[8.x] [ML] Default inference endpoint for ELSER

docs/changelog/113873.yaml

@@ -0,0 +1,5 @@
+pr: 113873
+summary: Default inference endpoint for ELSER
+area: Machine Learning
+type: enhancement
+issues: []

docs/reference/rest-api/usage.asciidoc

@@ -206,7 +206,12 @@ GET /_xpack/usage
   "inference": {
     "available" : true,
     "enabled" : true,
-    "models" : []
+    "models" : [{
+        "service": "elasticsearch",
+        "task_type": "SPARSE_EMBEDDING",
+        "count": 1
+      }
+    ]
   },
   "logstash" : {
     "available" : true,

server/src/main/java/org/elasticsearch/inference/InferenceService.java

@@ -191,4 +191,13 @@ default Set<TaskType> supportedStreamingTasks() {
     default boolean canStream(TaskType taskType) {
         return supportedStreamingTasks().contains(taskType);
     }
+
+    /**
+     * A service can define default configurations that can be
+     * used out of the box without creating an endpoint first.
+     * @return Default configurations provided by this service
+     */
+    default List<UnparsedModel> defaultConfigs() {
+        return List.of();
+    }
 }

server/src/main/java/org/elasticsearch/inference/UnparsedModel.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the "Elastic License
+ * 2.0", the "GNU Affero General Public License v3.0 only", and the "Server Side
+ * Public License v 1"; you may not use this file except in compliance with, at
+ * your election, the "Elastic License 2.0", the "GNU Affero General Public
+ * License v3.0 only", or the "Server Side Public License, v 1".
+ */
+
+package org.elasticsearch.inference;
+
+import java.util.Map;
+
+/**
+ * Semi parsed model where inference entity id, task type and service
+ * are known but the settings are not parsed.
+ */
+public record UnparsedModel(
+    String inferenceEntityId,
+    TaskType taskType,
+    String service,
+    Map<String, Object> settings,
+    Map<String, Object> secrets
+) {}

test/test-clusters/src/main/java/org/elasticsearch/test/cluster/FeatureFlag.java

@@ -19,7 +19,8 @@ public enum FeatureFlag {
     TIME_SERIES_MODE("es.index_mode_feature_flag_registered=true", Version.fromString("8.0.0"), null),
     FAILURE_STORE_ENABLED("es.failure_store_feature_flag_enabled=true", Version.fromString("8.12.0"), null),
     CHUNKING_SETTINGS_ENABLED("es.inference_chunking_settings_feature_flag_enabled=true", Version.fromString("8.16.0"), null),
-    INFERENCE_SCALE_TO_ZERO("es.inference_scale_to_zero_feature_flag_enabled=true", Version.fromString("8.16.0"), null);
+    INFERENCE_SCALE_TO_ZERO("es.inference_scale_to_zero_feature_flag_enabled=true", Version.fromString("8.16.0"), null),
+    INFERENCE_DEFAULT_ELSER("es.inference_default_elser_feature_flag_enabled=true", Version.fromString("8.16.0"), null);
 
     public final String systemProperty;
     public final Version from;

x-pack/plugin/build.gradle

@@ -201,5 +201,6 @@ tasks.named("precommit").configure {
 
 tasks.named("yamlRestTestV7CompatTransform").configure({ task ->
   task.skipTest("security/10_forbidden/Test bulk response with invalid credentials", "warning does not exist for compatibility")
+  task.skipTest("inference/inference_crud/Test get all", "Assertions on number of inference models break due to default configs")
 })
 

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/action/StartTrainedModelDeploymentAction.java

@@ -237,7 +237,9 @@ public int computeNumberOfAllocations() {
             if (numberOfAllocations != null) {
                 return numberOfAllocations;
             } else {
-                if (adaptiveAllocationsSettings == null || adaptiveAllocationsSettings.getMinNumberOfAllocations() == null) {
+                if (adaptiveAllocationsSettings == null
+                    || adaptiveAllocationsSettings.getMinNumberOfAllocations() == null
+                    || adaptiveAllocationsSettings.getMinNumberOfAllocations() == 0) {
                     return DEFAULT_NUM_ALLOCATIONS;
                 } else {
                     return adaptiveAllocationsSettings.getMinNumberOfAllocations();

x-pack/plugin/core/src/main/java/org/elasticsearch/xpack/core/ml/inference/assignment/AdaptiveAllocationsSettings.java

@@ -147,8 +147,8 @@ public AdaptiveAllocationsSettings merge(AdaptiveAllocationsSettings updates) {
     public ActionRequestValidationException validate() {
         ActionRequestValidationException validationException = new ActionRequestValidationException();
         boolean hasMinNumberOfAllocations = (minNumberOfAllocations != null && minNumberOfAllocations != -1);
-        if (hasMinNumberOfAllocations && minNumberOfAllocations < 1) {
-            validationException.addValidationError("[" + MIN_NUMBER_OF_ALLOCATIONS + "] must be a positive integer or null");
+        if (hasMinNumberOfAllocations && minNumberOfAllocations < 0) {
+            validationException.addValidationError("[" + MIN_NUMBER_OF_ALLOCATIONS + "] must be a non-negative integer or null");
         }
         boolean hasMaxNumberOfAllocations = (maxNumberOfAllocations != null && maxNumberOfAllocations != -1);
         if (hasMaxNumberOfAllocations && maxNumberOfAllocations < 1) {

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/inference/assignment/AdaptiveAllocationSettingsTests.java

@@ -17,7 +17,7 @@ public class AdaptiveAllocationSettingsTests extends AbstractWireSerializingTest
     public static AdaptiveAllocationsSettings testInstance() {
         return new AdaptiveAllocationsSettings(
             randomBoolean() ? null : randomBoolean(),
-            randomBoolean() ? null : randomIntBetween(1, 2),
+            randomBoolean() ? null : randomIntBetween(0, 2),
             randomBoolean() ? null : randomIntBetween(2, 4)
         );
     }

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/CustomElandModelIT.java

@@ -85,7 +85,7 @@ public void testSparse() throws IOException {
 
         var inferenceId = "sparse-inf";
         putModel(inferenceId, inferenceConfig, TaskType.SPARSE_EMBEDDING);
-        var results = inferOnMockService(inferenceId, List.of("washing", "machine"));
+        var results = infer(inferenceId, List.of("washing", "machine"));
         deleteModel(inferenceId);
         assertNotNull(results.get("sparse_embedding"));
     }

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/DefaultElserIT.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+package org.elasticsearch.xpack.inference;
+
+import org.elasticsearch.inference.TaskType;
+import org.elasticsearch.threadpool.TestThreadPool;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElasticsearchInternalService;
+import org.hamcrest.Matchers;
+import org.junit.After;
+import org.junit.Before;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.oneOf;
+
+public class DefaultElserIT extends InferenceBaseRestTest {
+
+    private TestThreadPool threadPool;
+
+    @Before
+    public void createThreadPool() {
+        threadPool = new TestThreadPool(DefaultElserIT.class.getSimpleName());
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        threadPool.close();
+        super.tearDown();
+    }
+
+    @SuppressWarnings("unchecked")
+    public void testInferCreatesDefaultElser() throws IOException {
+        assumeTrue("Default config requires a feature flag", DefaultElserFeatureFlag.isEnabled());
+        var model = getModel(ElasticsearchInternalService.DEFAULT_ELSER_ID);
+        assertDefaultElserConfig(model);
+
+        var inputs = List.of("Hello World", "Goodnight moon");
+        var queryParams = Map.of("timeout", "120s");
+        var results = infer(ElasticsearchInternalService.DEFAULT_ELSER_ID, TaskType.SPARSE_EMBEDDING, inputs, queryParams);
+        var embeddings = (List<Map<String, Object>>) results.get("sparse_embedding");
+        assertThat(results.toString(), embeddings, hasSize(2));
+    }
+
+    @SuppressWarnings("unchecked")
+    private static void assertDefaultElserConfig(Map<String, Object> modelConfig) {
+        assertEquals(modelConfig.toString(), ElasticsearchInternalService.DEFAULT_ELSER_ID, modelConfig.get("inference_id"));
+        assertEquals(modelConfig.toString(), ElasticsearchInternalService.NAME, modelConfig.get("service"));
+        assertEquals(modelConfig.toString(), TaskType.SPARSE_EMBEDDING.toString(), modelConfig.get("task_type"));
+
+        var serviceSettings = (Map<String, Object>) modelConfig.get("service_settings");
+        assertThat(modelConfig.toString(), serviceSettings.get("model_id"), is(oneOf(".elser_model_2", ".elser_model_2_linux-x86_64")));
+        assertEquals(modelConfig.toString(), 1, serviceSettings.get("num_threads"));
+
+        var adaptiveAllocations = (Map<String, Object>) serviceSettings.get("adaptive_allocations");
+        assertThat(
+            modelConfig.toString(),
+            adaptiveAllocations,
+            Matchers.is(Map.of("enabled", true, "min_number_of_allocations", 1, "max_number_of_allocations", 8))
+        );
+    }
+}

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/InferenceBaseRestTest.java

@@ -270,7 +270,7 @@ protected Map<String, Object> deployE5TrainedModels() throws IOException {
 
     @SuppressWarnings("unchecked")
     protected Map<String, Object> getModel(String modelId) throws IOException {
-        var endpoint = Strings.format("_inference/%s", modelId);
+        var endpoint = Strings.format("_inference/%s?error_trace", modelId);
         return ((List<Map<String, Object>>) getInternal(endpoint).get("endpoints")).get(0);
     }
 
@@ -293,9 +293,9 @@ private Map<String, Object> getInternal(String endpoint) throws IOException {
         return entityAsMap(response);
     }
 
-    protected Map<String, Object> inferOnMockService(String modelId, List<String> input) throws IOException {
+    protected Map<String, Object> infer(String modelId, List<String> input) throws IOException {
         var endpoint = Strings.format("_inference/%s", modelId);
-        return inferOnMockServiceInternal(endpoint, input);
+        return inferInternal(endpoint, input, Map.of());
     }
 
     protected Deque<ServerSentEvent> streamInferOnMockService(String modelId, TaskType taskType, List<String> input) throws Exception {
@@ -324,14 +324,23 @@ public void onFailure(Exception exception) {
         return responseConsumer.events();
     }
 
-    protected Map<String, Object> inferOnMockService(String modelId, TaskType taskType, List<String> input) throws IOException {
+    protected Map<String, Object> infer(String modelId, TaskType taskType, List<String> input) throws IOException {
         var endpoint = Strings.format("_inference/%s/%s", taskType, modelId);
-        return inferOnMockServiceInternal(endpoint, input);
+        return inferInternal(endpoint, input, Map.of());
+    }
+
+    protected Map<String, Object> infer(String modelId, TaskType taskType, List<String> input, Map<String, String> queryParameters)
+        throws IOException {
+        var endpoint = Strings.format("_inference/%s/%s?error_trace", taskType, modelId);
+        return inferInternal(endpoint, input, queryParameters);
     }
 
-    private Map<String, Object> inferOnMockServiceInternal(String endpoint, List<String> input) throws IOException {
+    private Map<String, Object> inferInternal(String endpoint, List<String> input, Map<String, String> queryParameters) throws IOException {
         var request = new Request("POST", endpoint);
         request.setJsonEntity(jsonBody(input));
+        if (queryParameters.isEmpty() == false) {
+            request.addParameters(queryParameters);
+        }
         var response = client().performRequest(request);
         assertOkOrCreated(response);
         return entityAsMap(response);

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/InferenceCrudIT.java

@@ -38,10 +38,12 @@ public void testGet() throws IOException {
         }
 
         var getAllModels = getAllModels();
-        assertThat(getAllModels, hasSize(9));
+        int numModels = DefaultElserFeatureFlag.isEnabled() ? 10 : 9;
+        assertThat(getAllModels, hasSize(numModels));
 
         var getSparseModels = getModels("_all", TaskType.SPARSE_EMBEDDING);
-        assertThat(getSparseModels, hasSize(5));
+        int numSparseModels = DefaultElserFeatureFlag.isEnabled() ? 6 : 5;
+        assertThat(getSparseModels, hasSize(numSparseModels));
         for (var sparseModel : getSparseModels) {
             assertEquals("sparse_embedding", sparseModel.get("task_type"));
         }
@@ -99,7 +101,7 @@ public void testApisWithoutTaskType() throws IOException {
         assertEquals(modelId, singleModel.get("inference_id"));
         assertEquals(TaskType.SPARSE_EMBEDDING.toString(), singleModel.get("task_type"));
 
-        var inference = inferOnMockService(modelId, List.of(randomAlphaOfLength(10)));
+        var inference = infer(modelId, List.of(randomAlphaOfLength(10)));
         assertNonEmptyInferenceResults(inference, 1, TaskType.SPARSE_EMBEDDING);
         deleteModel(modelId);
     }

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/MockDenseInferenceServiceIT.java

@@ -28,23 +28,20 @@ public void testMockService() throws IOException {
         }
 
         List<String> input = List.of(randomAlphaOfLength(10));
-        var inference = inferOnMockService(inferenceEntityId, input);
+        var inference = infer(inferenceEntityId, input);
         assertNonEmptyInferenceResults(inference, 1, TaskType.TEXT_EMBEDDING);
         // Same input should return the same result
-        assertEquals(inference, inferOnMockService(inferenceEntityId, input));
+        assertEquals(inference, infer(inferenceEntityId, input));
         // Different input values should not
-        assertNotEquals(
-            inference,
-            inferOnMockService(inferenceEntityId, randomValueOtherThan(input, () -> List.of(randomAlphaOfLength(10))))
-        );
+        assertNotEquals(inference, infer(inferenceEntityId, randomValueOtherThan(input, () -> List.of(randomAlphaOfLength(10)))));
     }
 
     public void testMockServiceWithMultipleInputs() throws IOException {
         String inferenceEntityId = "test-mock-with-multi-inputs";
         putModel(inferenceEntityId, mockDenseServiceModelConfig(), TaskType.TEXT_EMBEDDING);
 
         // The response is randomly generated, the input can be anything
-        var inference = inferOnMockService(
+        var inference = infer(
             inferenceEntityId,
             TaskType.TEXT_EMBEDDING,
             List.of(randomAlphaOfLength(5), randomAlphaOfLength(10), randomAlphaOfLength(15))

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/MockSparseInferenceServiceIT.java

@@ -30,23 +30,20 @@ public void testMockService() throws IOException {
         }
 
         List<String> input = List.of(randomAlphaOfLength(10));
-        var inference = inferOnMockService(inferenceEntityId, input);
+        var inference = infer(inferenceEntityId, input);
         assertNonEmptyInferenceResults(inference, 1, TaskType.SPARSE_EMBEDDING);
         // Same input should return the same result
-        assertEquals(inference, inferOnMockService(inferenceEntityId, input));
+        assertEquals(inference, infer(inferenceEntityId, input));
         // Different input values should not
-        assertNotEquals(
-            inference,
-            inferOnMockService(inferenceEntityId, randomValueOtherThan(input, () -> List.of(randomAlphaOfLength(10))))
-        );
+        assertNotEquals(inference, infer(inferenceEntityId, randomValueOtherThan(input, () -> List.of(randomAlphaOfLength(10)))));
     }
 
     public void testMockServiceWithMultipleInputs() throws IOException {
         String inferenceEntityId = "test-mock-with-multi-inputs";
         putModel(inferenceEntityId, mockSparseServiceModelConfig(), TaskType.SPARSE_EMBEDDING);
 
         // The response is randomly generated, the input can be anything
-        var inference = inferOnMockService(
+        var inference = infer(
             inferenceEntityId,
             TaskType.SPARSE_EMBEDDING,
             List.of(randomAlphaOfLength(5), randomAlphaOfLength(10), randomAlphaOfLength(15))
@@ -84,7 +81,7 @@ public void testMockService_DoesNotReturnHiddenField_InModelResponses() throws I
         }
 
         // The response is randomly generated, the input can be anything
-        var inference = inferOnMockService(inferenceEntityId, List.of(randomAlphaOfLength(10)));
+        var inference = infer(inferenceEntityId, List.of(randomAlphaOfLength(10)));
         assertNonEmptyInferenceResults(inference, 1, TaskType.SPARSE_EMBEDDING);
     }
 
@@ -102,7 +99,7 @@ public void testMockService_DoesReturnHiddenField_InModelResponses() throws IOEx
         }
 
         // The response is randomly generated, the input can be anything
-        var inference = inferOnMockService(inferenceEntityId, List.of(randomAlphaOfLength(10)));
+        var inference = infer(inferenceEntityId, List.of(randomAlphaOfLength(10)));
         assertNonEmptyInferenceResults(inference, 1, TaskType.SPARSE_EMBEDDING);
     }
 }

x-pack/plugin/inference/qa/inference-service-tests/src/javaRestTest/java/org/elasticsearch/xpack/inference/TextEmbeddingCrudIT.java

@@ -38,7 +38,7 @@ public void testPutE5Small_withPlatformAgnosticVariant() throws IOException {
         var models = getTrainedModel("_all");
         assertThat(models.toString(), containsString("deployment_id=" + inferenceEntityId));
 
-        Map<String, Object> results = inferOnMockService(
+        Map<String, Object> results = infer(
             inferenceEntityId,
             TaskType.TEXT_EMBEDDING,
             List.of("hello world", "this is the second document")
@@ -57,7 +57,7 @@ public void testPutE5Small_withPlatformSpecificVariant() throws IOException {
             var models = getTrainedModel("_all");
             assertThat(models.toString(), containsString("deployment_id=" + inferenceEntityId));
 
-            Map<String, Object> results = inferOnMockService(
+            Map<String, Object> results = infer(
                 inferenceEntityId,
                 TaskType.TEXT_EMBEDDING,
                 List.of("hello world", "this is the second document")