[LUCENE-9621] pendingNumDocs doesn't match totalMaxDoc if tragedy on flush()

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 8.6.3
• Component/s: core/index
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Michael Froh
• Created: 27/Nov/20 18:47
• Updated: 28/Aug/22 16:11

Description

While implementing a test to trigger an OutOfMemoryError on flush() in https://github.com/apache/lucene-solr/pull/2088, I noticed that the OOME was followed by an assertion failure on rollback with the following stacktrace:

java.lang.AssertionError: pendingNumDocs 1 != 0 totalMaxDoc
	at __randomizedtesting.SeedInfo.seed([ABBF17C4E0FCDEE5:DDC8E99910AFC8FF]:0)
	at org.apache.lucene.index.IndexWriter.rollbackInternal(IndexWriter.java:2398)
	at org.apache.lucene.index.IndexWriter.maybeCloseOnTragicEvent(IndexWriter.java:5196)
	at org.apache.lucene.index.IndexWriter.tragicEvent(IndexWriter.java:5186)
	at org.apache.lucene.index.IndexWriter.doFlush(IndexWriter.java:3932)
	at org.apache.lucene.index.IndexWriter.flush(IndexWriter.java:3874)
	at org.apache.lucene.index.IndexWriter.flush(IndexWriter.java:3853)
	at org.apache.lucene.index.TestIndexWriterDelete.testDeleteAllRepeated(TestIndexWriterDelete.java:496)

We should probably look into how exactly we behave with this kind of tragedy on flush().