Use bucket_space metric in retirement

This makes the Cluster Controller use the
vds.datastored.bucket_space.buckets_total, dimension bucketSpace=default, to
determine whether a content node manages zero buckets, and if so, will allow
the node to go permanently down. This is used when a node is retiring, and it
is to be removed from the application.

The change is guarded by the use-bucket-space-metric, default true. If the new
metric doesn't work as expected, we can revert to using the current/old metric
by flipping the flag. The flag can be controlled per application.

2 files changed, 11 insertions, 3 deletions

diff --git a/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java b/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
index cfa61560b29..9d561a79c75 100644
--- a/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
+++ b/config-model/src/main/java/com/yahoo/config/model/deploy/TestProperties.java
@@ -58,6 +58,7 @@ public class TestProperties implements ModelContext.Properties {
     @Override public boolean useDedicatedNodeForLogserver() { return useDedicatedNodeForLogserver; }
     @Override public Optional<TlsSecrets> tlsSecrets() { return tlsSecrets; }
     @Override public double defaultTermwiseLimit() { return defaultTermwiseLimit; }
+    @Override public boolean useBucketSpaceMetric() { return true; }
 
     public TestProperties setDefaultTermwiseLimit(double limit) {
         defaultTermwiseLimit = limit;
diff --git a/config-model/src/main/java/com/yahoo/vespa/model/content/ClusterControllerConfig.java b/config-model/src/main/java/com/yahoo/vespa/model/content/ClusterControllerConfig.java
index 1b0af3e9046..adff10ae580 100644
--- a/config-model/src/main/java/com/yahoo/vespa/model/content/ClusterControllerConfig.java
+++ b/config-model/src/main/java/com/yahoo/vespa/model/content/ClusterControllerConfig.java
@@ -40,6 +40,8 @@ public class ClusterControllerConfig extends AbstractConfigProducer implements F
                 bucketSplittingMinimumBits = clusterTuning.childAsInteger("bucket-splitting.minimum-bits");
             }
 
+            boolean useBucketSpaceMetric = deployState.getProperties().useBucketSpaceMetric();
+
             if (tuning != null) {
                 return new ClusterControllerConfig(ancestor, clusterName,
                         tuning.childAsDuration("init-progress-time"),
@@ -49,10 +51,11 @@ public class ClusterControllerConfig extends AbstractConfigProducer implements F
                         tuning.childAsDouble("min-distributor-up-ratio"),
                         tuning.childAsDouble("min-storage-up-ratio"),
                         bucketSplittingMinimumBits,
-                        minNodeRatioPerGroup);
+                        minNodeRatioPerGroup,
+                        useBucketSpaceMetric);
             } else {
                 return new ClusterControllerConfig(ancestor, clusterName, null, null, null, null, null, null,
-                        bucketSplittingMinimumBits, minNodeRatioPerGroup);
+                        bucketSplittingMinimumBits, minNodeRatioPerGroup, useBucketSpaceMetric);
             }
         }
     }
@@ -66,6 +69,7 @@ public class ClusterControllerConfig extends AbstractConfigProducer implements F
     Double minStorageUpRatio;
     Integer minSplitBits;
     private Double minNodeRatioPerGroup;
+    private boolean useBucketSpaceMetric;
 
     // TODO refactor; too many args
     private ClusterControllerConfig(AbstractConfigProducer parent,
@@ -77,7 +81,8 @@ public class ClusterControllerConfig extends AbstractConfigProducer implements F
                                     Double minDistributorUpRatio,
                                     Double minStorageUpRatio,
                                     Integer minSplitBits,
-                                    Double minNodeRatioPerGroup) {
+                                    Double minNodeRatioPerGroup,
+                                    boolean useBucketSpaceMetric) {
         super(parent, "fleetcontroller");
 
         this.clusterName = clusterName;
@@ -89,6 +94,7 @@ public class ClusterControllerConfig extends AbstractConfigProducer implements F
         this.minStorageUpRatio = minStorageUpRatio;
         this.minSplitBits = minSplitBits;
         this.minNodeRatioPerGroup = minNodeRatioPerGroup;
+        this.useBucketSpaceMetric = useBucketSpaceMetric;
     }
 
     @Override
@@ -105,6 +111,7 @@ public class ClusterControllerConfig extends AbstractConfigProducer implements F
         builder.index(0);
         builder.cluster_name(clusterName);
         builder.fleet_controller_count(getChildren().size());
+        builder.determine_buckets_from_bucket_space_metric(useBucketSpaceMetric);
 
         if (initProgressTime != null) {
             builder.init_progress_time((int) initProgressTime.getMilliSeconds());