Address Navneets comments

Signed-off-by: Martin Gaievski <[email protected]>

CHANGELOG.md

@@ -20,7 +20,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Features
 ### Enhancements
 ### Bug Fixes
-- Multiple identical subqueries in Hybrid query  ([#524](https://github.com/opensearch-project/neural-search/pull/524))
+- Fixing multiple issues reported in #497 ([#524](https://github.com/opensearch-project/neural-search/pull/524))
 ### Infrastructure
 ### Documentation
 ### Maintenance

src/main/java/org/opensearch/neuralsearch/processor/NormalizationProcessor.java

@@ -9,6 +9,7 @@
 
 import java.util.Arrays;
 import java.util.List;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.stream.Collectors;
@@ -155,7 +156,19 @@ private boolean shouldSkipProcessorDueToIncompatibleQueryAndFetchResults(
         SearchHits searchHits = fetchSearchResultOptional.get().hits();
         SearchHit[] searchHitArray = searchHits.getHits();
         // validate the both collections are of the same size
-        if (Objects.isNull(searchHitArray) || searchHitArray.length != docIds.size()) {
+        if (Objects.isNull(searchHitArray)) {
+            log.info("array of search hits in fetch phase results is null");
+            return true;
+        }
+        if (searchHitArray.length != docIds.size()) {
+            log.info(
+                String.format(
+                    Locale.ROOT,
+                    "number of documents in fetch results [%d] and query results [%d] is different",
+                    searchHitArray.length,
+                    docIds.size()
+                )
+            );
             return true;
         }
         return false;

src/main/java/org/opensearch/neuralsearch/processor/NormalizationProcessorWorkflow.java

@@ -139,7 +139,7 @@ private void updateOriginalFetchResults(
         // 3. update original scores to normalized and combined values
         // 4. order scores based on normalized and combined values
         FetchSearchResult fetchSearchResult = fetchSearchResultOptional.get();
-        SearchHit[] searchHitArray = getSearchHits(docIds, fetchSearchResult);
+        SearchHit[] searchHitArray = getSearchHits(fetchSearchResult);
 
         // create map of docId to index of search hits. This solves (2), duplicates are from
         // delimiter and start/stop elements, they all have same valid doc_id. For this map
@@ -169,21 +169,9 @@ private void updateOriginalFetchResults(
         fetchSearchResult.hits(updatedSearchHits);
     }
 
-    private SearchHit[] getSearchHits(final List<Integer> docIds, final FetchSearchResult fetchSearchResult) {
+    private SearchHit[] getSearchHits(final FetchSearchResult fetchSearchResult) {
         SearchHits searchHits = fetchSearchResult.hits();
-        SearchHit[] searchHitArray = searchHits.getHits();
-        // validate the both collections are of the same size
-        if (Objects.isNull(searchHitArray)) {
-            throw new IllegalStateException(
-                "Score normalization processor cannot produce final query result, for one shard case fetch does not have any results"
-            );
-        }
-        if (searchHitArray.length != docIds.size()) {
-            throw new IllegalStateException(
-                "Score normalization processor cannot produce final query result, for one shard case number of fetched documents does not match number of search hits"
-            );
-        }
-        return searchHitArray;
+        return searchHits.getHits();
     }
 
     private List<Integer> unprocessedDocIds(final List<QuerySearchResult> querySearchResults) {

src/main/java/org/opensearch/neuralsearch/query/HybridQueryScorer.java

@@ -5,6 +5,8 @@
 
 package org.opensearch.neuralsearch.query;
 
+import static java.util.Locale.ROOT;
+
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -118,12 +120,21 @@ public float[] hybridScores() throws IOException {
             }
             Query query = scorer.getWeight().getQuery();
             List<Integer> indexes = queryToIndex.get(query);
-            // we need to find the index of first sub-query that hasn't been updated yet
+            // we need to find the index of first sub-query that hasn't been set yet. Such score will have initial value of "0.0"
             int index = indexes.stream()
                 .mapToInt(idx -> idx)
-                .filter(index1 -> Float.compare(scores[index1], 0.0f) == 0)
+                .filter(idx -> Float.compare(scores[idx], 0.0f) == 0)
                 .findFirst()
-                .orElseThrow(() -> new IllegalStateException("cannot collect score for subquery"));
+                .orElseThrow(
+                    () -> new IllegalStateException(
+                        String.format(
+                            ROOT,
+                            "cannot set score for one of hybrid search subquery [%s] and document [%d]",
+                            query.toString(),
+                            scorer.docID()
+                        )
+                    )
+                );
             scores[index] = scorer.score();
         }
         return scores;

src/test/java/org/opensearch/neuralsearch/query/HybridQueryIT.java

@@ -174,6 +174,75 @@ public void testComplexQuery_whenMultipleSubqueries_thenSuccessful() {
         assertEquals(RELATION_EQUAL_TO, total.get("relation"));
     }
 
+    /**
+     * Tests complex query with multiple nested sub-queries, where soem sub-queries are same
+     * {
+     *     "query": {
+     *         "hybrid": {
+     *              "queries": [
+     *                  {
+     *                      "term": {
+     *                         "text": "word1"
+     *                       }
+     *                  },
+     *                  {
+     *                      "term": {
+     *                         "text": "word2"
+     *                       }
+     *                  },
+     *                  {
+     *                      "term": {
+     *                          "text": "word3"
+     *                      }
+     *                  }
+     *              ]
+     *          }
+     *      }
+     * }
+     */
+    @SneakyThrows
+    public void testComplexQuery_whenMultipleIdenticalSubQueries_thenSuccessful() {
+        initializeIndexIfNotExist(TEST_BASIC_VECTOR_DOC_FIELD_INDEX_NAME);
+
+        TermQueryBuilder termQueryBuilder1 = QueryBuilders.termQuery(TEST_TEXT_FIELD_NAME_1, TEST_QUERY_TEXT3);
+        TermQueryBuilder termQueryBuilder2 = QueryBuilders.termQuery(TEST_TEXT_FIELD_NAME_1, TEST_QUERY_TEXT4);
+        TermQueryBuilder termQueryBuilder3 = QueryBuilders.termQuery(TEST_TEXT_FIELD_NAME_1, TEST_QUERY_TEXT3);
+
+        HybridQueryBuilder hybridQueryBuilderThreeTerms = new HybridQueryBuilder();
+        hybridQueryBuilderThreeTerms.add(termQueryBuilder1);
+        hybridQueryBuilderThreeTerms.add(termQueryBuilder2);
+        hybridQueryBuilderThreeTerms.add(termQueryBuilder3);
+
+        Map<String, Object> searchResponseAsMap1 = search(
+            TEST_BASIC_VECTOR_DOC_FIELD_INDEX_NAME,
+            hybridQueryBuilderThreeTerms,
+            null,
+            10,
+            Map.of("search_pipeline", SEARCH_PIPELINE)
+        );
+
+        assertEquals(2, getHitCount(searchResponseAsMap1));
+
+        List<Map<String, Object>> hits1NestedList = getNestedHits(searchResponseAsMap1);
+        List<String> ids = new ArrayList<>();
+        List<Double> scores = new ArrayList<>();
+        for (Map<String, Object> oneHit : hits1NestedList) {
+            ids.add((String) oneHit.get("_id"));
+            scores.add((Double) oneHit.get("_score"));
+        }
+
+        // verify that scores are in desc order
+        assertTrue(IntStream.range(0, scores.size() - 1).noneMatch(idx -> scores.get(idx) < scores.get(idx + 1)));
+        // verify that all ids are unique
+        assertEquals(Set.copyOf(ids).size(), ids.size());
+
+        Map<String, Object> total = getTotalHits(searchResponseAsMap1);
+        assertNotNull(total.get("value"));
+        assertEquals(2, total.get("value"));
+        assertNotNull(total.get("relation"));
+        assertEquals(RELATION_EQUAL_TO, total.get("relation"));
+    }
+
     @SneakyThrows
     public void testNoMatchResults_whenOnlyTermSubQueryWithoutMatch_thenEmptyResult() {
         initializeIndexIfNotExist(TEST_MULTI_DOC_INDEX_NAME);