisioned:   return this.with(new Event(Event.Type.provisioned, agent, at));
@@ -82,14 +92,7 @@ public class History {
             case ready:         return this.withoutApplicationEvents().with(new Event(Event.Type.readied, agent, at));
             case active:        return this.with(new Event(Event.Type.activated, agent, at));
             case inactive:      return this.with(new Event(Event.Type.deactivated, agent, at));
-            case reserved: {
-                History history = this;
-                if (!events.isEmpty() && events.get(events.size() - 1).type() == Event.Type.reserved) {
-                    // Avoid repeating reserved event
-                    history = new History(events.subList(0, events.size() - 1));
-                }
-                return history.with(new Event(Event.Type.reserved, agent, at));
-            }
+            case reserved:      return this.with(new Event(Event.Type.reserved, agent, at));
             case failed:        return this.with(new Event(Event.Type.failed, agent, at));
             case dirty:         return this.with(new Event(Event.Type.deallocated, agent, at));
             case parked:        return this.with(new Event(Event.Type.parked, agent, at));
@@ -103,17 +106,17 @@ public class History {
      * This returns a copy of this history with all application level events removed. 
      */
     private History withoutApplicationEvents() {
-        return new History(asList().stream().filter(e -> ! e.type().isApplicationLevel()).collect(Collectors.toList()));
+        return new History(events().stream().filter(e -> ! e.type().isApplicationLevel()).collect(Collectors.toList()));
     }
 
     /** Returns the empty history */
-    public static History empty() { return new History(List.of()); }
+    public static History empty() { return new History(Collections.emptyList()); }
 
     @Override
     public String toString() {
         if (events.isEmpty()) return "history: (empty)";
         StringBuilder b = new StringBuilder("history: ");
-        for (Event e : events)
+        for (Event e : events.values())
             b.append(e).append(", ");
          b.setLength(b.length() - 2); // remove last comma
         return b.toString();
@@ -145,27 +148,27 @@ public class History {
             readied,
             reserved,
 
-            /** The node was scheduled for retirement (hard) */
+            // The node was scheduled for retirement (hard)
             wantToRetire(false),
-            /** The node was scheduled for retirement (soft) */
+            // The node was scheduled for retirement (soft)
             preferToRetire(false),
-            /** This node was scheduled for failing */
+            // This node was scheduled for failing
             wantToFail,
-            /** The active node was retired */
+            // The active node was retired
             retired,
-            /** The active node went down according to the service monitor */
+            // The active node went down according to the service monitor
             down,
-            /** The active node came up according to the service monitor */
+            // The active node came up according to the service monitor
             up,
-            /** The node made a config request, indicating it is live */
+            // The node made a config request, indicating it is live
             requested,
-            /** The node resources/flavor were changed */
+            // The node resources/flavor were changed
             resized(false),
-            /** The node was rebooted */
+            // The node was rebooted
             rebooted(false),
-            /** The node upgraded its OS (implies a reboot) */
+            // The node upgraded its OS (implies a reboot)
             osUpgraded(false),
-            /** The node verified its firmware (whether this resulted in a reboot depends on the node model) */
+            // The node verified its firmware (whether this resulted in a reboot depends on the node model)
             firmwareVerified(false);
 
             private final boolean applicationLevel;
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java
index c403dda1b74..d544ea76983 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/node/Nodes.java
@@ -840,7 +840,7 @@ public class Nodes {
         if (agent == Agent.operator) return false;
         if (node.type() == NodeType.tenant && node.status().wantToDeprovision()) return false;
         boolean retirementRequestedByOperator = node.status().wantToRetire() &&
-                                                node.history().lastEvent(History.Event.Type.wantToRetire)
+                                                node.history().event(History.Event.Type.wantToRetire)
                                                     .map(History.Event::agent)
                                                     .map(a -> a == Agent.operator)
                                                     .orElse(false);
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java
index 551a15aa804..4990c1e9db8 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializer.java
@@ -219,7 +219,7 @@ public class NodeSerializer {
     }
 
     private void toSlime(History history, Cursor array) {
-        for (History.Event event : history.asList())
+        for (History.Event event : history.events())
             toSlime(event, array.addObject());
     }
 
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java
index 2822114375f..922c8bc8e20 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/NodesResponse.java
@@ -197,7 +197,7 @@ class NodesResponse extends SlimeJsonResponse {
     }
 
     private void toSlime(History history, Cursor array) {
-        for (History.Event event : history.asList()) {
+        for (History.Event event : history.events()) {
             Cursor object = array.addObject();
             object.setString("event", event.type().name());
             object.setLong("at", event.at().toEpochMilli());
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java
index 74fe5800e89..078df5264a1 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/NodeRepositoryTest.java
@@ -185,7 +185,7 @@ public class NodeRepositoryTest {
         tester.clock().advance(Duration.ofSeconds(1));
         tester.addHost("id1", "host1", "default", NodeType.host);
         tester.addHost("id2", "host2", "default", NodeType.host);
-        assertFalse(tester.nodeRepository().nodes().node("host1").get().history().hasLastEventAfter(testStart, History.Event.Type.deprovisioned));
+        assertFalse(tester.nodeRepository().nodes().node("host1").get().history().hasEventAfter(History.Event.Type.deprovisioned, testStart));
 
         // Set host 1 properties and deprovision it
         try (var lock = tester.nodeRepository().nodes().lockAndGetRequired("host1")) {
@@ -208,7 +208,7 @@ public class NodeRepositoryTest {
         Node host1 = tester.nodeRepository().nodes().node("host1").get();
         Node host2 = tester.nodeRepository().nodes().node("host2").get();
         assertEquals(Node.State.deprovisioned, host1.state());
-        assertTrue(host1.history().hasLastEventAfter(testStart, History.Event.Type.deprovisioned));
+        assertTrue(host1.history().hasEventAfter(History.Event.Type.deprovisioned, testStart));
 
         // Adding it again preserves some information from the deprovisioned host and removes it
         tester.addHost("id2", "host1", "default", NodeType.host);
@@ -218,7 +218,7 @@ public class NodeRepositoryTest {
                     tester.nodeRepository().nodes().node("host1", Node.State.deprovisioned).isPresent());
         assertFalse("Not transferred from deprovisioned host", host1.status().wantToRetire());
         assertFalse("Not transferred from deprovisioned host", host1.status().wantToDeprovision());
-        assertTrue("Transferred from deprovisioned host", host1.history().hasLastEventAfter(testStart, History.Event.Type.deprovisioned));
+        assertTrue("Transferred from deprovisioned host", host1.history().hasEventAfter(History.Event.Type.deprovisioned, testStart));
         assertTrue("Transferred from deprovisioned host", host1.status().firmwareVerifiedAt().isPresent());
         assertEquals("Transferred from deprovisioned host", 1, host1.status().failCount());
         assertEquals("Transferred from deprovisioned host", 1, host1.reports().getReports().size());
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/InactiveAndFailedExpirerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/InactiveAndFailedExpirerTest.java
index 4972e9f6f20..5211b855fff 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/InactiveAndFailedExpirerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/InactiveAndFailedExpirerTest.java
@@ -78,7 +78,7 @@ public class InactiveAndFailedExpirerTest {
         Node ready = tester.nodeRepository().nodes().setReady(List.of(dirty.asList().get(0)), Agent.system, getClass().getSimpleName()).get(0);
         assertEquals("Allocated history is removed on readying",
                 List.of(History.Event.Type.provisioned, History.Event.Type.readied),
-                ready.history().asList().stream().map(History.Event::type).collect(Collectors.toList()));
+                ready.history().events().stream().map(History.Event::type).collect(Collectors.toList()));
 
         // Dirty times out for the other one
         tester.advanceTime(Duration.ofMinutes(14));
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooterTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooterTest.java
index 84270a54218..b8f6011d6bf 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooterTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/NodeRebooterTest.java
@@ -16,7 +16,6 @@ import org.junit.Test;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.List;
-import java.util.Optional;
 import java.util.stream.Collectors;
 
 import static org.junit.Assert.assertEquals;
@@ -61,8 +60,7 @@ public class NodeRebooterTest {
         // OS upgrade counts as reboot, so within 0x-1x there is no reboots
         tester.clock().advance(rebootInterval);
         rebooter.maintain();
-        scheduleOsUpgrade(nodeRepository);
-        simulateOsUpgrade(nodeRepository);
+        simulateReboot(nodeRepository);
         assertReadyHosts(15, nodeRepository, 1L);
 
         // OS upgrade counts as reboot, but within 1x-2x reboots are scheduled again
@@ -111,8 +109,6 @@ public class NodeRebooterTest {
 
     private void makeReadyHosts(int count, ProvisioningTester tester) {
         tester.makeReadyNodes(count, new NodeResources(64, 256, 1000, 10), NodeType.host, 10);
-        // Set initial OS version
-        tester.patchNodes(node -> node.type().isHost(), (node) -> node.with(node.status().withOsVersion(node.status().osVersion().withCurrent(Optional.of(Version.fromString("7.0"))))));
     }
 
     /** Set current reboot generation to the wanted reboot generation whenever it is larger (i.e record a reboot) */
@@ -126,7 +122,7 @@ public class NodeRebooterTest {
 
     /** Schedule OS upgrade for all host nodes */
     private void scheduleOsUpgrade(NodeRepository nodeRepository) {
-        nodeRepository.osVersions().setTarget(NodeType.host, Version.fromString("7.1"), Duration.ZERO, false);
+        nodeRepository.osVersions().setTarget(NodeType.host, Version.fromString("7.0"), Duration.ZERO, false);
     }
 
     /** Simulate completion of an OS upgrade */
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/node/HistoryTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/node/HistoryTest.java
deleted file mode 100644
index 62c5dda51a7..00000000000
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/node/HistoryTest.java
+++ /dev/null
@@ -1,43 +0,0 @@
-// Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
-package com.yahoo.vespa.hosted.provision.node;
-
-import com.yahoo.vespa.hosted.provision.node.History.Event;
-import org.junit.Test;
-
-import java.time.Instant;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-import java.util.stream.Collectors;
-
-import static org.junit.Assert.assertEquals;
-
-/**
- * @author mpolden
- */
-public class HistoryTest {
-
-    @Test
-    public void truncate_events() {
-        assertEquals(0, new History(List.of(), 2).asList().size());
-        assertEquals(1, new History(shuffledEvents(1), 2).asList().size());
-        assertEquals(2, new History(shuffledEvents(2), 2).asList().size());
-
-        History history = new History(shuffledEvents(5), 3);
-        assertEquals(3, history.asList().size());
-        assertEquals("Most recent events are kept",
-                     List.of(2L, 3L, 4L),
-                     history.asList().stream().map(e -> e.at().toEpochMilli()).collect(Collectors.toList()));
-    }
-
-    private static List<Event> shuffledEvents(int count) {
-        Instant start = Instant.ofEpochMilli(0);
-        List<Event> events = new ArrayList<>();
-        for (int i = 0; i < count; i++) {
-            events.add(new Event(Event.Type.values()[i], Agent.system, start.plusMillis(i)));
-        }
-        Collections.shuffle(events);
-        return events;
-    }
-
-}
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java
index f14675d1536..48ee23c7b60 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/NodeSerializerTest.java
@@ -71,7 +71,7 @@ public class NodeSerializerTest {
         assertEquals(node.id(), copy.id());
         assertEquals(node.state(), copy.state());
         assertFalse(copy.allocation().isPresent());
-        assertEquals(0, copy.history().asList().size());
+        assertEquals(0, copy.history().events().size());
     }
 
     @Test
@@ -81,14 +81,14 @@ public class NodeSerializerTest {
                                                              DiskSpeed.any, StorageType.any, Architecture.arm64);
 
         clock.advance(Duration.ofMinutes(3));
-        assertEquals(0, node.history().asList().size());
+        assertEquals(0, node.history().events().size());
         node = node.allocate(ApplicationId.from(TenantName.from("myTenant"),
                                                 ApplicationName.from("myApplication"),
                                                 InstanceName.from("myInstance")),
                              ClusterMembership.from("content/myId/0/0/stateful", Vtag.currentVersion, Optional.empty()),
                              requestedResources,
                              clock.instant());
-        assertEquals(1, node.history().asList().size());
+        assertEquals(1, node.history().events().size());
         node = node.withRestart(new Generation(1, 2));
         node = node.withReboot(new Generation(3, 4));
         node = node.with(FlavorConfigBuilder.createDummies("arm64").getFlavorOrThrow("arm64"), Agent.system, clock.instant());
@@ -112,8 +112,8 @@ public class NodeSerializerTest {
         assertEquals(node.allocation().get().membership(), copy.allocation().get().membership());
         assertEquals(node.allocation().get().requestedResources(), copy.allocation().get().requestedResources());
         assertEquals(node.allocation().get().isRemovable(), copy.allocation().get().isRemovable());
-        assertEquals(2, copy.history().asList().size());
-        assertEquals(clock.instant().truncatedTo(MILLIS), copy.history().lastEvent(History.Event.Type.reserved).get().at());
+        assertEquals(2, copy.history().events().size());
+        assertEquals(clock.instant().truncatedTo(MILLIS), copy.history().event(History.Event.Type.reserved).get().at());
         assertEquals(NodeType.tenant, copy.type());
     }
 
@@ -160,7 +160,7 @@ public class NodeSerializerTest {
         assertEquals(3, node.allocation().get().restartGeneration().wanted());
         assertEquals(4, node.allocation().get().restartGeneration().current());
         assertEquals(Arrays.asList(History.Event.Type.provisioned, History.Event.Type.reserved),
-                node.history().asList().stream().map(History.Event::type).collect(Collectors.toList()));
+                node.history().events().stream().map(History.Event::type).collect(Collectors.toList()));
         assertTrue(node.allocation().get().isRemovable());
         assertEquals(NodeType.tenant, node.type());
     }
@@ -170,21 +170,21 @@ public class NodeSerializerTest {
         Node node = createNode();
 
         clock.advance(Duration.ofMinutes(3));
-        assertEquals(0, node.history().asList().size());
+        assertEquals(0, node.history().events().size());
         node = node.allocate(ApplicationId.from(TenantName.from("myTenant"),
                                                 ApplicationName.from("myApplication"),
                                                 InstanceName.from("myInstance")),
                              ClusterMembership.from("content/myId/0/0/stateful", Vtag.currentVersion, Optional.empty()),
                              node.flavor().resources(),
                              clock.instant());
-        assertEquals(1, node.history().asList().size());
+        assertEquals(1, node.history().events().size());
         clock.advance(Duration.ofMinutes(2));
         node = node.retire(Agent.application, clock.instant());
         Node copy = nodeSerializer.fromJson(Node.State.provisioned, nodeSerializer.toJson(node));
-        assertEquals(2, copy.history().asList().size());
-        assertEquals(clock.instant().truncatedTo(MILLIS), copy.history().lastEvent(History.Event.Type.retired).get().at());
+        assertEquals(2, copy.history().events().size());
+        assertEquals(clock.instant().truncatedTo(MILLIS), copy.history().event(History.Event.Type.retired).get().at());
         assertEquals(Agent.application,
-                     (copy.history().lastEvent(History.Event.Type.retired).get()).agent());
+                     (copy.history().event(History.Event.Type.retired).get()).agent());
         assertTrue(copy.allocation().get().membership().retired());
 
         Node removable = copy.with(node.allocation().get().removable(true));
@@ -209,13 +209,13 @@ public class NodeSerializerTest {
                 "    \"wantedVespaVersion\": \"6.42.2\"\n" +
                 "  }\n" +
                 "}\n").getBytes());
-        assertEquals(0, node.history().asList().size());
+        assertEquals(0, node.history().events().size());
         assertTrue(node.allocation().isPresent());
         assertEquals("ugccloud-container", node.allocation().get().membership().cluster().id().value());
         assertEquals("container", node.allocation().get().membership().cluster().type().name());
         assertEquals(0, node.allocation().get().membership().cluster().group().get().index());
         Node copy = nodeSerializer.fromJson(Node.State.provisioned, nodeSerializer.toJson(node));
-        assertEquals(0, copy.history().asList().size());
+        assertEquals(0, copy.history().events().size());
     }
 
     @Test
@@ -296,7 +296,7 @@ public class NodeSerializerTest {
         Node copy = nodeSerializer.fromJson(Node.State.provisioned, nodeSerializer.toJson(node));
         assertEquals(1234, copy.flavor().resources().diskGb(), 0);
         assertEquals(node, copy);
-        assertTrue(node.history().lastEvent(History.Event.Type.resized).isPresent());
+        assertTrue(node.history().event(History.Event.Type.resized).isPresent());
     }
 
     @Test
@@ -351,12 +351,12 @@ public class NodeSerializerTest {
         assertFalse(serialized.status().osVersion().current().isPresent());
 
         // Update OS version
-        serialized = serialized.withCurrentOsVersion(Version.fromString("7.1"), Instant.ofEpochMilli(42))
-                               .withCurrentOsVersion(Version.fromString("7.2"), Instant.ofEpochMilli(123))
-                               .withCurrentOsVersion(Version.fromString("7.2"), Instant.ofEpochMilli(456));
+        serialized = serialized.withCurrentOsVersion(Version.fromString("7.1"), Instant.ofEpochMilli(123))
+                               // Another update for same version:
+                               .withCurrentOsVersion(Version.fromString("7.1"), Instant.ofEpochMilli(456));
         serialized = nodeSerializer.fromJson(State.provisioned, nodeSerializer.toJson(serialized));
-        assertEquals(Version.fromString("7.2"), serialized.status().osVersion().current().get());
-        var osUpgradedEvents = serialized.history().asList().stream()
+        assertEquals(Version.fromString("7.1"), serialized.status().osVersion().current().get());
+        var osUpgradedEvents = serialized.history().events().stream()
                                          .filter(event -> event.type() == History.Event.Type.osUpgraded)
                                          .collect(Collectors.toList());
         assertEquals("OS upgraded event is added", 1, osUpgradedEvents.size());
@@ -372,7 +372,7 @@ public class NodeSerializerTest {
         node = node.withFirmwareVerifiedAt(Instant.ofEpochMilli(100));
         node = nodeSerializer.fromJson(State.active, nodeSerializer.toJson(node));
         assertEquals(100, node.status().firmwareVerifiedAt().get().toEpochMilli());
-        assertEquals(Instant.ofEpochMilli(100), node.history().lastEvent(History.Event.Type.firmwareVerified).get().at());
+        assertEquals(Instant.ofEpochMilli(100), node.history().event(History.Event.Type.firmwareVerified).get().at());
     }
 
     @Test
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java
index a74eaf32bf8..94822c85a03 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java
@@ -880,7 +880,7 @@ public class ProvisioningTest {
         assertTrue("Time of event is updated for all nodes",
                    reserved.stream()
                            .allMatch(n -> n.history()
-                           .lastEvent(History.Event.Type.reserved)
+                           .event(History.Event.Type.reserved)
                            .get().at()
                            .equals(tester.clock().instant().truncatedTo(MILLIS))));
 
@@ -1167,7 +1167,7 @@ public class ProvisioningTest {
 
     /** A predicate that returns whether a node has been retired by the given agent */
     private static Predicate<Node> retiredBy(Agent agent) {
-        return (node) -> node.history().lastEvent(History.Event.Type.retired)
+        return (node) -> node.history().event(History.Event.Type.retired)
                 .filter(e -> e.type() == History.Event.Type.retired)
                 .filter(e -> e.agent() == agent)
                 .isPresent();
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/docker-node1-os-upgrade-complete.json b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/docker-node1-os-upgrade-complete.json
index cb874896927..09b5575ea02 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/docker-node1-os-upgrade-complete.json
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/docker-node1-os-upgrade-complete.json
@@ -55,6 +55,11 @@
       "event": "activated",
       "at": 123,
       "agent": "application"
+    },
+    {
+      "event": "osUpgraded",
+      "at": 123,
+      "agent": "system"
     }
   ],
   "ipAddresses": [
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/dockerhost1-with-firmware-data.json b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/dockerhost1-with-firmware-data.json
index 3e8b19135c0..a73e9a7bade 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/dockerhost1-with-firmware-data.json
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/dockerhost1-with-firmware-data.json
@@ -37,11 +37,6 @@
   "wantToRebuild": false,
   "history": [
     {
-      "event": "firmwareVerified",
-      "at": 100,
-      "agent": "system"
-    },
-    {
       "event": "provisioned",
       "at": 123,
       "agent": "system"
@@ -60,6 +55,11 @@
       "event": "activated",
       "at": 123,
       "agent": "application"
+    },
+    {
+      "event": "firmwareVerified",
+      "at": 100,
+      "agent": "system"
     }
   ],
   "ipAddresses": [