Merge pull request #10261 from indexity-io/3.1/lucene-ref-leak

Fix IndexReader ref leak when Lucene index modified and read in transaction
orientechnologies · Jun 26, 2024 · d8baccb · d8baccb
2 parents 539c6f0 + d82624e
commit d8baccb
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Showing 2 changed files with 11 additions and 6 deletions.
diff --git a/lucene/src/main/java/com/orientechnologies/lucene/collections/OLuceneResultSet.java b/lucene/src/main/java/com/orientechnologies/lucene/collections/OLuceneResultSet.java
@@ -209,10 +209,8 @@ public boolean hasNext() {
       final boolean hasNext = index < (totalHits - deletedMatchCount);
       if (!hasNext && !closed) {
         final IndexSearcher searcher = queryContext.getSearcher();
-        if (searcher.getIndexReader().getRefCount() > 1) {
-          engine.release(searcher);
-          closed = true;
-        }
+        engine.release(searcher);
+        closed = true;
       }
       return hasNext;
     }

diff --git a/lucene/src/main/java/com/orientechnologies/lucene/query/OLuceneQueryContext.java b/lucene/src/main/java/com/orientechnologies/lucene/query/OLuceneQueryContext.java
@@ -30,6 +30,7 @@
 import java.util.Map;
 import java.util.Optional;
 import org.apache.lucene.document.Document;
+import org.apache.lucene.index.IndexReader;
 import org.apache.lucene.index.MultiReader;
 import org.apache.lucene.search.IndexSearcher;
 import org.apache.lucene.search.Query;
@@ -104,9 +105,15 @@ public IndexSearcher getSearcher() {
   }
 
   private MultiReader multiReader(final OLuceneTxChanges luceneTxChanges) {
+    final IndexReader primaryReader = searcher.getIndexReader();
+    final IndexReader txReader = luceneTxChanges.searcher().getIndexReader();
     try {
-      return new MultiReader(
-          searcher.getIndexReader(), luceneTxChanges.searcher().getIndexReader());
+      // Transfer ownership to the MultiReader so the index searcher can be releases transparently.
+      // Without this, the primary IndexReader will leak a refcount each time it is wrapped.
+      MultiReader multiReader = new MultiReader(new IndexReader[] {primaryReader, txReader}, false);
+      primaryReader.decRef();
+      txReader.decRef();
+      return multiReader;
     } catch (final IOException e) {
       throw OException.wrapException(
           new OLuceneIndexException("unable to create reader on changes"), e);