Merge branch 'main' into indexLike_v3

Author: julian-elastic

.buildkite/hooks/pre-command

@@ -64,6 +64,14 @@ if [[ "${USE_LUCENE_SNAPSHOT_CREDS:-}" == "true" ]]; then
   unset data
 fi
 
+if [[ "${USE_MAVEN_GPG:-}" == "true" ]]; then
+  vault_path="kv/ci-shared/release-eng/team-release-secrets/es-delivery/gpg"
+  ORG_GRADLE_PROJECT_signingKey=$(vault kv get --field="private_key" $vault_path)
+  ORG_GRADLE_PROJECT_signingPassword=$(vault kv get --field="passphase" $vault_path)
+  export ORG_GRADLE_PROJECT_signingKey
+  export ORG_GRADLE_PROJECT_signingPassword
+fi
+
 if [[ "${USE_DRA_CREDENTIALS:-}" == "true" ]]; then
   DRA_VAULT_ROLE_ID_SECRET=$(vault read -field=role-id secret/ci/elastic-elasticsearch/legacy-vault-credentials)
   export DRA_VAULT_ROLE_ID_SECRET

.buildkite/pipelines/dra-workflow.yml

@@ -2,6 +2,7 @@ steps:
   - command: .buildkite/scripts/dra-workflow.sh
     env:
       USE_DRA_CREDENTIALS: "true"
+      USE_MAVEN_GPG: "true"
       USE_PROD_DOCKER_CREDENTIALS: "true"
     agents:
       provider: gcp

.buildkite/scripts/run-bc-upgrade-tests.sh

@@ -24,7 +24,7 @@ select(.active_release == true) |
 (.build_candidates | to_entries | sort_by(.value.completed_at))) |
 last | .value.manifest_url")"
 
-if [[ -z "$MANIFEST_URL" ]]; then
+if [[ -z "$MANIFEST_URL" ]] || [[ "$MANIFEST_URL" == "null" ]]; then
    echo "No snapshots or build candidates for branch [$BUILDKITE_BRANCH]."
    echo "Skipping BC upgrade tests."
    exit 0

.buildkite/scripts/run-pr-upgrade-tests.sh

@@ -18,7 +18,8 @@ fi
 
 # Identify the merge base of the current commit (branch) and the base branch of the pull request.
 # PR upgrade tests are run from the merge base to the current commit.
-BASE_COMMIT=$(git merge-base $BUILDKITE_PULL_REQUEST_BASE_BRANCH $BUILDKITE_COMMIT)
+git fetch origin $BUILDKITE_PULL_REQUEST_BASE_BRANCH
+BASE_COMMIT=$(git merge-base origin/$BUILDKITE_PULL_REQUEST_BASE_BRANCH $BUILDKITE_COMMIT)
 
 VERSION=$(sed -n 's/^elasticsearch[[:space:]]*=[[:space:]]*\(.*\)/\1/p' build-tools-internal/version.properties)
 

build-conventions/src/main/java/org/elasticsearch/gradle/internal/conventions/PublishPlugin.java

@@ -10,12 +10,11 @@
 package org.elasticsearch.gradle.internal.conventions;
 
 import groovy.util.Node;
+import nmcp.NmcpPlugin;
 
 import com.github.jengelman.gradle.plugins.shadow.ShadowExtension;
 import com.github.jengelman.gradle.plugins.shadow.ShadowPlugin;
 
-import nmcp.NmcpPlugin;
-
 import org.elasticsearch.gradle.internal.conventions.info.GitInfo;
 import org.elasticsearch.gradle.internal.conventions.precommit.PomValidationPrecommitPlugin;
 import org.elasticsearch.gradle.internal.conventions.util.Util;
@@ -41,6 +40,8 @@
 import org.gradle.api.tasks.bundling.Jar;
 import org.gradle.initialization.layout.BuildLayout;
 import org.gradle.language.base.plugins.LifecycleBasePlugin;
+import org.gradle.plugins.signing.SigningExtension;
+import org.gradle.plugins.signing.SigningPlugin;
 import org.w3c.dom.Element;
 
 import java.io.File;
@@ -69,6 +70,7 @@ public void apply(Project project) {
         project.getPluginManager().apply(PomValidationPrecommitPlugin.class);
         project.getPluginManager().apply(LicensingPlugin.class);
         project.getPluginManager().apply(NmcpPlugin.class);
+        project.getPluginManager().apply(SigningPlugin.class);
         configureJavadocJar(project);
         configureSourcesJar(project);
         configurePomGeneration(project);
@@ -79,6 +81,13 @@ public void apply(Project project) {
     private void configurePublications(Project project) {
         var publishingExtension = project.getExtensions().getByType(PublishingExtension.class);
         var publication = publishingExtension.getPublications().create("elastic", MavenPublication.class);
+        Provider<String> signingKey = project.getProviders().gradleProperty("signingKey");
+        if (signingKey.isPresent()) {
+            SigningExtension signing = project.getExtensions().getByType(SigningExtension.class);
+            signing.useInMemoryPgpKeys(signingKey.get(), project.getProviders().gradleProperty("signingPassword").get());
+            signing.sign(publication);
+        }
+
         project.afterEvaluate(project1 -> {
             if (project1.getPlugins().hasPlugin(ShadowPlugin.class)) {
                 configureWithShadowPlugin(project1, publication);

docs/changelog/125921.yaml

@@ -0,0 +1,18 @@
+pr: 125921
+summary: Allow direct IO for BBQ rescoring
+area: Vector Search
+type: feature
+highlight:
+  title: Allow direct IO for BBQ rescoring
+  body: |-
+    BBQ rescoring performance can be drastically affected by the amount of available
+    off-heap RAM for use by the system page cache. When there is not enough off-heap RAM
+    to fit all the vector data in memory, BBQ search latencies can be affected by as much as 5000x.
+    Specifying the `vector.rescoring.directio=true` Java option on all vector search
+    nodes modifies rescoring to use direct IO, which eliminates these very high latencies
+    from searches in low-memory scenarios, at a cost of a reduction
+    in vector search performance for BBQ indices when the vectors do all fit in memory.
+
+    This option is released in 9.1 as a tech preview whilst we analyse its effect
+    for a variety of use cases.
+issues: []

docs/changelog/129990.yaml

@@ -0,0 +1,5 @@
+pr: 129990
+summary: Make forecast write load accurate when shard numbers change
+area: Allocation
+type: bug
+issues: []

docs/reference/elasticsearch/configuration-reference/thread-pool-settings.md

@@ -71,6 +71,9 @@ $$$search-throttled$$$`search_throttled`
 `system_write`
 :   For write operations on system indices. Thread pool type is `fixed` with a default maximum size of `min(5, (`[`# of allocated processors`](#node.processors)`) / 2)`.
 
+`system_write_coordination`
+:   For bulk request coordination operations on system indices. Thread pool type is `fixed` with a default maximum size of `min(5, (`[`# of allocated processors`](#node.processors)`) / 2)`.
+
 `system_critical_read`
 :   For critical read operations on system indices. Thread pool type is `fixed` with a default maximum size of `min(5, (`[`# of allocated processors`](#node.processors)`) / 2)`.
 

docs/reference/query-languages/query-dsl/query-dsl-knn-query.md

@@ -229,6 +229,36 @@ A sample query can look like below:
 
 Note that nested `knn` only supports `score_mode=max`.
 
+## Knn query on a semantic_text field [knn-query-with-semantic-text]
+
+Elasticsearch supports knn queries over a [
+`semantic_text` field](/reference/elasticsearch/mapping-reference/semantic-text.md).
+
+Here is an example using the `query_vector_builder`:
+
+```json
+{
+  "query": {
+    "knn": {
+      "field": "inference_field",
+      "k": 10,
+      "num_candidates": 100,
+      "query_vector_builder": {
+        "text_embedding": {
+          "model_text": "test"
+        }
+      }
+    }
+  }
+}
+```
+
+Note that for `semantic_text` fields, the `model_id` does not have to be
+provided as it can be inferred from the `semantic_text` field mapping.
+
+Knn search using query vectors over `semantic_text` fields is also supported,
+with no change to the API.
+
 ## Knn query with aggregations [knn-query-aggregations]
 
 `knn` query calculates aggregations on top `k` documents from each shard. Thus, the final results from aggregations contain `k * number_of_shards` documents. This is different from the [top level knn section](docs-content://solutions/search/vector/knn.md) where aggregations are calculated on the global top `k` nearest documents.

docs/reference/search-connectors/es-connectors-mongodb.md

@@ -249,8 +249,23 @@ The full host in this example will look like this:
 
 A bug introduced in **8.12.0** causes the Connectors docker image to error out if run using MongoDB as its source. The command line will output the error `cannot import name 'coroutine' from 'asyncio'`. *** This issue is fixed in versions *8.12.2** and **8.13.0**. ** This bug does not affect Elastic managed connectors.
 
-See [Known issues](/release-notes/known-issues.md) for any issues affecting all connectors.
+#### UUIDs are not correctly deserialized, causing problems with ingesting documents into Elasticsearch
+
+MongoDB has special handling of UUID type: there is a legacy and a modern approach. You can read [official docs](https://pymongo.readthedocs.io/en/stable/examples/uuid.html) about the details.
+
+With connector framework version 9.0.3, we improved how standard UUIDs are handled. Now, the MongoDB connector can correctly deserialize UUIDs into valid Elasticsearch values. However, for legacy UUIDs or older connector versions, you might need to adjust the connection string to specify the UUID representation.
+
+For example, if you are using the modern UUID representation, adding the `uuidRepresentation=standard` query parameter to the MongoDB connection URI in the `host` Rich Configurable Field will allow the connector to properly handle UUIDs. With this change, the full `host` Rich Configurable Field value could look like this:`mongodb+srv://my_username:[email protected]/mydb?w=majority&uuidRepresentation=standard`
 
+If you’re using a legacy UUID representation, you should adjust the connection URI accordingly. For example:
+
+- C#: `uuidRepresentation=csharpLegacy`
+- Java: `uuidRepresentation=javaLegacy`
+- Python: `uuidRepresentation=pythonLegacy`
+
+You can find a full explanation in the [official docs](https://pymongo.readthedocs.io/en/stable/examples/uuid.html#configuring-a-uuid-representation).
+
+See [Known issues](/release-notes/known-issues.md) for any issues affecting all connectors.
 
 ### Troubleshooting [es-connectors-mongodb-client-troubleshooting]