Implement the point in time API.

src/main/asciidoc/reference/elasticsearch-misc.adoc

@@ -121,7 +121,7 @@ Query searchQuery = NativeQuery.builder()
     .withPageable(PageRequest.of(0, 10))
     .build();
 
-SearchHitsIterator<SampleEntity> stream = elasticsearchOperations.searchForStream(searchQuery, SampleEntity.class, 
+SearchHitsIterator<SampleEntity> stream = elasticsearchOperations.searchForStream(searchQuery, SampleEntity.class,
 index);
 
 List<SampleEntity> sampleEntities = new ArrayList<>();
@@ -134,7 +134,7 @@ stream.close();
 ====
 
 There are no methods in the `SearchOperations` API to access the scroll id, if it should be necessary to access this,
-the following methods of the `AbstractElasticsearchTemplate` can be used (this is the base implementation for the 
+the following methods of the `AbstractElasticsearchTemplate` can be used (this is the base implementation for the
 different `ElasticsearchOperations` implementations:
 
 ====
@@ -275,3 +275,42 @@ SearchHits<SomethingToBuy> searchHits = operations.search(query, SomethingToBuy.
 ====
 
 This works with every implementation of the `Query` interface.
+
+[[elasticsearch.misc.point-in-time]]
+== Point In Time (PIT) API
+
+`ElasticsearchOperations` supports the point in time API of Elasticsearch (see https://www.elastic
+.co/guide/en/elasticsearch/reference/8.3/point-in-time-api.html). The following code snippet shows how to use this
+feature with a fictional `Person` class:
+
+====
+[source,java]
+----
+ElasticsearchOperations operations; // autowired
+Duration tenSeconds = Duration.ofSeconds(10);
+
+String pit = operations.openPointInTime(IndexCoordinates.of("person"), tenSeconds); <.>
+
+// create query for the pit
+Query query1 = new CriteriaQueryBuilder(Criteria.where("lastName").is("Smith"))
+    .withPointInTime(new Query.PointInTime(pit, tenSeconds))                        <.>
+    .build();
+SearchHits<Person> searchHits1 = operations.search(query1, Person.class);
+// do something with the data
+
+// create 2nd query for the pit, use the id returned in the previous result
+Query query2 = new CriteriaQueryBuilder(Criteria.where("lastName").is("Miller"))
+    .withPointInTime(
+        new Query.PointInTime(searchHits1.getPointInTimeId(), tenSeconds))          <.>
+    .build();
+SearchHits<Person> searchHits2 = operations.search(query2, Person.class);
+// do something with the data
+
+operations.closePointInTime(searchHits2.getPointInTimeId());                        <.>
+
+----
+<.> create a point in time for an index (can be multiple names) and a keep-alive duration and retrieve its id
+<.> pass that id into the query to search together with the next keep-alive value
+<.> for the next query, use the id returned from the previous search
+<.> when done, close the point in time using the last returned id
+====

src/main/java/org/springframework/data/elasticsearch/client/ClientConfiguration.java

@@ -26,9 +26,6 @@
 import javax.net.ssl.HostnameVerifier;
 import javax.net.ssl.SSLContext;
 
-import org.elasticsearch.client.RestClientBuilder.HttpClientConfigCallback;
-import org.springframework.data.elasticsearch.client.erhlc.ReactiveRestClients;
-import org.springframework.data.elasticsearch.client.erhlc.RestClients;
 import org.springframework.http.HttpHeaders;
 import org.springframework.lang.Nullable;
 import org.springframework.web.reactive.function.client.WebClient;

src/main/java/org/springframework/data/elasticsearch/client/ClientConfigurationBuilder.java

@@ -31,8 +31,6 @@
 import org.springframework.data.elasticsearch.client.ClientConfiguration.ClientConfigurationBuilderWithRequiredEndpoint;
 import org.springframework.data.elasticsearch.client.ClientConfiguration.MaybeSecureClientConfigurationBuilder;
 import org.springframework.data.elasticsearch.client.ClientConfiguration.TerminalClientConfigurationBuilder;
-import org.springframework.data.elasticsearch.client.erhlc.ReactiveRestClients;
-import org.springframework.data.elasticsearch.client.erhlc.RestClients;
 import org.springframework.http.HttpHeaders;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;

src/main/java/org/springframework/data/elasticsearch/client/UnsupportedClientOperationException.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.elasticsearch.client;
+
+/**
+ * @author Peter-Josef Meisch
+ */
+public class UnsupportedClientOperationException extends RuntimeException {
+	public UnsupportedClientOperationException(Class<?> clientClass, String operation) {
+		super("Client %1$s does not support the operation %2$s".formatted(clientClass, operation));
+	}
+}

src/main/java/org/springframework/data/elasticsearch/client/elc/DocumentAdapters.java

@@ -73,7 +73,7 @@ public static SearchDocument from(Hit<?> hit, JsonpMapper jsonpMapper) {
 		Map<String, SearchDocumentResponse> innerHits = new LinkedHashMap<>();
 		hit.innerHits().forEach((name, innerHitsResult) -> {
 			// noinspection ReturnOfNull
-			innerHits.put(name, SearchDocumentResponseBuilder.from(innerHitsResult.hits(), null, null, null,
+			innerHits.put(name, SearchDocumentResponseBuilder.from(innerHitsResult.hits(), null, null, null, null,
 					searchDocument -> null, jsonpMapper));
 		});
 

src/main/java/org/springframework/data/elasticsearch/client/elc/ElasticsearchTemplate.java

@@ -27,6 +27,7 @@
 import co.elastic.clients.transport.Version;
 
 import java.io.IOException;
+import java.time.Duration;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Iterator;
@@ -475,8 +476,30 @@ private List<SearchHits<?>> doMultiSearch(List<MultiSearchQueryParameter> multiS
 	/**
 	 * value class combining the information needed for a single query in a multisearch request.
 	 */
-		record MultiSearchQueryParameter(Query query, Class<?> clazz, IndexCoordinates index) {
+	record MultiSearchQueryParameter(Query query, Class<?> clazz, IndexCoordinates index) {
 	}
+
+	@Override
+	public String openPointInTime(IndexCoordinates index, Duration keepAlive, Boolean ignoreUnavailable) {
+
+		Assert.notNull(index, "index must not be null");
+		Assert.notNull(keepAlive, "keepAlive must not be null");
+		Assert.notNull(ignoreUnavailable, "ignoreUnavailable must not be null");
+
+		var request = requestConverter.searchOpenPointInTimeRequest(index, keepAlive, ignoreUnavailable);
+		return execute(client -> client.openPointInTime(request)).id();
+	}
+
+	@Override
+	public Boolean closePointInTime(String pit) {
+
+		Assert.notNull(pit, "pit must not be null");
+
+		ClosePointInTimeRequest request = requestConverter.searchClosePointInTime(pit);
+		var response = execute(client -> client.closePointInTime(request));
+		return response.succeeded();
+	}
+
 	// endregion
 
 	// region client callback

src/main/java/org/springframework/data/elasticsearch/client/elc/RequestConverter.java

@@ -32,16 +32,7 @@
 import co.elastic.clients.elasticsearch._types.mapping.TypeMapping;
 import co.elastic.clients.elasticsearch._types.query_dsl.Like;
 import co.elastic.clients.elasticsearch.cluster.HealthRequest;
-import co.elastic.clients.elasticsearch.core.BulkRequest;
-import co.elastic.clients.elasticsearch.core.DeleteByQueryRequest;
-import co.elastic.clients.elasticsearch.core.DeleteRequest;
-import co.elastic.clients.elasticsearch.core.GetRequest;
-import co.elastic.clients.elasticsearch.core.IndexRequest;
-import co.elastic.clients.elasticsearch.core.MgetRequest;
-import co.elastic.clients.elasticsearch.core.MsearchRequest;
-import co.elastic.clients.elasticsearch.core.SearchRequest;
-import co.elastic.clients.elasticsearch.core.UpdateByQueryRequest;
-import co.elastic.clients.elasticsearch.core.UpdateRequest;
+import co.elastic.clients.elasticsearch.core.*;
 import co.elastic.clients.elasticsearch.core.bulk.BulkOperation;
 import co.elastic.clients.elasticsearch.core.bulk.CreateOperation;
 import co.elastic.clients.elasticsearch.core.bulk.IndexOperation;
@@ -52,6 +43,7 @@
 import co.elastic.clients.elasticsearch.core.search.Rescore;
 import co.elastic.clients.elasticsearch.core.search.SourceConfig;
 import co.elastic.clients.elasticsearch.indices.*;
+import co.elastic.clients.elasticsearch.indices.ExistsRequest;
 import co.elastic.clients.elasticsearch.indices.update_aliases.Action;
 import co.elastic.clients.json.JsonData;
 import co.elastic.clients.json.JsonpDeserializer;
@@ -1164,10 +1156,24 @@ private <T> void prepareSearchRequest(Query query, @Nullable Class<T> clazz, Ind
 		ElasticsearchPersistentEntity<?> persistentEntity = getPersistentEntity(clazz);
 
 		builder //
-				.index(Arrays.asList(indexNames)) //
 				.version(true) //
 				.trackScores(query.getTrackScores());
 
+		var pointInTime = query.getPointInTime();
+		if (pointInTime != null) {
+			builder.pit(pb -> pb.id(pointInTime.id()).keepAlive(time(pointInTime.keepAlive())));
+		} else {
+			builder.index(Arrays.asList(indexNames));
+
+			if (query.getRoute() != null) {
+				builder.routing(query.getRoute());
+			}
+
+			if (query.getPreference() != null) {
+				builder.preference(query.getPreference());
+			}
+		}
+
 		if (persistentEntity != null && persistentEntity.hasSeqNoPrimaryTermProperty()) {
 			builder.seqNoPrimaryTerm(true);
 		}
@@ -1205,10 +1211,6 @@ private <T> void prepareSearchRequest(Query query, @Nullable Class<T> clazz, Ind
 			builder.minScore((double) query.getMinScore());
 		}
 
-		if (query.getPreference() != null) {
-			builder.preference(query.getPreference());
-		}
-
 		builder.searchType(searchType(query.getSearchType()));
 
 		if (query.getSort() != null) {
@@ -1233,10 +1235,6 @@ private <T> void prepareSearchRequest(Query query, @Nullable Class<T> clazz, Ind
 			builder.trackTotalHits(th -> th.count(query.getTrackTotalHitsUpTo()));
 		}
 
-		if (query.getRoute() != null) {
-			builder.routing(query.getRoute());
-		}
-
 		builder.timeout(timeStringMs(query.getTimeout()));
 
 		if (query.getExplain()) {
@@ -1507,6 +1505,27 @@ public co.elastic.clients.elasticsearch._types.query_dsl.MoreLikeThisQuery moreL
 		return moreLikeThisQuery;
 	}
 
+	public OpenPointInTimeRequest searchOpenPointInTimeRequest(IndexCoordinates index, Duration keepAlive,
+			Boolean ignoreUnavailable) {
+
+		Assert.notNull(index, "index must not be null");
+		Assert.notNull(keepAlive, "keepAlive must not be null");
+		Assert.notNull(ignoreUnavailable, "ignoreUnavailable must not be null");
+
+		return OpenPointInTimeRequest.of(opit -> opit //
+				.index(Arrays.asList(index.getIndexNames())) //
+				.ignoreUnavailable(ignoreUnavailable) //
+				.keepAlive(time(keepAlive)) //
+		);
+	}
+
+	public ClosePointInTimeRequest searchClosePointInTime(String pit) {
+
+		Assert.notNull(pit, "pit must not be null");
+
+		return ClosePointInTimeRequest.of(cpit -> cpit.id(pit));
+	}
+
 	// endregion
 
 	// region helper functions

src/main/java/org/springframework/data/elasticsearch/client/elc/SearchDocumentResponseBuilder.java

@@ -75,8 +75,9 @@ public static <T> SearchDocumentResponse from(ResponseBody<EntityAsMap> response
 		String scrollId = responseBody.scrollId();
 		Map<String, Aggregate> aggregations = responseBody.aggregations();
 		Map<String, List<Suggestion<EntityAsMap>>> suggest = responseBody.suggest();
+		var pointInTimeId = responseBody.pitId();
 
-		return from(hitsMetadata, scrollId, aggregations, suggest, entityCreator, jsonpMapper);
+		return from(hitsMetadata, scrollId, pointInTimeId, aggregations, suggest, entityCreator, jsonpMapper);
 	}
 
 	/**
@@ -93,8 +94,9 @@ public static <T> SearchDocumentResponse from(ResponseBody<EntityAsMap> response
 	 * @return the {@link SearchDocumentResponse}
 	 */
 	public static <T> SearchDocumentResponse from(HitsMetadata<?> hitsMetadata, @Nullable String scrollId,
-			@Nullable Map<String, Aggregate> aggregations, Map<String, List<Suggestion<EntityAsMap>>> suggestES,
-			SearchDocumentResponse.EntityCreator<T> entityCreator, JsonpMapper jsonpMapper) {
+			@Nullable String pointInTimeId, @Nullable Map<String, Aggregate> aggregations,
+			Map<String, List<Suggestion<EntityAsMap>>> suggestES, SearchDocumentResponse.EntityCreator<T> entityCreator,
+			JsonpMapper jsonpMapper) {
 
 		Assert.notNull(hitsMetadata, "hitsMetadata must not be null");
 
@@ -126,7 +128,7 @@ public static <T> SearchDocumentResponse from(HitsMetadata<?> hitsMetadata, @Nul
 
 		Suggest suggest = suggestFrom(suggestES, entityCreator);
 
-		return new SearchDocumentResponse(totalHits, totalHitsRelation, maxScore, scrollId, searchDocuments,
+		return new SearchDocumentResponse(totalHits, totalHitsRelation, maxScore, scrollId, pointInTimeId, searchDocuments,
 				aggregationsContainer, suggest);
 	}
 

src/main/java/org/springframework/data/elasticsearch/client/erhlc/SearchDocumentResponseBuilder.java

@@ -113,7 +113,8 @@ public static <T> SearchDocumentResponse from(SearchHits searchHits, @Nullable S
 				: null;
 		Suggest suggest = suggestFrom(suggestES, entityCreator);
 
-		return new SearchDocumentResponse(totalHits, totalHitsRelation, maxScore, scrollId, searchDocuments,
+		// no pointInTimeId for the deprecated implementation
+		return new SearchDocumentResponse(totalHits, totalHitsRelation, maxScore, scrollId, null, searchDocuments,
 				aggregationsContainer, suggest);
 	}
 

src/main/java/org/springframework/data/elasticsearch/core/AbstractElasticsearchTemplate.java

@@ -28,6 +28,7 @@
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.data.convert.EntityReader;
+import org.springframework.data.elasticsearch.client.UnsupportedClientOperationException;
 import org.springframework.data.elasticsearch.core.convert.ElasticsearchConverter;
 import org.springframework.data.elasticsearch.core.convert.MappingElasticsearchConverter;
 import org.springframework.data.elasticsearch.core.document.Document;
@@ -423,6 +424,16 @@ public void searchScrollClear(String scrollId) {
 
 	abstract public void searchScrollClear(List<String> scrollIds);
 
+	@Override
+	public String openPointInTime(IndexCoordinates index, Duration keepAlive, Boolean ignoreUnavailable) {
+		throw new UnsupportedClientOperationException(getClass(), "openPointInTime");
+	}
+
+	@Override
+	public Boolean closePointInTime(String pit) {
+		throw new UnsupportedClientOperationException(getClass(), "closePointInTime");
+	}
+
 	// endregion
 
 	// region Helper methods

src/main/java/org/springframework/data/elasticsearch/core/SearchHitMapping.java

@@ -85,6 +85,7 @@ private SearchHitsImpl<T> mapHitsFromResponse(SearchDocumentResponse searchDocum
 		long totalHits = searchDocumentResponse.getTotalHits();
 		float maxScore = searchDocumentResponse.getMaxScore();
 		String scrollId = searchDocumentResponse.getScrollId();
+		String pointInTimeId = searchDocumentResponse.getPointInTimeId();
 
 		List<SearchHit<T>> searchHits = new ArrayList<>();
 		List<SearchDocument> searchDocuments = searchDocumentResponse.getSearchDocuments();
@@ -100,7 +101,8 @@ private SearchHitsImpl<T> mapHitsFromResponse(SearchDocumentResponse searchDocum
 		Suggest suggest = searchDocumentResponse.getSuggest();
 		mapHitsInCompletionSuggestion(suggest);
 
-		return new SearchHitsImpl<>(totalHits, totalHitsRelation, maxScore, scrollId, searchHits, aggregations, suggest);
+		return new SearchHitsImpl<>(totalHits, totalHitsRelation, maxScore, scrollId, pointInTimeId, searchHits,
+				aggregations, suggest);
 	}
 
 	@SuppressWarnings("unchecked")
@@ -232,6 +234,7 @@ private SearchHits<?> mapInnerDocuments(SearchHits<SearchDocument> searchHits, C
 						searchHits.getTotalHitsRelation(), //
 						searchHits.getMaxScore(), //
 						scrollId, //
+						searchHits.getPointInTimeId(), //
 						convertedSearchHits, //
 						searchHits.getAggregations(), //
 						searchHits.getSuggest());

src/main/java/org/springframework/data/elasticsearch/core/SearchHits.java

@@ -100,4 +100,12 @@ default Iterator<SearchHit<T>> iterator() {
 		return getSearchHits().iterator();
 	}
 
+	/**
+	 * When doing a search with a point in time, the response contains a new point in time id value.
+	 *
+	 * @return the new point in time id, if one was returned from Elasticsearch
+	 * @since 5.0
+	 */
+	@Nullable
+	String getPointInTimeId();
 }