[Inference API] Deprecate elser service

docs/changelog/113216.yaml

@@ -0,0 +1,10 @@
+pr: 113216
+summary: "[Inference API] Deprecate elser service"
+area: Machine Learning
+type: deprecation
+issues: []
+deprecation:
+  title: "[Inference API] Deprecate elser service"
+  area: REST API
+  details: The `elser` service of the inference API will be removed in an upcoming release. Please use the elasticsearch service instead. 
+  impact: In the current version there is no impact. In a future version, users of the `elser` service will no longer be able to use it, and will be required to use the `elasticsearch` service to access elser through the inference API.

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

@@ -46,7 +46,13 @@ public Map<String, InferenceService> getServices() {
     }
 
     public Optional<InferenceService> getService(String serviceName) {
-        return Optional.ofNullable(services.get(serviceName));
+
+        if ("elser".equals(serviceName)) { // ElserService.NAME before removal
+            // here we are aliasing the elser service to use the elasticsearch service instead
+            return Optional.ofNullable(services.get("elasticsearch")); // ElasticsearchInternalService.NAME
+        } else {
+            return Optional.ofNullable(services.get(serviceName));
+        }
     }
 
     public List<NamedWriteableRegistry.Entry> getNamedWriteables() {

x-pack/plugin/inference/src/internalClusterTest/java/org/elasticsearch/xpack/inference/integration/ModelRegistryIT.java

@@ -28,11 +28,10 @@
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xpack.inference.InferencePlugin;
 import org.elasticsearch.xpack.inference.registry.ModelRegistry;
-import org.elasticsearch.xpack.inference.services.elser.ElserInternalModel;
-import org.elasticsearch.xpack.inference.services.elser.ElserInternalService;
-import org.elasticsearch.xpack.inference.services.elser.ElserInternalServiceSettingsTests;
-import org.elasticsearch.xpack.inference.services.elser.ElserInternalServiceTests;
-import org.elasticsearch.xpack.inference.services.elser.ElserMlNodeTaskSettingsTests;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElasticsearchInternalModel;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElasticsearchInternalService;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElserInternalServiceSettingsTests;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElserMlNodeTaskSettingsTests;
 import org.junit.Before;
 
 import java.io.IOException;
@@ -118,10 +117,10 @@ public void testGetModel() throws Exception {
 
         assertEquals(model.getConfigurations().getService(), modelHolder.get().service());
 
-        var elserService = new ElserInternalService(
+        var elserService = new ElasticsearchInternalService(
             new InferenceServiceExtension.InferenceServiceFactoryContext(mock(Client.class), mock(ThreadPool.class))
         );
-        ElserInternalModel roundTripModel = elserService.parsePersistedConfigWithSecrets(
+        ElasticsearchInternalModel roundTripModel = (ElasticsearchInternalModel) elserService.parsePersistedConfigWithSecrets(
             modelHolder.get().inferenceEntityId(),
             modelHolder.get().taskType(),
             modelHolder.get().settings(),
@@ -277,7 +276,17 @@ public void testGetModelWithSecrets() throws InterruptedException {
     }
 
     private Model buildElserModelConfig(String inferenceEntityId, TaskType taskType) {
-        return ElserInternalServiceTests.randomModelConfig(inferenceEntityId, taskType);
+        return switch (taskType) {
+            case SPARSE_EMBEDDING -> new org.elasticsearch.xpack.inference.services.elasticsearch.ElserInternalModel(
+                inferenceEntityId,
+                taskType,
+                ElasticsearchInternalService.NAME,
+                ElserInternalServiceSettingsTests.createRandom(),
+                ElserMlNodeTaskSettingsTests.createRandom()
+            );
+            default -> throw new IllegalArgumentException("task type " + taskType + " is not supported");
+        };
+
     }
 
     protected <T> void blockingCall(Consumer<ActionListener<T>> function, AtomicReference<T> response, AtomicReference<Exception> error)
@@ -300,7 +309,7 @@ private static Model buildModelWithUnknownField(String inferenceEntityId) {
             new ModelWithUnknownField(
                 inferenceEntityId,
                 TaskType.SPARSE_EMBEDDING,
-                ElserInternalService.NAME,
+                ElasticsearchInternalService.NAME,
                 ElserInternalServiceSettingsTests.createRandom(),
                 ElserMlNodeTaskSettingsTests.createRandom()
             )

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/InferenceNamedWriteablesProvider.java

@@ -64,9 +64,9 @@
 import org.elasticsearch.xpack.inference.services.elasticsearch.CustomElandInternalTextEmbeddingServiceSettings;
 import org.elasticsearch.xpack.inference.services.elasticsearch.CustomElandRerankTaskSettings;
 import org.elasticsearch.xpack.inference.services.elasticsearch.ElasticsearchInternalServiceSettings;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElserInternalServiceSettings;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElserMlNodeTaskSettings;
 import org.elasticsearch.xpack.inference.services.elasticsearch.MultilingualE5SmallInternalServiceSettings;
-import org.elasticsearch.xpack.inference.services.elser.ElserInternalServiceSettings;
-import org.elasticsearch.xpack.inference.services.elser.ElserMlNodeTaskSettings;
 import org.elasticsearch.xpack.inference.services.googleaistudio.completion.GoogleAiStudioCompletionServiceSettings;
 import org.elasticsearch.xpack.inference.services.googleaistudio.embeddings.GoogleAiStudioEmbeddingsServiceSettings;
 import org.elasticsearch.xpack.inference.services.googlevertexai.GoogleVertexAiSecretSettings;

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/InferencePlugin.java

@@ -86,7 +86,6 @@
 import org.elasticsearch.xpack.inference.services.elastic.ElasticInferenceServiceFeature;
 import org.elasticsearch.xpack.inference.services.elastic.ElasticInferenceServiceSettings;
 import org.elasticsearch.xpack.inference.services.elasticsearch.ElasticsearchInternalService;
-import org.elasticsearch.xpack.inference.services.elser.ElserInternalService;
 import org.elasticsearch.xpack.inference.services.googleaistudio.GoogleAiStudioService;
 import org.elasticsearch.xpack.inference.services.googlevertexai.GoogleVertexAiService;
 import org.elasticsearch.xpack.inference.services.huggingface.HuggingFaceService;
@@ -229,7 +228,6 @@ public void loadExtensions(ExtensionLoader loader) {
 
     public List<InferenceServiceExtension.Factory> getInferenceServiceFactories() {
         return List.of(
-            ElserInternalService::new,
             context -> new HuggingFaceElserService(httpFactory.get(), serviceComponents.get()),
             context -> new HuggingFaceService(httpFactory.get(), serviceComponents.get()),
             context -> new OpenAiService(httpFactory.get(), serviceComponents.get()),

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/action/TransportInferenceAction.java

@@ -11,6 +11,7 @@
 import org.elasticsearch.action.ActionListener;
 import org.elasticsearch.action.support.ActionFilters;
 import org.elasticsearch.action.support.HandledTransportAction;
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.common.util.concurrent.EsExecutors;
 import org.elasticsearch.common.xcontent.ChunkedToXContent;
 import org.elasticsearch.inference.InferenceService;
@@ -42,6 +43,7 @@ public class TransportInferenceAction extends HandledTransportAction<InferenceAc
     private final InferenceServiceRegistry serviceRegistry;
     private final InferenceStats inferenceStats;
     private final StreamingTaskManager streamingTaskManager;
+    private static final DeprecationLogger DEPRECATION_LOGGER = DeprecationLogger.getLogger(TransportInferenceAction.class);
 
     @Inject
     public TransportInferenceAction(

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/action/TransportPutInferenceModelAction.java

@@ -41,11 +41,14 @@
 import org.elasticsearch.xpack.core.ml.utils.ExceptionsHelper;
 import org.elasticsearch.xpack.inference.InferencePlugin;
 import org.elasticsearch.xpack.inference.registry.ModelRegistry;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElasticsearchInternalService;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.Map;
 
 import static org.elasticsearch.core.Strings.format;
+import static org.elasticsearch.xpack.inference.services.elasticsearch.ElasticsearchInternalService.OLD_ELSER_SERVICE_NAME;
 
 public class TransportPutInferenceModelAction extends TransportMasterNodeAction<
     PutInferenceModelAction.Request,
@@ -110,6 +113,10 @@ protected void masterOperation(
             return;
         }
 
+        if (List.of(OLD_ELSER_SERVICE_NAME, ElasticsearchInternalService.NAME).contains(serviceName)) {
+            // required for BWC of elser service in elasticsearch service TODO remove when elser service deprecated
+            requestAsMap.put(ModelConfigurations.SERVICE, serviceName);
+        }
         var service = serviceRegistry.getService(serviceName);
         if (service.isEmpty()) {
             listener.onFailure(new ElasticsearchStatusException("Unknown service [{}]", RestStatus.BAD_REQUEST, serviceName));

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elastic/ElasticInferenceServiceSparseEmbeddingsModel.java

@@ -18,7 +18,7 @@
 import org.elasticsearch.xpack.inference.external.action.ExecutableAction;
 import org.elasticsearch.xpack.inference.external.action.elastic.ElasticInferenceServiceActionVisitor;
 import org.elasticsearch.xpack.inference.services.ConfigurationParseContext;
-import org.elasticsearch.xpack.inference.services.elser.ElserModels;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElserModels;
 
 import java.net.URI;
 import java.net.URISyntaxException;

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elastic/ElasticInferenceServiceSparseEmbeddingsServiceSettings.java

@@ -17,7 +17,7 @@
 import org.elasticsearch.inference.ServiceSettings;
 import org.elasticsearch.xcontent.XContentBuilder;
 import org.elasticsearch.xpack.inference.services.ConfigurationParseContext;
-import org.elasticsearch.xpack.inference.services.elser.ElserModels;
+import org.elasticsearch.xpack.inference.services.elasticsearch.ElserModels;
 import org.elasticsearch.xpack.inference.services.settings.FilteredXContentObject;
 import org.elasticsearch.xpack.inference.services.settings.RateLimitSettings;
 

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elasticsearch/BaseElasticsearchInternalService.java

@@ -32,7 +32,6 @@
 import org.elasticsearch.xpack.core.ml.inference.trainedmodel.InferenceConfigUpdate;
 import org.elasticsearch.xpack.core.ml.utils.MlPlatformArchitecturesUtil;
 import org.elasticsearch.xpack.inference.InferencePlugin;
-import org.elasticsearch.xpack.inference.services.elser.ElserInternalModel;
 
 import java.io.IOException;
 import java.util.EnumSet;

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elasticsearch/ElasticsearchInternalService.java

@@ -7,11 +7,14 @@
 
 package org.elasticsearch.xpack.inference.services.elasticsearch;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.elasticsearch.ElasticsearchStatusException;
 import org.elasticsearch.TransportVersion;
 import org.elasticsearch.TransportVersions;
 import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.common.ValidationException;
+import org.elasticsearch.common.logging.DeprecationCategory;
+import org.elasticsearch.common.logging.DeprecationLogger;
 import org.elasticsearch.core.Nullable;
 import org.elasticsearch.core.TimeValue;
 import org.elasticsearch.inference.ChunkedInferenceServiceResults;
@@ -55,10 +58,13 @@
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.removeFromMap;
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.removeFromMapOrThrowIfNull;
 import static org.elasticsearch.xpack.inference.services.ServiceUtils.throwIfNotEmptyMap;
+import static org.elasticsearch.xpack.inference.services.elasticsearch.ElserModels.ELSER_V2_MODEL;
+import static org.elasticsearch.xpack.inference.services.elasticsearch.ElserModels.ELSER_V2_MODEL_LINUX_X86;
 
 public class ElasticsearchInternalService extends BaseElasticsearchInternalService {
 
     public static final String NAME = "elasticsearch";
+    public static final String OLD_ELSER_SERVICE_NAME = "elser";
 
     static final String MULTILINGUAL_E5_SMALL_MODEL_ID = ".multilingual-e5-small";
     static final String MULTILINGUAL_E5_SMALL_MODEL_ID_LINUX_X86 = ".multilingual-e5-small_linux-x86_64";
@@ -67,6 +73,9 @@ public class ElasticsearchInternalService extends BaseElasticsearchInternalServi
         MULTILINGUAL_E5_SMALL_MODEL_ID_LINUX_X86
     );
 
+    private static final Logger logger = LogManager.getLogger(ElasticsearchInternalService.class);
+    private static final DeprecationLogger DEPRECATION_LOGGER = DeprecationLogger.getLogger(ElasticsearchInternalService.class);
+
     public ElasticsearchInternalService(InferenceServiceExtension.InferenceServiceFactoryContext context) {
         super(context);
     }
@@ -94,19 +103,41 @@ public void parseRequestConfig(
         try {
             Map<String, Object> serviceSettingsMap = removeFromMapOrThrowIfNull(config, ModelConfigurations.SERVICE_SETTINGS);
             Map<String, Object> taskSettingsMap = removeFromMap(config, ModelConfigurations.TASK_SETTINGS);
+            String serviceName = (String) config.remove(ModelConfigurations.SERVICE); // required for elser service in elasticsearch service
 
             throwIfNotEmptyMap(config, name());
 
             String modelId = (String) serviceSettingsMap.get(ElasticsearchInternalServiceSettings.MODEL_ID);
             if (modelId == null) {
-                throw new ValidationException().addValidationError("Error parsing request config, model id is missing");
-            }
-            if (MULTILINGUAL_E5_SMALL_VALID_IDS.contains(modelId)) {
+                if (OLD_ELSER_SERVICE_NAME.equals(serviceName)) {
+                    // TODO complete deprecation of null model ID
+                    // throw new ValidationException().addValidationError("Error parsing request config, model id is missing");
+                    DEPRECATION_LOGGER.critical(
+                        DeprecationCategory.API,
+                        "inference_api_null_model_id_in_elasticsearch_service",
+                        "Putting elasticsearch service inference endpoints (including elser service) without a model_id field is"
+                            + " deprecated and will be removed in a future release. Please specify a model_id field."
+                    );
+                    platformArch.accept(
+                        modelListener.delegateFailureAndWrap(
+                            (delegate, arch) -> elserCase(inferenceEntityId, taskType, config, arch, serviceSettingsMap, modelListener)
+                        )
+                    );
+                } else {
+                    throw new IllegalArgumentException("Error parsing service settings, model_id must be provided");
+                }
+            } else if (MULTILINGUAL_E5_SMALL_VALID_IDS.contains(modelId)) {
                 platformArch.accept(
                     modelListener.delegateFailureAndWrap(
                         (delegate, arch) -> e5Case(inferenceEntityId, taskType, config, arch, serviceSettingsMap, modelListener)
                     )
                 );
+            } else if (ElserModels.isValidModel(modelId)) {
+                platformArch.accept(
+                    modelListener.delegateFailureAndWrap(
+                        (delegate, arch) -> elserCase(inferenceEntityId, taskType, config, arch, serviceSettingsMap, modelListener)
+                    )
+                );
             } else {
                 customElandCase(inferenceEntityId, taskType, serviceSettingsMap, taskSettingsMap, modelListener);
             }
@@ -239,7 +270,86 @@ static boolean modelVariantValidForArchitecture(Set<String> platformArchitecture
             // platform agnostic model is always compatible
             return true;
         }
+        return modelId.equals(
+            selectDefaultModelVariantBasedOnClusterArchitecture(
+                platformArchitectures,
+                MULTILINGUAL_E5_SMALL_MODEL_ID_LINUX_X86,
+                MULTILINGUAL_E5_SMALL_MODEL_ID
+            )
+        );
+    }
 
+    private void elserCase(
+        String inferenceEntityId,
+        TaskType taskType,
+        Map<String, Object> config,
+        Set<String> platformArchitectures,
+        Map<String, Object> serviceSettingsMap,
+        ActionListener<Model> modelListener
+    ) {
+        var esServiceSettingsBuilder = ElasticsearchInternalServiceSettings.fromRequestMap(serviceSettingsMap);
+        final String defaultModelId = selectDefaultModelVariantBasedOnClusterArchitecture(
+            platformArchitectures,
+            ELSER_V2_MODEL_LINUX_X86,
+            ELSER_V2_MODEL
+        );
+        if (false == defaultModelId.equals(esServiceSettingsBuilder.getModelId())) {
+
+            if (esServiceSettingsBuilder.getModelId() == null) {
+                // TODO remove this case once we remove the option to not pass model ID
+                esServiceSettingsBuilder.setModelId(defaultModelId);
+            } else if (esServiceSettingsBuilder.getModelId().equals(ELSER_V2_MODEL)) {
+                logger.warn(
+                    "The platform agnostic model [{}] was requested on Linux x86_64. "
+                        + "It is recommended to use the optimized model instead [{}]",
+                    ELSER_V2_MODEL,
+                    ELSER_V2_MODEL_LINUX_X86
+                );
+            } else {
+                throw new IllegalArgumentException(
+                    "Error parsing request config, model id does not match any models available on this platform. Was ["
+                        + esServiceSettingsBuilder.getModelId()
+                        + "]. You may need to use a platform agnostic model."
+                );
+            }
+        }
+
+        DEPRECATION_LOGGER.warn(
+            DeprecationCategory.API,
+            "inference_api_elser_service",
+            "The [{}] service is deprecated and will be removed in a future release. Use the [{}] service instead, with"
+                + " [model_id] set to [{}] in the [service_settings]",
+            OLD_ELSER_SERVICE_NAME,
+            ElasticsearchInternalService.NAME,
+            defaultModelId
+        );
+
+        if (modelVariantDoesNotMatchArchitecturesAndIsNotPlatformAgnostic(platformArchitectures, esServiceSettingsBuilder.getModelId())) {
+            throw new IllegalArgumentException(
+                "Error parsing request config, model id does not match any models available on this platform. Was ["
+                    + esServiceSettingsBuilder.getModelId()
+                    + "]"
+            );
+        }
+
+        throwIfNotEmptyMap(config, name());
+        throwIfNotEmptyMap(serviceSettingsMap, name());
+
+        modelListener.onResponse(
+            new ElserInternalModel(
+                inferenceEntityId,
+                taskType,
+                NAME,
+                new ElserInternalServiceSettings(esServiceSettingsBuilder.build()),
+                ElserMlNodeTaskSettings.DEFAULT
+            )
+        );
+    }
+
+    private static boolean modelVariantDoesNotMatchArchitecturesAndIsNotPlatformAgnostic(
+        Set<String> platformArchitectures,
+        String modelId
+    ) {
         return modelId.equals(
             selectDefaultModelVariantBasedOnClusterArchitecture(
                 platformArchitectures,
@@ -276,6 +386,14 @@ public Model parsePersistedConfig(String inferenceEntityId, TaskType taskType, M
                 NAME,
                 new MultilingualE5SmallInternalServiceSettings(ElasticsearchInternalServiceSettings.fromPersistedMap(serviceSettingsMap))
             );
+        } else if (ElserModels.isValidModel(modelId)) {
+            return new ElserInternalModel(
+                inferenceEntityId,
+                taskType,
+                NAME,
+                new ElserInternalServiceSettings(ElasticsearchInternalServiceSettings.fromPersistedMap(serviceSettingsMap)),
+                ElserMlNodeTaskSettings.DEFAULT
+            );
         } else {
             return createCustomElandModel(
                 inferenceEntityId,

x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/elasticsearch/ElasticsearchInternalServiceSettings.java

@@ -83,7 +83,7 @@ protected static ElasticsearchInternalServiceSettings.Builder fromMap(
             validationException
         );
 
-        // model id is optional as the ELSER and E5 service will default it
+        // model id is optional as the ELSER service will default it. TODO make this a required field once the elser service is removed
         String modelId = extractOptionalString(map, MODEL_ID, ModelConfigurations.SERVICE_SETTINGS, validationException);
 
         if (numAllocations == null && adaptiveAllocationsSettings == null) {