vespa-engine · hmusum · Jan 6, 2025 · Jan 6, 2025
diff --git a/config-model-api/abi-spec.json b/config-model-api/abi-spec.json
@@ -1343,7 +1343,8 @@
       "public boolean distributionConfigFromClusterController()",
       "public boolean useLegacyWandQueryParsing()",
       "public boolean forwardAllLogLevels()",
-      "public long zookeeperPreAllocSize()"
+      "public long zookeeperPreAllocSize()",
+      "public int distributionBitsInDev()"
     ],
     "fields" : [ ]
   },
@@ -1812,8 +1813,8 @@
       "public final java.lang.String toString()",
       "public final int hashCode()",
       "public final boolean equals(java.lang.Object)",
-      "public java.lang.String name()",
-      "public java.lang.String id()"
+      "public java.lang.String id()",
+      "public java.lang.String name()"
     ],
     "fields" : [ ]
   },

diff --git a/config-model-api/src/main/java/com/yahoo/config/model/api/ModelContext.java b/config-model-api/src/main/java/com/yahoo/config/model/api/ModelContext.java
@@ -125,6 +125,7 @@ interface FeatureFlags {
         @ModelFeatureFlag(owners = {"arnej"}) default boolean useLegacyWandQueryParsing() { return true; }
         @ModelFeatureFlag(owners = {"hmusum"}) default boolean forwardAllLogLevels() { return true; }
         @ModelFeatureFlag(owners = {"hmusum"}) default long zookeeperPreAllocSize() { return 65536L; }
+        @ModelFeatureFlag(owners = {"hmusum"}) default int distributionBitsInDev() { return 0; }
     }
 
     /** Warning: As elsewhere in this package, do not make backwards incompatible changes that will break old config models! */

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
@@ -88,6 +88,7 @@ public class TestProperties implements ModelContext.Properties, ModelContext.Fea
     private boolean symmetricPutAndActivateReplicaSelection = false;
     private boolean enforceStrictlyIncreasingClusterStateVersions = false;
     private boolean distributionConfigFromClusterController = false;
+    private int distributionBitsInDev = 0;
 
     @Override public ModelContext.FeatureFlags featureFlags() { return this; }
     @Override public boolean multitenant() { return multitenant; }
@@ -150,6 +151,7 @@ public class TestProperties implements ModelContext.Properties, ModelContext.Fea
     @Override public boolean symmetricPutAndActivateReplicaSelection() { return symmetricPutAndActivateReplicaSelection; }
     @Override public boolean enforceStrictlyIncreasingClusterStateVersions() { return enforceStrictlyIncreasingClusterStateVersions; }
     @Override public boolean distributionConfigFromClusterController() { return distributionConfigFromClusterController; }
+    @Override public int distributionBitsInDev() { return distributionBitsInDev; }
 
     public TestProperties sharedStringRepoNoReclaim(boolean sharedStringRepoNoReclaim) {
         this.sharedStringRepoNoReclaim = sharedStringRepoNoReclaim;
@@ -410,6 +412,11 @@ public TestProperties setContainerEndpoints(Set<ContainerEndpoint> containerEndp
         return this;
     }
 
+    public TestProperties setDistributionBitsInDev(int bits) {
+        this.distributionBitsInDev = bits;
+        return this;
+    }
+
     public static class Spec implements ConfigServerSpec {
 
         private final String hostName;

diff --git a/config-model/src/main/java/com/yahoo/vespa/model/content/cluster/ContentCluster.java b/config-model/src/main/java/com/yahoo/vespa/model/content/cluster/ContentCluster.java
@@ -4,6 +4,7 @@
 import com.google.common.base.Preconditions;
 import com.yahoo.config.application.api.DeployLogger;
 import com.yahoo.config.model.ConfigModelContext;
+import com.yahoo.config.model.api.ModelContext;
 import com.yahoo.config.model.deploy.DeployState;
 import com.yahoo.config.model.producer.AnyConfigProducer;
 import com.yahoo.config.model.producer.TreeConfigProducer;
@@ -63,9 +64,9 @@
 import java.util.Optional;
 import java.util.Set;
 import java.util.TreeMap;
-import java.util.logging.Level;
 
 import static com.yahoo.vespa.model.content.DistributionBitCalculator.getDistributionBits;
+import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 
 /**
@@ -98,6 +99,7 @@ public class ContentCluster extends TreeConfigProducer<AnyConfigProducer> implem
     private Integer maxNodesPerMerge;
     private final Zone zone;
     private final Optional<Integer> distributionBitsInPreviousModel;
+    private final ModelContext.FeatureFlags featureFlags;
 
     public enum DistributionMode { LEGACY, STRICT, LOOSE }
     private DistributionMode distributionMode;
@@ -339,7 +341,7 @@ else if (admin.multitenant()) { // system tests: cluster controllers on logserve
                     if (hosts.size() > 1) {
                         var message = "When having content clusters and more than 1 config server " +
                                       "it is recommended to configure cluster controllers explicitly.";
-                        deployState.getDeployLogger().logApplicationPackage(Level.INFO, message);
+                        deployState.getDeployLogger().logApplicationPackage(INFO, message);
                     }
                     admin.setClusterControllers(createClusterControllers(admin,
                                                                          hosts,
@@ -438,6 +440,7 @@ private ContentCluster(TreeConfigProducer<?> parent, String clusterId,
         this.documentSelection = routingSelection;
         this.zone = deployState.zone();
         this.distributionBitsInPreviousModel = distributionBitsInPreviousModel(deployState, clusterId);
+        this.featureFlags = deployState.featureFlags();
     }
 
     public ClusterSpec.Id id() { return ClusterSpec.Id.from(clusterId); }
@@ -561,8 +564,17 @@ public int distributionBits() {
         // Avoid number of distribution bits being reduced
         if (distributionBitsInPreviousModel.isPresent() && distributionBitsInPreviousModel.get() > distributionBits)
             return distributionBitsInPreviousModel.get();
-        else
+
+        if (isHosted && zone.environment() == Environment.dev) {
+            var overriddenDistributionBits = featureFlags.distributionBitsInDev();
+            if (overriddenDistributionBits == 0) return distributionBits;
+
+            log.log(INFO, "Overriding distribution bits to be " + overriddenDistributionBits);
+            return overriddenDistributionBits;
+        }
+        else {
             return distributionBits;
+        }
     }
 
     private boolean zoneEnvImplies16DistributionBits() {

diff --git a/config-model/src/test/java/com/yahoo/vespa/model/content/ContentClusterTest.java b/config-model/src/test/java/com/yahoo/vespa/model/content/ContentClusterTest.java
@@ -643,6 +643,14 @@ void testZoneDependentDistributionBits() throws Exception {
 
         ContentCluster stagingNot16Bits = createWithZone(xml, new Zone(Environment.staging, RegionName.from("us-east-3")));
         assertDistributionBitsInConfig(stagingNot16Bits, 8);
+
+        // Default should be 8 bits
+        ContentCluster dev8Bits = createWithZone(xml, new Zone(Environment.dev, RegionName.from("us-east-3")));
+        assertDistributionBitsInConfig(dev8Bits, 8);
+
+        // Overriding feature flag with 16 bits
+        ContentCluster dev16Bits = createWithZone(xml, new Zone(Environment.dev, RegionName.from("us-east-3")), 16);
+        assertDistributionBitsInConfig(dev16Bits, 16);
     }
 
     @Test
@@ -1194,10 +1202,19 @@ void test_routing_with_multiple_clusters() {
         assertRoute(spec.getRoute(9), "storage/cluster.foo_c", "route:foo_c");
     }
 
+
     private ContentCluster createWithZone(String clusterXml, Zone zone) throws Exception {
+        return createWithZone(clusterXml, zone, 0);
+    }
+
+    private ContentCluster createWithZone(String clusterXml, Zone zone, int bitsInDev) throws Exception {
         DeployState.Builder deployStateBuilder = new DeployState.Builder()
-                .zone(zone)
-                .properties(new TestProperties().setHostedVespa(true));
+                .zone(zone);
+        var properties = new TestProperties().setHostedVespa(true);
+        if (bitsInDev != 0)
+            properties.setDistributionBitsInDev(bitsInDev);
+        deployStateBuilder.properties(properties);
+
         List<String> schemas = SchemaBuilder.createSchemas("test");
         MockRoot root = ContentClusterUtils.createMockRoot(schemas, deployStateBuilder);
         ContentCluster cluster = ContentClusterUtils.createCluster(clusterXml, root);

diff --git a/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ModelContextImpl.java b/configserver/src/main/java/com/yahoo/vespa/config/server/deploy/ModelContextImpl.java
@@ -216,6 +216,7 @@ public static class FeatureFlags implements ModelContext.FeatureFlags {
         private final boolean useLegacyWandQueryParsing;
         private final boolean forwardAllLogLevels;
         private final long zookeeperPreAllocSize;
+        private final int distributionBitsInDev;
 
         public FeatureFlags(FlagSource source, ApplicationId appId, Version version) {
             this.defaultTermwiseLimit = Flags.DEFAULT_TERM_WISE_LIMIT.bindTo(source).with(appId).with(version).value();
@@ -268,6 +269,7 @@ public FeatureFlags(FlagSource source, ApplicationId appId, Version version) {
             this.useLegacyWandQueryParsing = Flags.USE_LEGACY_WAND_QUERY_PARSING.bindTo(source).with(appId).with(version).value();
             this.forwardAllLogLevels = PermanentFlags.FORWARD_ALL_LOG_LEVELS.bindTo(source).with(appId).with(version).value();
             this.zookeeperPreAllocSize = Flags.ZOOKEEPER_PRE_ALLOC_SIZE_KIB.bindTo(source).value();
+            this.distributionBitsInDev = Flags.DISTRIBUTION_BITS_IN_DEV.bindTo(source).value();
         }
 
         @Override public int heapSizePercentage() { return heapPercentage; }
@@ -326,6 +328,7 @@ public FeatureFlags(FlagSource source, ApplicationId appId, Version version) {
         @Override public boolean useLegacyWandQueryParsing() { return useLegacyWandQueryParsing; }
         @Override public boolean forwardAllLogLevels() { return forwardAllLogLevels; }
         @Override public long zookeeperPreAllocSize() { return zookeeperPreAllocSize; }
+        @Override public int distributionBitsInDev() { return distributionBitsInDev; }
     }
 
     public static class Properties implements ModelContext.Properties {

diff --git a/flags/src/main/java/com/yahoo/vespa/flags/Flags.java b/flags/src/main/java/com/yahoo/vespa/flags/Flags.java
@@ -461,6 +461,13 @@ public class Flags {
             "Use new RPC method for triggering download of file reference",
             "Takes effect immediately");
 
+    public static final UnboundIntFlag DISTRIBUTION_BITS_IN_DEV = defineIntFlag(
+            "distribution-bits-in-dev", 0,
+            List.of("hmusum", "vekterli"), "2025-01-06", "2025-02-01",
+            "If non-zero, override number of distribution bits to use in dev zone in hosted Vespa for an application.",
+            "Takes effect at redeployment",
+            INSTANCE_ID);
+
     /** WARNING: public for testing: All flags should be defined in {@link Flags}. */
     public static UnboundBooleanFlag defineFeatureFlag(String flagId, boolean defaultValue, List<String> owners,
                                                        String createdAt, String expiresAt, String description,