Merge pull request #25667 from vespa-engine/bratseth/group-size

Support a group size constraint in content clusters

35 files changed, 633 insertions, 160 deletions

diff --git a/config-model/src/main/java/com/yahoo/config/model/provision/InMemoryProvisioner.java b/config-model/src/main/java/com/yahoo/config/model/provision/InMemoryProvisioner.java
index f44849e185f..105a9669d1f 100644
--- a/config-model/src/main/java/com/yahoo/config/model/provision/InMemoryProvisioner.java
+++ b/config-model/src/main/java/com/yahoo/config/model/provision/InMemoryProvisioner.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.config.model.provision;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.collections.ListMap;
 import com.yahoo.collections.Pair;
 import com.yahoo.config.model.api.HostProvisioner;
@@ -153,13 +154,18 @@ public class InMemoryProvisioner implements HostProvisioner {
             requested = requested.withLimits(requested.minResources().withNodes(1),
                                              requested.maxResources().withNodes(1));
         }
-        if (useMaxResources)
-            return prepare(cluster, requested.maxResources(), requested.isRequired(), requested.canFail());
-        else
-            return prepare(cluster, requested.minResources(), requested.isRequired(), requested.canFail());
+        IntRange groupRange = IntRange.of(requested.minResources().groups(), requested.maxResources().groups());
+        if (useMaxResources) {
+            int groups = groupRange.fit(requested.maxResources().nodes() / requested.groupSize().to().orElse(1));
+            return prepare(cluster, requested.maxResources(),groups, requested.isRequired(), requested.canFail());
+        }
+        else {
+            int groups = groupRange.fit(requested.minResources().nodes() / requested.groupSize().from().orElse(1));
+            return prepare(cluster, requested.minResources(), groups, requested.isRequired(), requested.canFail());
+        }
     }
 
-    public List<HostSpec> prepare(ClusterSpec cluster, ClusterResources requested, boolean required, boolean canFail) {
+    public List<HostSpec> prepare(ClusterSpec cluster, ClusterResources requested, int groups, boolean required, boolean canFail) {
         if (cluster.group().isPresent() && requested.groups() > 1)
             throw new IllegalArgumentException("Cannot both be specifying a group and ask for groups to be created");
 
@@ -169,7 +175,7 @@ public class InMemoryProvisioner implements HostProvisioner {
         if (alwaysReturnOneNode)
             nodes = 1;
 
-        int groups = Math.min(requested.groups(), nodes);
+        groups = Math.min(groups, nodes);
 
         List<HostSpec> allocation = new ArrayList<>();
         if (groups == 1) {
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/NodesSpecification.java b/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/NodesSpecification.java
index aac968f9038..352e08af4a3 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/NodesSpecification.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/builder/xml/dom/NodesSpecification.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.model.builder.xml.dom;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.collections.Pair;
 import com.yahoo.component.Version;
 import com.yahoo.config.application.api.DeployLogger;
@@ -34,6 +35,8 @@ public class NodesSpecification {
 
     private final ClusterResources min, max;
 
+    private final IntRange groupSize;
+
     private final boolean dedicated;
 
     /** The Vespa version we want the nodes to run */
@@ -63,6 +66,7 @@ public class NodesSpecification {
 
     private NodesSpecification(ClusterResources min,
                                ClusterResources max,
+                               IntRange groupSize,
                                boolean dedicated, Version version,
                                boolean required, boolean canFail, boolean exclusive,
                                Optional<DockerImage> dockerImageRepo,
@@ -83,6 +87,7 @@ public class NodesSpecification {
 
         this.min = min;
         this.max = max;
+        this.groupSize = groupSize;
         this.dedicated = dedicated;
         this.version = version;
         this.required = required;
@@ -99,10 +104,11 @@ public class NodesSpecification {
                                              Optional<CloudAccount> cloudAccount) {
         var resolvedElement = resolveElement(nodesElement);
         var combinedId = findCombinedId(nodesElement, resolvedElement);
-        var resources = toResources(resolvedElement);
+        var resourceConstraints = toResourceConstraints(resolvedElement);
         boolean hasCountAttribute = resolvedElement.stringAttribute("count") != null;
-        return new NodesSpecification(resources.getFirst(),
-                                      resources.getSecond(),
+        return new NodesSpecification(resourceConstraints.min,
+                                      resourceConstraints.max,
+                                      resourceConstraints.groupSize,
                                       dedicated,
                                       version,
                                       resolvedElement.booleanAttribute("required", false),
@@ -114,14 +120,27 @@ public class NodesSpecification {
                                       hasCountAttribute);
     }
 
-    private static Pair<ClusterResources, ClusterResources> toResources(ModelElement nodesElement) {
-        Pair<Integer, Integer> nodes =  toRange(nodesElement.stringAttribute("count"),  1, Integer::parseInt);
-        Pair<Integer, Integer> groups = toRange(nodesElement.stringAttribute("groups"), 1, Integer::parseInt);
-        var min = new ClusterResources(nodes.getFirst(),  groups.getFirst(),  nodeResources(nodesElement).getFirst());
-        var max = new ClusterResources(nodes.getSecond(), groups.getSecond(), nodeResources(nodesElement).getSecond());
-        return new Pair<>(min, max);
+    private static ResourceConstraints toResourceConstraints(ModelElement nodesElement) {
+        var nodes =  rangeFrom(nodesElement, "count");
+        var groups =  rangeFrom(nodesElement, "groups");
+        var groupSize =  rangeFrom(nodesElement, "group-size");
+        int defaultMaxGroups = groupSize.isEmpty() ? 1 : nodes.to().orElse(1); // Don't constrain the number of groups if group size is set
+        var min = new ClusterResources(nodes.from().orElse(1),  groups.from().orElse(1),  nodeResources(nodesElement).getFirst());
+        var max = new ClusterResources(nodes.to().orElse(1), groups.to().orElse(defaultMaxGroups), nodeResources(nodesElement).getSecond());
+        return new ResourceConstraints(min, max, groupSize);
     }
 
+    private static IntRange rangeFrom(ModelElement element, String name) {
+        try {
+            return IntRange.from(element.stringAttribute(name, ""));
+        }
+        catch (IllegalArgumentException e) {
+            throw new IllegalArgumentException("Illegal " + name + " value", e);
+        }
+    }
+
+    private record ResourceConstraints(ClusterResources min, ClusterResources max, IntRange groupSize) {}
+
     /** Returns the ID of the cluster referencing this node specification, if any */
     private static Optional<String> findCombinedId(ModelElement nodesElement, ModelElement resolvedElement) {
         if (resolvedElement != nodesElement) {
@@ -143,18 +162,6 @@ public class NodesSpecification {
     }
 
     /**
-     * Returns a requirement for dedicated nodes taken from the <code>nodes</code> element
-     * contained in the given parent element, or empty if the parent element is null, or the nodes elements
-     * is not present.
-     */
-    public static Optional<NodesSpecification> fromParent(ModelElement parentElement, ConfigModelContext context) {
-        if (parentElement == null) return Optional.empty();
-        ModelElement nodesElement = parentElement.child("nodes");
-        if (nodesElement == null) return Optional.empty();
-        return Optional.of(from(nodesElement, context));
-    }
-
-    /**
      * Returns a requirement for non-dedicated or dedicated nodes taken from the <code>nodes</code> element
      * contained in the given parent element, or empty if the parent element is null, or the nodes elements
      * is not present.
@@ -178,6 +185,7 @@ public class NodesSpecification {
     public static NodesSpecification nonDedicated(int count, ConfigModelContext context) {
         return new NodesSpecification(new ClusterResources(count, 1, NodeResources.unspecified()),
                                       new ClusterResources(count, 1, NodeResources.unspecified()),
+                                      IntRange.empty(),
                                       false,
                                       context.getDeployState().getWantedNodeVespaVersion(),
                                       false,
@@ -193,6 +201,7 @@ public class NodesSpecification {
     public static NodesSpecification dedicated(int count, ConfigModelContext context) {
         return new NodesSpecification(new ClusterResources(count, 1, NodeResources.unspecified()),
                                       new ClusterResources(count, 1, NodeResources.unspecified()),
+                                      IntRange.empty(),
                                       true,
                                       context.getDeployState().getWantedNodeVespaVersion(),
                                       false,
@@ -219,6 +228,7 @@ public class NodesSpecification {
                                                                                            .toList();
         return new NodesSpecification(new ClusterResources(count, 1, resources),
                                       new ClusterResources(count, 1, resources),
+                                      IntRange.empty(),
                                       true,
                                       context.getDeployState().getWantedNodeVespaVersion(),
                                       allContent.stream().anyMatch(content -> content.required),
@@ -232,6 +242,7 @@ public class NodesSpecification {
 
     public ClusterResources minResources() { return min; }
     public ClusterResources maxResources() { return max; }
+    public IntRange groupSize() { return groupSize; }
 
     /**
      * Returns whether this requires dedicated nodes.
@@ -275,7 +286,7 @@ public class NodesSpecification {
                                          .loadBalancerSettings(zoneEndpoint)
                                          .stateful(stateful)
                                          .build();
-        return hostSystem.allocateHosts(cluster, Capacity.from(min, max, required, canFail, cloudAccount), logger);
+        return hostSystem.allocateHosts(cluster, Capacity.from(min, max, groupSize, required, canFail, cloudAccount), logger);
     }
 
     private static Pair<NodeResources, NodeResources> nodeResources(ModelElement nodesElement) {
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java b/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java
index 4c7bad575d2..62a3d004ac0 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/container/xml/ContainerModelBuilder.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.model.container.xml;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.component.ComponentSpecification;
 import com.yahoo.component.Version;
 import com.yahoo.component.chain.dependencies.Dependencies;
@@ -926,6 +927,7 @@ public class ContainerModelBuilder extends ConfigModelBuilder<ContainerModel> {
             ClusterResources resources = new ClusterResources(nodeCount, 1, NodeResources.unspecified());
             Capacity capacity = Capacity.from(resources,
                                               resources,
+                                              IntRange.empty(),
                                               false,
                                               !deployState.getProperties().isBootstrap(),
                                               context.getDeployState().getProperties().cloudAccount());
@@ -945,16 +947,21 @@ public class ContainerModelBuilder extends ConfigModelBuilder<ContainerModel> {
     }
 
     private List<ApplicationContainer> createNodesFromNodeCount(ApplicationContainerCluster cluster, Element containerElement, Element nodesElement, ConfigModelContext context) {
-        NodesSpecification nodesSpecification = NodesSpecification.from(new ModelElement(nodesElement), context);
-        ClusterSpec.Id clusterId = ClusterSpec.Id.from(cluster.name());
-        ZoneEndpoint zoneEndpoint = zoneEndpoint(context, clusterId);
-        Map<HostResource, ClusterMembership> hosts = nodesSpecification.provision(cluster.getRoot().hostSystem(),
-                                                                                  ClusterSpec.Type.container,
-                                                                                  clusterId,
-                                                                                  zoneEndpoint,
-                                                                                  log,
-                                                                                  getZooKeeper(containerElement) != null);
-        return createNodesFromHosts(hosts, cluster, context.getDeployState());
+        try {
+            NodesSpecification nodesSpecification = NodesSpecification.from(new ModelElement(nodesElement), context);
+            ClusterSpec.Id clusterId = ClusterSpec.Id.from(cluster.name());
+            ZoneEndpoint zoneEndpoint = zoneEndpoint(context, clusterId);
+            Map<HostResource, ClusterMembership> hosts = nodesSpecification.provision(cluster.getRoot().hostSystem(),
+                                                                                      ClusterSpec.Type.container,
+                                                                                      clusterId,
+                                                                                      zoneEndpoint,
+                                                                                      log,
+                                                                                      getZooKeeper(containerElement) != null);
+            return createNodesFromHosts(hosts, cluster, context.getDeployState());
+        }
+        catch (IllegalArgumentException e) {
+            throw new IllegalArgumentException("In " + cluster, e);
+        }
     }
 
     private List<ApplicationContainer> createNodesFromNodeType(ApplicationContainerCluster cluster, Element nodesElement, ConfigModelContext context) {
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionValidator.java b/config-model/src/main/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionValidator.java
index dbe813bfb2d..b4a83efd2aa 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionValidator.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionValidator.java
@@ -30,17 +30,18 @@ public class IndexedHierarchicDistributionValidator {
     public void validate() {
         validateThatWeHaveOneGroupLevel();
         validateThatLeafGroupsHasEqualNumberOfNodes();
-        validateThatLeafGroupsCountIsAFactorOfRedundancy(clusterName, redundancy.effectiveFinalRedundancy(), rootGroup.getSubgroups().size());
+        validateThatLeafGroupsCountIsAFactorOfRedundancy(redundancy.effectiveFinalRedundancy(), rootGroup.getSubgroups().size());
         validateThatRedundancyPerGroupIsEqual();
-        validateThatReadyCopiesIsCompatibleWithRedundancy(clusterName, redundancy.effectiveFinalRedundancy(), redundancy.effectiveReadyCopies(), rootGroup.getSubgroups().size());
+        validateThatReadyCopiesIsCompatibleWithRedundancy(redundancy.effectiveFinalRedundancy(), redundancy.effectiveReadyCopies(), rootGroup.getSubgroups().size());
     }
 
     private void validateThatWeHaveOneGroupLevel() {
         for (StorageGroup group : rootGroup.getSubgroups()) {
             if (group.getSubgroups().size() > 0) {
-                throw new IllegalArgumentException(getErrorMsgPrefix(clusterName) + "Expected all groups under root group '" +
-                                                   rootGroup.getName() + "' to be leaf groups only containing nodes, but sub group '" + group.getName() + "' contains " +
-                                                   group.getSubgroups().size() + " sub groups.");
+                throw new IllegalArgumentException("Expected all groups under root group '" +
+                                                   rootGroup.getName() + "' to be leaf groups only containing nodes, but sub group '" +
+                                                   group.getName() + "' contains " +
+                                                   group.getSubgroups().size() + " sub groups");
             }
         }
     }
@@ -56,18 +57,19 @@ public class IndexedHierarchicDistributionValidator {
             }
 
             if (group.getNodes().size() != previousGroup.getNodes().size())
-                throw new IllegalArgumentException(getErrorMsgPrefix(clusterName) + "Expected leaf groups to contain an equal number of nodes, but leaf group '" +
-                        previousGroup.getName() + "' contains " + previousGroup.getNodes().size() + " node(s) while leaf group '" +
-                        group.getName() + "' contains " + group.getNodes().size() + " node(s).");
+                throw new IllegalArgumentException("Expected leaf groups to contain an equal number of nodes, but leaf group '" +
+                                                   previousGroup.getName() + "' contains " + previousGroup.getNodes().size() +
+                                                   " node(s) while leaf group '" + group.getName() +
+                                                   "' contains " + group.getNodes().size() + " node(s)");
             previousGroup = group;
         }
     }
 
-    static public void validateThatLeafGroupsCountIsAFactorOfRedundancy(String clusterName, int totalRedundancy, int subGroups) {
+    static public void validateThatLeafGroupsCountIsAFactorOfRedundancy(int totalRedundancy, int subGroups) {
         if (totalRedundancy % subGroups != 0) {
-            throw new IllegalArgumentException(getErrorMsgPrefix(clusterName) + "Expected number of leaf groups (" +
+            throw new IllegalArgumentException("Expected number of leaf groups (" +
                                                subGroups + ") to be a factor of redundancy (" +
-                                               totalRedundancy + "), but it is not.");
+                                               totalRedundancy + "), but it is not");
         }
     }
 
@@ -75,9 +77,10 @@ public class IndexedHierarchicDistributionValidator {
         int redundancyPerGroup = redundancy.effectiveFinalRedundancy() / rootGroup.getSubgroups().size();
         String expPartitions = createDistributionPartitions(redundancyPerGroup, rootGroup.getSubgroups().size());
         if (!rootGroup.getPartitions().get().equals(expPartitions)) {
-            throw new IllegalArgumentException(getErrorMsgPrefix(clusterName) + "Expected redundancy per leaf group to be " +
+            throw new IllegalArgumentException("Expected redundancy per leaf group to be " +
                                                redundancyPerGroup + ", but it is not according to distribution partitions '" +
-                                               rootGroup.getPartitions().get() + "'. Expected distribution partitions should be '" + expPartitions + "'.");
+                                               rootGroup.getPartitions().get() +
+                                               "'. Expected distribution partitions should be '" + expPartitions + "'");
         }
     }
 
@@ -91,20 +94,17 @@ public class IndexedHierarchicDistributionValidator {
         return sb.toString();
     }
 
-    static public void validateThatReadyCopiesIsCompatibleWithRedundancy(String clusterName, int totalRedundancy, int totalReadyCopies, int groupCount) {
+    static public void validateThatReadyCopiesIsCompatibleWithRedundancy(int totalRedundancy, int totalReadyCopies, int groupCount) {
         if (totalRedundancy % groupCount != 0) {
-            throw new IllegalArgumentException(getErrorMsgPrefix(clusterName) + "Expected equal redundancy per group.");
+            throw new IllegalArgumentException("Expected equal redundancy per group");
         }
         if (totalReadyCopies % groupCount != 0) {
-            throw new IllegalArgumentException(getErrorMsgPrefix(clusterName) + "Expected equal amount of ready copies per group, but " +
+            throw new IllegalArgumentException("Expected equal amount of ready copies per group, but " +
                                                totalReadyCopies + " ready copies is specified with " + groupCount + " groups");
         }
         if (totalReadyCopies == 0) {
-            throw new IllegalArgumentException(getErrorMsgPrefix(clusterName) + "Warning. No ready copies configured. At least one is required.");
+            throw new IllegalArgumentException("No ready copies configured. At least 1 is required.");
         }
     }
 
-    static private String getErrorMsgPrefix(String clusterName) {
-        return "In indexed content cluster '" + clusterName + "' using hierarchic distribution: ";
-    }
 }
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/content/StorageGroup.java b/config-model/src/main/java/com/yahoo/vespa/model/content/StorageGroup.java
index aef00be5ea9..36090aa7349 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/content/StorageGroup.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/content/StorageGroup.java
@@ -204,30 +204,35 @@ public class StorageGroup {
         }
 
         public StorageGroup buildRootGroup(DeployState deployState, RedundancyBuilder redundancyBuilder, ContentCluster owner) {
-            if (owner.isHosted())
-                validateRedundancyAndGroups(deployState.zone().environment());
+            try {
+                if (owner.isHosted())
+                    validateRedundancyAndGroups(deployState.zone().environment());
 
-            Optional<ModelElement> group = Optional.ofNullable(clusterElement.child("group"));
-            Optional<ModelElement> nodes = getNodes(clusterElement);
+                Optional<ModelElement> group = Optional.ofNullable(clusterElement.child("group"));
+                Optional<ModelElement> nodes = getNodes(clusterElement);
 
-            if (group.isPresent() && nodes.isPresent())
-                throw new IllegalArgumentException("Both <group> and <nodes> is specified: Only one of these tags can be used in the same configuration");
-            if (group.isPresent() && (group.get().integerAttribute("distribution-key") != null)) {
-                deployState.getDeployLogger().logApplicationPackage(Level.INFO, "'distribution-key' attribute on a content cluster's root group is ignored");
-            }
+                if (group.isPresent() && nodes.isPresent())
+                    throw new IllegalArgumentException("Both <group> and <nodes> is specified: Only one of these tags can be used in the same configuration");
+                if (group.isPresent() && (group.get().integerAttribute("distribution-key") != null)) {
+                    deployState.getDeployLogger().logApplicationPackage(Level.INFO, "'distribution-key' attribute on a content cluster's root group is ignored");
+                }
 
-            GroupBuilder groupBuilder = collectGroup(owner.isHosted(), group, nodes, null, null);
-            StorageGroup storageGroup = owner.isHosted()
-                                        ? groupBuilder.buildHosted(deployState, owner, Optional.empty())
-                                        : groupBuilder.buildNonHosted(deployState, owner, Optional.empty());
+                GroupBuilder groupBuilder = collectGroup(owner.isHosted(), group, nodes, null, null);
+                StorageGroup storageGroup = owner.isHosted()
+                                            ? groupBuilder.buildHosted(deployState, owner, Optional.empty())
+                                            : groupBuilder.buildNonHosted(deployState, owner, Optional.empty());
 
-            Redundancy redundancy = redundancyBuilder.build(owner.getName(), owner.isHosted(), storageGroup.subgroups.size(),
-                                                            storageGroup.getNumberOfLeafGroups(), storageGroup.countNodes(false));
-            owner.setRedundancy(redundancy);
-            if (storageGroup.partitions.isEmpty() && (redundancy.groups() > 1)) {
-                storageGroup.partitions = Optional.of(computePartitions(redundancy.finalRedundancy(), redundancy.groups()));
+                Redundancy redundancy = redundancyBuilder.build(owner.isHosted(), storageGroup.subgroups.size(),
+                                                                storageGroup.getNumberOfLeafGroups(), storageGroup.countNodes(false));
+                owner.setRedundancy(redundancy);
+                if (storageGroup.partitions.isEmpty() && (redundancy.groups() > 1)) {
+                    storageGroup.partitions = Optional.of(computePartitions(redundancy.finalRedundancy(), redundancy.groups()));
+                }
+                return storageGroup;
+            }
+            catch (IllegalArgumentException e) {
+                throw new IllegalArgumentException("In " + owner, e);
             }
-            return storageGroup;
         }
 
         private void validateRedundancyAndGroups(Environment environment) {
@@ -242,11 +247,11 @@ public class StorageGroup {
             // Allow dev deployment of self-hosted app (w/o count attribute): absent count => 1 node
             if (!nodesSpec.hasCountAttribute() && environment == Environment.dev) return;
 
-            int minNodesPerGroup = (int)Math.ceil((double)nodesSpec.minResources().nodes() / nodesSpec.minResources().groups());
+            int minNodesPerGroup = (int) Math.ceil((double) nodesSpec.minResources().nodes() / nodesSpec.minResources().groups());
 
             if (minNodesPerGroup < redundancy) {
-                throw new IllegalArgumentException("Cluster '" + clusterElement.stringAttribute("id") + "' " +
-                                                   "specifies redundancy " + redundancy + ", but it cannot be higher than " +
+                throw new IllegalArgumentException("This cluster specifies redundancy " + redundancy +
+                                                   ", but this cannot be higher than " +
                                                    "the minimum nodes per group, which is " + minNodesPerGroup);
             }
         }
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/content/cluster/RedundancyBuilder.java b/config-model/src/main/java/com/yahoo/vespa/model/content/cluster/RedundancyBuilder.java
index 1948cc1bd71..853a90cd8fa 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/content/cluster/RedundancyBuilder.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/content/cluster/RedundancyBuilder.java
@@ -37,14 +37,15 @@ public class RedundancyBuilder {
             }
         }
     }
-    public Redundancy build(String clusterName, boolean isHosted, int subGroups, int leafGroups,  int totalNodes) {
+    public Redundancy build(boolean isHosted, int subGroups, int leafGroups,  int totalNodes) {
         if (isHosted) {
             return new Redundancy(initialRedundancy, finalRedundancy, readyCopies, leafGroups, totalNodes);
         } else {
             subGroups = Math.max(1, subGroups);
-            IndexedHierarchicDistributionValidator.validateThatLeafGroupsCountIsAFactorOfRedundancy(clusterName, finalRedundancy, subGroups);
-            IndexedHierarchicDistributionValidator.validateThatReadyCopiesIsCompatibleWithRedundancy(clusterName, finalRedundancy, readyCopies, subGroups);
-            return new Redundancy(initialRedundancy/subGroups, finalRedundancy/subGroups, readyCopies/subGroups, subGroups, totalNodes);
+            IndexedHierarchicDistributionValidator.validateThatLeafGroupsCountIsAFactorOfRedundancy(finalRedundancy, subGroups);
+            IndexedHierarchicDistributionValidator.validateThatReadyCopiesIsCompatibleWithRedundancy(finalRedundancy, readyCopies, subGroups);
+            return new Redundancy(initialRedundancy/subGroups, finalRedundancy/subGroups,
+                                  readyCopies/subGroups, subGroups, totalNodes);
         }
     }
 
diff --git a/config-model/src/main/resources/schema/content.rnc b/config-model/src/main/resources/schema/content.rnc
index 3d1873507ce..703001f0107 100644
--- a/config-model/src/main/resources/schema/content.rnc
+++ b/config-model/src/main/resources/schema/content.rnc
@@ -226,7 +226,8 @@ ContentNodes = element nodes {
         attribute required { xsd:boolean }? &
         attribute exclusive { xsd:boolean }? &
         attribute docker-image { xsd:string }? &
-        attribute groups { xsd:positiveInteger | xsd:string }?
+        attribute groups { xsd:positiveInteger | xsd:string }? &
+        attribute group-size { xsd:positiveInteger | xsd:string }?
       )
       |
       ContentNode +
diff --git a/config-model/src/test/java/com/yahoo/config/model/provision/ModelProvisioningTest.java b/config-model/src/test/java/com/yahoo/config/model/provision/ModelProvisioningTest.java
index 635ed4c8659..6f8547c3701 100644
--- a/config-model/src/test/java/com/yahoo/config/model/provision/ModelProvisioningTest.java
+++ b/config-model/src/test/java/com/yahoo/config/model/provision/ModelProvisioningTest.java
@@ -501,14 +501,14 @@ public class ModelProvisioningTest {
                 "     <documents>" +
                 "       <document type='type1' mode='index'/>" +
                 "     </documents>" +
-                "     <nodes count='27' groups='9'/>" +
+                "     <nodes count='27' groups='9' group-size='[2, 3]'/>" +
                 "  </content>" +
                 "  <content version='1.0' id='baz'>" +
                 "     <redundancy>1</redundancy>" +
                 "     <documents>" +
                 "       <document type='type1' mode='index'/>" +
                 "     </documents>" +
-                "     <nodes count='27' groups='27'/>" +
+                "     <nodes count='27' groups='27' group-size='1'/>" +
                 "   </content>" +
                 "</services>";
 
@@ -595,6 +595,126 @@ public class ModelProvisioningTest {
     }
 
     @Test
+    public void testUsingGroups() {
+        String services =
+                "<?xml version='1.0' encoding='utf-8' ?>\n" +
+                "<services>" +
+                "  <admin version='4.0'/>" +
+                "  <container version='1.0' id='foo'>" +
+                "     <nodes count='10'/>" +
+                "  </container>" +
+                "  <content version='1.0' id='bar'>" +
+                "     <redundancy>2</redundancy>" +
+                "     <documents>" +
+                "       <document type='type1' mode='index'/>" +
+                "     </documents>" +
+                "     <nodes count='30' groups='2'/>" +
+                "  </content>" +
+                "  <content version='1.0' id='baz'>" +
+                "     <redundancy>1</redundancy>" +
+                "     <documents>" +
+                "       <document type='type1' mode='index'/>" +
+                "     </documents>" +
+                "     <nodes count='30' groups='30'/>" +
+                "   </content>" +
+                "</services>";
+
+        int numberOfHosts = 73;
+        VespaModelTester tester = new VespaModelTester();
+        tester.addHosts(numberOfHosts);
+        VespaModel model = tester.createModel(services, true);
+        assertEquals(numberOfHosts, model.getRoot().hostSystem().getHosts().size());
+
+        ContentCluster cluster = model.getContentClusters().get("bar");
+        List<StorageGroup> subGroups = cluster.getRootGroup().getSubgroups();
+        assertEquals( 0, cluster.getRootGroup().getNodes().size());
+        assertEquals( 2, subGroups.size());
+        assertEquals(15, subGroups.get(0).getNodes().size());
+
+        cluster = model.getContentClusters().get("baz");
+        subGroups = cluster.getRootGroup().getSubgroups();
+        assertEquals( 0, cluster.getRootGroup().getNodes().size());
+        assertEquals(30, subGroups.size());
+        assertEquals( 1, subGroups.get(0).getNodes().size());
+    }
+
+    // Same as the test above but setting groupSize only
+    @Test
+    public void testUsingGroupSizeNotGroups() {
+        String services =
+                "<?xml version='1.0' encoding='utf-8' ?>\n" +
+                "<services>" +
+                "  <admin version='4.0'/>" +
+                "  <container version='1.0' id='foo'>" +
+                "     <nodes count='10'/>" +
+                "  </container>" +
+                "  <content version='1.0' id='bar'>" +
+                "     <redundancy>2</redundancy>" +
+                "     <documents>" +
+                "       <document type='type1' mode='index'/>" +
+                "     </documents>" +
+                "     <nodes count='30' group-size='[15, 30]'/>" +
+                "  </content>" +
+                "  <content version='1.0' id='baz'>" +
+                "     <redundancy>1</redundancy>" +
+                "     <documents>" +
+                "       <document type='type1' mode='index'/>" +
+                "     </documents>" +
+                "     <nodes count='30' group-size='1'/>" +
+                "   </content>" +
+                "</services>";
+
+        int numberOfHosts = 73;
+        VespaModelTester tester = new VespaModelTester();
+        tester.addHosts(numberOfHosts);
+        VespaModel model = tester.createModel(services, true);
+        assertEquals(numberOfHosts, model.getRoot().hostSystem().getHosts().size());
+
+        ContentCluster cluster = model.getContentClusters().get("bar");
+        List<StorageGroup> subGroups = cluster.getRootGroup().getSubgroups();
+        assertEquals( 0, cluster.getRootGroup().getNodes().size());
+        assertEquals( 2, subGroups.size());
+        assertEquals(15, subGroups.get(0).getNodes().size());
+
+        cluster = model.getContentClusters().get("baz");
+        subGroups = cluster.getRootGroup().getSubgroups();
+        assertEquals( 0, cluster.getRootGroup().getNodes().size());
+        assertEquals(30, subGroups.size());
+        assertEquals( 1, subGroups.get(0).getNodes().size());
+    }
+
+    @Test
+    public void testIllegalGroupSize() {
+        String services =
+                "<?xml version='1.0' encoding='utf-8' ?>\n" +
+                "<services>" +
+                "  <admin version='4.0'/>" +
+                "  <container version='1.0' id='foo'>" +
+                "     <nodes count='2'/>" +
+                "  </container>" +
+                "  <content version='1.0' id='bar'>" +
+                "     <redundancy>2</redundancy>" +
+                "     <documents>" +
+                "       <document type='type1' mode='index'/>" +
+                "     </documents>" +
+                "     <nodes count='5' group-size='[2, --]'/>" +
+                "  </content>" +
+                "</services>";
+
+        int numberOfHosts = 10;
+        VespaModelTester tester = new VespaModelTester();
+        tester.addHosts(numberOfHosts);
+        try {
+            tester.createModel(services, true);
+            fail("Expected exception");
+        }
+        catch (IllegalArgumentException e) {
+            assertEquals("In content cluster 'bar': Illegal group-size value: " +
+                         "Expected a number or range on the form [min, max], but got '[2, --]': '--' is not an integer", Exceptions.toMessageString(e));
+        }
+    }
+
+    @Test
     public void testSlobroksOnContainersIfNoContentClusters() {
         String services =
                 "<?xml version='1.0' encoding='utf-8' ?>\n" +
@@ -1104,7 +1224,8 @@ public class ModelProvisioningTest {
             fail("Expected exception");
         }
         catch (IllegalArgumentException e) {
-            assertEquals("Cluster 'bar' specifies redundancy 2, but it cannot be higher than the minimum nodes per group, which is 1", Exceptions.toMessageString(e));
+            assertEquals("In content cluster 'bar': This cluster specifies redundancy 2, " +
+                         "but this cannot be higher than the minimum nodes per group, which is 1", Exceptions.toMessageString(e));
         }
     }
 
@@ -1449,7 +1570,7 @@ public class ModelProvisioningTest {
         tester.addHosts(new NodeResources(85,   200, 1000_000_000, 0.3), 20);
         tester.addHosts(new NodeResources( 0.5,   2,           10, 0.3), 3);
         VespaModel model = tester.createModel(services, true);
-        assertEquals(totalHosts + 3, model.getRoot().hostSystem().getHosts().size());
+        assertEquals(4 + 6 + 1, model.getRoot().hostSystem().getHosts().size());
     }
 
     @Test
@@ -1700,7 +1821,9 @@ public class ModelProvisioningTest {
             VespaModel model = tester.createModel(new Zone(Environment.staging, RegionName.from("us-central-1")), services, true);
             fail("expected failure");
         } catch (IllegalArgumentException e) {
-            assertTrue(e.getMessage().startsWith("Clusters in hosted environments must have a <nodes count='N'> tag"));
+            assertEquals("In content cluster 'bar': Clusters in hosted environments must have a <nodes count='N'> tag\n" +
+                         "matching all zones, and having no <node> subtags,\nsee https://cloud.vespa.ai/en/reference/services",
+                         Exceptions.toMessageString(e));
         }
     }
 
diff --git a/config-model/src/test/java/com/yahoo/vespa/model/application/validation/change/CloudAccountChangeValidatorTest.java b/config-model/src/test/java/com/yahoo/vespa/model/application/validation/change/CloudAccountChangeValidatorTest.java
index 46d0fcb3123..91493bab480 100644
--- a/config-model/src/test/java/com/yahoo/vespa/model/application/validation/change/CloudAccountChangeValidatorTest.java
+++ b/config-model/src/test/java/com/yahoo/vespa/model/application/validation/change/CloudAccountChangeValidatorTest.java
@@ -1,5 +1,6 @@
 package com.yahoo.vespa.model.application.validation.change;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.application.api.ValidationOverrides;
 import com.yahoo.config.model.api.Provisioned;
 import com.yahoo.config.model.deploy.DeployState;
@@ -55,6 +56,7 @@ class CloudAccountChangeValidatorTest {
         NodeResources nodeResources = new NodeResources(4, 8, 100, 10);
         return Capacity.from(new ClusterResources(2, 1, nodeResources),
                              new ClusterResources(2, 1, nodeResources),
+                             IntRange.empty(),
                              false,
                              false,
                              Optional.of(cloudAccount).filter(account -> !account.isUnspecified()));
diff --git a/config-model/src/test/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionTest.java b/config-model/src/test/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionTest.java
index 07c032a52a5..7fba5ba12e9 100644
--- a/config-model/src/test/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionTest.java
+++ b/config-model/src/test/java/com/yahoo/vespa/model/content/IndexedHierarchicDistributionTest.java
@@ -6,6 +6,7 @@ import com.yahoo.vespa.model.content.cluster.ContentCluster;
 import com.yahoo.vespa.model.search.DispatchGroup;
 import com.yahoo.vespa.model.search.SearchInterface;
 import com.yahoo.vespa.model.search.SearchNode;
+import com.yahoo.yolean.Exceptions;
 import org.junit.jupiter.api.Test;
 
 import java.util.ArrayList;
@@ -176,7 +177,8 @@ public class IndexedHierarchicDistributionTest {
             getIllegalMultipleGroupsLevelCluster();
             fail("Did not get expected Exception");
         } catch (Exception e) {
-            assertTrue(e.getMessage().contains("sub group 'group0' contains 2 sub groups."));
+            assertEquals("Expected all groups under root group 'null' to be leaf groups only containing nodes, but sub group 'group0' contains 2 sub groups",
+                         Exceptions.toMessageString(e));
         }
     }
 
@@ -220,7 +222,8 @@ public class IndexedHierarchicDistributionTest {
             getTwoGroupsCluster(3, 3, "2|*");
             fail("Did not get expected Exception");
         } catch (Exception e) {
-            assertTrue(e.getMessage().contains("Expected number of leaf groups (2) to be a factor of redundancy (3)"));
+            assertEquals("In content cluster 'mycluster': Expected number of leaf groups (2) to be a factor of redundancy (3), but it is not",
+                         Exceptions.toMessageString(e));
         }
     }
 
@@ -240,7 +243,7 @@ public class IndexedHierarchicDistributionTest {
             getTwoGroupsCluster(4, 3, "2|*");
             fail("Did not get expected Exception");
         } catch (Exception e) {
-            assertTrue(e.getMessage().contains("Expected equal amount of ready copies per group"));
+            assertEquals("In content cluster 'mycluster': Expected equal amount of ready copies per group, but 3 ready copies is specified with 2 groups", Exceptions.toMessageString(e));
         }
     }
 
diff --git a/config-model/src/test/java/com/yahoo/vespa/model/content/StorageClusterTest.java b/config-model/src/test/java/com/yahoo/vespa/model/content/StorageClusterTest.java
index 9fb4eefba75..57ee15a1dc4 100644
--- a/config-model/src/test/java/com/yahoo/vespa/model/content/StorageClusterTest.java
+++ b/config-model/src/test/java/com/yahoo/vespa/model/content/StorageClusterTest.java
@@ -21,6 +21,7 @@ import static com.yahoo.config.model.test.TestUtil.joinLines;
 import com.yahoo.vespa.model.content.cluster.ContentCluster;
 import com.yahoo.vespa.model.content.storagecluster.StorageCluster;
 import com.yahoo.vespa.model.content.utils.ContentClusterUtils;
+import com.yahoo.yolean.Exceptions;
 import org.junit.jupiter.api.Test;
 
 
@@ -432,8 +433,8 @@ public class StorageClusterTest {
             ContentClusterUtils.createCluster(xml, root);
             fail("Did not fail when having both group and nodes");
         } catch (RuntimeException e) {
-            assertEquals("Both <group> and <nodes> is specified: Only one of these tags can be used in the same configuration",
-                    e.getMessage());
+            assertEquals("In content cluster 'storage': Both <group> and <nodes> is specified: Only one of these tags can be used in the same configuration",
+                         Exceptions.toMessageString(e));
         }
     }
 
@@ -507,7 +508,7 @@ public class StorageClusterTest {
             ContentClusterUtils.createCluster(xml, new MockRoot());
             fail("Did not get exception with missing distribution element");
         } catch (RuntimeException e) {
-            assertEquals("'distribution' attribute is required with multiple subgroups", e.getMessage());
+            assertEquals("In content cluster 'storage': 'distribution' attribute is required with multiple subgroups", Exceptions.toMessageString(e));
         }
     }
 }
diff --git a/config-model/src/test/schema-test-files/services-hosted.xml b/config-model/src/test/schema-test-files/services-hosted.xml
index caf56881475..2697cc871e2 100644
--- a/config-model/src/test/schema-test-files/services-hosted.xml
+++ b/config-model/src/test/schema-test-files/services-hosted.xml
@@ -31,7 +31,7 @@
 
   <content id="ml" version="1.0">
     <redundancy>2</redundancy>
-    <nodes count="[10,20]" flavor="large" groups="[1,3]" vespamalloc-debug-stacktrace="proton">
+    <nodes count="[10,20]" flavor="large" groups="[1,3]" group-size="[1,2]" vespamalloc-debug-stacktrace="proton">
       <resources vcpu="[3.0, 4]" memory="[32000.0Mb, 33Gb]" disk="[300 Gb, 1Tb]"/>
     </nodes>
   </content>
diff --git a/config-provisioning/src/main/java/com/yahoo/config/provision/Capacity.java b/config-provisioning/src/main/java/com/yahoo/config/provision/Capacity.java
index e63750e0e11..993ab686675 100644
--- a/config-provisioning/src/main/java/com/yahoo/config/provision/Capacity.java
+++ b/config-provisioning/src/main/java/com/yahoo/config/provision/Capacity.java
@@ -1,6 +1,8 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.config.provision;
 
+import com.yahoo.collections.IntRange;
+
 import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Stream;
@@ -15,12 +17,19 @@ public final class Capacity {
 
     /** Resources should stay between these values, inclusive */
     private final ClusterResources min, max;
+    private final IntRange groupSize;
     private final boolean required;
     private final boolean canFail;
     private final NodeType type;
     private final Optional<CloudAccount> cloudAccount;
 
-    private Capacity(ClusterResources min, ClusterResources max, boolean required, boolean canFail, NodeType type, Optional<CloudAccount> cloudAccount) {
+    private Capacity(ClusterResources min,
+                     ClusterResources max,
+                     IntRange groupSize,
+                     boolean required,
+                     boolean canFail,
+                     NodeType type,
+                     Optional<CloudAccount> cloudAccount) {
         validate(min);
         validate(max);
         if (max.smallerThan(min))
@@ -30,6 +39,7 @@ public final class Capacity {
             throw new IllegalArgumentException("Capacity range does not allow GPU, got min " + min + " and max " + max);
         this.min = min;
         this.max = max;
+        this.groupSize = groupSize;
         this.required = required;
         this.canFail = canFail;
         this.type = type;
@@ -45,6 +55,7 @@ public final class Capacity {
 
     public ClusterResources minResources() { return min; }
     public ClusterResources maxResources() { return max; }
+    public IntRange groupSize() { return groupSize; }
 
     /** Returns whether the requested number of nodes must be met exactly for a request for this to succeed */
     public boolean isRequired() { return required; }
@@ -69,7 +80,11 @@ public final class Capacity {
     }
 
     public Capacity withLimits(ClusterResources min, ClusterResources max) {
-        return new Capacity(min, max, required, canFail, type, cloudAccount);
+        return withLimits(min, max, IntRange.empty());
+    }
+
+    public Capacity withLimits(ClusterResources min, ClusterResources max, IntRange groupSize) {
+        return new Capacity(min, max, groupSize, required, canFail, type, cloudAccount);
     }
 
     @Override
@@ -85,29 +100,34 @@ public final class Capacity {
 
     /** Create a non-required, failable capacity request */
     public static Capacity from(ClusterResources min, ClusterResources max) {
-        return from(min, max, false, true);
+        return from(min, max, IntRange.empty(), false, true, Optional.empty());
     }
 
     public static Capacity from(ClusterResources resources, boolean required, boolean canFail) {
         return from(resources, required, canFail, NodeType.tenant);
     }
 
-    // TODO(mpolden): Remove when config models < 7.590 are gone
+    // TODO: Remove after February 2023
     public static Capacity from(ClusterResources min, ClusterResources max, boolean required, boolean canFail) {
-        return from(min, max, required, canFail, Optional.empty());
+        return new Capacity(min, max, IntRange.empty(), required, canFail, NodeType.tenant, Optional.empty());
     }
 
+    // TODO: Remove after February 2023
     public static Capacity from(ClusterResources min, ClusterResources max, boolean required, boolean canFail, Optional<CloudAccount> cloudAccount) {
-        return new Capacity(min, max, required, canFail, NodeType.tenant, cloudAccount);
+        return new Capacity(min, max, IntRange.empty(), required, canFail, NodeType.tenant, cloudAccount);
+    }
+
+    public static Capacity from(ClusterResources min, ClusterResources max, IntRange groupSize, boolean required, boolean canFail, Optional<CloudAccount> cloudAccount) {
+        return new Capacity(min, max, groupSize, required, canFail, NodeType.tenant, cloudAccount);
     }
 
     /** Creates this from a node type */
     public static Capacity fromRequiredNodeType(NodeType type) {
-        return from(new ClusterResources(0, 0, NodeResources.unspecified()), true, false, type);
+        return from(new ClusterResources(0, 1, NodeResources.unspecified()), true, false, type);
     }
 
     private static Capacity from(ClusterResources resources, boolean required, boolean canFail, NodeType type) {
-        return new Capacity(resources, resources, required, canFail, type, Optional.empty());
+        return new Capacity(resources, resources, IntRange.empty(), required, canFail, type, Optional.empty());
     }
 
 }
diff --git a/config-provisioning/src/main/java/com/yahoo/config/provision/ClusterResources.java b/config-provisioning/src/main/java/com/yahoo/config/provision/ClusterResources.java
index 9938823768b..5511a9ed1ed 100644
--- a/config-provisioning/src/main/java/com/yahoo/config/provision/ClusterResources.java
+++ b/config-provisioning/src/main/java/com/yahoo/config/provision/ClusterResources.java
@@ -21,7 +21,7 @@ public class ClusterResources {
 
     public ClusterResources(int nodes, int groups, NodeResources nodeResources) {
         this.nodes = nodes;
-        this.groups = groups;
+        this.groups = groups == 0 ? 1 : groups; // TODO: Throw on groups == 0 after February 2023
         this.nodeResources = Objects.requireNonNull(nodeResources);
     }
 
@@ -73,9 +73,8 @@ public class ClusterResources {
     @Override
     public boolean equals(Object o) {
         if (o == this) return true;
-        if ( ! (o instanceof ClusterResources)) return false;
+        if ( ! (o instanceof ClusterResources other)) return false;
 
-        ClusterResources other = (ClusterResources)o;
         if (other.nodes != this.nodes) return false;
         if (other.groups != this.groups) return false;
         if ( ! other.nodeResources.equals(this.nodeResources)) return false;
diff --git a/config-provisioning/src/test/java/com/yahoo/config/provision/CapacityTest.java b/config-provisioning/src/test/java/com/yahoo/config/provision/CapacityTest.java
index a6ddb401b2f..ca552003f7a 100644
--- a/config-provisioning/src/test/java/com/yahoo/config/provision/CapacityTest.java
+++ b/config-provisioning/src/test/java/com/yahoo/config/provision/CapacityTest.java
@@ -1,8 +1,11 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.config.provision;
 
+import com.yahoo.collections.IntRange;
 import org.junit.jupiter.api.Test;
 
+import java.util.Optional;
+
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.fail;
 
@@ -15,8 +18,11 @@ public class CapacityTest {
     void testCapacityValidation() {
         // Equal min and max is allowed
         Capacity.from(new ClusterResources(4, 2, new NodeResources(1, 2, 3, 4)),
-                               new ClusterResources(4, 2, new NodeResources(1, 2, 3, 4)),
-                               false, true);
+                      new ClusterResources(4, 2, new NodeResources(1, 2, 3, 4)),
+                      IntRange.empty(),
+                      false,
+                      true,
+                      Optional.empty());
         assertValidationFailure(new ClusterResources(4, 2, new NodeResources(1, 2, 3, 4)),
                                new ClusterResources(2, 2, new NodeResources(1, 2, 3, 4)));
         assertValidationFailure(new ClusterResources(4, 4, new NodeResources(1, 2, 3, 4)),
@@ -36,7 +42,7 @@ public class CapacityTest {
 
     private void assertValidationFailure(ClusterResources min, ClusterResources max) {
         try {
-            Capacity.from(min, max, false, true);
+            Capacity.from(min, max, IntRange.empty(), false, true, Optional.empty());
             fail("Expected exception with min " + min + " and max " + max);
         }
         catch (IllegalArgumentException e) {
diff --git a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/application/responses/application-clusters.json b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/application/responses/application-clusters.json
index d9021b1d894..b5ae4efd752 100644
--- a/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/application/responses/application-clusters.json
+++ b/controller-server/src/test/java/com/yahoo/vespa/hosted/controller/restapi/application/responses/application-clusters.json
@@ -88,7 +88,7 @@
         {
           "from": {
             "nodes": 0,
-            "groups": 0,
+            "groups": 1,
             "nodeResources": {
               "vcpu": 0.0,
               "memoryGb": 0.0,
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/applications/Cluster.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/applications/Cluster.java
index 0a731f66418..60a5682101f 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/applications/Cluster.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/applications/Cluster.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.applications;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.Capacity;
 import com.yahoo.config.provision.ClusterResources;
 import com.yahoo.config.provision.ClusterSpec;
@@ -28,6 +29,7 @@ public class Cluster {
     private final ClusterSpec.Id id;
     private final boolean exclusive;
     private final ClusterResources min, max;
+    private final IntRange groupSize;
     private final boolean required;
     private final Autoscaling suggested;
     private final Autoscaling target;
@@ -39,6 +41,7 @@ public class Cluster {
                    boolean exclusive,
                    ClusterResources minResources,
                    ClusterResources maxResources,
+                   IntRange groupSize,
                    boolean required,
                    Autoscaling suggested,
                    Autoscaling target,
@@ -47,6 +50,7 @@ public class Cluster {
         this.exclusive = exclusive;
         this.min = Objects.requireNonNull(minResources);
         this.max = Objects.requireNonNull(maxResources);
+        this.groupSize = Objects.requireNonNull(groupSize);
         this.required = required;
         this.suggested = Objects.requireNonNull(suggested);
         Objects.requireNonNull(target);
@@ -68,6 +72,9 @@ public class Cluster {
     /** Returns the configured maximal resources in this cluster */
     public ClusterResources maxResources() { return max; }
 
+    /** Returns the configured group size range in this cluster */
+    public IntRange groupSize() { return groupSize; }
+
     /**
      * Returns whether the resources of this cluster are required to be within the specified min and max.
      * Otherwise they may be adjusted by capacity policies.
@@ -105,16 +112,16 @@ public class Cluster {
 
     public Cluster withConfiguration(boolean exclusive, Capacity capacity) {
         return new Cluster(id, exclusive,
-                           capacity.minResources(), capacity.maxResources(), capacity.isRequired(),
+                           capacity.minResources(), capacity.maxResources(), capacity.groupSize(), capacity.isRequired(),
                            suggested, target, scalingEvents);
     }
 
     public Cluster withSuggested(Autoscaling suggested) {
-        return new Cluster(id, exclusive, min, max, required, suggested, target, scalingEvents);
+        return new Cluster(id, exclusive, min, max, groupSize, required, suggested, target, scalingEvents);
     }
 
     public Cluster withTarget(Autoscaling target) {
-        return new Cluster(id, exclusive, min, max, required, suggested, target, scalingEvents);
+        return new Cluster(id, exclusive, min, max, groupSize, required, suggested, target, scalingEvents);
     }
 
     /** Add or update (based on "at" time) a scaling event */
@@ -128,7 +135,7 @@ public class Cluster {
             scalingEvents.add(scalingEvent);
 
         prune(scalingEvents);
-        return new Cluster(id, exclusive, min, max, required, suggested, target, scalingEvents);
+        return new Cluster(id, exclusive, min, max, groupSize, required, suggested, target, scalingEvents);
     }
 
     @Override
@@ -158,7 +165,8 @@ public class Cluster {
     }
 
     public static Cluster create(ClusterSpec.Id id, boolean exclusive, Capacity requested) {
-        return new Cluster(id, exclusive, requested.minResources(), requested.maxResources(), requested.isRequired(),
+        return new Cluster(id, exclusive,
+                           requested.minResources(), requested.maxResources(), requested.groupSize(), requested.isRequired(),
                            Autoscaling.empty(), Autoscaling.empty(), List.of());
     }
 
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/AllocationOptimizer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/AllocationOptimizer.java
index 56a6d61ebee..c3dc0ff250f 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/AllocationOptimizer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/AllocationOptimizer.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.autoscale;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.ClusterResources;
 import com.yahoo.config.provision.NodeResources;
 import com.yahoo.vespa.hosted.provision.NodeRepository;
@@ -38,7 +39,8 @@ public class AllocationOptimizer {
         int minimumNodes = AllocationOptimizer.minimumNodes;
         if (limits.isEmpty())
             limits = Limits.of(new ClusterResources(minimumNodes,    1, NodeResources.unspecified()),
-                               new ClusterResources(maximumNodes, maximumNodes, NodeResources.unspecified()));
+                               new ClusterResources(maximumNodes, maximumNodes, NodeResources.unspecified()),
+                               IntRange.empty());
         else
             limits = atLeast(minimumNodes, limits).fullySpecified(current.clusterSpec(), nodeRepository, clusterModel.application().id());
         Optional<AllocatableClusterResources> bestAllocation = Optional.empty();
@@ -50,6 +52,7 @@ public class AllocationOptimizer {
         for (int groups = limits.min().groups(); groups <= limits.max().groups(); groups++) {
             for (int nodes = limits.min().nodes(); nodes <= limits.max().nodes(); nodes++) {
                 if (nodes % groups != 0) continue;
+                if ( ! limits.groupSize().includes(nodes / groups)) continue;
 
                 var resources = new ClusterResources(nodes,
                                                      groups,
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Limits.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Limits.java
index cb5d8dd5042..9de7134a6d7 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Limits.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Limits.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.autoscale;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.Capacity;
 import com.yahoo.config.provision.ClusterResources;
@@ -19,13 +20,15 @@ import java.util.Objects;
  */
 public class Limits {
 
-    private static final Limits empty = new Limits(null, null);
+    private static final Limits empty = new Limits(null, null, IntRange.empty());
 
     private final ClusterResources min, max;
+    private final IntRange groupSize;
 
-    private Limits(ClusterResources min, ClusterResources max) {
+    private Limits(ClusterResources min, ClusterResources max, IntRange groupSize) {
         this.min = min;
         this.max = max;
+        this.groupSize = groupSize;
     }
 
     public static Limits empty() { return empty; }
@@ -42,12 +45,14 @@ public class Limits {
         return max;
     }
 
+    public IntRange groupSize() { return groupSize; }
+
     public Limits withMin(ClusterResources min) {
-        return new Limits(min, max);
+        return new Limits(min, max, groupSize);
     }
 
     public Limits withMax(ClusterResources max) {
-        return new Limits(min, max);
+        return new Limits(min, max, groupSize);
     }
 
     /** Caps the given resources at the limits of this. If it is empty the node resources are returned as-is */
@@ -66,7 +71,7 @@ public class Limits {
         var defaultResources = new CapacityPolicies(nodeRepository).defaultNodeResources(clusterSpec, applicationId);
         var specifiedMin = min.nodeResources().isUnspecified() ? min.with(defaultResources) : min;
         var specifiedMax = max.nodeResources().isUnspecified() ? max.with(defaultResources) : max;
-        return new Limits(specifiedMin, specifiedMax);
+        return new Limits(specifiedMin, specifiedMax, groupSize);
     }
 
     private double between(double min, double max, double value) {
@@ -76,21 +81,23 @@ public class Limits {
     }
 
     public static Limits of(Cluster cluster) {
-        return new Limits(cluster.minResources(), cluster.maxResources());
+        return new Limits(cluster.minResources(), cluster.maxResources(), cluster.groupSize());
     }
 
     public static Limits of(Capacity capacity) {
-        return new Limits(capacity.minResources(), capacity.maxResources());
+        return new Limits(capacity.minResources(), capacity.maxResources(), capacity.groupSize());
     }
 
-    public static Limits of(ClusterResources min, ClusterResources max) {
-        return new Limits(Objects.requireNonNull(min, "min"), Objects.requireNonNull(max, "max"));
+    public static Limits of(ClusterResources min, ClusterResources max, IntRange groupSize) {
+        return new Limits(Objects.requireNonNull(min, "min"),
+                          Objects.requireNonNull(max, "max"),
+                          Objects.requireNonNull(groupSize, "groupSize"));
     }
 
     @Override
     public String toString() {
         if (isEmpty()) return "no limits";
-        return "limits: from " + min + " to " + max;
+        return "limits: from " + min + " to " + max + ( groupSize.isEmpty() ? "" : " with group size " + groupSize);
     }
 
 }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializer.java
index 2f5b057e927..4d2fae8a4d7 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializer.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.persistence;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.ClusterResources;
 import com.yahoo.config.provision.ClusterSpec;
@@ -23,6 +24,7 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 import java.util.Optional;
+import java.util.OptionalInt;
 
 /**
  * Application JSON serializer
@@ -48,6 +50,7 @@ public class ApplicationSerializer {
     private static final String exclusiveKey = "exclusive";
     private static final String minResourcesKey = "min";
     private static final String maxResourcesKey = "max";
+    private static final String groupSizeKey = "groupSize";
     private static final String requiredKey = "required";
     private static final String suggestedKey = "suggested";
     private static final String resourcesKey = "resources";
@@ -122,6 +125,7 @@ public class ApplicationSerializer {
         clusterObject.setBool(exclusiveKey, cluster.exclusive());
         toSlime(cluster.minResources(), clusterObject.setObject(minResourcesKey));
         toSlime(cluster.maxResources(), clusterObject.setObject(maxResourcesKey));
+        toSlime(cluster.groupSize(), clusterObject.setObject(groupSizeKey));
         clusterObject.setBool(requiredKey, cluster.required());
         toSlime(cluster.suggested(), clusterObject.setObject(suggestedKey));
         toSlime(cluster.target(), clusterObject.setObject(targetKey));
@@ -133,6 +137,7 @@ public class ApplicationSerializer {
                            clusterObject.field(exclusiveKey).asBool(),
                            clusterResourcesFromSlime(clusterObject.field(minResourcesKey)),
                            clusterResourcesFromSlime(clusterObject.field(maxResourcesKey)),
+                           intRangeFromSlime(clusterObject.field(groupSizeKey)),
                            clusterObject.field(requiredKey).asBool(),
                            autoscalingFromSlime(clusterObject.field(suggestedKey), clusterObject.field("nonExisting")),
                            autoscalingFromSlime(clusterObject.field(targetKey), clusterObject.field(autoscalingStatusObjectKey)),
@@ -165,6 +170,16 @@ public class ApplicationSerializer {
                                     NodeResourcesSerializer.resourcesFromSlime(clusterResourcesObject.field(nodeResourcesKey)));
     }
 
+    private static void toSlime(IntRange range, Cursor rangeObject) {
+        range.from().ifPresent(from -> rangeObject.setLong(fromKey, from));
+        range.to().ifPresent(from -> rangeObject.setLong(toKey, from));
+    }
+
+    private static IntRange intRangeFromSlime(Inspector rangeObject) {
+        if ( ! rangeObject.valid()) return IntRange.empty();
+        return new IntRange(optionalInt(rangeObject.field(fromKey)), optionalInt(rangeObject.field(toKey)));
+    }
+
     private static void toSlime(Load load, Cursor loadObject) {
         loadObject.setDouble(cpuKey, load.cpu());
         loadObject.setDouble(memoryKey, load.memory());
@@ -257,4 +272,8 @@ public class ApplicationSerializer {
         return inspector.valid() ? Optional.of(Instant.ofEpochMilli(inspector.asLong())) : Optional.empty();
     }
 
+    private static OptionalInt optionalInt(Inspector inspector) {
+        return inspector.valid() ? OptionalInt.of((int)inspector.asLong()) : OptionalInt.empty();
+    }
+
 }
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/CapacityPolicies.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/CapacityPolicies.java
index a1400626658..839e10ba096 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/CapacityPolicies.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/CapacityPolicies.java
@@ -39,8 +39,11 @@ public class CapacityPolicies {
     }
 
     public Capacity applyOn(Capacity capacity, ApplicationId application, boolean exclusive) {
-        return capacity.withLimits(applyOn(capacity.minResources(), capacity, application, exclusive),
-                                   applyOn(capacity.maxResources(), capacity, application, exclusive));
+        var min = applyOn(capacity.minResources(), capacity, application, exclusive);
+        var max = applyOn(capacity.maxResources(), capacity, application, exclusive);
+        var groupSize = capacity.groupSize().fromAtMost(max.nodes() / min.groups())
+                                            .toAtLeast(min.nodes() / max.groups());
+        return capacity.withLimits(min, max, groupSize);
     }
 
     private ClusterResources applyOn(ClusterResources resources, Capacity capacity, ApplicationId application, boolean exclusive) {
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/NodeRepositoryProvisioner.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/NodeRepositoryProvisioner.java
index 59e67f65f8f..bc623b495c8 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/NodeRepositoryProvisioner.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/provisioning/NodeRepositoryProvisioner.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.provisioning;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.component.annotation.Inject;
 import com.yahoo.config.provision.ActivationContext;
 import com.yahoo.config.provision.ApplicationId;
@@ -98,7 +99,7 @@ public class NodeRepositoryProvisioner implements Provisioner {
             cluster = capacityPolicies.decideExclusivity(requested, cluster);
             Capacity actual = capacityPolicies.applyOn(requested, application, cluster.isExclusive());
             ClusterResources target = decideTargetResources(application, cluster, actual);
-            ensureRedundancy(target.nodes(), cluster, actual.canFail(), application);
+            validate(actual, target, cluster, application);
             logIfDownscaled(requested.minResources().nodes(), actual.minResources().nodes(), cluster, logger);
 
             groups = target.groups();
@@ -204,18 +205,17 @@ public class NodeRepositoryProvisioner implements Provisioner {
                                   .advertisedResources();
     }
 
-    /**
-     * Throw if the node count is 1 for container and content clusters and we're in a production zone
-     *
-     * @throws IllegalArgumentException if only one node is requested and we can fail
-     */
-    private void ensureRedundancy(int nodeCount, ClusterSpec cluster, boolean canFail, ApplicationId application) {
-        if (! application.instance().isTester() &&
-            canFail &&
-            nodeCount == 1 &&
-            requiresRedundancy(cluster.type()) &&
-            zone.environment().isProduction())
-            throw new IllegalArgumentException("Deployments to prod require at least 2 nodes per cluster for redundancy. Not fulfilled for " + cluster);
+    private void validate(Capacity actual, ClusterResources target, ClusterSpec cluster, ApplicationId application) {
+        if ( ! actual.canFail()) return;
+
+        if (! application.instance().isTester() && zone.environment().isProduction() &&
+            requiresRedundancy(cluster.type()) && target.nodes() == 1)
+            throw new IllegalArgumentException("In " + cluster +
+                                               ": Deployments to prod require at least 2 nodes per cluster for redundancy.");
+
+        if ( ! actual.groupSize().includes(target.nodes() / target.groups()))
+            throw new IllegalArgumentException("In " + cluster + ": Group size with " + target +
+                                               " is not within allowed group size " + actual.groupSize());
     }
 
     private static boolean requiresRedundancy(ClusterSpec.Type clusterType) {
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/ApplicationSerializer.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/ApplicationSerializer.java
index cb927c72eb5..6936a767936 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/ApplicationSerializer.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/restapi/ApplicationSerializer.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.restapi;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.ClusterResources;
 import com.yahoo.slime.Cursor;
 import com.yahoo.slime.Slime;
@@ -62,6 +63,8 @@ public class ApplicationSerializer {
         Limits limits = Limits.of(cluster).fullySpecified(nodes.clusterSpec(), nodeRepository, application.id());
         toSlime(limits.min(), clusterObject.setObject("min"));
         toSlime(limits.max(), clusterObject.setObject("max"));
+        if ( ! cluster.groupSize().isEmpty())
+            toSlime(cluster.groupSize(), clusterObject.setObject("groupSize"));
         toSlime(currentResources, clusterObject.setObject("current"));
         if (cluster.shouldSuggestResources(currentResources))
             toSlime(cluster.suggested(), clusterObject.setObject("suggested"));
@@ -85,6 +88,11 @@ public class ApplicationSerializer {
         NodeResourcesSerializer.toSlime(resources.nodeResources(), clusterResourcesObject.setObject("resources"));
     }
 
+    private static void toSlime(IntRange range, Cursor rangeObject) {
+        range.from().ifPresent(from -> rangeObject.setLong("from", range.from().getAsInt()));
+        range.to().ifPresent(to -> rangeObject.setLong("to", range.to().getAsInt()));
+    }
+
     private static void toSlime(Load load, Cursor utilizationObject) {
         utilizationObject.setDouble("cpu", load.cpu());
         utilizationObject.setDouble("memory", load.memory());
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java
index 92ffe9828c3..e50db5c0d55 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/testutils/MockNodeRepository.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.testutils;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.component.Version;
 import com.yahoo.config.provision.ActivationContext;
 import com.yahoo.config.provision.ApplicationId;
@@ -193,7 +194,11 @@ public class MockNodeRepository extends NodeRepository {
         activate(provisioner.prepare(app1Id,
                                      cluster1Id,
                                      Capacity.from(new ClusterResources(2, 1, new NodeResources(2, 8, 50, 1)),
-                                                   new ClusterResources(8, 2, new NodeResources(4, 16, 1000, 1)), false, true),
+                                                   new ClusterResources(8, 2, new NodeResources(4, 16, 1000, 1)),
+                                                   IntRange.empty(),
+                                                   false,
+                                                   true,
+                                                   Optional.empty()),
                                 null), app1Id, provisioner);
         Application app1 = applications().get(app1Id).get();
         Cluster cluster1 = app1.cluster(cluster1Id.id()).get();
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTest.java
index e1b32726070..35197da4315 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTest.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.autoscale;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.Capacity;
 import com.yahoo.config.provision.ClusterResources;
 import com.yahoo.config.provision.ClusterSpec;
@@ -353,6 +354,23 @@ public class AutoscalingTest {
     }
 
     @Test
+    public void autoscaling_respects_group_size_limit() {
+        var min = new ClusterResources( 2, 2, new NodeResources(1, 1, 1, 1));
+        var now = new ClusterResources(5, 5, new NodeResources(3.0, 10, 10, 1));
+        var max = new ClusterResources(18, 6, new NodeResources(100, 1000, 1000, 1));
+        var fixture = AutoscalingTester.fixture()
+                                       .awsProdSetup(true)
+                                       .initialResources(Optional.of(now))
+                                       .capacity(Capacity.from(min, max, IntRange.of(2, 3), false, true, Optional.empty()))
+                                       .build();
+        fixture.tester().clock().advance(Duration.ofDays(2));
+        fixture.loader().applyCpuLoad(0.4, 240);
+        fixture.tester().assertResources("Scaling cpu up",
+                                         12, 6, 2.8,  4.3, 10.0,
+                                         fixture.autoscale());
+    }
+
+    @Test
     public void test_autoscaling_limits_when_min_equals_max() {
         ClusterResources min = new ClusterResources( 2, 1, new NodeResources(1, 1, 1, 1));
         var fixture = AutoscalingTester.fixture().awsProdSetup(true).capacity(Capacity.from(min, min)).build();
@@ -427,7 +445,7 @@ public class AutoscalingTest {
     }
 
     @Test
-    public void test_autoscaling_group_size_1() {
+    public void test_autoscaling_group_size_unconstrained() {
         var min = new ClusterResources( 2, 2, new NodeResources(1, 1, 1, 1));
         var now = new ClusterResources(5, 5, new NodeResources(3, 100, 100, 1));
         var max = new ClusterResources(20, 20, new NodeResources(10, 1000, 1000, 1));
@@ -444,6 +462,23 @@ public class AutoscalingTest {
     }
 
     @Test
+    public void test_autoscaling_group_size_1() {
+        var min = new ClusterResources( 2, 2, new NodeResources(1, 1, 1, 1));
+        var now = new ClusterResources(5, 5, new NodeResources(3, 100, 100, 1));
+        var max = new ClusterResources(20, 20, new NodeResources(10, 1000, 1000, 1));
+        var fixture = AutoscalingTester.fixture()
+                                       .awsProdSetup(true)
+                                       .initialResources(Optional.of(now))
+                                       .capacity(Capacity.from(min, max, IntRange.of(1), false, true, Optional.empty()))
+                                       .build();
+        fixture.tester().clock().advance(Duration.ofDays(2));
+        fixture.loader().applyCpuLoad(0.9, 120);
+        fixture.tester().assertResources("Scaling up to 2 nodes, scaling memory and disk down at the same time",
+                                         7, 7, 9.4,  80.8, 85.2,
+                                         fixture.autoscale());
+    }
+
+    @Test
     public void test_autoscaling_groupsize_by_cpu_read_dominated() {
         var min = new ClusterResources( 3, 1, new NodeResources(1, 1, 1, 1));
         var now = new ClusterResources(6, 2, new NodeResources(3, 100, 100, 1));
@@ -672,6 +707,23 @@ public class AutoscalingTest {
                    fixture.autoscale().resources().isEmpty());
     }
 
+    @Test
+    public void test_autoscaling_in_dev_with_cluster_size_constraint() {
+        var min = new ClusterResources(4, 1,
+                                       new NodeResources(1, 4, 10, 1, NodeResources.DiskSpeed.any));
+        var max = new ClusterResources(20, 20,
+                                       new NodeResources(100, 1000, 1000, 1, NodeResources.DiskSpeed.any));
+        var fixture = AutoscalingTester.fixture()
+                                       .awsSetup(true, Environment.dev)
+                                       .capacity(Capacity.from(min, max, IntRange.of(3, 5), false, true, Optional.empty()))
+                                       .build();
+        fixture.tester().clock().advance(Duration.ofDays(2));
+        fixture.loader().applyLoad(new Load(1.0, 1.0, 1.0), 200);
+        fixture.tester().assertResources("Scale only to a single node and group since this is dev",
+                                         1, 1, 0.1,  24.8, 131.1,
+                                         fixture.autoscale());
+    }
+
     /** Same setup as test_autoscaling_in_dev(), just with required = true */
     @Test
     public void test_autoscaling_in_dev_with_required_resources_preprovisioned() {
@@ -680,8 +732,10 @@ public class AutoscalingTest {
                                                    new NodeResources(1, 1, 1, 1, NodeResources.DiskSpeed.any)),
                               new ClusterResources(20, 1,
                                                    new NodeResources(100, 1000, 1000, 1, NodeResources.DiskSpeed.any)),
+                              IntRange.empty(),
                               true,
-                              true);
+                              true,
+                              Optional.empty());
 
         var fixture = AutoscalingTester.fixture()
                                        .hostCount(5)
@@ -700,8 +754,10 @@ public class AutoscalingTest {
         var requiredCapacity =
                 Capacity.from(new ClusterResources(1, 1, NodeResources.unspecified()),
                               new ClusterResources(3, 1, NodeResources.unspecified()),
+                              IntRange.empty(),
+                              true,
                               true,
-                              true);
+                              Optional.empty());
 
         var fixture = AutoscalingTester.fixture()
                                        .hostCount(5)
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTester.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTester.java
index 4e6b8dec9ef..05d0822758d 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTester.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/autoscale/AutoscalingTester.java
@@ -131,6 +131,7 @@ class AutoscalingTester {
                               cluster.exclusive(),
                               cluster.minResources(),
                               cluster.maxResources(),
+                              cluster.groupSize(),
                               cluster.required(),
                               cluster.suggested(),
                               cluster.target(),
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainerTest.java
index 2da65fc1a2f..af47001cd84 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/AutoscalingMaintainerTest.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.maintenance;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.Capacity;
 import com.yahoo.config.provision.ClusterResources;
@@ -61,10 +62,10 @@ public class AutoscalingMaintainerTest {
 
         tester.deploy(app1, cluster1, Capacity.from(new ClusterResources(5, 1, new NodeResources(4, 4, 10, 0.1)),
                                                     new ClusterResources(5, 1, new NodeResources(4, 4, 10, 0.1)),
-                                                    false, true));
+                                                    IntRange.empty(), false, true, Optional.empty()));
         tester.deploy(app2, cluster2, Capacity.from(new ClusterResources(5, 1, new NodeResources(4, 4, 10, 0.1)),
                                                     new ClusterResources(10, 1, new NodeResources(6.5, 9, 20, 0.1)),
-                                                    false, true));
+                                                    IntRange.empty(), false, true, Optional.empty()));
 
         tester.clock().advance(Duration.ofMinutes(10));
         tester.maintainer().maintain(); // noop
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java
index 27a944a471e..58589f540cf 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/HostCapacityMaintainerTest.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.maintenance;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.component.Version;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.Capacity;
@@ -466,7 +467,7 @@ public class HostCapacityMaintainerTest {
         ClusterSpec spec = ProvisioningTester.contentClusterSpec();
         ClusterResources resources = new ClusterResources(2, 1, new NodeResources(16, 24, 100, 1));
         CloudAccount cloudAccount0 = CloudAccount.from("000000000000");
-        Capacity capacity0 = Capacity.from(resources, resources, false, true, Optional.of(cloudAccount0));
+        Capacity capacity0 = Capacity.from(resources, resources, IntRange.empty(), false, true, Optional.of(cloudAccount0));
         List<HostSpec> prepared = provisioningTester.prepare(applicationId, spec, capacity0);
 
         // Hosts are provisioned in requested account
@@ -476,7 +477,7 @@ public class HostCapacityMaintainerTest {
 
         // Redeployment in different account provisions a new set of hosts
         CloudAccount cloudAccount1 = CloudAccount.from("100000000000");
-        Capacity capacity1 = Capacity.from(resources, resources, false, true, Optional.of(cloudAccount1));
+        Capacity capacity1 = Capacity.from(resources, resources, IntRange.empty(), false, true, Optional.of(cloudAccount1));
         prepared = provisioningTester.prepare(applicationId, spec, capacity1);
         provisionHostsIn(cloudAccount1, 2, tester);
         assertEquals(2, provisioningTester.activate(applicationId, prepared).size());
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/ScalingSuggestionsMaintainerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/ScalingSuggestionsMaintainerTest.java
index c94d864ba9d..36c9819e10d 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/ScalingSuggestionsMaintainerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/maintenance/ScalingSuggestionsMaintainerTest.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.maintenance;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.collections.Pair;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.Capacity;
@@ -56,10 +57,10 @@ public class ScalingSuggestionsMaintainerTest {
 
         tester.deploy(app1, cluster1, Capacity.from(new ClusterResources(5, 1, new NodeResources(4, 4, 10, 0.1)),
                                                     new ClusterResources(5, 1, new NodeResources(4, 4, 10, 0.1)),
-                                                    false, true));
+                                                    IntRange.empty(), false, true, Optional.empty()));
         tester.deploy(app2, cluster2, Capacity.from(new ClusterResources(5, 1, new NodeResources(4, 4, 10, 0.1)),
                                                     new ClusterResources(10, 1, new NodeResources(6.5, 5, 15, 0.1)),
-                                                    false, true));
+                                                    IntRange.empty(), false, true, Optional.empty()));
 
         tester.clock().advance(Duration.ofHours(13));
         Duration timeAdded = addMeasurements(0.90f, 0.90f, 0.90f, 0, 500, app1, tester.nodeRepository());
@@ -96,7 +97,8 @@ public class ScalingSuggestionsMaintainerTest {
         addMeasurements(0.7f, 0.7f, 0.7f, 0, 500, app1, tester.nodeRepository());
         maintainer.maintain();
         var suggested = tester.nodeRepository().applications().get(app1).get().cluster(cluster1.id()).get().suggested().resources().get();
-        tester.deploy(app1, cluster1, Capacity.from(suggested, suggested, false, true));
+        tester.deploy(app1, cluster1, Capacity.from(suggested, suggested,
+                                                    IntRange.empty(), false, true, Optional.empty()));
         tester.clock().advance(Duration.ofDays(2));
         addMeasurements(0.2f, 0.65f, 0.6f,
                         0, 500, app1, tester.nodeRepository());
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializerTest.java
index a05cc388bea..51f775c7286 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/persistence/ApplicationSerializerTest.java
@@ -1,6 +1,7 @@
 // Copyright Yahoo. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.vespa.hosted.provision.persistence;
 
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.ClusterResources;
 import com.yahoo.config.provision.ClusterSpec;
@@ -34,6 +35,7 @@ public class ApplicationSerializerTest {
                                  false,
                                  new ClusterResources( 8, 4, new NodeResources(1, 2,  3,  4)),
                                  new ClusterResources(12, 6, new NodeResources(3, 6, 21, 24)),
+                                 IntRange.empty(),
                                  true,
                                  Autoscaling.empty(),
                                  Autoscaling.empty(),
@@ -43,6 +45,7 @@ public class ApplicationSerializerTest {
                                  true,
                                  new ClusterResources( 8, 4, minResources),
                                  new ClusterResources(14, 7, new NodeResources(3, 6, 21, 24)),
+                                 IntRange.of(3, 5),
                                  false,
                                  new Autoscaling(Autoscaling.Status.unavailable,
                                                  "",
@@ -79,11 +82,11 @@ public class ApplicationSerializerTest {
             Cluster serializedCluster = serialized.clusters().get(originalCluster.id());
             assertNotNull(serializedCluster);
             assertNotSame(originalCluster, serializedCluster);
-            assertEquals(originalCluster, serializedCluster);
             assertEquals(originalCluster.id(), serializedCluster.id());
             assertEquals(originalCluster.exclusive(), serializedCluster.exclusive());
             assertEquals(originalCluster.minResources(), serializedCluster.minResources());
             assertEquals(originalCluster.maxResources(), serializedCluster.maxResources());
+            assertEquals(originalCluster.groupSize(), serializedCluster.groupSize());
             assertEquals(originalCluster.required(), serializedCluster.required());
             assertEquals(originalCluster.suggested(), serializedCluster.suggested());
             assertEquals(originalCluster.target(), serializedCluster.target());
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java
index 3653e20d848..9a18bbb76ee 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/LoadBalancerProvisionerTest.java
@@ -3,6 +3,7 @@ package com.yahoo.vespa.hosted.provision.provisioning;
 
 import ai.vespa.http.DomainName;
 import com.google.common.collect.Iterators;
+import com.yahoo.collections.IntRange;
 import com.yahoo.config.provision.ApplicationId;
 import com.yahoo.config.provision.Capacity;
 import com.yahoo.config.provision.CloudAccount;
@@ -316,7 +317,7 @@ public class LoadBalancerProvisionerTest {
     @Test
     public void load_balancer_with_custom_settings() {
         ClusterResources resources = new ClusterResources(3, 1, nodeResources);
-        Capacity capacity = Capacity.from(resources, resources, false, true, Optional.of(CloudAccount.empty));
+        Capacity capacity = Capacity.from(resources, resources, IntRange.empty(), false, true, Optional.of(CloudAccount.empty));
         tester.activate(app1, prepare(app1, capacity, clusterRequest(ClusterSpec.Type.container, ClusterSpec.Id.from("c1"))));
         LoadBalancerList loadBalancers = tester.nodeRepository().loadBalancers().list();
         assertEquals(1, loadBalancers.size());
@@ -336,7 +337,7 @@ public class LoadBalancerProvisionerTest {
         ClusterResources resources = new ClusterResources(3, 1, nodeResources);
         CloudAccount cloudAccount0 = CloudAccount.empty;
         {
-            Capacity capacity = Capacity.from(resources, resources, false, true, Optional.of(cloudAccount0));
+            Capacity capacity = Capacity.from(resources, resources, IntRange.empty(), false, true, Optional.of(cloudAccount0));
             tester.activate(app1, prepare(app1, capacity, clusterRequest(ClusterSpec.Type.container, ClusterSpec.Id.from("c1"))));
         }
         LoadBalancerList loadBalancers = tester.nodeRepository().loadBalancers().list();
@@ -345,7 +346,7 @@ public class LoadBalancerProvisionerTest {
 
         // Changing account fails if there is an existing LB in the previous account.
         CloudAccount cloudAccount1 = CloudAccount.from("111111111111");
-        Capacity capacity = Capacity.from(resources, resources, false, true, Optional.of(cloudAccount1));
+        Capacity capacity = Capacity.from(resources, resources, IntRange.empty(), false, true, Optional.of(cloudAccount1));
         try {
             prepare(app1, capacity, clusterRequest(ClusterSpec.Type.container, ClusterSpec.Id.from("c1")));
             fail("Expected exception");
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application1.json b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application1.json
index ead4e5fd06a..c9046998e91 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application1.json
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application1.json
@@ -103,7 +103,7 @@
         {
           "from": {
             "nodes": 0,
-            "groups": 0,
+            "groups": 1,
             "resources": {
               "vcpu" : 0.0,
               "memoryGb": 0.0,
diff --git a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application2.json b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application2.json
index f60fdf3e602..4166d20ad8d 100644
--- a/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application2.json
+++ b/node-repository/src/test/java/com/yahoo/vespa/hosted/provision/restapi/responses/application2.json
@@ -62,7 +62,7 @@
         {
           "from": {
             "nodes": 0,
-            "groups": 0,
+            "groups": 1,
             "resources": {
               "vcpu" : 0.0,
               "memoryGb": 0.0,
diff --git a/vespajlib/src/main/java/com/yahoo/collections/IntRange.java b/vespajlib/src/main/java/com/yahoo/collections/IntRange.java
new file mode 100644
index 00000000000..b745322d458
--- /dev/null
+++ b/vespajlib/src/main/java/com/yahoo/collections/IntRange.java
@@ -0,0 +1,132 @@
+package com.yahoo.collections;
+
+import java.util.Objects;
+import java.util.OptionalInt;
+
+/**
+ * An integer range.
+ *
+ * @author bratseth
+ */
+public class IntRange {
+
+    private static final IntRange empty = new IntRange(OptionalInt.empty(), OptionalInt.empty());
+
+    private final OptionalInt from, to;
+
+    public IntRange(OptionalInt from, OptionalInt to) {
+        if (from.isPresent() && to.isPresent() && from.getAsInt() > to.getAsInt())
+            throw new IllegalArgumentException("from " + from.getAsInt() + " is greater than to " + to.getAsInt());
+        this.from = from;
+        this.to = to;
+    }
+
+    /** Returns the minimum value which is in this range, or empty if it is open downwards. */
+    public OptionalInt from() { return from; }
+
+    /** Returns the maximum value which is in this range, or empty if it is open upwards. */
+    public OptionalInt to() { return to; }
+
+    public boolean isEmpty() {
+        return from.isEmpty() && to.isEmpty();
+    }
+
+    /** Returns whether the given value is in this range. */
+    public boolean includes(int value) {
+        if (from.isPresent() && value < from.getAsInt()) return false;
+        if (to.isPresent() && value > to.getAsInt()) return false;
+        return true;
+    }
+
+    /** Returns the given value adjusted minimally to fit within this range. */
+    public int fit(int value) {
+        if (from.isPresent() && value < from.getAsInt()) return from.getAsInt();
+        if (to.isPresent() && value > to.getAsInt()) return to.getAsInt();
+        return value;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if ( ! (o instanceof IntRange other)) return false;
+        if ( ! this.from.equals(other.from)) return false;
+        if ( ! this.to.equals(other.to)) return false;
+        return true;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(from, to);
+    }
+
+    @Override
+    public String toString() {
+        if (isEmpty()) return "[]";
+        if (from.equals(to)) return String.valueOf(from.getAsInt());
+        return "[" + (from.isPresent() ? from.getAsInt() : "") + ", " + (to.isPresent() ? to.getAsInt() : "") + "]";
+    }
+
+    public static IntRange empty() { return empty; }
+
+    public static IntRange from(int from) {
+        return new IntRange(OptionalInt.of(from), OptionalInt.empty());
+    }
+
+    public static IntRange to(int to) {
+        return new IntRange(OptionalInt.empty(), OptionalInt.of(to));
+    }
+
+    public static IntRange of(int fromTo) {
+        return new IntRange(OptionalInt.of(fromTo), OptionalInt.of(fromTo));
+    }
+
+    public static IntRange of(int from, int to) {
+        return new IntRange(OptionalInt.of(from), OptionalInt.of(to));
+    }
+
+    /** Returns this with a 'from' limit which is at most the given value */
+    public IntRange fromAtMost(int minLimit) {
+        if (from.isEmpty()) return this;
+        if (from.getAsInt() <= minLimit) return this;
+        return new IntRange(OptionalInt.of(minLimit), to);
+    }
+
+    /** Returns this with a 'to' limit which is at least the given value */
+    public IntRange toAtLeast(int maxLimit) {
+        if (to.isEmpty()) return this;
+        if (to.getAsInt() >= maxLimit) return this;
+        return new IntRange(from, OptionalInt.of(maxLimit));
+    }
+
+    /** Parses a value ("value"), value range ("[min-value?, max-value?]"), or empty. */
+    public static IntRange from(String s) {
+        try {
+            s = s.trim();
+            if (s.startsWith("[") && s.endsWith("]")) {
+                String innards = s.substring(1, s.length() - 1).trim();
+                if (innards.isEmpty()) return empty();
+                String[] numbers = (" " + innards + " ").split(","); // pad to make sure we get 2 elements
+                if (numbers.length != 2) throw new IllegalArgumentException("Expected two numbers");
+                return new IntRange(parseOptionalInt(numbers[0]), parseOptionalInt(numbers[1]));
+            } else {
+                var fromTo = parseOptionalInt(s);
+                return new IntRange(fromTo, fromTo);
+            }
+        }
+        catch (IllegalArgumentException e) {
+            throw new IllegalArgumentException("Expected a number or range on the form [min, max], but got '" + s + "'", e);
+        }
+    }
+
+    private static OptionalInt parseOptionalInt(String s) {
+        try {
+            s = s.trim();
+            if (s.isEmpty()) return OptionalInt.empty();
+            return OptionalInt.of(Integer.parseInt(s));
+        }
+        catch (IllegalArgumentException e) {
+            throw new IllegalArgumentException("'" + s + "' is not an integer");
+        }
+    }
+
+}
diff --git a/vespajlib/src/test/java/com/yahoo/collections/IntRangeTestCase.java b/vespajlib/src/test/java/com/yahoo/collections/IntRangeTestCase.java
new file mode 100644
index 00000000000..dc3c39ea19b
--- /dev/null
+++ b/vespajlib/src/test/java/com/yahoo/collections/IntRangeTestCase.java
@@ -0,0 +1,38 @@
+package com.yahoo.collections;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author bratseth
+ */
+public class IntRangeTestCase {
+
+    @Test
+    public void testStringAndEquals() {
+        assertEquals(IntRange.empty(), IntRange.from(IntRange.from("[]").toString()));
+        assertEquals(IntRange.from(1), IntRange.from(IntRange.from("[1,]").toString()));
+        assertEquals(IntRange.to(3), IntRange.from(IntRange.from("[,3]").toString()));
+        assertEquals(IntRange.of(1, 3), IntRange.from(IntRange.from("[1,3]").toString()));
+        assertEquals(IntRange.of(1, 3), IntRange.from(IntRange.from("[1, 3]").toString()));
+    }
+
+    @Test
+    public void testInclusion() {
+        assertFalse(IntRange.of(3, 5).includes(2));
+        assertTrue(IntRange.of(3, 5).includes(3));
+        assertTrue(IntRange.of(3, 5).includes(4));
+        assertTrue(IntRange.of(3, 5).includes(5));
+        assertFalse(IntRange.of(3, 5).includes(6));
+
+        assertTrue(IntRange.from(3).includes(1000));
+        assertFalse(IntRange.from(3).includes(2));
+
+        assertTrue(IntRange.to(5).includes(-1000));
+        assertFalse(IntRange.to(3).includes(4));
+    }
+
+}