Scale load as late as possible

3 files changed, 13 insertions, 11 deletions

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 84ecaa3453d..2befd69f893 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
@@ -26,13 +26,13 @@ public class AllocationOptimizer {
     }
 
     /**
-     * Searches the space of possible allocations given a target
+     * Searches the space of possible allocations given a target relative load
      * and (optionally) cluster limits and returns the best alternative.
      *
      * @return the best allocation, if there are any possible legal allocations, fulfilling the target
      *         fully or partially, within the limits
      */
-    public Optional<AllocatableClusterResources> findBestAllocation(NodeResources target,
+    public Optional<AllocatableClusterResources> findBestAllocation(Load targetLoad,
                                                                     AllocatableClusterResources current,
                                                                     ClusterModel clusterModel,
                                                                     Limits limits) {
@@ -51,7 +51,7 @@ public class AllocationOptimizer {
                 ClusterResources next = new ClusterResources(nodes,
                                                              groups,
                                                              nodeResourcesWith(nodes, groups,
-                                                                               limits, target, current, clusterModel));
+                                                                               limits, targetLoad, current, clusterModel));
                 var allocatableResources = AllocatableClusterResources.from(next, current.clusterSpec(), limits,
                                                                             hosts, nodeRepository);
                 if (allocatableResources.isEmpty()) continue;
@@ -64,16 +64,19 @@ public class AllocationOptimizer {
 
     /**
      * For the observed load this instance is initialized with, returns the resources needed per node to be at
-     * ideal load given a target node count
+     * the target relative load, given a target node and group count.
      */
     private NodeResources nodeResourcesWith(int nodes,
                                             int groups,
                                             Limits limits,
-                                            NodeResources target,
+                                            Load targetLoad,
                                             AllocatableClusterResources current,
                                             ClusterModel clusterModel) {
-        var scaled = clusterModel.loadWith(nodes, groups)
-                                 .scaled(Load.one().divide(clusterModel.redundancyAdjustment()).scaled(target));
+        var scaled = targetLoad                                      // redundancy aware target relative to current load
+                     .multiply(clusterModel.loadWith(nodes, groups)) // redundancy aware adjustment with these counts
+                     .divide(clusterModel.redundancyAdjustment())    // correct for double redundancy adjustment
+                     .scaled(current.realResources().nodeResources());
+
         // Combine the scaled resource values computed here
         // with the currently configured non-scaled values, given in the limits, if any
         var nonScaled = limits.isEmpty() || limits.min().nodeResources().isUnspecified()
diff --git a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Autoscaler.java b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Autoscaler.java
index 0931fc6af3b..7a02fa9eb7e 100644
--- a/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Autoscaler.java
+++ b/node-repository/src/main/java/com/yahoo/vespa/hosted/provision/autoscale/Autoscaler.java
@@ -89,10 +89,8 @@ public class Autoscaler {
                                " nodes, but require from " + clusterNodes.size());
 
         var currentAllocation = new AllocatableClusterResources(clusterNodes.asList(), nodeRepository);
-        var target = clusterModel.loadAdjustment().scaled(currentAllocation.realResources().nodeResources());
-
         Optional<AllocatableClusterResources> bestAllocation =
-                allocationOptimizer.findBestAllocation(target, currentAllocation, clusterModel, limits);
+                allocationOptimizer.findBestAllocation(clusterModel.loadAdjustment(), currentAllocation, clusterModel, limits);
         if (bestAllocation.isEmpty())
             return Advice.dontScale(Status.insufficient, "No allocations are possible within configured limits");
 
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 0ce84559d1a..065293ca5d8 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
@@ -27,6 +27,7 @@ import com.yahoo.vespa.hosted.provision.autoscale.AllocatableClusterResources;
 import com.yahoo.vespa.hosted.provision.autoscale.AllocationOptimizer;
 import com.yahoo.vespa.hosted.provision.autoscale.ClusterModel;
 import com.yahoo.vespa.hosted.provision.autoscale.Limits;
+import com.yahoo.vespa.hosted.provision.autoscale.Load;
 import com.yahoo.vespa.hosted.provision.node.Allocation;
 import com.yahoo.vespa.hosted.provision.node.filter.ApplicationFilter;
 import com.yahoo.vespa.hosted.provision.node.filter.NodeHostFilter;
@@ -195,7 +196,7 @@ public class NodeRepositoryProvisioner implements Provisioner {
         if (! firstDeployment && currentAsAdvertised.isWithin(limits.min(), limits.max())) return currentAsAdvertised;
 
         // Otherwise, find an allocation that preserves the current resources as well as possible
-        return allocationOptimizer.findBestAllocation(current.realResources().nodeResources(),
+        return allocationOptimizer.findBestAllocation(Load.one(),
                                                       current,
                                                       clusterModel,
                                                       limits)