fix: testJVectorKnnIndex_filter_maxInnerProduct test (#688)

Signed-off-by: ergun-kezer <ergun.kezer@ibm.com>
Co-authored-by: ergun-kezer <ergun.kezer@ibm.com>
(cherry picked from commit be0ed0a)
Signed-off-by: opensearch-ci-bot <opensearch-infra@amazon.com>

Author: 2 people

CHANGELOG.md

@@ -10,6 +10,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 ### Enhancements
 
 ### Bug Fixes
+- Fix flaky testJVectorKnnIndex_filter_maxInnerProduct test case [681](https://github.com/opensearch-project/opensearch-jvector/pull/681)
 
 ### Infrastructure
 ### Documentation

src/test/java/org/opensearch/knn/index/codec/jvector/KNNJVectorTests.java

@@ -216,6 +216,7 @@ public void testJVectorKnnIndex_filter_maxInnerProduct() throws IOException {
         indexWriterConfig.setUseCompoundFile(false);
         indexWriterConfig.setCodec(getCodec(random().nextBoolean()));
         indexWriterConfig.setMergePolicy(new ForceMergesOnlyMergePolicy());
+        indexWriterConfig.setMaxBufferedDocs(totalNumberOfDocs);
         final Path indexPath = createTempDir();
         log.info("Index path: {}", indexPath);
         try (FSDirectory dir = FSDirectory.open(indexPath); IndexWriter w = new IndexWriter(dir, indexWriterConfig)) {
@@ -231,7 +232,8 @@ public void testJVectorKnnIndex_filter_maxInnerProduct() throws IOException {
             w.commit();
 
             try (IndexReader reader = DirectoryReader.open(w)) {
-                log.info("We should now have a single segment with 10 documents");
+                log.info("We should now have a single segment with {} documents", totalNumberOfDocs);
+
                 Assert.assertEquals(1, reader.getContext().leaves().size());
                 Assert.assertEquals(totalNumberOfDocs, reader.numDocs());