Add flag to enable multi-threaded indexing for a hnsw index.

27 files changed, 159 insertions, 4 deletions

diff --git a/config-model/src/main/java/com/yahoo/searchdefinition/derived/AttributeFields.java b/config-model/src/main/java/com/yahoo/searchdefinition/derived/AttributeFields.java
index 004e44a7659..210f54de6a6 100644
--- a/config-model/src/main/java/com/yahoo/searchdefinition/derived/AttributeFields.java
+++ b/config-model/src/main/java/com/yahoo/searchdefinition/derived/AttributeFields.java
@@ -250,6 +250,7 @@ public class AttributeFields extends Derived implements AttributesConfig.Produce
             ib.hnsw.neighborstoexploreatinsert(params.neighborsToExploreAtInsert());
             var dm = AttributesConfig.Attribute.Index.Hnsw.Distancemetric.Enum.valueOf(dma.toString());
             ib.hnsw.distancemetric(dm);
+            ib.hnsw.multithreadedindexing(params.multiThreadedIndexing());
             aaB.index(ib);
         }
         return aaB;
diff --git a/config-model/src/main/java/com/yahoo/searchdefinition/document/HnswIndexParams.java b/config-model/src/main/java/com/yahoo/searchdefinition/document/HnswIndexParams.java
index 2f084d3e513..f4f4cedd2aa 100644
--- a/config-model/src/main/java/com/yahoo/searchdefinition/document/HnswIndexParams.java
+++ b/config-model/src/main/java/com/yahoo/searchdefinition/document/HnswIndexParams.java
@@ -16,10 +16,12 @@ public class HnswIndexParams {
 
     private final Optional<Integer> maxLinksPerNode;
     private final Optional<Integer> neighborsToExploreAtInsert;
+    private final Optional<Boolean> multiThreadedIndexing;
 
     public static class Builder {
         private Optional<Integer> maxLinksPerNode = Optional.empty();
         private Optional<Integer> neighborsToExploreAtInsert = Optional.empty();
+        private Optional<Boolean> multiThreadedIndexing = Optional.empty();
 
         public void setMaxLinksPerNode(int value) {
             maxLinksPerNode = Optional.of(value);
@@ -27,20 +29,26 @@ public class HnswIndexParams {
         public void setNeighborsToExploreAtInsert(int value) {
             neighborsToExploreAtInsert = Optional.of(value);
         }
+        public void setMultiThreadedIndexing(boolean value) {
+            multiThreadedIndexing = Optional.of(value);
+        }
         public HnswIndexParams build() {
-            return new HnswIndexParams(maxLinksPerNode, neighborsToExploreAtInsert);
+            return new HnswIndexParams(maxLinksPerNode, neighborsToExploreAtInsert, multiThreadedIndexing);
         }
     }
 
     public HnswIndexParams() {
         this.maxLinksPerNode = Optional.empty();
         this.neighborsToExploreAtInsert = Optional.empty();
+        this.multiThreadedIndexing = Optional.empty();
     }
 
     public HnswIndexParams(Optional<Integer> maxLinksPerNode,
-                           Optional<Integer> neighborsToExploreAtInsert) {
+                           Optional<Integer> neighborsToExploreAtInsert,
+                           Optional<Boolean> multiThreadedIndexing) {
         this.maxLinksPerNode = maxLinksPerNode;
         this.neighborsToExploreAtInsert = neighborsToExploreAtInsert;
+        this.multiThreadedIndexing = multiThreadedIndexing;
     }
 
     /**
@@ -51,7 +59,8 @@ public class HnswIndexParams {
         if (! other.isPresent()) return this;
         HnswIndexParams rhs = other.get();
         return new HnswIndexParams(rhs.maxLinksPerNode.or(() ->  maxLinksPerNode),
-                rhs.neighborsToExploreAtInsert.or(() ->  neighborsToExploreAtInsert));
+                rhs.neighborsToExploreAtInsert.or(() ->  neighborsToExploreAtInsert),
+                rhs.multiThreadedIndexing.or(() -> multiThreadedIndexing));
     }
 
     public int maxLinksPerNode() {
@@ -61,4 +70,8 @@ public class HnswIndexParams {
     public int neighborsToExploreAtInsert() {
         return neighborsToExploreAtInsert.orElse(DEFAULT_NEIGHBORS_TO_EXPLORE_AT_INSERT);
     }
+
+    public boolean multiThreadedIndexing() {
+        return multiThreadedIndexing.orElse(false);
+    }
 }
diff --git a/config-model/src/main/javacc/SDParser.jj b/config-model/src/main/javacc/SDParser.jj
index 75ef3a831e8..68dafc5e578 100644
--- a/config-model/src/main/javacc/SDParser.jj
+++ b/config-model/src/main/javacc/SDParser.jj
@@ -337,6 +337,7 @@ TOKEN :
 | < MAXLINKSPERNODE: "max-links-per-node" >
 | < DISTANCEMETRIC: "distance-metric" >
 | < NEIGHBORSTOEXPLOREATINSERT: "neighbors-to-explore-at-insert" >
+| < MULTITHREADEDINDEXING: "multi-threaded-indexing" >
 | < SUMMARYFEATURES_SL: "summary-features" (" ")* ":" (~["}","\n"])* ("\n")? >
 | < SUMMARYFEATURES_ML: "summary-features" (<SEARCHLIB_SKIP>)? "{" (~["}"])* "}" >
 | < SUMMARYFEATURES_ML_INHERITS: "summary-features inherits " (<IDENTIFIER>) (<SEARCHLIB_SKIP>)? "{" (~["}"])* "}" >
@@ -1841,7 +1842,8 @@ void hnswIndexBody(HnswIndexParams.Builder params) :
 }
 {
     ( <MAXLINKSPERNODE> <COLON> num = integer() { params.setMaxLinksPerNode(num); }
-      | <NEIGHBORSTOEXPLOREATINSERT> <COLON> num = integer() { params.setNeighborsToExploreAtInsert(num); } )
+      | <NEIGHBORSTOEXPLOREATINSERT> <COLON> num = integer() { params.setNeighborsToExploreAtInsert(num); }
+      | <MULTITHREADEDINDEXING> { params.setMultiThreadedIndexing(true); } )
 }
 
 /**
diff --git a/config-model/src/test/derived/advanced/attributes.cfg b/config-model/src/test/derived/advanced/attributes.cfg
index 0217d957432..7f0c2400b9a 100644
--- a/config-model/src/test/derived/advanced/attributes.cfg
+++ b/config-model/src/test/derived/advanced/attributes.cfg
@@ -24,3 +24,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/array_of_struct_attribute/attributes.cfg b/config-model/src/test/derived/array_of_struct_attribute/attributes.cfg
index 8391a8a9bdd..807b514c8d6 100644
--- a/config-model/src/test/derived/array_of_struct_attribute/attributes.cfg
+++ b/config-model/src/test/derived/array_of_struct_attribute/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "elem_array.weight"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -50,3 +51,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/attributeprefetch/attributes.cfg b/config-model/src/test/derived/attributeprefetch/attributes.cfg
index 448f9a82d36..b872efa3db8 100644
--- a/config-model/src/test/derived/attributeprefetch/attributes.cfg
+++ b/config-model/src/test/derived/attributeprefetch/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "multibyte"
 attribute[].datatype INT8
 attribute[].collectiontype ARRAY
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "wsbyte"
 attribute[].datatype INT8
 attribute[].collectiontype WEIGHTEDSET
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "singleint"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "multiint"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "wsint"
 attribute[].datatype INT32
 attribute[].collectiontype WEIGHTEDSET
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "singlelong"
 attribute[].datatype INT64
 attribute[].collectiontype SINGLE
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "multilong"
 attribute[].datatype INT64
 attribute[].collectiontype ARRAY
@@ -206,6 +213,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "wslong"
 attribute[].datatype INT64
 attribute[].collectiontype WEIGHTEDSET
@@ -232,6 +240,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "singlefloat"
 attribute[].datatype FLOAT
 attribute[].collectiontype SINGLE
@@ -258,6 +267,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "multifloat"
 attribute[].datatype FLOAT
 attribute[].collectiontype ARRAY
@@ -284,6 +294,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "wsfloat"
 attribute[].datatype FLOAT
 attribute[].collectiontype WEIGHTEDSET
@@ -310,6 +321,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "singledouble"
 attribute[].datatype DOUBLE
 attribute[].collectiontype SINGLE
@@ -336,6 +348,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "multidouble"
 attribute[].datatype DOUBLE
 attribute[].collectiontype ARRAY
@@ -362,6 +375,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "wsdouble"
 attribute[].datatype DOUBLE
 attribute[].collectiontype WEIGHTEDSET
@@ -388,6 +402,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "singlestring"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -414,6 +429,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "multistring"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -440,6 +456,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "wsstring"
 attribute[].datatype STRING
 attribute[].collectiontype WEIGHTEDSET
@@ -466,3 +483,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/attributes/attributes.cfg b/config-model/src/test/derived/attributes/attributes.cfg
index d88c6b8b70a..750749de45c 100644
--- a/config-model/src/test/derived/attributes/attributes.cfg
+++ b/config-model/src/test/derived/attributes/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a2"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a3"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a5"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a6"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b1"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b2"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b3"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -206,6 +213,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b4"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -232,6 +240,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b5"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -258,6 +267,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b6"
 attribute[].datatype INT64
 attribute[].collectiontype ARRAY
@@ -284,6 +294,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b7"
 attribute[].datatype DOUBLE
 attribute[].collectiontype WEIGHTEDSET
@@ -310,6 +321,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a9"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -336,6 +348,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a10"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -362,6 +375,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a11"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -388,6 +402,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a12"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -414,6 +429,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a7_arr"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -440,6 +456,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "a8_arr"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -466,3 +483,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/complex/attributes.cfg b/config-model/src/test/derived/complex/attributes.cfg
index 337b736471d..f1449cf52be 100644
--- a/config-model/src/test/derived/complex/attributes.cfg
+++ b/config-model/src/test/derived/complex/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "fleeting"
 attribute[].datatype FLOAT
 attribute[].collectiontype ARRAY
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "fleeting2"
 attribute[].datatype FLOAT
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "foundat"
 attribute[].datatype INT64
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "collapseby"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "ts"
 attribute[].datatype INT64
 attribute[].collectiontype SINGLE
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "combineda"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "year_arr"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -206,6 +213,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "year_sub"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -232,3 +240,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/hnsw_index/attributes.cfg b/config-model/src/test/derived/hnsw_index/attributes.cfg
index 087a116f4cd..9cea76174c7 100644
--- a/config-model/src/test/derived/hnsw_index/attributes.cfg
+++ b/config-model/src/test/derived/hnsw_index/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled true
 attribute[].index.hnsw.maxlinkspernode 32
 attribute[].index.hnsw.distancemetric ANGULAR
 attribute[].index.hnsw.neighborstoexploreatinsert 300
+attribute[].index.hnsw.multithreadedindexing true
 attribute[].name "t2"
 attribute[].datatype TENSOR
 attribute[].collectiontype SINGLE
@@ -50,3 +51,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/hnsw_index/test.sd b/config-model/src/test/derived/hnsw_index/test.sd
index 82291be9747..373624c9e7b 100644
--- a/config-model/src/test/derived/hnsw_index/test.sd
+++ b/config-model/src/test/derived/hnsw_index/test.sd
@@ -9,6 +9,7 @@ search test {
         hnsw {
           max-links-per-node: 32
           neighbors-to-explore-at-insert: 300
+          multi-threaded-indexing
         }
       }
     }
diff --git a/config-model/src/test/derived/imported_position_field/attributes.cfg b/config-model/src/test/derived/imported_position_field/attributes.cfg
index 685f708768a..75184c66789 100644
--- a/config-model/src/test/derived/imported_position_field/attributes.cfg
+++ b/config-model/src/test/derived/imported_position_field/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_pos_zcurve"
 attribute[].datatype INT64
 attribute[].collectiontype SINGLE
@@ -50,3 +51,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/imported_struct_fields/attributes.cfg b/config-model/src/test/derived/imported_struct_fields/attributes.cfg
index e8b7a7b6235..6256f98d05f 100644
--- a/config-model/src/test/derived/imported_struct_fields/attributes.cfg
+++ b/config-model/src/test/derived/imported_struct_fields/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_elem_array.name"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_elem_array.weight"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_elem_map.key"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_elem_map.value.name"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_elem_map.value.weight"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_str_int_map.key"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_str_int_map.value"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -206,3 +213,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/importedfields/attributes.cfg b/config-model/src/test/derived/importedfields/attributes.cfg
index 6f3514102b4..87a841a95e0 100644
--- a/config-model/src/test/derived/importedfields/attributes.cfg
+++ b/config-model/src/test/derived/importedfields/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b_ref"
 attribute[].datatype REFERENCE
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "b_ref_with_summary"
 attribute[].datatype REFERENCE
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_int_field"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_string_field"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_int_array_field"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_int_wset_field"
 attribute[].datatype INT32
 attribute[].collectiontype WEIGHTEDSET
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "my_ancient_int_field"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -206,3 +213,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/inheritance/attributes.cfg b/config-model/src/test/derived/inheritance/attributes.cfg
index 541092622ff..f5ced387e8e 100644
--- a/config-model/src/test/derived/inheritance/attributes.cfg
+++ b/config-model/src/test/derived/inheritance/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "overridden"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "onlymother"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -76,3 +78,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/inheritfromparent/attributes.cfg b/config-model/src/test/derived/inheritfromparent/attributes.cfg
index dda86f765be..26b0f77417a 100644
--- a/config-model/src/test/derived/inheritfromparent/attributes.cfg
+++ b/config-model/src/test/derived/inheritfromparent/attributes.cfg
@@ -24,3 +24,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/map_attribute/attributes.cfg b/config-model/src/test/derived/map_attribute/attributes.cfg
index 702e065d15a..7f224ff0c6a 100644
--- a/config-model/src/test/derived/map_attribute/attributes.cfg
+++ b/config-model/src/test/derived/map_attribute/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "str_map.value"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "int_map.key"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -76,3 +78,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/map_of_struct_attribute/attributes.cfg b/config-model/src/test/derived/map_of_struct_attribute/attributes.cfg
index 3eca0d5bbf8..f08fd4e8907 100644
--- a/config-model/src/test/derived/map_of_struct_attribute/attributes.cfg
+++ b/config-model/src/test/derived/map_of_struct_attribute/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "str_elem_map.value.name"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "str_elem_map.value.weight"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "int_elem_map.key"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "int_elem_map.value.name"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -128,3 +132,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/music/attributes.cfg b/config-model/src/test/derived/music/attributes.cfg
index f75b8e06b80..d33313c30eb 100644
--- a/config-model/src/test/derived/music/attributes.cfg
+++ b/config-model/src/test/derived/music/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "pto"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "mid"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "weight"
 attribute[].datatype FLOAT
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "bgnpfrom"
 attribute[].datatype FLOAT
 attribute[].collectiontype SINGLE
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "newestedition"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "year"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "did"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -206,6 +213,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "cbid"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -232,6 +240,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "hiphopvalue_arr"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -258,6 +267,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "metalvalue_arr"
 attribute[].datatype STRING
 attribute[].collectiontype ARRAY
@@ -284,3 +294,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/newrank/attributes.cfg b/config-model/src/test/derived/newrank/attributes.cfg
index 303ea35223a..ae3a33e49c3 100644
--- a/config-model/src/test/derived/newrank/attributes.cfg
+++ b/config-model/src/test/derived/newrank/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "pto"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "mid"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "weight"
 attribute[].datatype FLOAT
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "bgnpfrom"
 attribute[].datatype FLOAT
 attribute[].collectiontype SINGLE
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "newestedition"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "year"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "did"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -206,6 +213,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "scorekey"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -232,6 +240,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "cbid"
 attribute[].datatype INT32
 attribute[].collectiontype SINGLE
@@ -258,3 +267,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/predicate_attribute/attributes.cfg b/config-model/src/test/derived/predicate_attribute/attributes.cfg
index d095b68752a..b70804ed36d 100644
--- a/config-model/src/test/derived/predicate_attribute/attributes.cfg
+++ b/config-model/src/test/derived/predicate_attribute/attributes.cfg
@@ -24,3 +24,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/prefixexactattribute/attributes.cfg b/config-model/src/test/derived/prefixexactattribute/attributes.cfg
index 5cae6b784ff..5e9930317cd 100644
--- a/config-model/src/test/derived/prefixexactattribute/attributes.cfg
+++ b/config-model/src/test/derived/prefixexactattribute/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "attributefield2"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -50,3 +51,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/reference_fields/attributes.cfg b/config-model/src/test/derived/reference_fields/attributes.cfg
index ec3ca030373..6bc8f93a4d4 100644
--- a/config-model/src/test/derived/reference_fields/attributes.cfg
+++ b/config-model/src/test/derived/reference_fields/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "other_ref"
 attribute[].datatype REFERENCE
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "yet_another_ref"
 attribute[].datatype REFERENCE
 attribute[].collectiontype SINGLE
@@ -76,3 +78,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/sorting/attributes.cfg b/config-model/src/test/derived/sorting/attributes.cfg
index 6e50bd625ee..a957e1ae4dd 100644
--- a/config-model/src/test/derived/sorting/attributes.cfg
+++ b/config-model/src/test/derived/sorting/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "syntaxcheck2"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "infieldonly"
 attribute[].datatype STRING
 attribute[].collectiontype SINGLE
@@ -76,3 +78,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/tensor/attributes.cfg b/config-model/src/test/derived/tensor/attributes.cfg
index 6ed960728c2..38d25a0faf0 100644
--- a/config-model/src/test/derived/tensor/attributes.cfg
+++ b/config-model/src/test/derived/tensor/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "f3"
 attribute[].datatype TENSOR
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "f4"
 attribute[].datatype TENSOR
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "f5"
 attribute[].datatype TENSOR
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "f6"
 attribute[].datatype FLOAT
 attribute[].collectiontype SINGLE
@@ -128,3 +132,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/derived/types/attributes.cfg b/config-model/src/test/derived/types/attributes.cfg
index 8e37a1f1c63..536a2acba73 100644
--- a/config-model/src/test/derived/types/attributes.cfg
+++ b/config-model/src/test/derived/types/attributes.cfg
@@ -24,6 +24,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "along"
 attribute[].datatype INT64
 attribute[].collectiontype SINGLE
@@ -50,6 +51,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "abool"
 attribute[].datatype BOOL
 attribute[].collectiontype SINGLE
@@ -76,6 +78,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "ashortfloat"
 attribute[].datatype FLOAT16
 attribute[].collectiontype SINGLE
@@ -102,6 +105,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "arrayfield"
 attribute[].datatype INT32
 attribute[].collectiontype ARRAY
@@ -128,6 +132,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "setfield"
 attribute[].datatype STRING
 attribute[].collectiontype WEIGHTEDSET
@@ -154,6 +159,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "setfield2"
 attribute[].datatype STRING
 attribute[].collectiontype WEIGHTEDSET
@@ -180,6 +186,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "setfield3"
 attribute[].datatype STRING
 attribute[].collectiontype WEIGHTEDSET
@@ -206,6 +213,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "setfield4"
 attribute[].datatype STRING
 attribute[].collectiontype WEIGHTEDSET
@@ -232,6 +240,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "tagfield"
 attribute[].datatype STRING
 attribute[].collectiontype WEIGHTEDSET
@@ -258,6 +267,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "juletre"
 attribute[].datatype INT64
 attribute[].collectiontype SINGLE
@@ -284,6 +294,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "album1"
 attribute[].datatype STRING
 attribute[].collectiontype WEIGHTEDSET
@@ -310,6 +321,7 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
 attribute[].name "other"
 attribute[].datatype INT64
 attribute[].collectiontype SINGLE
@@ -336,3 +348,4 @@ attribute[].index.hnsw.enabled false
 attribute[].index.hnsw.maxlinkspernode 16
 attribute[].index.hnsw.distancemetric EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert 200
+attribute[].index.hnsw.multithreadedindexing false
diff --git a/config-model/src/test/java/com/yahoo/searchdefinition/document/HnswIndexParamsTestCase.java b/config-model/src/test/java/com/yahoo/searchdefinition/document/HnswIndexParamsTestCase.java
index e3dcc925e5e..44379d25012 100644
--- a/config-model/src/test/java/com/yahoo/searchdefinition/document/HnswIndexParamsTestCase.java
+++ b/config-model/src/test/java/com/yahoo/searchdefinition/document/HnswIndexParamsTestCase.java
@@ -17,29 +17,37 @@ public class HnswIndexParamsTestCase {
         var empty = new HnswIndexParams();
         var builder = new HnswIndexParams.Builder();
         builder.setMaxLinksPerNode(7);
+        builder.setMultiThreadedIndexing(false);
         var one = builder.build();
         builder.setNeighborsToExploreAtInsert(42);
         var three = builder.build();
         builder.setMaxLinksPerNode(17);
         builder.setNeighborsToExploreAtInsert(500);
+        builder.setMultiThreadedIndexing(true);
         var four = builder.build();
 
         assertThat(empty.maxLinksPerNode(), is(16));
         assertThat(empty.neighborsToExploreAtInsert(), is(200));
+        assertThat(empty.multiThreadedIndexing(), is(false));
 
         assertThat(one.maxLinksPerNode(), is(7));
+        assertThat(one.multiThreadedIndexing(), is(false));
         assertThat(three.neighborsToExploreAtInsert(), is(42));
 
         assertThat(four.maxLinksPerNode(), is(17));
         assertThat(four.neighborsToExploreAtInsert(), is(500));
+        assertThat(four.multiThreadedIndexing(), is(true));
 
         var five = four.overrideFrom(Optional.of(empty));
         assertThat(five.maxLinksPerNode(), is(17));
         assertThat(five.neighborsToExploreAtInsert(), is(500));
+        assertThat(five.multiThreadedIndexing(), is(true));
 
         var six = four.overrideFrom(Optional.of(one));
         assertThat(six.maxLinksPerNode(), is(7));
         assertThat(six.neighborsToExploreAtInsert(), is(500));
+        // This is explicitly set to false in 'one'
+        assertThat(six.multiThreadedIndexing(), is(false));
     }
 
 }
diff --git a/configdefinitions/src/vespa/attributes.def b/configdefinitions/src/vespa/attributes.def
index 3602c2b0fd7..a091fbc573c 100644
--- a/configdefinitions/src/vespa/attributes.def
+++ b/configdefinitions/src/vespa/attributes.def
@@ -41,3 +41,5 @@ attribute[].index.hnsw.maxlinkspernode int default=16
 # Deprecated: Remove on Vespa 8 or before when possible.
 attribute[].index.hnsw.distancemetric enum { EUCLIDEAN, ANGULAR, GEODEGREES } default=EUCLIDEAN
 attribute[].index.hnsw.neighborstoexploreatinsert int default=200
+# Whether multi-threaded indexing is enabled for this hnsw index.
+attribute[].index.hnsw.multithreadedindexing bool default=false