[LUCENE-6287] Corrupt index (missing .si file) on first 4.x commit to a 3.x index

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 4.10.4
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Michael McCandless
• Created: 24/Feb/15 15:45
• Updated: 5 days ago 16:13
• Resolved: 24/Feb/15 22:34

Description

If you have a 3.x index, and you open it with a 4.x IndexWriter for
the first time, and you do something that kicks of merges while
concurrently committing, it's possible the index will corrupt itself
with exceptions like this:

java.nio.file.NoSuchFileException: /l/tmp/reruns.TestBackwardsCompatibility3x.testMergeDuringUpgrade.t2/lucene.index.TestBackwardsCompatibility3x-71F31CCCEF6853A-001/manysegments.362-006/_0.si
	at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
	at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
	at sun.nio.fs.UnixFileSystemProvider.newFileChannel(UnixFileSystemProvider.java:177)
	at java.nio.channels.FileChannel.open(FileChannel.java:287)
	at java.nio.channels.FileChannel.open(FileChannel.java:334)
	at org.apache.lucene.store.NIOFSDirectory.openInput(NIOFSDirectory.java:81)
	at org.apache.lucene.store.FilterDirectory.openInput(FilterDirectory.java:80)
	at org.apache.lucene.codecs.lucene3x.Lucene3xSegmentInfoReader.read(Lucene3xSegmentInfoReader.java:106)
	at org.apache.lucene.index.SegmentInfos.read(SegmentInfos.java:358)
	at org.apache.lucene.index.SegmentInfos$1.doBody(SegmentInfos.java:454)
	at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:906)
	at org.apache.lucene.index.SegmentInfos$FindSegmentsFile.run(SegmentInfos.java:752)
	at org.apache.lucene.index.SegmentInfos.read(SegmentInfos.java:457)
	at org.apache.lucene.index.CheckIndex.checkIndex(CheckIndex.java:414)
	at org.apache.lucene.util.TestUtil.checkIndex(TestUtil.java:207)
	at org.apache.lucene.util.TestUtil.checkIndex(TestUtil.java:196)
	at org.apache.lucene.store.BaseDirectoryWrapper.close(BaseDirectoryWrapper.java:45)
	at org.apache.lucene.index.TestBackwardsCompatibility3x.testMergeDuringUpgrade(TestBackwardsCompatibility3x.java:1035)

Back compat tests in Elasticsearch hit this, and at first I thought maybe LUCENE-6279 was the cause (I still think we should fix that) but after further debugging there is a different concurrency bug lurking here.

I have a test case which after substantial beasting is able to reproduce the bug, but I don't yet have a fix. I think IW is missing a checkpoint after writing a new commit...