java.lang.RuntimeException: MockDirectoryWrapper: cannot close: there are still open files: {_47.frq=1, _47.tis=1, _47.fdx=1, _47.fdt=1} at org.apache.lucene.store.MockDirectoryWrapper.close(MockDirectoryWrapper.java:555) at org.apache.lucene.index.TestStressNRT.test(TestStressNRT.java:385) at org.apache.lucene.util.LuceneTestCase$SubclassSetupTeardownRule$1.evaluate(LuceneTestCase.java:743) at org.apache.lucene.util.LuceneTestCase$InternalSetupTeardownRule$1.evaluate(LuceneTestCase.java:639) at org.apache.lucene.util.SystemPropertiesInvariantRule$1.evaluate(SystemPropertiesInvariantRule.java:22) at org.apache.lucene.util.LuceneTestCase$TestResultInterceptorRule$1.evaluate(LuceneTestCase.java:538) at org.apache.lucene.util.LuceneTestCase$RememberThreadRule$1.evaluate(LuceneTestCase.java:600) at org.apache.lucene.util.LuceneTestCaseRunner.runChild(LuceneTestCaseRunner.java:164) at org.apache.lucene.util.LuceneTestCaseRunner.runChild(LuceneTestCaseRunner.java:57) at org.apache.lucene.util.StoreClassNameRule$1.evaluate(StoreClassNameRule.java:21) at org.apache.lucene.util.SystemPropertiesInvariantRule$1.evaluate(SystemPropertiesInvariantRule.java:22) Caused by: java.lang.RuntimeException: unclosed IndexInput: _47.tis at org.apache.lucene.store.MockDirectoryWrapper.addFileHandle(MockDirectoryWrapper.java:479) at org.apache.lucene.store.MockDirectoryWrapper.openInput(MockDirectoryWrapper.java:504) at org.apache.lucene.codecs.lucene3x.TermInfosReader.<init>(TermInfosReader.java:112) at org.apache.lucene.codecs.lucene3x.Lucene3xFields.<init>(Lucene3xFields.java:84) at org.apache.lucene.codecs.lucene3x.PreFlexRWPostingsFormat$1.<init>(PreFlexRWPostingsFormat.java:51) at org.apache.lucene.codecs.lucene3x.PreFlexRWPostingsFormat.fieldsProducer(PreFlexRWPostingsFormat.java:51) at org.apache.lucene.index.SegmentCoreReaders.<init>(SegmentCoreReaders.java:108) at org.apache.lucene.index.SegmentReader.<init>(SegmentReader.java:51) at org.apache.lucene.index.IndexWriter$ReadersAndLiveDocs.getMergeReader(IndexWriter.java:521) at org.apache.lucene.index.IndexWriter.mergeMiddle(IndexWriter.java:3587) at org.apache.lucene.index.IndexWriter.merge(IndexWriter.java:3257) at org.apache.lucene.index.ConcurrentMergeScheduler.doMerge(ConcurrentMergeScheduler.java:382) at org.apache.lucene.index.ConcurrentMergeScheduler$MergeThread.run(ConcurrentMergeScheduler.java:451)