DATAES-817 - StreamQueries does only delete the last scrollid.

src/main/java/org/springframework/data/elasticsearch/client/reactive/DefaultReactiveElasticsearchClient.java

@@ -36,10 +36,7 @@
 import java.net.InetSocketAddress;
 import java.nio.charset.StandardCharsets;
 import java.time.Duration;
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
-import java.util.List;
 import java.util.Map.Entry;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
@@ -93,7 +90,6 @@
 import org.elasticsearch.index.reindex.DeleteByQueryRequest;
 import org.elasticsearch.rest.BytesRestResponse;
 import org.elasticsearch.rest.RestStatus;
-import org.elasticsearch.search.Scroll;
 import org.elasticsearch.search.SearchHit;
 import org.elasticsearch.search.SearchHits;
 import org.elasticsearch.search.aggregations.Aggregation;
@@ -105,6 +101,7 @@
 import org.springframework.data.elasticsearch.client.reactive.HostProvider.Verification;
 import org.springframework.data.elasticsearch.client.reactive.ReactiveElasticsearchClient.Indices;
 import org.springframework.data.elasticsearch.client.util.NamedXContents;
+import org.springframework.data.elasticsearch.client.util.ScrollState;
 import org.springframework.data.util.Lazy;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
@@ -115,7 +112,6 @@
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
 import org.springframework.util.ReflectionUtils;
-import org.springframework.util.StringUtils;
 import org.springframework.web.client.HttpClientErrorException;
 import org.springframework.web.client.HttpServerErrorException;
 import org.springframework.web.reactive.function.BodyExtractors;
@@ -835,8 +831,7 @@ private <T> Publisher<? extends T> handleClientError(String logId, Request reque
 								.error(new ElasticsearchStatusException(content, RestStatus.fromCode(response.statusCode().value())));
 					}
 					return Mono.just(content);
-				})
-				.doOnNext(it -> ClientLogger.logResponse(logId, response.statusCode(), it)) //
+				}).doOnNext(it -> ClientLogger.logResponse(logId, response.statusCode(), it)) //
 				.flatMap(content -> doDecode(response, responseType, content));
 	}
 
@@ -893,42 +888,5 @@ public Collection<ElasticsearchHost> hosts() {
 		}
 	}
 
-	/**
-	 * Mutable state object holding scrollId to be used for {@link SearchScrollRequest#scroll(Scroll)}
-	 *
-	 * @author Christoph Strobl
-	 * @since 3.2
-	 */
-	private static class ScrollState {
-
-		private final Object lock = new Object();
-
-		private final List<String> pastIds = new ArrayList<>(1);
-		@Nullable private String scrollId;
-
-		@Nullable
-		String getScrollId() {
-			return scrollId;
-		}
-
-		List<String> getScrollIds() {
-
-			synchronized (lock) {
-				return Collections.unmodifiableList(new ArrayList<>(pastIds));
-			}
-		}
-
-		void updateScrollId(String scrollId) {
-
-			if (StringUtils.hasText(scrollId)) {
-
-				synchronized (lock) {
-
-					this.scrollId = scrollId;
-					pastIds.add(scrollId);
-				}
-			}
-		}
-	}
 	// endregion
 }

src/main/java/org/springframework/data/elasticsearch/client/util/ScrollState.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2020 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.util;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.elasticsearch.action.search.SearchScrollRequest;
+import org.elasticsearch.search.Scroll;
+import org.springframework.lang.Nullable;
+import org.springframework.util.StringUtils;
+
+/**
+ * Mutable state object holding scrollId to be used for {@link SearchScrollRequest#scroll(Scroll)}
+ *
+ * @author Christoph Strobl
+ * @author Peter-Josef Meisch
+ * @since 3.2
+ */
+public class ScrollState {
+
+	private final Object lock = new Object();
+
+	private final Set<String> pastIds = new LinkedHashSet<>();
+	@Nullable private String scrollId;
+
+	public ScrollState() {}
+
+	public ScrollState(String scrollId) {
+		updateScrollId(scrollId);
+	}
+
+	@Nullable
+	public String getScrollId() {
+		return scrollId;
+	}
+
+	public List<String> getScrollIds() {
+
+		synchronized (lock) {
+			return Collections.unmodifiableList(new ArrayList<>(pastIds));
+		}
+	}
+
+	public void updateScrollId(String scrollId) {
+
+		if (StringUtils.hasText(scrollId)) {
+
+			synchronized (lock) {
+
+				this.scrollId = scrollId;
+				pastIds.add(scrollId);
+			}
+		}
+	}
+}

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

@@ -17,6 +17,7 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
@@ -341,7 +342,14 @@ abstract protected <T> SearchScrollHits<T> searchScrollContinue(@Nullable String
 	/*
 	 * internal use only, not for public API
 	 */
-	abstract protected void searchScrollClear(String scrollId);
+	protected void searchScrollClear(String scrollId) {
+		searchScrollClear(Collections.singletonList(scrollId));
+	}
+
+	/*
+	 * internal use only, not for public API
+	 */
+	abstract protected void searchScrollClear(List<String> scrollIds);
 
 	abstract protected MultiSearchResponse.Item[] getMultiSearchResult(MultiSearchRequest request);
 	// endregion

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

@@ -299,9 +299,9 @@ public <T> SearchScrollHits<T> searchScrollContinue(@Nullable String scrollId, l
 	}
 
 	@Override
-	public void searchScrollClear(String scrollId) {
+	public void searchScrollClear(List<String> scrollIds) {
 		ClearScrollRequest request = new ClearScrollRequest();
-		request.addScrollId(scrollId);
+		request.scrollIds(scrollIds);
 		execute(client -> client.clearScroll(request, RequestOptions.DEFAULT));
 	}
 

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

@@ -321,8 +321,8 @@ public <T> SearchScrollHits<T> searchScrollContinue(@Nullable String scrollId, l
 	}
 
 	@Override
-	public void searchScrollClear(String scrollId) {
-		client.prepareClearScroll().addScrollId(scrollId).execute().actionGet();
+	public void searchScrollClear(List<String> scrollIds) {
+		client.prepareClearScroll().setScrollIds(scrollIds).execute().actionGet();
 	}
 
 	@Override

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

@@ -16,11 +16,13 @@
 package org.springframework.data.elasticsearch.core;
 
 import java.util.Iterator;
+import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
 import org.elasticsearch.search.aggregations.Aggregations;
+import org.springframework.data.elasticsearch.client.util.ScrollState;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
@@ -38,12 +40,12 @@ abstract class StreamQueries {
 	 *
 	 * @param searchHits the initial hits
 	 * @param continueScrollFunction function to continue scrolling applies to the current scrollId.
-	 * @param clearScrollConsumer consumer to clear the scroll context by accepting the current scrollId.
+	 * @param clearScrollConsumer consumer to clear the scroll context by accepting the scrollIds to clear.
 	 * @param <T>
 	 * @return the {@link SearchHitsIterator}.
 	 */
 	static <T> SearchHitsIterator<T> streamResults(SearchScrollHits<T> searchHits,
-			Function<String, SearchScrollHits<T>> continueScrollFunction, Consumer<String> clearScrollConsumer) {
+			Function<String, SearchScrollHits<T>> continueScrollFunction, Consumer<List<String>> clearScrollConsumer) {
 
 		Assert.notNull(searchHits, "searchHits must not be null.");
 		Assert.notNull(searchHits.getScrollId(), "scrollId of searchHits must not be null.");
@@ -59,17 +61,17 @@ static <T> SearchHitsIterator<T> streamResults(SearchScrollHits<T> searchHits,
 
 			// As we couldn't retrieve single result with scroll, store current hits.
 			private volatile Iterator<SearchHit<T>> scrollHits = searchHits.iterator();
-			private volatile String scrollId = searchHits.getScrollId();
 			private volatile boolean continueScroll = scrollHits.hasNext();
+			private volatile ScrollState scrollState = new ScrollState(searchHits.getScrollId());
 
 			@Override
 			public void close() {
 
 				try {
-					clearScrollConsumer.accept(scrollId);
+					clearScrollConsumer.accept(scrollState.getScrollIds());
 				} finally {
 					scrollHits = null;
-					scrollId = null;
+					scrollState = null;
 				}
 			}
 
@@ -102,9 +104,9 @@ public boolean hasNext() {
 				}
 
 				if (!scrollHits.hasNext()) {
-					SearchScrollHits<T> nextPage = continueScrollFunction.apply(scrollId);
+					SearchScrollHits<T> nextPage = continueScrollFunction.apply(scrollState.getScrollId());
 					scrollHits = nextPage.iterator();
-					scrollId = nextPage.getScrollId();
+					scrollState.updateScrollId(nextPage.getScrollId());
 					continueScroll = scrollHits.hasNext();
 				}
 
@@ -127,6 +129,5 @@ public void remove() {
 	}
 
 	// utility constructor
-	private StreamQueries() {
-	}
+	private StreamQueries() {}
 }

src/test/java/org/springframework/data/elasticsearch/client/util/ScrollStateTest.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2020 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.util;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.Arrays;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author Peter-Josef Meisch
+ */
+class ScrollStateTest {
+
+	@Test // DATAES-817
+	void shouldReturnLastSetScrollId() {
+		ScrollState scrollState = new ScrollState();
+
+		scrollState.updateScrollId("id-1");
+		scrollState.updateScrollId("id-2");
+
+		assertThat(scrollState.getScrollId()).isEqualTo("id-2");
+	}
+
+	@Test
+	void shouldReturnUniqueListOfUsedScrollIdsInCorrectOrder() {
+
+		ScrollState scrollState = new ScrollState();
+
+		scrollState.updateScrollId("id-1");
+		scrollState.updateScrollId("id-2");
+		scrollState.updateScrollId("id-1");
+		scrollState.updateScrollId("id-3");
+		scrollState.updateScrollId("id-2");
+
+		assertThat(scrollState.getScrollIds()).isEqualTo(Arrays.asList("id-1", "id-2", "id-3"));
+	}
+}