[Backport 2.x] [Star tree] Handle delete cases for star tree

server/src/main/java/org/apache/lucene/index/DocValuesProducerUtil.java

@@ -0,0 +1,33 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.apache.lucene.index;
+
+import org.apache.lucene.codecs.DocValuesProducer;
+
+import java.util.Collections;
+import java.util.Set;
+
+/**
+ * Utility class for DocValuesProducers
+ * @opensearch.internal
+ */
+public class DocValuesProducerUtil {
+    /**
+     * Returns the segment doc values producers for the given doc values producer.
+     * If the given doc values producer is not a segment doc values producer, an empty set is returned.
+     * @param docValuesProducer the doc values producer
+     * @return the segment doc values producers
+     */
+    public static Set<DocValuesProducer> getSegmentDocValuesProducers(DocValuesProducer docValuesProducer) {
+        if (docValuesProducer instanceof SegmentDocValuesProducer) {
+            return (((SegmentDocValuesProducer) docValuesProducer).dvProducers);
+        }
+        return Collections.emptySet();
+    }
+}

server/src/main/java/org/opensearch/index/codec/composite/composite912/Composite912DocValuesReader.java

@@ -185,7 +185,13 @@ public Composite912DocValuesReader(DocValuesProducer producer, SegmentReadState
                 // populates the dummy list of field infos to fetch doc id set iterators for respective fields.
                 // the dummy field info is used to fetch the doc id set iterators for respective fields based on field name
                 FieldInfos fieldInfos = new FieldInfos(getFieldInfoList(fields));
-                this.readState = new SegmentReadState(readState.directory, readState.segmentInfo, fieldInfos, readState.context);
+                this.readState = new SegmentReadState(
+                    readState.directory,
+                    readState.segmentInfo,
+                    fieldInfos,
+                    readState.context,
+                    readState.segmentSuffix
+                );
 
                 // initialize star-tree doc values producer
 

server/src/main/java/org/opensearch/index/codec/composite/composite912/Composite912DocValuesWriter.java

@@ -12,6 +12,7 @@
 import org.apache.lucene.codecs.DocValuesConsumer;
 import org.apache.lucene.codecs.DocValuesProducer;
 import org.apache.lucene.index.DocValues;
+import org.apache.lucene.index.DocValuesProducerUtil;
 import org.apache.lucene.index.DocValuesType;
 import org.apache.lucene.index.EmptyDocValuesProducer;
 import org.apache.lucene.index.FieldInfo;
@@ -35,7 +36,6 @@
 import org.opensearch.index.mapper.CompositeMappedFieldType;
 import org.opensearch.index.mapper.DocCountFieldMapper;
 import org.opensearch.index.mapper.MapperService;
-import org.opensearch.index.mapper.StarTreeMapper;
 
 import java.io.IOException;
 import java.util.ArrayList;
@@ -221,12 +221,8 @@
         }
         // we have all the required fields to build composite fields
         if (compositeFieldSet.isEmpty()) {
-            for (CompositeMappedFieldType mappedType : compositeMappedFieldTypes) {
-                if (mappedType instanceof StarTreeMapper.StarTreeFieldType) {
-                    try (StarTreesBuilder starTreesBuilder = new StarTreesBuilder(state, mapperService, fieldNumberAcrossCompositeFields)) {
-                        starTreesBuilder.build(metaOut, dataOut, fieldProducerMap, compositeDocValuesConsumer);
-                    }
-                }
+            try (StarTreesBuilder starTreesBuilder = new StarTreesBuilder(state, mapperService, fieldNumberAcrossCompositeFields)) {
+                starTreesBuilder.build(metaOut, dataOut, fieldProducerMap, compositeDocValuesConsumer);
             }
         }
     }
@@ -285,27 +281,27 @@
             if (mergeState.docValuesProducers[i] instanceof CompositeIndexReader) {
                 reader = (CompositeIndexReader) mergeState.docValuesProducers[i];
             } else {
-                continue;
+                Set<DocValuesProducer> docValuesProducers = DocValuesProducerUtil.getSegmentDocValuesProducers(
+                    mergeState.docValuesProducers[i]
+                );
+                for (DocValuesProducer docValuesProducer : docValuesProducers) {
+                    if (docValuesProducer instanceof CompositeIndexReader) {
+                        reader = (CompositeIndexReader) docValuesProducer;
+                        List<CompositeIndexFieldInfo> compositeFieldInfo = reader.getCompositeIndexFields();
+                        if (compositeFieldInfo.isEmpty() == false) {
+                            break;
+                        }
+                    }
+                }
             }
-
+            if (reader == null) continue;
             List<CompositeIndexFieldInfo> compositeFieldInfo = reader.getCompositeIndexFields();
             for (CompositeIndexFieldInfo fieldInfo : compositeFieldInfo) {
                 if (fieldInfo.getType().equals(CompositeMappedFieldType.CompositeFieldType.STAR_TREE)) {
                     CompositeIndexValues compositeIndexValues = reader.getCompositeIndexValues(fieldInfo);
                     if (compositeIndexValues instanceof StarTreeValues) {
                         StarTreeValues starTreeValues = (StarTreeValues) compositeIndexValues;
                         List<StarTreeValues> fieldsList = starTreeSubsPerField.getOrDefault(fieldInfo.getField(), new ArrayList<>());
-                        if (starTreeField == null) {
-                            starTreeField = starTreeValues.getStarTreeField();
-                        }
-                        // assert star tree configuration is same across segments
-                        else {
-                            if (starTreeField.equals(starTreeValues.getStarTreeField()) == false) {
-                                throw new IllegalArgumentException(
-                                    "star tree field configuration must match the configuration of the field being merged"
-                                );
-                            }
-                        }
                         fieldsList.add(starTreeValues);
                         starTreeSubsPerField.put(fieldInfo.getField(), fieldsList);
                     }
@@ -340,7 +336,8 @@
             segmentInfo,
             segmentWriteState.fieldInfos,
             segmentWriteState.segUpdates,
-            segmentWriteState.context
+            segmentWriteState.context,
+            segmentWriteState.segmentSuffix
         );
     }
 

server/src/main/java/org/opensearch/index/compositeindex/datacube/startree/builder/BaseStarTreeBuilder.java

@@ -735,7 +735,6 @@ private SequentialDocValuesIterator getIteratorForNumericField(
      * @throws IOException throws an exception if we are unable to add the doc
      */
     private void appendToStarTree(StarTreeDocument starTreeDocument) throws IOException {
-
         appendStarTreeDocument(starTreeDocument);
         numStarTreeDocs++;
     }

server/src/test/java/org/opensearch/index/codec/composite912/datacube/startree/StarTreeDocValuesFormatTests.java

@@ -15,11 +15,14 @@
 import org.apache.lucene.codecs.Codec;
 import org.apache.lucene.codecs.lucene912.Lucene912Codec;
 import org.apache.lucene.document.Document;
+import org.apache.lucene.document.Field;
 import org.apache.lucene.document.SortedNumericDocValuesField;
+import org.apache.lucene.document.StringField;
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.IndexWriterConfig;
 import org.apache.lucene.index.LeafReaderContext;
 import org.apache.lucene.index.SegmentReader;
+import org.apache.lucene.index.Term;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.tests.index.BaseDocValuesFormatTestCase;
 import org.apache.lucene.tests.index.RandomIndexWriter;
@@ -58,9 +61,12 @@
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import static org.opensearch.common.util.FeatureFlags.STAR_TREE_INDEX;
+import static org.opensearch.index.compositeindex.CompositeIndexConstants.STAR_TREE_DOCS_COUNT;
 import static org.opensearch.index.compositeindex.datacube.startree.StarTreeTestUtils.assertStarTreeDocuments;
 
 /**
@@ -207,6 +213,100 @@ public void testStarTreeDocValues() throws IOException {
         directory.close();
     }
 
+    public void testStarTreeDocValuesWithDeletions() throws IOException {
+        Directory directory = newDirectory();
+        IndexWriterConfig conf = newIndexWriterConfig(null);
+        conf.setMergePolicy(newLogMergePolicy());
+        RandomIndexWriter iw = new RandomIndexWriter(random(), directory, conf);
+
+        int iterations = 3;
+        Map<String, Integer> map = new HashMap<>();
+        List<String> allIds = new ArrayList<>();
+        for (int iter = 0; iter < iterations; iter++) {
+            // Add 10 documents
+            for (int i = 0; i < 10; i++) {
+                String id = String.valueOf(random().nextInt() + i);
+                allIds.add(id);
+                Document doc = new Document();
+                doc.add(new StringField("_id", id, Field.Store.YES));
+                int fieldValue = random().nextInt(5) + 1;
+                doc.add(new SortedNumericDocValuesField("field", fieldValue));
+
+                int sndvValue = random().nextInt(3);
+
+                doc.add(new SortedNumericDocValuesField("sndv", sndvValue));
+                int dvValue = random().nextInt(3);
+
+                doc.add(new SortedNumericDocValuesField("dv", dvValue));
+                map.put(sndvValue + "-" + dvValue, fieldValue + map.getOrDefault(sndvValue + "-" + dvValue, 0));
+                iw.addDocument(doc);
+            }
+            iw.flush();
+        }
+        iw.commit();
+        // Delete random number of documents
+        int docsToDelete = random().nextInt(9); // Delete up to 9 documents
+        for (int i = 0; i < docsToDelete; i++) {
+            if (!allIds.isEmpty()) {
+                String idToDelete = allIds.remove(random().nextInt(allIds.size() - 1));
+                iw.deleteDocuments(new Term("_id", idToDelete));
+                allIds.remove(idToDelete);
+            }
+        }
+        iw.flush();
+        iw.commit();
+        iw.forceMerge(1);
+        iw.close();
+
+        DirectoryReader ir = DirectoryReader.open(directory);
+        TestUtil.checkReader(ir);
+        assertEquals(1, ir.leaves().size());
+
+        // Assert star tree documents
+        for (LeafReaderContext context : ir.leaves()) {
+            SegmentReader reader = Lucene.segmentReader(context.reader());
+            CompositeIndexReader starTreeDocValuesReader = (CompositeIndexReader) reader.getDocValuesReader();
+            List<CompositeIndexFieldInfo> compositeIndexFields = starTreeDocValuesReader.getCompositeIndexFields();
+
+            for (CompositeIndexFieldInfo compositeIndexFieldInfo : compositeIndexFields) {
+                StarTreeValues starTreeValues = (StarTreeValues) starTreeDocValuesReader.getCompositeIndexValues(compositeIndexFieldInfo);
+                StarTreeDocument[] actualStarTreeDocuments = StarTreeTestUtils.getSegmentsStarTreeDocuments(
+                    List.of(starTreeValues),
+                    List.of(
+                        NumberFieldMapper.NumberType.DOUBLE,
+                        NumberFieldMapper.NumberType.LONG,
+                        NumberFieldMapper.NumberType.DOUBLE,
+                        NumberFieldMapper.NumberType.DOUBLE,
+                        NumberFieldMapper.NumberType.DOUBLE,
+                        NumberFieldMapper.NumberType.LONG,
+                        NumberFieldMapper.NumberType.DOUBLE,
+                        NumberFieldMapper.NumberType.DOUBLE,
+                        NumberFieldMapper.NumberType.LONG
+                    ),
+                    Integer.parseInt(starTreeValues.getAttributes().get(STAR_TREE_DOCS_COUNT))
+                );
+                for (StarTreeDocument starDoc : actualStarTreeDocuments) {
+                    Long sndvVal = null;
+                    if (starDoc.dimensions[0] != null) {
+                        sndvVal = starDoc.dimensions[0];
+                    }
+                    Long dvVal = null;
+                    if (starDoc.dimensions[1] != null) {
+                        dvVal = starDoc.dimensions[1];
+                    }
+                    if (starDoc.metrics[0] != null) {
+                        double metric = (double) starDoc.metrics[0];
+                        if (map.containsKey(sndvVal + "-" + dvVal)) {
+                            assertEquals((long) map.get(sndvVal + "-" + dvVal), (long) metric);
+                        }
+                    }
+                }
+            }
+        }
+        ir.close();
+        directory.close();
+    }
+
     private XContentBuilder getExpandedMapping() throws IOException {
         return topMapping(b -> {
             b.startObject("composite");