Merge branch 'main' into increase_sparse_pruning_test_coverage

Author: mromaios

.buildkite/pipelines/intake.yml

@@ -65,7 +65,7 @@ steps:
         timeout_in_minutes: 300
         matrix:
           setup:
-            BWC_VERSION: ["8.17.10", "8.18.5", "8.19.0", "9.0.5", "9.1.1", "9.2.0"]
+            BWC_VERSION: ["8.17.10", "8.18.5", "8.19.1", "9.0.5", "9.1.1", "9.2.0"]
         agents:
           provider: gcp
           image: family/elasticsearch-ubuntu-2404

.buildkite/pipelines/periodic-packaging.yml

@@ -334,8 +334,8 @@ steps:
         env:
           BWC_VERSION: 8.18.5
 
-      - label: "{{matrix.image}} / 8.19.0 / packaging-tests-upgrade"
-        command: ./.ci/scripts/packaging-test.sh -Dbwc.checkout.align=true destructiveDistroUpgradeTest.v8.19.0
+      - label: "{{matrix.image}} / 8.19.1 / packaging-tests-upgrade"
+        command: ./.ci/scripts/packaging-test.sh -Dbwc.checkout.align=true destructiveDistroUpgradeTest.v8.19.1
         timeout_in_minutes: 300
         matrix:
           setup:
@@ -348,7 +348,7 @@ steps:
           machineType: custom-16-32768
           buildDirectory: /dev/shm/bk
         env:
-          BWC_VERSION: 8.19.0
+          BWC_VERSION: 8.19.1
 
       - label: "{{matrix.image}} / 9.0.5 / packaging-tests-upgrade"
         command: ./.ci/scripts/packaging-test.sh -Dbwc.checkout.align=true destructiveDistroUpgradeTest.v9.0.5

.buildkite/pipelines/periodic.yml

@@ -363,8 +363,8 @@ steps:
             - signal_reason: agent_stop
               limit: 3
 
-      - label: 8.19.0 / bwc
-        command: .ci/scripts/run-gradle.sh -Dbwc.checkout.align=true v8.19.0#bwcTest
+      - label: 8.19.1 / bwc
+        command: .ci/scripts/run-gradle.sh -Dbwc.checkout.align=true v8.19.1#bwcTest
         timeout_in_minutes: 300
         agents:
           provider: gcp
@@ -373,7 +373,7 @@ steps:
           buildDirectory: /dev/shm/bk
           preemptible: true
         env:
-          BWC_VERSION: 8.19.0
+          BWC_VERSION: 8.19.1
         retry:
           automatic:
             - exit_status: "-1"
@@ -506,7 +506,7 @@ steps:
           setup:
             ES_RUNTIME_JAVA:
               - openjdk21
-            BWC_VERSION: ["8.17.10", "8.18.5", "8.19.0", "9.0.5", "9.1.1", "9.2.0"]
+            BWC_VERSION: ["8.17.10", "8.18.5", "8.19.1", "9.0.5", "9.1.1", "9.2.0"]
         agents:
           provider: gcp
           image: family/elasticsearch-ubuntu-2404
@@ -550,7 +550,7 @@ steps:
             ES_RUNTIME_JAVA:
               - openjdk21
               - openjdk23
-            BWC_VERSION: ["8.17.10", "8.18.5", "8.19.0", "9.0.5", "9.1.1", "9.2.0"]
+            BWC_VERSION: ["8.17.10", "8.18.5", "8.19.1", "9.0.5", "9.1.1", "9.2.0"]
         agents:
           provider: gcp
           image: family/elasticsearch-ubuntu-2404

.ci/bwcVersions

@@ -18,7 +18,7 @@ BWC_VERSION:
   - "8.16.6"
   - "8.17.10"
   - "8.18.5"
-  - "8.19.0"
+  - "8.19.1"
   - "9.0.5"
   - "9.1.1"
   - "9.2.0"

.ci/snapshotBwcVersions

@@ -1,7 +1,7 @@
 BWC_VERSION:
   - "8.17.10"
   - "8.18.5"
-  - "8.19.0"
+  - "8.19.1"
   - "9.0.5"
   - "9.1.1"
   - "9.2.0"

docs/changelog/130658.yaml

@@ -0,0 +1,5 @@
+pr: 130658
+summary: Add support for weighted RRF in retrievers
+area: Relevance
+type: enhancement
+issues: []

docs/changelog/132088.yaml

@@ -0,0 +1,5 @@
+pr: 132088
+summary: Fix combine result for `ingest_took`
+area: ES|QL
+type: bug
+issues: []

docs/changelog/132162.yaml

@@ -0,0 +1,6 @@
+pr: 132162
+summary: Fix default missing index sort value of `data_nanos` pre 7.14
+area: Search
+type: bug
+issues:
+ - 132040

docs/reference/elasticsearch/rest-apis/retrievers/linear-retriever.md

@@ -91,3 +91,37 @@ The `linear` retriever supports the following normalizers:
     score = (score - min) / (max - min)
     ```
 * `l2_norm`: Normalizes scores using the L2 norm of the score values {applies_to}`stack: ga 9.1`
+
+## Example
+
+This example of a hybrid search weights KNN results five times more heavily than BM25 results in the final ranking.
+
+```console
+GET my_index/_search
+{
+  "retriever": {
+    "linear": {
+      "retrievers": [
+        {
+          "retriever": {
+            "knn": {
+              ...
+            }
+          },
+          "weight": 5 # KNN query weighted 5x
+        },
+        {
+          "retriever": {
+            "standard": {
+              ...
+            }
+          },
+          "weight": 1.5 # BM25 query weighted 1.5x
+        }
+      ]
+    }
+  }
+}
+```
+
+See also [this hybrid search example](retrievers-examples.md#retrievers-examples-linear-retriever).

docs/release-notes/index.md

@@ -361,6 +361,7 @@ Machine Learning:
 * Mark token pruning for sparse vector as GA [#128854](https://github.com/elastic/elasticsearch/pull/128854)
 * Move to the Cohere V2 API for new inference endpoints [#129884](https://github.com/elastic/elasticsearch/pull/129884)
 * Semantic Text Chunking Indexing Pressure [#125517](https://github.com/elastic/elasticsearch/pull/125517)
+* Track memory used in the hierarchical results normalizer [#2831](https://github.com/elastic/ml-cpp/pull/2831)
 * Upgrade AWS v2 SDK to 2.30.38 [#124738](https://github.com/elastic/elasticsearch/pull/124738)
 * [Inference API] Propagate product use case http header to EIS [#124025](https://github.com/elastic/elasticsearch/pull/124025)
 * [ML] Add HuggingFace Chat Completion support to the Inference Plugin [#127254](https://github.com/elastic/elasticsearch/pull/127254)