Stop setting OS upgrade budget

15 files changed, 47 insertions, 169 deletions

diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java
index 22ce4db10e5..b40db745fd7 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/Controller.java
@@ -1,10 +1,10 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.controller;
 
-import com.yahoo.component.annotation.Inject;
 import com.yahoo.component.AbstractComponent;
 import com.yahoo.component.Version;
 import com.yahoo.component.Vtag;
+import com.yahoo.component.annotation.Inject;
 import com.yahoo.concurrent.maintenance.JobControl;
 import com.yahoo.config.provision.CloudName;
 import com.yahoo.config.provision.HostName;
@@ -37,7 +37,6 @@ import com.yahoo.vespa.hosted.rotation.config.RotationsConfig;
 import com.yahoo.yolean.concurrent.Sleeper;
 
 import java.time.Clock;
-import java.time.Duration;
 import java.time.Instant;
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -222,7 +221,7 @@ public class Controller extends AbstractComponent {
     }
 
     /** Set the target OS version for given cloud in this system */
-    public void upgradeOsIn(CloudName cloudName, Version version, Duration upgradeBudget, boolean force) {
+    public void upgradeOsIn(CloudName cloudName, Version version, boolean force) {
         if (version.isEmpty()) {
             throw new IllegalArgumentException("Invalid version '" + version.toFullString() + "'");
         }
@@ -241,15 +240,13 @@ public class Controller extends AbstractComponent {
                     throw new IllegalArgumentException("Cannot downgrade cloud '" + cloudName.value() + "' to version " +
                                                        version.toFullString());
                 }
-                if (currentTarget.osVersion().version().equals(version) &&
-                    currentTarget.upgradeBudget().equals(upgradeBudget)) return; // Version and budget unchanged
+                if (currentTarget.osVersion().version().equals(version)) return; // Version unchanged
             }
 
-            OsVersionTarget newTarget = new OsVersionTarget(new OsVersion(version, cloudName), upgradeBudget, scheduledAt);
+            OsVersionTarget newTarget = new OsVersionTarget(new OsVersion(version, cloudName), scheduledAt);
             targets.put(cloudName, newTarget);
             curator.writeOsVersionTargets(new TreeSet<>(targets.values()));
-            log.info("Triggered OS upgrade to " + version.toFullString() + " in cloud " +
-                     cloudName.value() + ", with upgrade budget " + upgradeBudget);
+            log.info("Triggered OS upgrade to " + version.toFullString() + " in cloud " + cloudName.value());
         }
     }
 
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeScheduler.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeScheduler.java
index 502b3b0188f..f930e64fc5a 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeScheduler.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeScheduler.java
@@ -38,7 +38,7 @@ public class OsUpgradeScheduler extends ControllerMaintainer {
             Optional<Change> change = changeIn(cloud, now);
             if (change.isEmpty()) continue;
             if (!change.get().scheduleAt(now)) continue;
-            controller().upgradeOsIn(cloud, change.get().version(), change.get().upgradeBudget(), false);
+            controller().upgradeOsIn(cloud, change.get().version(), false);
         }
         return 1.0;
     }
@@ -101,12 +101,11 @@ public class OsUpgradeScheduler extends ControllerMaintainer {
 
     }
 
-    /** OS version change, its budget and the earliest time it can be scheduled */
-    public record Change(Version version, Duration upgradeBudget, Instant scheduleAt) {
+    /** OS version change and the earliest time it can be scheduled */
+    public record Change(Version version, Instant scheduleAt) {
 
         public Change {
             Objects.requireNonNull(version);
-            Objects.requireNonNull(upgradeBudget);
             Objects.requireNonNull(scheduleAt);
         }
 
@@ -131,7 +130,7 @@ public class OsUpgradeScheduler extends ControllerMaintainer {
             if (!release.version().isAfter(currentVersion)) return Optional.empty();
             Duration cooldown = remainingCooldownOf(cooldown(), release.age(instant));
             Instant scheduleAt = schedulingInstant(instant.plus(cooldown), system);
-            return Optional.of(new Change(release.version(), Duration.ZERO, scheduleAt));
+            return Optional.of(new Change(release.version(), scheduleAt));
         }
 
         /** Returns the release tag tracked by this system */
@@ -174,7 +173,7 @@ public class OsUpgradeScheduler extends ControllerMaintainer {
             }
             Duration cooldown = remainingCooldownOf(cooldown(), version.age(instant));
             Instant schedulingInstant = schedulingInstant(instant.plus(cooldown), system);
-            return Optional.of(new Change(version.version(), upgradeBudget(), schedulingInstant));
+            return Optional.of(new Change(version.version(), schedulingInstant));
         }
 
         private Duration cooldown() {
@@ -183,10 +182,6 @@ public class OsUpgradeScheduler extends ControllerMaintainer {
                     : Duration.ofDays(7 - RELEASE_DAY.ordinal()); // non-CD: Wait until start of the following week
         }
 
-        private Duration upgradeBudget() {
-            return system.isCd() ? Duration.ZERO : Duration.ofDays(14);
-        }
-
         /** Find the most recent version available according to the scheduling step, relative to now */
         static CalendarVersion findVersion(Instant now, Version currentVersion) {
             Instant candidate = START_OF_SCHEDULE;
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgrader.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgrader.java
index f4dcf7f6088..b44643b4405 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgrader.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgrader.java
@@ -44,14 +44,11 @@ public class OsUpgrader extends InfrastructureUpgrader<OsVersionTarget> {
 
     @Override
     protected void upgrade(OsVersionTarget target, SystemApplication application, ZoneApi zone) {
-        Duration zoneUpgradeBudget = zoneBudgetOf(target.upgradeBudget(), zone);
-        log.info(Text.format("Upgrading OS of %s to version %s in %s in cloud %s%s", application.id(),
+        log.info(Text.format("Upgrading OS of %s to version %s in %s in cloud %s", application.id(),
                                target.osVersion().version().toFullString(),
-                               zone.getVirtualId(), zone.getCloudName(),
-                               " with time budget " + zoneUpgradeBudget));
+                               zone.getVirtualId(), zone.getCloudName()));
         controller().serviceRegistry().configServer().nodeRepository().upgradeOs(zone.getVirtualId(), application.nodeType(),
-                                                                                 target.osVersion().version(),
-                                                                                 zoneUpgradeBudget);
+                                                                                 target.osVersion().version());
     }
 
     @Override
@@ -85,20 +82,6 @@ public class OsUpgrader extends InfrastructureUpgrader<OsVersionTarget> {
                            .orElse(true);
     }
 
-    /** Returns the available upgrade budget for given zone */
-    private Duration zoneBudgetOf(Duration totalBudget, ZoneApi zone) {
-        if (!spendBudgetOn(zone)) return Duration.ZERO;
-        long consecutiveZones = upgradePolicy.steps().stream()
-                                             .filter(step -> step.zones().stream().anyMatch(this::spendBudgetOn))
-                                             .count();
-        return totalBudget.dividedBy(consecutiveZones);
-    }
-
-    /** Returns whether to spend upgrade budget on given zone */
-    private boolean spendBudgetOn(ZoneApi zone) {
-        return !controller().zoneRegistry().systemZone().getVirtualId().equals(zone.getVirtualId()); // Do not spend budget on controller zone
-    }
-
     /** Returns whether node currently allows upgrades */
     public static boolean canUpgrade(Node node, boolean includeDeferring) {
         return (includeDeferring || !node.deferOsUpgrade()) && upgradableNodeStates.contains(node.state());
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializer.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializer.java
index 9cad402832f..c06a36d3a1d 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializer.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializer.java
@@ -9,7 +9,6 @@ import com.yahoo.slime.SlimeUtils;
 import com.yahoo.vespa.hosted.controller.versions.OsVersion;
 import com.yahoo.vespa.hosted.controller.versions.OsVersionTarget;
 
-import java.time.Duration;
 import java.time.Instant;
 import java.util.Collections;
 import java.util.Set;
@@ -25,7 +24,6 @@ public class OsVersionTargetSerializer {
     private final OsVersionSerializer osVersionSerializer;
 
     private static final String versionsField = "versions";
-    private static final String upgradeBudgetField = "upgradeBudget";
     private static final String scheduledAtField = "scheduledAt";
 
     public OsVersionTargetSerializer(OsVersionSerializer osVersionSerializer) {
@@ -45,16 +43,14 @@ public class OsVersionTargetSerializer {
         Set<OsVersionTarget> osVersionTargets = new TreeSet<>();
         array.traverse((ArrayTraverser) (i, inspector) -> {
             OsVersion osVersion = osVersionSerializer.fromSlime(inspector);
-            Duration upgradeBudget = SlimeUtils.duration(inspector.field(upgradeBudgetField));
             Instant scheduledAt = SlimeUtils.instant(inspector.field(scheduledAtField));
-            osVersionTargets.add(new OsVersionTarget(osVersion, upgradeBudget, scheduledAt));
+            osVersionTargets.add(new OsVersionTarget(osVersion, scheduledAt));
         });
         return Collections.unmodifiableSet(osVersionTargets);
     }
 
     private void toSlime(OsVersionTarget target, Cursor object) {
         osVersionSerializer.toSlime(target.osVersion(), object);
-        object.setLong(upgradeBudgetField, target.upgradeBudget().toMillis());
         object.setLong(scheduledAtField, target.scheduledAt().toEpochMilli());
     }
 
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiHandler.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiHandler.java
index 704bafe7082..8675f4f18c6 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiHandler.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiHandler.java
@@ -146,11 +146,10 @@ public class OsApiHandler extends AuditLoggingRequestHandler {
             return new MessageResponse("Cleared target OS version for cloud '" + cloud.value() + "'");
         }
         Version target = parseStringField("version", root, Version::fromString);
-        Duration upgradeBudget = parseStringField("upgradeBudget", root, Duration::parse);
         boolean force = root.field("force").asBool();
-        controller.upgradeOsIn(cloud, target, upgradeBudget, force);
+        controller.upgradeOsIn(cloud, target, force);
         return new MessageResponse("Set target OS version for cloud '" + cloud.value() + "' to " +
-                                   target.toFullString() + " with upgrade budget " + upgradeBudget);
+                                   target.toFullString());
     }
 
     private Slime osVersions() {
@@ -166,7 +165,7 @@ public class OsApiHandler extends AuditLoggingRequestHandler {
             Optional<OsVersionTarget> target = targets.stream().filter(t -> t.osVersion().equals(osVersion)).findFirst();
             currentVersionObject.setBool("targetVersion", target.isPresent());
             target.ifPresent(t -> {
-                currentVersionObject.setString("upgradeBudget", t.upgradeBudget().toString());
+                currentVersionObject.setString("upgradeBudget", Duration.ZERO.toString());
                 currentVersionObject.setLong("scheduledAt", t.scheduledAt().toEpochMilli());
                 Optional<Change> nextChange = osUpgradeScheduler.changeIn(t.osVersion().cloud(), now);
                 nextChange.ifPresent(c -> {
diff --git a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/versions/OsVersionTarget.java b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/versions/OsVersionTarget.java
index 0a13244ce5e..471670ec399 100644
--- a/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/versions/OsVersionTarget.java
+++ b/controller-server/src/main/java/com/yahoo/vespa/hosted/controller/versions/OsVersionTarget.java
@@ -3,24 +3,19 @@ package com.yahoo.vespa.hosted.controller.versions;
 
 import com.yahoo.component.Version;
 
-import java.time.Duration;
 import java.time.Instant;
 import java.util.Objects;
 
 /**
- * The OS version target for a cloud/system, containing the {@link OsVersion} and its upgrade budget.
+ * The OS version target for a cloud and the time it was scheduled.
  *
  * @author mpolden
  */
-public record OsVersionTarget(OsVersion osVersion,
-                              Duration upgradeBudget,
-                              Instant scheduledAt) implements VersionTarget, Comparable<OsVersionTarget> {
+public record OsVersionTarget(OsVersion osVersion, Instant scheduledAt) implements VersionTarget, Comparable<OsVersionTarget> {
 
     public OsVersionTarget {
         Objects.requireNonNull(osVersion);
-        Objects.requireNonNull(upgradeBudget);
         Objects.requireNonNull(scheduledAt);
-        if (upgradeBudget.isNegative()) throw new IllegalArgumentException("upgradeBudget cannot be negative");
     }
 
     @Override
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/integration/NodeRepositoryMock.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/integration/NodeRepositoryMock.java
index f39eb6e161d..f440d724b56 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/integration/NodeRepositoryMock.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/integration/NodeRepositoryMock.java
@@ -20,10 +20,8 @@ import com.yahoo.vespa.hosted.controller.api.integration.configserver.NodeReposi
 import com.yahoo.vespa.hosted.controller.api.integration.configserver.TargetVersions;
 
 import java.net.URI;
-import java.time.Duration;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Optional;
 import java.util.TreeMap;
 import java.util.concurrent.ConcurrentHashMap;
@@ -39,7 +37,6 @@ public class NodeRepositoryMock implements NodeRepository {
     private final Map<ZoneId, Map<HostName, Node>> nodeRepository = new ConcurrentHashMap<>();
     private final Map<ZoneId, Map<ApplicationId, Application>> applications = new ConcurrentHashMap<>();
     private final Map<ZoneId, TargetVersions> targetVersions = new ConcurrentHashMap<>();
-    private final Map<Integer, Duration> osUpgradeBudgets = new ConcurrentHashMap<>();
     private final Map<DeploymentId, Pair<Double, Double>> trafficFractions = new ConcurrentHashMap<>();
     private final Map<ZoneId, Map<TenantName, URI>> archiveUris = new ConcurrentHashMap<>();
 
@@ -148,8 +145,7 @@ public class NodeRepositoryMock implements NodeRepository {
     }
 
     @Override
-    public void upgradeOs(ZoneId zone, NodeType type, Version version, Duration upgradeBudget) {
-        this.osUpgradeBudgets.put(Objects.hash(zone, type, version), upgradeBudget);
+    public void upgradeOs(ZoneId zone, NodeType type, Version version) {
         this.targetVersions.compute(zone, (ignored, targetVersions) -> {
             if (targetVersions == null) {
                 targetVersions = TargetVersions.EMPTY;
@@ -280,10 +276,6 @@ public class NodeRepositoryMock implements NodeRepository {
         putNodes(zone, List.of(nodeA, nodeB));
     }
 
-    public Optional<Duration> osUpgradeBudget(ZoneId zone, NodeType type, Version version) {
-        return Optional.ofNullable(osUpgradeBudgets.get(Objects.hash(zone, type, version)));
-    }
-
     public void doUpgrade(DeploymentId deployment, Optional<HostName> hostName, Version version) {
         patchNodes(deployment, hostName, node -> {
             return Node.builder(node)
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/MetricsReporterTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/MetricsReporterTest.java
index 64baa107a1c..4072fef3395 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/MetricsReporterTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/MetricsReporterTest.java
@@ -365,7 +365,7 @@ public class MetricsReporterTest {
 
         // All nodes upgrade to initial OS version
         var version0 = Version.fromString("8.0");
-        tester.controller().upgradeOsIn(cloud, version0, Duration.ZERO, false);
+        tester.controller().upgradeOsIn(cloud, version0, false);
         osUpgrader.maintain();
         tester.configServer().setOsVersion(version0, SystemApplication.tenantHost.id(), zone);
         tester.configServer().setOsVersion(version0, SystemApplication.configServerHost.id(), zone);
@@ -379,7 +379,7 @@ public class MetricsReporterTest {
             var currentVersion = i == 0 ? version0 : targets.get(i - 1);
             var nextVersion = targets.get(i);
             // System starts upgrading to next OS version
-            tester.controller().upgradeOsIn(cloud, nextVersion, Duration.ZERO, false);
+            tester.controller().upgradeOsIn(cloud, nextVersion, false);
             runAll(osUpgrader, statusUpdater, reporter);
             assertOsChangeDuration(Duration.ZERO, hosts);
             assertOsNodeCount(hosts.size(), currentVersion);
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeSchedulerTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeSchedulerTest.java
index 3034b926c62..899745c7a39 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeSchedulerTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgradeSchedulerTest.java
@@ -47,7 +47,7 @@ public class OsUpgradeSchedulerTest {
 
         // Target is set manually
         Version version0 = Version.fromString("7.0.0.20220101");
-        tester.controller().upgradeOsIn(cloud, version0, Duration.ofDays(1), false);
+        tester.controller().upgradeOsIn(cloud, version0, false);
 
         // Target remains unchanged as it hasn't expired yet
         for (var interval : List.of(Duration.ZERO, Duration.ofDays(30))) {
@@ -106,7 +106,7 @@ public class OsUpgradeSchedulerTest {
 
         // Set initial target
         Version version0 = Version.fromString("7.0.0.20220101");
-        tester.controller().upgradeOsIn(cloud, version0, Duration.ofDays(1), false);
+        tester.controller().upgradeOsIn(cloud, version0, false);
 
         // Next version is triggered
         Version version1 = Version.fromString("7.0.0.20220301");
@@ -137,7 +137,7 @@ public class OsUpgradeSchedulerTest {
         // Set initial target
         CloudName cloud = tester.controller().clouds().iterator().next();
         Version version0 = Version.fromString("8.0");
-        tester.controller().upgradeOsIn(cloud, version0, Duration.ZERO, false);
+        tester.controller().upgradeOsIn(cloud, version0, false);
 
         // Stable release (tagged outside trigger period) is scheduled once trigger period opens
         Version version1 = Version.fromString("8.1");
@@ -151,7 +151,7 @@ public class OsUpgradeSchedulerTest {
 
         // A newer version is triggered manually
         Version version3 = Version.fromString("8.3");
-        tester.controller().upgradeOsIn(cloud, version3, Duration.ZERO, false);
+        tester.controller().upgradeOsIn(cloud, version3, false);
 
         // Nothing happens in next iteration as tagged release is older than manually triggered version
         scheduleUpgradeAfter(Duration.ofDays(7), version3, scheduler, tester);
@@ -168,7 +168,7 @@ public class OsUpgradeSchedulerTest {
         // Set initial target
         CloudName cloud = tester.controller().clouds().iterator().next();
         Version version0 = Version.fromString("8.0");
-        tester.controller().upgradeOsIn(cloud, version0, Duration.ZERO, false);
+        tester.controller().upgradeOsIn(cloud, version0, false);
 
         // Latest release is not scheduled immediately
         Version version1 = Version.fromString("8.1");
@@ -207,7 +207,6 @@ public class OsUpgradeSchedulerTest {
         CloudName cloud = tester.controller().clouds().iterator().next();
         OsVersionTarget target = tester.controller().osVersionTarget(cloud).get();
         assertEquals(version, target.osVersion().version());
-        assertEquals(Duration.ZERO, target.upgradeBudget(), "No budget when scheduling a tagged release");
     }
 
     private static ZoneApi zone(String id, CloudName cloud) {
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgraderTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgraderTest.java
index dbe559de418..0f5bb605c37 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgraderTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsUpgraderTest.java
@@ -72,8 +72,8 @@ public class OsUpgraderTest {
 
         // New OS version released
         Version version1 = Version.fromString("7.1");
-        tester.controller().upgradeOsIn(cloud1, Version.fromString("7.0"), Duration.ZERO, false);
-        tester.controller().upgradeOsIn(cloud1, version1, Duration.ZERO, false);
+        tester.controller().upgradeOsIn(cloud1, Version.fromString("7.0"), false);
+        tester.controller().upgradeOsIn(cloud1, version1, false);
         assertEquals(1, tester.controller().osVersionTargets().size()); // Only allows one version per cloud
         statusUpdater.maintain();
 
@@ -135,76 +135,6 @@ public class OsUpgraderTest {
     }
 
     @Test
-    void upgrade_os_with_budget() {
-        CloudName cloud = CloudName.from("cloud");
-        ZoneApi zone0 = zone("prod.us-north-42", "prod.controller", cloud);
-        ZoneApi zone1 = zone("dev.us-east-1", cloud);
-        ZoneApi zone2 = zone("prod.us-west-1", cloud);
-        ZoneApi zone3 = zone("prod.us-central-1", cloud);
-        ZoneApi zone4 = zone("prod.eu-west-1", cloud);
-        UpgradePolicy upgradePolicy = UpgradePolicy.builder()
-                .upgrade(zone0)
-                .upgrade(zone1)
-                .upgradeInParallel(zone2, zone3)
-                .upgrade(zone4)
-                .build();
-        OsUpgrader osUpgrader = osUpgrader(upgradePolicy, cloud, true);
-
-        // Bootstrap system
-        List<SystemApplication> nodeTypes = List.of(SystemApplication.configServerHost, SystemApplication.tenantHost);
-        tester.configServer().bootstrap(List.of(zone1.getId(), zone2.getId(), zone3.getId(), zone4.getId()),
-                nodeTypes);
-        tester.configServer().addNodes(List.of(zone0.getVirtualId()), List.of(SystemApplication.controllerHost));
-
-        // Upgrade with budget
-        Version version = Version.fromString("7.1");
-        tester.controller().upgradeOsIn(cloud, version, Duration.ofHours(12), false);
-        assertEquals(Duration.ofHours(12), tester.controller().osVersionTarget(cloud).get().upgradeBudget());
-        statusUpdater.maintain();
-        osUpgrader.maintain();
-
-        // Controllers upgrade first
-        osUpgrader.maintain();
-        assertWanted(version, SystemApplication.controllerHost, zone0);
-        assertEquals(Duration.ZERO, upgradeBudget(zone0, SystemApplication.controllerHost, version), "Controller zone gets a zero budget");
-        completeUpgrade(version, SystemApplication.controllerHost, zone0);
-        statusUpdater.maintain();
-        assertEquals(3, nodesOn(version).size());
-
-        // First zone upgrades
-        osUpgrader.maintain();
-        for (var nodeType : nodeTypes) {
-            assertEquals(Duration.ofHours(4), upgradeBudget(zone1, nodeType, version));
-            completeUpgrade(version, nodeType, zone1);
-        }
-
-        // Next set of zones upgrade
-        osUpgrader.maintain();
-        for (var zone : List.of(zone1, zone2, zone3)) {
-            for (var nodeType : nodeTypes) {
-                assertEquals(Duration.ofHours(4),
-                        upgradeBudget(zone, nodeType, version),
-                        "Parallel prod zones share the budget of a single zone");
-                completeUpgrade(version, nodeType, zone);
-            }
-        }
-
-        // Last zone upgrades
-        osUpgrader.maintain();
-        for (var nodeType : nodeTypes) {
-            assertEquals(Duration.ofHours(4),
-                    upgradeBudget(zone4, nodeType, version),
-                    nodeType + " in last prod zone gets the budget of a single zone");
-            completeUpgrade(version, nodeType, zone4);
-        }
-
-        // All host applications upgraded
-        statusUpdater.maintain();
-        assertTrue(tester.controller().osVersionStatus().nodesIn(cloud).stream()
-                .allMatch(node -> node.currentVersion().equals(version)), "All nodes on target version");
-    }
-
-    @Test
     void upgrade_os_nodes_choose_newer_version() {
         CloudName cloud = CloudName.from("cloud");
         ZoneApi zone1 = zone("dev.us-east-1", cloud);
@@ -221,8 +151,8 @@ public class OsUpgraderTest {
 
         // New OS version released
         Version version = Version.fromString("7.1");
-        tester.controller().upgradeOsIn(cloud, Version.fromString("7.0"), Duration.ZERO, false);
-        tester.controller().upgradeOsIn(cloud, version, Duration.ZERO, false); // Replaces existing target
+        tester.controller().upgradeOsIn(cloud, Version.fromString("7.0"), false);
+        tester.controller().upgradeOsIn(cloud, version, false); // Replaces existing target
         statusUpdater.maintain();
 
         // zone 1 upgrades
@@ -247,13 +177,6 @@ public class OsUpgraderTest {
                 .noneMatch(node -> node.currentVersion().isBefore(version)), "All nodes on target version or newer");
     }
 
-    private Duration upgradeBudget(ZoneApi zone, SystemApplication application, Version version) {
-        var upgradeBudget = tester.configServer().nodeRepository().osUpgradeBudget(zone.getVirtualId(), application.nodeType(), version);
-        assertTrue(upgradeBudget.isPresent(),
-                   "Expected budget for upgrade to " + version + " of " + application.id() + " in " + zone.getVirtualId());
-        return upgradeBudget.get();
-    }
-
     private List<NodeVersion> nodesOn(Version version) {
         return tester.controller().osVersionStatus().versions().entrySet().stream()
                      .filter(entry -> entry.getKey().version().equals(version))
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsVersionStatusUpdaterTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsVersionStatusUpdaterTest.java
index 454a1ac9ee9..d4d146f0834 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsVersionStatusUpdaterTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/maintenance/OsVersionStatusUpdaterTest.java
@@ -40,7 +40,7 @@ public class OsVersionStatusUpdaterTest {
         // Setting a new target adds it to current status
         Version version1 = Version.fromString("7.1");
         CloudName cloud = CloudName.DEFAULT;
-        tester.controller().upgradeOsIn(cloud, version1, Duration.ZERO, false);
+        tester.controller().upgradeOsIn(cloud, version1, false);
         statusUpdater.maintain();
 
         var osVersions = tester.controller().osVersionStatus().versions();
@@ -49,7 +49,7 @@ public class OsVersionStatusUpdaterTest {
         assertTrue(osVersions.get(new OsVersion(version1, cloud)).isEmpty(), "No nodes on current target");
 
         CloudName otherCloud = CloudName.AWS;
-        tester.controller().upgradeOsIn(otherCloud, version1, Duration.ZERO, false);
+        tester.controller().upgradeOsIn(otherCloud, version1, false);
         statusUpdater.maintain();
 
         osVersions = tester.controller().osVersionStatus().versions();
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializerTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializerTest.java
index 0f8a1c1b056..55d940ca6f9 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializerTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/persistence/OsVersionTargetSerializerTest.java
@@ -8,7 +8,6 @@ import com.yahoo.vespa.hosted.controller.versions.OsVersion;
 import com.yahoo.vespa.hosted.controller.versions.OsVersionTarget;
 import org.junit.jupiter.api.Test;
 
-import java.time.Duration;
 import java.time.Instant;
 import java.util.Set;
 
@@ -23,8 +22,8 @@ public class OsVersionTargetSerializerTest {
     void serialization() {
         OsVersionTargetSerializer serializer = new OsVersionTargetSerializer(new OsVersionSerializer());
         Set<OsVersionTarget> targets = ImmutableSet.of(
-                new OsVersionTarget(new OsVersion(Version.fromString("7.1"), CloudName.DEFAULT), Duration.ZERO, Instant.ofEpochMilli(123)),
-                new OsVersionTarget(new OsVersion(Version.fromString("7.1"), CloudName.from("foo")), Duration.ofDays(1), Instant.ofEpochMilli(456))
+                new OsVersionTarget(new OsVersion(Version.fromString("7.1"), CloudName.DEFAULT), Instant.ofEpochMilli(123)),
+                new OsVersionTarget(new OsVersion(Version.fromString("7.1"), CloudName.from("foo")), Instant.ofEpochMilli(456))
         );
         Set<OsVersionTarget> serialized = serializer.fromSlime(serializer.toSlime(targets));
         assertEquals(targets, serialized);
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiTest.java b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiTest.java
index 64bb6aeca04..1067db31473 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiTest.java
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/OsApiTest.java
@@ -80,10 +80,10 @@ public class OsApiTest extends ControllerContainerTest {
         // All nodes are initially on empty version
         upgradeAndUpdateStatus();
         // Upgrade OS to a different version in each cloud
-        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.5.2\", \"cloud\": \"cloud1\", \"upgradeBudget\": \"PT0S\"}", Request.Method.PATCH),
-                "{\"message\":\"Set target OS version for cloud 'cloud1' to 7.5.2 with upgrade budget PT0S\"}", 200);
-        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"8.2.1\", \"cloud\": \"cloud2\", \"upgradeBudget\": \"PT24H\"}", Request.Method.PATCH),
-                "{\"message\":\"Set target OS version for cloud 'cloud2' to 8.2.1 with upgrade budget PT24H\"}", 200);
+        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.5.2\", \"cloud\": \"cloud1\"}", Request.Method.PATCH),
+                "{\"message\":\"Set target OS version for cloud 'cloud1' to 7.5.2\"}", 200);
+        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"8.2.1\", \"cloud\": \"cloud2\"}", Request.Method.PATCH),
+                "{\"message\":\"Set target OS version for cloud 'cloud2' to 8.2.1\"}", 200);
 
         // Status is updated after some zones are upgraded
         upgradeAndUpdateStatus();
@@ -96,8 +96,8 @@ public class OsApiTest extends ControllerContainerTest {
         assertFile(new Request("http://localhost:8080/os/v1/"), "versions-all-upgraded.json");
 
         // Downgrade with force is permitted
-        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.5.1\", \"cloud\": \"cloud1\", \"force\": true, \"upgradeBudget\": \"PT0S\"}", Request.Method.PATCH),
-                "{\"message\":\"Set target OS version for cloud 'cloud1' to 7.5.1 with upgrade budget PT0S\"}", 200);
+        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.5.1\", \"cloud\": \"cloud1\", \"force\": true}", Request.Method.PATCH),
+                "{\"message\":\"Set target OS version for cloud 'cloud1' to 7.5.1\"}", 200);
 
         // Clear target for a given cloud
         assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": null, \"cloud\": \"cloud2\"}", Request.Method.PATCH),
@@ -110,17 +110,17 @@ public class OsApiTest extends ControllerContainerTest {
                 "{\"error-code\":\"BAD_REQUEST\",\"message\":\"Field 'version' is required\"}", 400);
 
         // Error: Invalid versions
-        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"0.0.0\", \"cloud\": \"cloud1\", \"upgradeBudget\": \"PT0S\"}", Request.Method.PATCH),
+        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"0.0.0\", \"cloud\": \"cloud1\"}", Request.Method.PATCH),
                 "{\"error-code\":\"BAD_REQUEST\",\"message\":\"Invalid version '0.0.0'\"}", 400);
-        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"foo\", \"cloud\": \"cloud1\", \"upgradeBudget\": \"PT0S\"}", Request.Method.PATCH),
+        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"foo\", \"cloud\": \"cloud1\"}", Request.Method.PATCH),
                 "{\"error-code\":\"BAD_REQUEST\",\"message\":\"Invalid version 'foo': For input string: \\\"foo\\\"\"}", 400);
 
         // Error: Invalid cloud
-        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.6\", \"cloud\": \"foo\", \"upgradeBudget\": \"PT0S\"}", Request.Method.PATCH),
+        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.6\", \"cloud\": \"foo\"}", Request.Method.PATCH),
                 "{\"error-code\":\"BAD_REQUEST\",\"message\":\"Cloud 'foo' does not exist in this system\"}", 400);
 
         // Error: Downgrade OS
-        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.4.1\", \"cloud\": \"cloud1\", \"upgradeBudget\": \"PT0S\"}", Request.Method.PATCH),
+        assertResponse(new Request("http://localhost:8080/os/v1/", "{\"version\": \"7.4.1\", \"cloud\": \"cloud1\"}", Request.Method.PATCH),
                 "{\"error-code\":\"BAD_REQUEST\",\"message\":\"Cannot downgrade cloud 'cloud1' to version 7.4.1\"}", 400);
 
         // Request firmware checks in all zones.
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-all-upgraded.json b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-all-upgraded.json
index 7f31b67d77b..92a2cad86f1 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-all-upgraded.json
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-all-upgraded.json
@@ -102,7 +102,7 @@
     {
       "version": "8.2.1",
       "targetVersion": true,
-      "upgradeBudget": "PT24H",
+      "upgradeBudget": "PT0S",
       "scheduledAt": 1234,
       "nextVersion": "8.2.1.20211228",
       "nextScheduledAt": 1640743200000,
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-partially-upgraded.json b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-partially-upgraded.json
index 68ac684b0fb..662ff4bb373 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-partially-upgraded.json
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/os/responses/versions-partially-upgraded.json
@@ -161,7 +161,7 @@
     {
       "version": "8.2.1",
       "targetVersion": true,
-      "upgradeBudget": "PT24H",
+      "upgradeBudget": "PT0S",
       "scheduledAt": 1234,
       "nextVersion": "8.2.1.20211228",
       "nextScheduledAt": 1640743200000,