[LUCENE-10228] PerFieldKnnVectorsFormat can write to wrong format name

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 9.0, 9.1
• Labels: vector-based-search
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Julie Tibshirani
• Created: 09/Nov/21 22:02
• Updated: 28/Aug/22 16:30
• Resolved: 10/Nov/21 17:59

Description

Currently when creating a KnnVectorsWriter for merging, we consult the existing "PER_FIELD_SUFFIX_KEY" attribute to determine the format's per-field suffix. This isn't correct since we could be using a new codec (that produces different formats/ suffixes).

The attached PR modifies TestPerFieldDocValuesFormat#testMergeUsesNewFormat to trigger the problem. Without the fix we get an error like "java.nio.file.FileAlreadyExistsException: File "_3_Lucene90HnswVectorsFormat_0.vem" was already written to."

 

Issue Links

• links to: GitHub Pull Request #432